JP4786953B2 - Caisson housing, press-fit caisson method using the caisson housing, and friction reducing sheet - Google Patents

Description

  The present invention presses and sinks a caisson housing having a caisson blade with an inner blade shape at the tip into the ground or the seabed for each predetermined stroke, and discharges the mud within the caisson housing to the outside while excavating it. A caisson housing used in a press-in caisson method for constructing a caisson shaft having a predetermined depth by adding a subsequent housing above the caisson housing, a press-in caisson method using the caisson housing, and a friction reducing sheet. is there.

  For example, when building a bridge pier in the ground or on the seabed, or when excavating a shaft for starting or reaching in shield construction, a structure with an inner blade-like edge formed at the tip, which has been conventionally called “caisson” A frame is used, and the “press-in caisson method” using this “caisson” is being implemented. The "press-in caisson method" is an "open type press-in caisson method" in which caisson is press-fitted into the ground using the weight of caisson, etc. “Press-fit caisson method”, “push-in caisson method (pneumatic caisson method combined with press-fitting)” that presses and sinks caisson into the ground using air, or a combination of these There is a press-in caisson method.

  Of these, if the “hydraulic press-fitting caisson method” is taken as an example, a rod-like support member called “earth anchor” that has been driven in advance outside the excavation site is supported by a hydraulic jack, and the hydraulic jack is hydraulically driven. By doing so, the above-mentioned “caisson” is submerged for a predetermined stroke into the ground or the seabed. Then, the ground inside the caisson was excavated using an automatic underwater excavator or the like, and the excavated mud was discharged to the outside using a bucket-like “hydraulic grab” or the like. In addition, by placing the succeeding chassis precast on the caisson that has been pressed and settled for a predetermined stroke and repeating the caisson press-in, mud excavation and discharge, and the subsequent expansion of the succeeding chassis, the predetermined depth is finally reached. A caisson shaft was built.

  A problem in such a press-in caisson method is the frictional resistance between the ground and the caisson body, or between the ground and the following body, which occurs when the caisson body is pressed and settled. The following Patent Document 1 discloses a construction method for the purpose of reducing the frictional resistance mainly used when placing a steel sheet pile or the like. That is, it is a construction method in which a friction-reducing resin material is applied to the surface of a sinking body that is in sliding contact with the ground. However, if the friction reducing resin material is simply thinly applied to the surface of the sedimentary body, it gradually peels off as the sedimentary body is press-fitted and settled, so that the desired friction reduction effect may not be exhibited. . In addition, the friction-reducing resin material stays in the ground permanently or for a long time together with the sedimentary body, so that organic solvents, etc. in the friction-reducing resin material may permeate into the ground and adversely affect the surrounding environment. Is also a concern.

  Patent Document 2 below discloses a method for reducing frictional resistance used in caisson press-fitting. That is, the feeding tip of the friction reducing metal sheet having a small friction coefficient is attached in close contact with the outer peripheral surface of the caisson that is in sliding contact with the ground, and the friction reducing metal sheet is gradually pulled down into the ground as the caisson press-fits. It is a construction method. However, if only such a friction reducing metal sheet is used, the sliding contact resistance between the ground and the caisson can be avoided, but the sliding contact resistance between the friction reducing metal sheet and the caisson cannot be avoided, so a sufficient friction reducing action cannot always be obtained. There is a case. In such a case, incidental and auxiliary measures have been taken to reduce the frictional resistance by sending compressed air between the ground and the friction reducing metal sheet.

  In addition, a slight gap is inevitably formed between the adjacent friction reducing metal sheets. Accordingly, mud may flow from the gap between the friction-reducing metal sheet and the caisson. In such a case, the mud mud increases frictional resistance, which makes it difficult to press and sink the caisson. . Furthermore, in the case of the construction method disclosed in Patent Document 2, the friction reducing metal sheet remains in the ground together with the caisson, so a new friction reducing metal sheet is prepared each time the caisson is pressed and settled. I had to. In addition, if the desired friction reduction action cannot be obtained, the earth anchor equipment must be constructed more robustly, and the number of earth anchors to be used increases, which increases the material, construction cost, and construction labor. The construction period was lengthened.

JP 2003-55982 A Japanese Patent No. 788314

  The present invention has been made in view of the existence of such background technology and the problems of the background technology, and is effective by using a friction reducing material layer and a friction reducing metal sheet in combination when the caisson housing is pressed and settled. The friction-reducing metal sheet that has been drawn out into the ground is recovered by pulling it out of the ground, thereby effectively using the members and preventing adverse effects on the surrounding environment. It is an object of the present invention to provide a caisson housing having a very high utility value and a press-in caisson method using the caisson housing that can reduce construction cost, construction labor, and construction period.

In order to solve the above-described problem, the caisson housing according to the first aspect of the present invention is configured to press-set and sink a caisson housing in which a caisson blade having an inner blade shape at the tip is formed into the ground for each predetermined stroke. A caisson housing used in a press-in caisson construction method for constructing a caisson shaft of a predetermined depth by excavating the mud inside and discharging to the outside while further adding a subsequent housing above the caisson housing. The caisson housing is wound with a long friction reducing sheet having a friction reducing material layer applied or pasted on the inner surface thereof in a roll shape so that the caisson housing is substantially connected to a plurality of locations along the outer peripheral surface of the caisson housing. It is arranged in such a state that the friction reducing sheet is gradually drawn out as the caisson housing is pressed and settled. That.
Here, “underground” is used to mean not only under the ground but also under the seabed or under the river.

  According to the first aspect of the present invention, the caisson housing or the subsequent housing is slidably contacted with the friction reducing sheet that is gradually drawn out when the caisson housing is press-fitted and settled. Since the friction reducing material layer is applied or pasted on the inner surface, the frictional resistance due to this sliding contact can be effectively reduced.

The caisson housing according to the second aspect of the present invention is characterized in that, in the first aspect of the present invention, a friction reducing material layer is applied to or pasted on the outer surface of the friction reducing sheet. .
Furthermore, the caisson housing according to the third aspect of the present invention is configured so that, in the second embodiment of the present invention, after the caisson housing is press-fitted and settled, the friction reducing sheet can be pulled upward. It is a feature.

  According to the second to third aspects of the present invention, since the friction reducing material layer is also applied or pasted on the outer surface of the friction reducing sheet, the friction reducing sheet slides against the ground when the friction reducing sheet is pulled out. However, the frictional resistance due to the sliding contact can be effectively reduced. In addition, since the friction reducing sheet can be pulled upward, it is possible to collect the friction reducing sheet that has been used once, and the material cost can be reduced through the effective use of the members. By preventing the layer from remaining in the ground, adverse effects on the natural environment and the like can be prevented. And by pulling out the friction reducing sheet, it becomes possible to use the frictional force based on the direct contact between the caisson housing and the subsequent housing and the ground, and it has a role as a support pile that exerts the frictional force and handles the upper load. Can be made.

  The caisson housing according to a fourth aspect of the present invention is the caisson housing according to any one of the first to third aspects of the present invention, wherein the friction reducing material layer is disposed from the winding base end side of the friction reducing sheet to the feeding leading end side. It is characterized by being applied or pasted in a laminated state on the friction reducing sheet so that the thickness increases stepwise.

  According to the fourth aspect of the present invention, the friction is reduced on the leading end side that receives the frictional resistance for the longest time when the friction reducing sheet that is gradually extended when the caisson housing is press-fitted and extended is extended. The thickness of the material layer is the largest, and the thickness of the friction reducing material layer is gradually reduced toward the winding base end that receives the frictional resistance for the shortest time. Accordingly, it is possible to prevent a decrease in the friction reducing action accompanying peeling or wear of the friction reducing material layer without excessively increasing the amount of the friction reducing material layer used.

  The caisson housing according to a fifth aspect of the present invention is the caisson housing according to any one of the first to fourth embodiments of the present invention, wherein the friction reducing sheet is provided in a substantially connected state along the outer peripheral surface of the caisson housing. And a joint sheet disposed in a gap between adjacent main sheets, and the main sheet and the joint sheet are mounted up and down while being wound so as not to interfere with each other. It is characterized by being provided with a shifted position.

  According to the fifth aspect of the present invention, since the inflow of mud from the gap portion between the main sheets is prevented by the joint sheet, a further friction reducing action can be achieved. As a result, the structure of the earth anchor facility can be simplified, and the material and construction cost can be reduced, the construction labor can be reduced, and the construction period can be shortened.

In the caisson housing according to the sixth aspect of the present invention, in the fifth aspect of the present invention, the joining surface of the main sheet and the joint sheet is provided with an adhesion means for bringing the main sheet and the joint sheet into an adhesion state in use. Or the contact means is configured to act.
According to the sixth aspect of the present invention, since the adhesion between the main sheet and the joint sheet is improved by employing the adhesion means, it is possible to reliably prevent the inflow of mud and ground water from the external ground. Further, since all the main sheets are integrated through the joint sheet, the main sheet and the joint sheet can be drawn and pulled out more smoothly.

The press-fitting caisson method using the caisson casing according to the seventh aspect of the present invention is configured to press fit and sink a caisson casing in which a caisson blade having an inner blade shape at the tip is formed into the ground for each predetermined stroke, It is a press-fitting caisson method for constructing a caisson shaft with a predetermined depth by excavating the mud of mud and discharging it to the outside, and further adding a subsequent frame above the caisson frame. A caisson housing provided with a long friction reducing sheet on which a layer is applied or pasted is used, and the friction reducing sheet is initially attached to the caisson housing in a state of being wound in a roll, and the friction reducing sheet The caisson housing is gradually drawn downward by press-fitting and sinking while holding the leading end of the caisson. Subsequent skeleton being out added together to is characterized in that the sliding contact against the friction reducing sheet via the friction reducing material layer.
According to the seventh aspect of the present invention, the same effect as that of the first aspect can be obtained. Here, “underground” is used to mean not only under the ground but also under the seabed or under the river.

In the press-fitting caisson method using the caisson housing according to the eighth aspect of the present invention, in the seventh embodiment, a friction reducing material layer is applied or pasted on the outer surface of the friction reducing sheet, and the caisson housing is press-fitted. After completion of the settling, the winding base end portion of the friction reducing sheet is disengaged from the caisson housing, and the friction reducing sheet is pulled upward.
According to the present invention, the same effect as the second aspect or the third aspect can be obtained.

  The friction reducing sheet according to the ninth aspect of the present invention is a friction reducing sheet used in the caisson housing according to any of the first to sixth aspects, and a friction reducing material layer is applied or pasted thereon. It is characterized by being.

  A friction reducing sheet according to a tenth aspect of the present invention is a friction reducing sheet used in a press-fitting caisson method using the caisson housing of the seventh aspect or the eighth aspect, and the friction reducing material layer is applied or pasted. It is characterized by being provided.

  According to the present invention, the friction reducing material layer and the friction reducing sheet can be used in combination when the caisson housing is press-fitted and settled, so that a further friction reducing action can be obtained, and the friction reducing sheet once drawn into the ground is pulled out from the ground. By recovering, it is possible to effectively use the members and prevent adverse effects on the surrounding environment, and also to reduce the materials and construction costs, reduce the construction labor, and shorten the construction period. It becomes possible to provide a press-fitting caisson method using a caisson housing.

  Hereinafter, the caisson housing and the press-fitting caisson method using the caisson housing according to the present invention will be described with reference to the following Example 1 and Example 2. First, an outline of the press-fitting caisson method according to the present invention and mechanical equipment necessary for executing the press-fitting caisson method will be described.

  FIG. 1 is a side sectional view showing an example of mechanical equipment used to execute a press-fitting caisson method using the caisson housing of the present invention. FIG. 2 is a mechanical equipment used to execute a press-fitting caisson method using the caisson housing of the present invention. It is a top view which shows an example.

  There are three types of press-in caisson methods as described above. Here, a press-in caisson method combining an open-type press-in caisson method and a hydraulic press-in caisson method will be described. In this press-fitting caisson method, a caisson casing 1 having a caisson cutting edge 2 inclined at the tip is formed at the tip, a pressurizing girder 9 utilizing its own weight as a press-fitting settling means of the caisson casing 1, and a press-fitting device The hydraulic jack 13 is used.

  In this press-fitting caisson method, the caisson enclosure 1 is pressed and settled by a predetermined stroke into the ground G in the ground (including the seabed and under the river), and further mud soil (including earth and sand) R inside the caisson enclosure 1 is excavated. It discharges outside the caisson housing 1 (for example, on the ground). Then, as an example precast above the caisson housing 1, a caisson shaft 5 having a predetermined depth is constructed by adding a subsequent concrete housing 4 made of concrete. The press-fitting caisson method is used when a shaft for constructing a pier, a shaft for starting or reaching when a shield tunnel 15 is constructed underground, or the like is constructed.

  And in order to implement such a press-fitting caisson method, the formwork 10 for precasting the mechanical installation 6 and the subsequent frame 4 as shown in figure, the work scaffold 8, etc. are used (FIG. 5). As the mechanical equipment 6, a crane 7 that is installed and fixed on the ground around the site where the caisson shaft 5 is constructed, and a suspension that is attached to the lower end of a suspension wire that is suspended from the tip of a suspension arm of the crane 7. A hook 16 (FIG. 5) or a grab bucket 14 exists. The crane 7 shown in the figure is a crawler type crane that can move in any direction. However, the crane 7 is a fixed crane that is installed in a completely fixed state on the ground or a large crane that is supported by a larger portal machine frame. Of course, it is also possible to adopt.

  The hydraulic jack 13 is placed in advance in the ground where the caisson shaft 5 is constructed, and the caisson housing 1 is placed in the ground by a cooperative action with the earth anchor 17 which is a bar-like support member raised upward. It is a device for press-fitting into the ground G. In the illustrated mechanical equipment 6, twelve earth anchors 17 are provided as shown in FIG. 2, and one of the pressure girders 9 and two hydraulic jacks are used by using two of the earth anchors 17. 13 constitutes a set of press-fit sedimentation means. The hydraulic jack 13 used in the present invention is a center hole jack in which a hole for receiving the gripper rod is formed at the center. When the earth anchor 17 is clamped by the anchor chuck 18 provided at the lower end of the gripper rod, the hydraulic jack 13 is hydraulic. The jack 13 and the ground anchor 17 are connected, and when the anchor chuck 18 is released, the hydraulic jack 13 and the ground anchor 17 are disconnected.

  Further, the grab bucket 14 is constituted by a pair of bucket elements that are pivotably opened and closed and provided with comb-like claws for excavating the ground G at the tip. Can be captured and drained of the captured mud R. The hanging hook 16 is a hanging tool used for hanging, moving, and installing the caisson casing 1, the succeeding casing 4, or the piece 19 (FIG. 8) that is an element of the succeeding casing 4. is there.

[Example 1]
Next, the caisson housing 1 of the present invention constructed using such mechanical equipment 6 and the press-fitting caisson method of the present invention using the caisson housing 1 will be described with reference to the embodiment 1 shown in FIGS. Take and explain. FIG. 3 is a side sectional view showing an example of the caisson casing of the present invention, and FIG. 4 is a transverse sectional view (a) showing an example of the caisson casing of the present invention, and a partially enlarged view (b) thereof. FIG. 5 is a side cross-sectional view of the first half part (a) to (d) showing an example of the press-fitting caisson method of the present invention for each process, and FIG. 6 is the second half part (a) to FIG. It is a sectional side view of (d). FIG. 7 is a side sectional view showing a stretched state of the friction reducing sheet that is fed out as the caisson housing is pressed and settled, and FIG. 8 is a perspective view showing various aspects of the caisson shaft constructed by the caisson housing of the present invention. Further, FIG. 9 is a perspective view showing stepwise the locked state of the winding base end portion of the friction reducing sheet, and FIG. 10 is an enlarged perspective view showing a part of the sheet unit arranged in an annular shape.

  The illustrated caisson housing 1 is used when a cylindrical caisson shaft 5 as shown in FIGS. 8B and 8D is constructed. Therefore, it has a cylindrical housing portion 20 (FIG. 4), and the caisson blade 2 having an inner blade shape is formed in an annular shape at the tip (end portion on the press-fitting and settling side) of the housing portion 20. (Figure 3). Furthermore, a sheet storage portion 22 for storing a long friction reducing sheet 21 wound up in a roll shape is provided on the outer peripheral portion at a position slightly above the center of the housing portion 20. The sheet accommodating portion 22 is provided with a sheet magazine 23 that holds the friction reducing sheet 21 so as to freely rotate. In this embodiment, a case where a metal (iron) sheet is used as the friction reducing sheet 21 (hereinafter referred to as “friction reducing metal sheet”) will be described, but it is needless to say that the present invention is not limited to this material.

  As shown in FIGS. 4 and 10, the sheet magazine 23 is a substantially rectangular box-like member that is processed by appropriately bending a metal thin plate, and the outer end surface thereof does not protrude from the outer peripheral surface of the housing portion 20. Is set to be almost flush with each other. A winding shaft 24 serving as a rotating shaft of the friction-reduced metal sheet 21 in a wound state is stretched horizontally between the left and right side plates facing the sheet magazine 23. As shown in FIG. 3, the friction reducing metal sheet 21 is housed in a holding cylinder 25 formed of glass wool or the like as an example, so that the wound state is maintained. The slit 26 formed in the sheet magazine 23 and the feeding opening 27 formed in the sheet magazine 23 are guided to the ground along the outer peripheral surface of the caisson casing 1 and the subsequent casing 4 installed above it. ing.

  In addition, the internal space of the sheet magazine 23 outside the holding cylinder 25 is filled with a filler 28 made of glass wool, for example. The filler 28 has a role of preventing inflow of mud R or the like from the outside. The sheet unit 29 including the sheet magazine 23, the winding shaft 24, the holding cylinder 25, the filler 28, and the friction reducing metal sheet 21 is configured as shown in FIGS. 4 and 10. A plurality of units are provided in a state of being substantially connected over a plurality of locations along the outer peripheral surface.

  As the friction-reducing metal sheet 21 used in the present invention, a thin iron plate having a thickness of about 0.2 mm to 0.3 mm can be adopted, and the surface thereof is smoothly processed. The friction-reducing metal sheet 21 has a mechanical strength sufficient to withstand feeding and pulling out while being able to exhibit good coating property or pasting property of the reducing material layer 30.

  A friction reducing material layer 30 is applied to or pasted on the inner surface 31 of the friction reducing metal sheet 21. In this embodiment, the friction reduction in the molten state is performed so that the thickness increases gradually from the winding base end side of the friction reduction metal sheet 21 toward the leading end side with respect to the inner surface 31 of the friction reduction metal sheet 21. The material of the material layer is applied to form a friction reducing material layer 30 in a laminated state composed of a plurality of layers. Here, as a raw material of the friction reducing material layer 30, a friction reducing resin coating containing water-absorbing resin (a), hydrophilic binder resin (b) and solvent (c) as essential components can be used.

  The friction reducing resin paint will be described below. The water-absorbent resin (a) used in the friction-reducing resin coating is a resin that swells by absorbing water and has a water absorption ratio of 3 times or more (25 ° C., 1 hour) with respect to its own weight. There is no particular limitation. However, the synthetic water-absorbent resin obtained by crosslinking a water-soluble hydrophilic compound (monomer and / or polymer) with a crosslinking agent, as exemplified below, has a swelling ratio and water capacity higher than those of natural water-swellable substances (gelatin, agar, etc.). These are preferable to natural water-swellable materials (gelatin, agar, etc.) because they have a good balance of dissolved content, water absorption rate, strength, etc. and can be easily adjusted.

  Specific examples of the water absorbent resin (a) as described above include, for example, a crosslinked poly (meth) acrylic acid, a crosslinked poly (meth) acrylate, and a poly (meth) acrylic acid having a sulfonic acid group. Cross-linked ester, cross-linked poly (meth) acrylate ester having polyoxyalkylene group, cross-linked poly (meth) acrylamide, cross-linked copolymer of (meth) acrylate and (meth) acrylamide, (meth) acrylic Copolymerized crosslinked product of hydroxyalkyl acid and (meth) acrylate, crosslinked polydioxolane, crosslinked polyethylene oxide, crosslinked polyvinylpyrrolidone, sulfonated polystyrene crosslinked product, crosslinked polyvinylpyridine, starch-poly (meth) acrylonitrile graft copolymer Saponification of coalescence, starch-poly (meth) acrylic acid (salt) graft cross-linking copolymer Coalescing, reaction products of polyvinyl alcohol and maleic acid (salt), cross-linked polyvinyl alcohol sulfonate, polyvinyl alcohol - acrylic acid graft copolymers, polyisobutylene maleic acid (salt) cross-linked polymer, and the like. These water-absorbing resins (a) may be used alone or in combination of two or more.

  In the present invention, it is preferable to use a salt-resistant water-absorbing resin as the water-absorbing resin (a). The reason why salt-resistant water-absorbent resins are preferred is that salt-resistant water-absorbent resins have a relatively high water absorption capacity of hard water containing polyvalent metals and are not significantly affected by the water quality in the soil when used in friction-reducing resin coatings. This is because the friction reducing effect can be exhibited.

  The salt-resistant water-absorbent resin in the present invention is not particularly limited as long as the water absorption ratio (25 ° C., 24 hours) in artificial seawater is 10 times or more. For example, the water-absorbent resin (a) exemplified above is used. Among them, those having a nonionic group and / or a sulfonic acid (salt) group are more preferred, and those having an amide group or a hydroxyalkyl group are more preferred. Examples of the salt-resistant water-absorbing resin as described above include, for example, a copolymer crosslinked product of (meth) acrylate and (meth) acrylamide, and a copolymer of hydroxyalkyl (meth) acrylate and (meth) acrylate. A crosslinked body etc. are mentioned. Further, those having a polyoxyalkylene group are particularly preferred. Examples of such a water absorbent resin (a) include a crosslinked copolymer of (meth) acrylate having a methoxypolyoxyalkylene group and (meth) acrylate.

  These salt-resistant water-absorbing resins can swell up to a certain magnification regardless of the nature of the water in the soil (soft water, hard water, etc.), and more reliably exhibit the friction reducing function. it can.

  Furthermore, the production method of the water-absorbent resin (a) used for the friction-reducing resin coating is not particularly limited. For example, a single amount containing a water-soluble ethylenically unsaturated monomer and, if necessary, a crosslinking agent. And a method of polymerizing body components. The water-absorbing resin (a) obtained by (co) polymerizing an ethylenically unsaturated monomer is excellent in water absorption with respect to water and is generally inexpensive. In addition, said crosslinking agent is not specifically limited.

  Specific examples of the ethylenically unsaturated monomer include acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, citraconic acid, vinyl sulfonic acid, and (meth) allyl sulfonic acid. 2- (meth) acrylamido-2-methylpropanesulfonic acid, 2- (meth) acryloylethanesulfonic acid, 2- (meth) acryloylpropanesulfonic acid, and alkali metal salts and ammonium salts of these monomers; N , N-dimethylaminoethyl (meth) acrylate and quaternized products thereof; (meth) acrylamide, N, N-dimethyl (meth) acrylamide, 2-hydroxyethyl (meth) acrylamide, diacetone (meth) acrylamide, N- Isopropyl (meth) acrylamide, (meth) acryloyl morpho (Meth) acrylamides such as ethylene, and derivatives of these monomers; hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate; polyethylene glycol mono (meth) Polyalkylene glycol mono (meth) acrylates such as acrylate, polypropylene glycol mono (meth) acrylate, methoxypolyethylene glycol mono (meth) acrylate, methoxypolypropylene glycol mono (meth) acrylate; N-vinyl-2-pyrrolidone, N-vinylsuccinimide N-vinyl monomers such as N-vinylformamide, N-vinyl-N-methylformamide, N-vinylacetamide, N-vinyl-N-methylacetamide, etc. Monomer, vinyl methyl ether; but like, but is not particularly limited. These ethylenically unsaturated monomers may be used alone or in combination of two or more.

  Among the ethylenically unsaturated monomers exemplified above, those composed of an ethylenically unsaturated monomer having a nonionic group and / or a sulfonic acid (salt) group are more preferable because of high salt resistance. Examples of the monomer include 2- (meth) acrylamide-2-methylpropanesulfonic acid, 2- (meth) acryloylethanesulfonic acid, 2- (meth) acryloylpropanesulfonic acid, (meth) acrylamide, and hydroxyalkyl. (Meth) acrylate, methoxypolyethylene glycol mono (meth) acrylate and the like can be mentioned. Furthermore, an ethylenically unsaturated monomer having a polyoxyalkylene group is particularly preferred.

  As a more preferable combination when two or more ethylenically unsaturated monomers are used in combination as the monomer component, for example, a combination of an alkali metal salt of (meth) acrylic acid such as sodium acrylate and acrylamide, (meta ) A combination of an alkali metal salt of acrylic acid and methoxypolyethylene glycol mono (meth) acrylate is exemplified, but is not particularly limited.

  A water-absorbing resin (a) is obtained by polymerizing the monomer components. The average molecular weight, shape, average particle size, etc. of the water-absorbent resin (a) may be set according to the composition of the friction reducing agent coating, the type of binder, physical properties, working environment, etc., and are particularly limited. However, the average particle diameter of the water absorbent resin (a) is preferably 30 to 800 μm, more preferably 30 to 600 μm, and most preferably 30 to 400 μm.

  When the average particle diameter of the water-absorbent resin (a) used in the friction-reducing resin coating exceeds 800 μm, the particle diameter is too large, and the water-absorbent resin (a) is added to the solvent (c) solution of the hydrophilic binder resin (b). When mixed, the particles of the water absorbent resin (a) are liable to settle, which is not preferable.

  On the other hand, when the average particle diameter of the water-absorbent resin (a) is less than 30 μm, the handling becomes very difficult (e.g., it is easily scattered as fine powder), which is not preferable.

Next, the hydrophilic binder resin (b) constituting the friction-reducing resin paint will be described.
The hydrophilic binder resin (b) used in the friction reducing resin coating is (i) water-soluble or water-swellable, and (ii) has a function of fixing the water-absorbing resin (a) to the substrate as a binder. And (iii) is not particularly limited as long as it is soluble in the solvent (c). For example, (meth) acrylic acid ester copolymer, polyurethane, polyester, polycarbonate, polyvinyl alcohol resin, poly Examples thereof include a partial hydrolyzate of vinyl acetate and an ethylene-polyvinyl alcohol copolymer, and one or a mixture of two or more thereof can be used.

  If the hydrophilic binder resin (b) is too low in hydrophilicity, it inhibits the swelling of the water-absorbent resin (a), reduces the absorption of moisture in the soil, and reduces the friction reducing function of the paint for friction reducing agent. This is not preferable. On the other hand, when the hydrophilicity of the hydrophilic binder resin (b) is too high, the adhesive force of the binder to the base material is excessively reduced when water is absorbed in the soil, and the entire coating film is peeled off too quickly. For the reasons as described above, the hydrophilic binder resin (b) preferably has moderate hydrophilicity.

  The acid value of the hydrophilic binder resin (b) is preferably 40 mgKOH / g or more, more preferably 50 mgKOH / g or more, and more preferably 70 mgKOH / g or more in order to have appropriate hydrophilicity. preferable.

  When the acid value of the hydrophilic binder resin (b) is less than 40 mgKOH / g, the hydrophilicity becomes too low, which is not preferable. Moreover, in order to maintain the binder function at the time of water absorption, it is preferably 500 mgKOH / g or less, more preferably 300 mgKOH / g or less, and even more preferably 200 mgKOH / g or less. When the acid value of the hydrophilic binder resin (b) exceeds 500 mgKOH / g, the hydrophilicity becomes too high, which is not preferable.

  Next, the glass transition temperature of the hydrophilic binder resin (b) is not particularly limited, but the adhesion to the friction-reducing metal sheet 21 serving as the base material and the workability when the base material is embedded in the ground G From the viewpoint of coexistence of the toughness of the coating film of the friction-reducing resin coating, it is preferable to have a glass transition temperature of -20 ° C to 120 ° C. When the glass transition temperature is −20 ° C. or lower, the coating film of the friction-reducing resin coating tends to be sticky. In particular, when the substrate after application is immediately wound and left, blocking may occur. In addition, since the strength of the friction-reducing resin coating is insufficient, it is not preferable because the base material is easily peeled when embedded in the ground G. For this reason, the glass transition temperature is more preferably 0 ° C. or higher.

  In addition, when the glass transition temperature of the hydrophilic binder resin (b) is 120 ° C. or higher, the adhesion preventing material layer becomes too hard, the adhesion to the base material, the flexibility of the coating film of the friction reducing resin paint becomes poor, Again, when the base material is embedded in the ground G, peeling and dropping of the water absorbent resin (a) are likely to occur, which is not preferable. From this, the glass transition temperature is more preferably 100 ° C. or less, and when the glass transition temperature is between 0 ° C. and 20 ° C. and between 20 ° C. and 100 ° C., the softening component and the shape retention component Good balance and more preferable.

  The weight average molecular weight (Mw) of the hydrophilic binder resin (b) is not particularly limited, but is preferably in the range of 30,000 to 300,000, and more preferably in the range of 50,000 to 200,000. By using the above resin having a weight average molecular weight, it becomes easy to balance the toughness of the anti-adhesive material and the solubility in alkaline water.

  As the hydrophilic binder resin (b), it is preferable to use an alkali water-soluble resin or a resin having an acid value of 40 to 500 mgKOH / g because the hydrophilicity can be easily adjusted by adjusting the acid value.

  Below, alkali water soluble resin is demonstrated. The alkaline water-soluble resin, which is one of the hydrophilic binder resins (b) constituting the friction-reducing resin coating, is a resin that dissolves in a 0.4% by weight NaOH aqueous solution and does not dissolve in neutral or acidic water. is there. The alkaline water-soluble resin is not particularly limited as long as it has the solubility defined above. For example, co-polymerization of an α, β-unsaturated carboxylic acid monomer and other monomers copolymerizable therewith. Coalescence can be mentioned.

  In addition, although it is the solubility to the above-mentioned alkaline water, the solubility degree is not particularly limited, but the preferable solubility degree of the alkaline water-soluble resin as a binder resin that can be preferably used in the following description is shown. Moreover, although it is the term alkaline water-soluble resin, it may be expressed as an alkali-soluble resin in another expression. Since it is clearer to use the alkaline water-soluble resin, the alkaline water-soluble resin is used in this specification.

  Moreover, although it is the solubility to the alkaline water of the alkaline water soluble resin which can be used preferably, it will not specifically limit unless the desired friction reduction effect | action is inhibited.

  This value is preferably 50% -100% for the alkaline water-soluble resin. More preferably, it is 60-100%. More preferably, it is 70-100 weight%. If no resin remains after filtration, it is dissolved.

  The production method of the alkaline water-soluble resin and the hydrophilic binder resin having an acid value of 40 to 500 mgKOH / g is not particularly limited, but the following α, β-unsaturated carboxylic acid monomer can be copolymerized with α, β- A copolymer obtainable by polymerization using an unsaturated monomer component composed of a monomer other than the unsaturated carboxylic acid monomer is preferred.

  For example, as an α, β-unsaturated carboxylic acid monomer used for the production of an alkaline water-soluble resin and a hydrophilic binder resin having an acid value of 40 to 500 mgKOH / g, for example, acrylic acid, methacrylic acid, maleic acid Α, β-unsaturated carboxylic acids such as itaconic acid and fumaric acid; α, β-unsaturated carboxylic acid anhydrides such as maleic anhydride and itaconic anhydride; maleic acid monoester, fumaric acid monoester and itaconic acid mono Examples include α, β-unsaturated dicarboxylic acid monoesters such as esters. The α, β-unsaturated carboxylic acid monomer may be only one type or two or more types. Among these, acrylic acid and / or methacrylic acid, which are acrylic α, β-unsaturated carboxylic acids, are preferably used because they are inexpensive and have good copolymerizability with other unsaturated monomers.

  Next, other monomers that can be copolymerized with the α, β-unsaturated carboxylic acid monomer include, for example, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, stearyl acrylate, methyl methacrylate, ethyl methacrylate, propyl Esters of C1-C18 monohydric alcohols such as methacrylate, butyl methacrylate, stearyl methacrylate and (meth) acrylic acid; nitrile group-containing vinyl monomers such as acrylonitrile, methacrylonitrile; acrylamide, methacrylamide, etc. Amide group-containing vinyl monomers; hydroxyl group-containing vinyl monomers such as hydroxyethyl acrylate and hydroxypropyl methacrylate; epoxy group-containing vinyl monomers such as glycidyl methacrylate; zinc acrylate , Metal salts of α, β-unsaturated carboxylic acids such as zinc methacrylate; aromatic vinyl monomers such as styrene and α-methylstyrene; aliphatic vinyl monomers such as vinyl acetate; vinyl chloride, odor Halogen-containing vinyl monomers such as vinyl iodide, vinyl iodide and vinylidene chloride; allyl ethers; maleic acid derivatives such as dialkyl esters of maleic acid; fumaric acid derivatives such as dialkyl esters of fumaric acid; maleimide, N-methyl Maleimide derivatives such as maleimide, stearylmaleimide, N-phenylmaleimide, N-cyclohexylmaleimide; Itaconic acid derivatives such as mono and dialkyl esters of itaconic acid, itaconic amides, itaconic imides, itaconic amide esters; alkenes such as ethylene and propylene Class: butadiene, isoprene and other die Vinyl ethers; unsaturated monomers having a sulfonic acid (salt) group such as 2- (meth) acryloylpropanesulfonic acid (salt), 3-allyloxy-2-hydroxypropanesulfonic acid (salt), polyalkylene A glycol (meth) acrylate etc. can be mentioned, It can use by 1 type (s) or 2 or more types in these.

  Among these, (meth) acrylic acid alkyl esters are easily available as esters having various properties, and by appropriately combining them, the binder resin Tg (hardness, softness), base material The adhesiveness to the resin can be easily adjusted, and the copolymerizability with the α, β-unsaturated carboxylic acid monomer is relatively good, which is preferable.

  The (meth) acrylic acid alkyl ester is preferably used in an amount of 30% to 100% by weight based on 100% by weight of the total amount of other monomers copolymerizable with the α, β-unsaturated carboxylic acid monomer. More preferably, it is used in an amount of 50 to 100% by weight. More preferably, it is 60-100 weight%, More preferably, it is 70-100 weight%. That is, the use of an acrylic monomer as another monomer is a preferred embodiment as a form of an alkaline water-soluble resin as the hydrophilic binder resin (b).

  The proportion of the unsaturated monomer component composed of the above α, β-unsaturated carboxylic acid monomer and another monomer copolymerizable therewith is not particularly limited. For example, α, β-unsaturated carboxylic acid When the unsaturated monomer component consisting of a monomer and another monomer copolymerizable therewith is 100% by weight, the proportion of α, β-unsaturated carboxylic acid in the total monomer component is preferably Is 7 to 80% by weight in the total amount of unsaturated monomers. More preferably, it is 7 to 50% by weight. More preferably, it is 9 to 30% by weight.

  When the ratio of the α, β-unsaturated carboxylic acid monomer in all monomers in the alkaline water-soluble resin is less than 7% by weight, the hydrophilicity tends to be too low due to the low acid value. On the other hand, if the ratio exceeds 80% by weight, the hydrophilicity becomes too high, and problems are likely to occur.

  Α, β-unsaturation used as a raw material for producing a hydrophilic binder resin having an acid value of 40 mgKOH / g or more and 500 mgKOH / g or less, that is, a binder resin obtained by polymerizing the unsaturated monomer component. The amount of the copolymerizable monomer other than the carboxylic acid monomer is the unsaturated monomer comprising the above α, β-unsaturated carboxylic acid monomer and another monomer copolymerizable therewith. Based on 100% by weight of all components, preferably 93 to 20% by weight in all of the unsaturated monomer components. More preferably, it is 93 to 50% by weight. More preferably, it is 91-70 weight%.

  If the proportion of the α, β-unsaturated carboxylic acid monomer is less than 20%, the hydrophilicity is lowered, and if it exceeds 93%, the hydrophilicity becomes too high.

  The method for producing the alkaline water-soluble resin is not particularly limited, and generally known polymerization methods such as solution polymerization, bulk polymerization, emulsion polymerization, suspension polymerization and the like can be used, and among them, it is manufactured by solution polymerization in an organic solvent. Is preferred.

  This is because a friction-reducing resin coating can be produced by mixing a water-absorbing resin as it is with a solution or dispersion containing an alkaline water-soluble resin obtained by solution polymerization.

  Moreover, radical polymerization, anionic polymerization, cationic polymerization, coordination polymerization, etc. are mentioned as a polymerization form, However, radical polymerization is preferable as an industrial manufacturing method.

  Examples of the reaction vessel used for the production of the raw material polymer include a tank reactor and a tubular reactor such as a kneader and a static mixer. These reactors can be used in combination as required. A dripping tank is also used if necessary. The pressure in the reaction vessel may be any of reduced pressure, normal pressure, and increased pressure.

  Next, the radical polymerization initiator used in the radical polymerization is not particularly limited. Specific examples thereof include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethyl). Azo initiators such as valeronitrile) and peroxide initiators such as benzoyl peroxide and di-t-butyl peroxide. Two or more kinds of these radical polymerization initiators may be used in combination.

  The solvent used in the solution polymerization is not particularly limited as long as it does not interfere with the radical polymerization reaction. For example, alcohols such as methanol, ethanol and isopropyl alcohol; aromatic hydrocarbons such as benzene and toluene; acetone , Ketones such as methyl ethyl ketone; aliphatic esters such as ethyl acetate and butyl acetate; ethylene glycol derivatives such as ethylene glycol and ethylene glycol monomethyl ether; propylene glycol derivatives such as propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate Etc. Two or more of these solvents may be used in combination.

  Next, the solvent (c) used for the friction-reducing resin paint will be described. The solvent (c) can be used without any particular limitation as long as it is a known solvent used for ordinary paints, for example, one or more of the solvents exemplified in the description of the method for producing the alkaline water-soluble resin. It can be used in a combination of two or more.

  Further, as a method for selecting the solvent (c), it is preferable to select a solvent having a boiling point, safety, etc. suitable for application to the substrate. If a low-boiling solvent is selected, it can be quickly dried and a coating can be formed in a short time, so that thick coating and the like are easy, and if a high-boiling solvent is selected, the working time can be extended. By using an organic solvent as a medium, the water-absorbing resin does not swell due to water absorption when a medium containing water is used, and the coating operation is facilitated because it does not become a gel. In addition, when a highly volatile solvent such as methyl ethyl ketone or methanol is used, it can be dried in about 10 minutes and can be transferred to the next operation or process quickly because it dries much faster than when water is used as a medium. The construction period or the time required for application to the substrate can be remarkably shortened.

  As long as the friction-reducing resin paint of the present invention contains the water-absorbent resin (a), the hydrophilic binder resin (b) and the solvent (c) described above as essential components, the characteristics thereof are not impaired. As other additives (h), other resins, pigments, various stabilizers, various fillers and the like may be contained.

  The ratio of the water-absorbing resin (a), the hydrophilic binder (b) and the solvent (c) to the other additive (h) is not particularly limited, but in order to fully exhibit the characteristics of the friction-reducing resin paint, Ratio ([(a) + (b) + (c)] / [(a) + (b) + () of the total of the resin (a), the hydrophilic binder (b) and the solvent (c)) c) + (h)] × 100 (%)) is preferably 50% or more, more preferably 70% or more, and most preferably 80% or more.

  Also, the ratio of the water-absorbing resin (a), the hydrophilic binder (b), the solvent (c) and other additives (h) is not particularly limited, but in order to fully exhibit the characteristics of the friction-reducing resin paint. The water-absorbing resin (a) is 5 to 60% by weight, the hydrophilic binder (b) is 10 to 70% by weight, the solvent (c) is 5 to 70% by weight, and the other additives (h) are 0 to 50% by weight. %, The water-absorbing resin (a) is 10 to 50% by weight, the hydrophilic binder (b) is 10 to 60% by weight, the solvent (c) is 10 to 60% by weight, and the other additives (h) are 0%. -30% by weight is more preferred.

  The method of applying the friction-reducing resin paint to various substrates is not particularly limited as long as it is a known paint application method. For example, a brush, a roller or the like may be used, or a spray device such as a lysing gun is used. Spray painting.

  In this embodiment, the friction reducing resin coating material forming the friction reducing material layer 300 is also applied or pasted on the outer surface of the friction reducing metal sheet 21. The friction-reducing metal sheet 21 coated with such a friction-reducing resin coating is gradually drawn downward as the caisson housing 1 is press-fitted and settled, and can be pulled upward after the caisson housing 1 is pressed and settled. It is configured as follows. That is, as shown in FIG. 9A, the winding shaft 24 is provided with a locking slit 32 penetrating in a direction perpendicular to the shaft, and as shown in FIG. 9B, the friction reducing metal sheet. The friction reducing metal sheet 21 is inserted by inserting the winding base end 33 of the coil 21 into the locking slit 32 and winding the friction reducing metal sheet 21 around the winding shaft 24 as shown in FIG. Is attached to the winding shaft 24.

  The friction-reducing metal sheet 21 wound around the take-up shaft 24 is gradually fed by the caisson housing 1 being press-fitted and settled with the feeding tip 34 of the friction-reducing metal sheet 21 held on the ground. Go (Figure 7). And since the connection state with the winding shaft 24 is finally released when the winding base end portion 33 of the friction reducing metal sheet 21 passes through the locking slit 32, the friction reducing metal sheet 21 is pulled upward. Be able to.

  Next, the press-fitting caisson method of the present invention executed by using such a caisson housing 1 will be described. In the press-fitting caisson method of the present invention, the caisson casing 1 of the present invention described above is used, and the friction-reducing metal sheet 21 in the wound state is gradually drawn downward by press-fitting the caisson casing 1. In addition, the sliding contact between the ground G and the caisson housing 1 or the subsequent housing 4 added above is prevented, and after the caisson housing 1 is pressed and settled, the winding base end 33 is connected to the caisson housing 1. It is characterized in that it is configured so that it can be released and pulled upward.

  Hereinafter, a specific configuration of the press-fitting caisson method according to the present invention will be described with reference to FIGS. That is, the press-fitting caisson method of the present invention includes (1) edge cutting / mound installation step, (2) primary press-fitting preparation step, (3) primary press-fitting / excavation step, (4) secondary press-fitting preparation step, (5) ) Secondary press-fitting / excavation step, (6) press-fitting / excavation completion step, (7) friction reducing metal sheet drawing step, and (8) bottom slab concrete placing step.

(1) Edge cutting and mound setting process (see Fig. 5 (a))
In this step, a steel sheet pile 3 or the like is placed in the ground G in order to cut the ground G forming the caisson shaft 5 and the surrounding ground. Incidentally, when the steel sheet pile 3 or the like is placed, propagation of vibrations and the like given to the surrounding ground is prevented, and various effects caused by the propagation are blocked. A mound (replacement sand) M is provided in preparation for the installation of the caisson housing 1.

(2) Primary press-fitting preparation process (see FIG. 5B)
In this step, the earth anchor 17 is driven and the pressure girder 9 is bridged over the earth anchor 17. Then, the hydraulic jack 13 is installed on the pressure beam 9 and the upper portion of the earth anchor 17 is chucked by the anchor chuck 18. In addition, the caisson housing 1 is set on the lower surface of the presser girder 9 with the caisson blade edge 2 facing downward to prepare for press-fitting of the caisson housing 1.
At this time, the feeding leading end 34 of the friction reducing metal sheet 21 is held by the pressure beam 9 or the like.

(3) Primary press-fitting and excavation process (see FIGS. 5C and 7A)
In this step, the caisson housing 1 is press-fitted and settled into the ground G by the press-fitting action using the pressure girder 9 and the weight of the caisson housing 1 and the hydraulic pressure of the hydraulic jack 13. Then, excavation of the ground G inside the caisson housing 1 is advanced using the crane 7 and the grab bucket 14 while the press-fitting and sinking of the caisson housing 1 is advanced.
At this time, the sheet unit 29 attached to the caisson housing 1 also moves downward as the caisson housing 1 is press-fitted and settled, so that the friction reducing metal sheet 21 in the wound state is unwound little by little.

(4) Secondary press-fitting preparation process (see FIG. 5 (d))
In this step, after the press-in sedimentation of the caisson housing 1 is completed, preparations for the press-in sedimentation of the subsequent housing 4 to be added above the caisson housing 1 are performed. In this case, the installed pressure girder 9, hydraulic jack 13 and the like are temporarily removed using the crane 7 and the hanging hook 16 and the like. Then, the scaffold 8 and the mold 10 are installed, the raw material is poured into the mold 10 above the caisson casing 1 press-fitted into the ground G, and the subsequent casing 4 is precast. And after confirming solidification of the subsequent frame 4, the said scaffold 8 and the formwork 10 are removed.

(5) Secondary press-fitting and excavation process (see FIGS. 6 (a), 7 (b) and 7 (c))
In this step, the pressure girder 9 is again laid over the earth anchor 17, the hydraulic jack 13 is installed on the pressure girder 9, and the upper portion of the earth anchor 17 is chucked by the anchor chuck 18. Then, similarly to the above (3) primary press-fitting and excavation process, excavation of the ground G inside the caisson housing 1 is advanced while the press-in settling of the caisson housing 1 and the subsequent housing 4 is preceded.

  Further, at this time, the friction reducing metal sheet 21 coated with the friction reducing material layer 30 is located between the outer peripheral surface of the caisson casing 1 and the subsequent casing 4 and the outer ground G. The frictional resistance is kept extremely low, and the caisson housing 1 and the following housing 4 are smoothly and smoothly pressed into the ground G.

  Further, according to the present embodiment, the friction is reduced on the leading end side that receives the frictional resistance for the longest time when the friction reducing metal sheet 21 that is gradually extended when the caisson casing 1 is press-fitted and extended is extended. The thickness of the reducing material layer 30 is the largest, and the thickness of the friction reducing material layer 30 is gradually reduced toward the winding base end side that receives the frictional resistance for the shortest time. Accordingly, it is possible to prevent a decrease in the friction reducing action due to peeling or wear of the friction reducing material layer 30 without excessively increasing the amount of the friction reducing material layer 30 used.

(6) Press-in and excavation completion process (see Fig. 6 (b))
Hereinafter, by repeating the above (4) secondary press-fitting preparation step and (5) secondary press-fitting and excavation step, all of the caisson housing 1 and the predetermined number of subsequent housings 4 are pressed and settled, and the ground G inside the caisson housing 1 Complete excavation. Further, while the excavation of the ground G is proceeding, there is a case where it reaches the part where the groundwater W or the like flows on the way. In such a case, the groundwater W or the like flowing into the caisson housing 1 and the subsequent housing 4 is not shown. And so on.

(7) Friction reducing metal sheet drawing process (see FIG. 6C)
When the caisson housing 1 is pressed and settled, the winding base end portion 33 of the friction reducing metal sheet 21 is disengaged from the locking slit 32 of the winding shaft 24 that has been locked, so that the friction reducing metal sheet 21 is pulled upward. Is possible. Along with this, the friction reducing metal sheet 21 is pulled upward, and the earth anchor 17, the pressure girder 9, the hydraulic jack 13, the steel sheet pile 3 and the like are removed.

  At this time, in this embodiment, since the friction reducing material layer 300 is applied or pasted on the outer surface of the friction reducing metal sheet 21, the outer surface of the friction reducing metal sheet 21 is ground G when the friction reducing metal sheet 21 is pulled out. The frictional resistance due to the sliding contact can be effectively reduced. Further, the inner surface of the friction reducing metal sheet 21 is in sliding contact with the outer peripheral surfaces of the caisson pair 1 and the extension pair 4, and the frictional resistance due to this sliding contact can be effectively reduced by the friction reducing material layer 30. it can. Furthermore, since the friction reducing metal sheet 21 is configured to be pulled upward, the friction reducing metal sheet 21 that has been used can be collected, and material costs can be reduced through effective use of the members. In addition, adverse effects on the natural environment and the like can be prevented through preventing the friction reducing material layer from remaining in the ground.

(8) Bottom slab concrete placing process (see Fig. 6 (d))
Then, the caisson shaft 5 having a predetermined depth is completed by placing the underwater concrete 12 and the bottom slab concrete 11 inside the caisson frame 1 that has been press-fitted and settled. The caisson shaft 5 is used as a start shaft or a reaching shaft of the shield tunnel 15.

[Example 2]
Next, the caisson housing 1 according to the second embodiment in which the configuration of the seat unit 29 shown in FIGS. 11 to 13 is different will be described. FIG. 11 is an enlarged perspective view showing a part of a sheet unit arranged in two upper and lower stages in an annular shape, and FIG. 12 shows two types of sheet units in which the shape of the sheet magazine and the shaft diameter of the take-up shaft are different. It is a sectional side view which shows a and (b). FIG. 13 is a cross-sectional view showing various modes (a) to (c) of the close contact means applied between the main sheet and the joint sheet. The caisson housing 1 according to the second embodiment is different from the caisson housing 1 according to the first embodiment except for the disposition of the seat unit 29 and the differences in the configuration of a part of the seat unit 29 and the friction reducing metal sheet 21. Since it is the same, here, it explains focusing on the peculiar structure of the caisson housing 1 concerning Example 2. FIG.

  In the second embodiment, the friction reducing metal sheet 21 is disposed in the gap 36 between the main sheet 35 provided in a substantially connected state along the outer peripheral surface of the caisson housing 1 and the adjacent main sheets 35. The joint sheet 37 is provided. The main seat 35 and the joint seat 37 are partially overlapped in a state of being wound so as not to interfere with each other, and are provided in a state where the mounting positions are shifted up and down. Specifically, as shown in FIG. 11, the seat unit 29A for the main seat 35 is positioned upward, and the sheet unit 29B for the joint seat 37 is positioned downward by a half pitch shift in the circumferential direction. ing. Accordingly, the gap 36 existing between the adjacent main sheets 35 is closed by the joint sheet 37 as shown in the figure, so that it is difficult for mud R and groundwater W to flow in from the outside.

  In FIG. 11, a sheet magazine 23 is provided for each individual sheet unit 29. However, as shown in FIG. 12, a vertically long main sheet 35 and a joint sheet 37 positioned below can be accommodated simultaneously. The sheet magazine 23 can also be used. Incidentally, in FIG. 12A, a partition plate 38 is provided at the height inside the sheet magazine 23 and in the vicinity of the center of the sheet magazine 23 to separate the main sheet 35 and the joint sheet 37 from each other. The same diameter is shown in FIG. On the other hand, in FIG. 12B, the partition plate 38 does not exist, the main shaft 35 has a small diameter on the winding shaft 24 on the main sheet 35 side, and the large diameter on the winding shaft 24 on the joint sheet 37 side. In the figure, the joint sheet 37 is smoothly drawn out.

  Further, the contact surface between the main sheet 35 and the joint sheet 37 is provided with a close contact means 39 as shown in FIG. 13 for bringing the main sheet 35 and the joint sheet 37 into a close contact state in use, or the close contact means 39 acts. It is also possible to configure. Incidentally, in FIG. 13A, a contact means 39 provided with a concave and convex engaging portion 40 that engages with the joint surface of the main sheet 35 to the joint sheet 37 and the joint surface of the joint sheet 37 to the main sheet 35 is illustrated. .

  In FIG. 13B, a seal member 41 that improves the adhesion of the joint surface is provided between the main sheet 35 and the joint sheet 37, and friction-reducing air A that is injected from the inside of the caisson housing 1 is provided. A close contact means 39 is shown in which the pressure between the main sheet 35 and the joint sheet 37 is increased by using the pressure of the pressure. In this case, the seal member 41 can be replaced by a friction reducing resin material 30 applied to the surface of the friction reducing metal sheet 21. Furthermore, as shown in FIG. 13 (c), it is also possible to constitute the concave / convex engaging portion 40 by coating the friction reducing resin material 30 in a streak shape.

[Other embodiments]
The caisson housing 1 according to the present invention and the press-fitting caisson method using the caisson housing 1 have the above-described configuration as an example. However, the caisson housing 1 has a partial configuration within the scope of the present invention. Of course, changes and omissions can be made. For example, the shape of the caisson housing 1 is not limited to a cylindrical shape, and may be a square tube shape. If the rectangular tube-shaped caisson housing 1 is used, a rectangular tube shape as shown in FIGS. The caisson shaft 5 can be constructed. Further, the caisson shaft 5 that can be constructed by the caisson housing 1 of the present invention is not limited to the structure shown in FIGS. 8A and 8B in which the subsequent housing 4 formed in a cylindrical shape is added from the beginning. A structure as shown in FIGS. 8C and 8D in which the plate-like piece 19 is joined using the bolt joint 42 is also included.

  Further, the succeeding casing 4 crushed on the caisson casing 1 is not limited to a concrete casing but may be a casing formed of other materials such as steel. Further, the width dimension of the main sheet 35 and the joint sheet 37 is not necessarily the same dimension, and the width dimension of the joint sheet 37 can be shortened within a range in which the gap portion 36 can be closed.

  Further, the friction reducing material layers 30 and 300 provided on the surface of the friction reducing metal sheet 21 are not limited to those according to the above-described embodiment in which the raw material of the friction reducing material layer in a molten state is applied and then dried and cured. Of course, the sheet-like friction reducing material layer 30 in a solid state may be pasted using an adhesive or the like from the beginning.

  The present invention can be used when building a caisson shaft using a caisson skeleton at a construction site of a bridge pier or a shield work, especially when the frictional resistance when pressuring and sinking the caisson skeleton is large. It can be used when you want to reduce the pressure caisson method efficiently.

It is a sectional side view which shows an example of the mechanical installation used for execution of the press-fitting caisson method using the caisson housing of this invention. It is a top view which shows an example of the mechanical installation used for execution of the press fit caisson method using the caisson housing of this invention. It is a sectional side view which shows an example of the caisson housing of this invention. It is the cross-sectional view (a) which shows an example of the caisson housing of this invention, and its partial enlarged view (b). It is side sectional drawing of the first half part (a)-(d) which shows an example of the press-fitting caisson method of this invention according to a process. It is a sectional side view of the latter half part (a)-(d) which shows an example of the press-fitting caisson method of this invention according to a process. It is a sectional side view which shows the extension state of the friction reduction metal sheet drawn out with the press-fit sedimentation of a caisson housing. It is a perspective view which shows the various aspect of the caisson shaft constructed | assembled by the caisson frame of this invention. It is a perspective view which shows the latching state of the winding base end part of a friction reduction metal sheet in steps. It is a perspective view which expands and shows some sheet units arrange | positioned by the annular | circular shape. It is a perspective view which expands and shows a part of sheet unit arrange | positioned at the annular | circular shaped upper and lower two steps. It is a sectional side view showing two types of sheet units (a) and (b) in which the shape of the sheet magazine and the shaft diameter of the take-up shaft are different. It is a cross-sectional view which shows the various aspects (a)-(c) of the contact | adherence means applied between a main sheet | seat and a joint sheet | seat.

Explanation of symbols

1 caisson housing, 2 caisson blade, 3 steel sheet pile, 4 following housing,
5 Caisson shaft 6 Machine equipment, 7 Crane, 8 Scaffolding, 9 Pressure girder, 10 Formwork 11 Bottom slab concrete, 12 Underwater concrete, 13 Hydraulic jack (press-fit device),
14 grab buckets, 15 shield tunnels, 16 hanging hooks,
17 earth anchor, 18 anchor chuck, 19 pieces, 20 housing,
21 Friction reducing metal sheet, 22 sheet storage part, 23 sheet magazine,
24 winding shaft, 25 holding cylinder, 26 slit, 27 feeding opening, 28 filler, 29 sheet unit, 29A sheet unit (for main sheet),
29B sheet unit (for joint sheet), 30 friction reducing material layer, 31 inner surface,
32 Locking slit, 33 Winding base end, 34 Feeding tip, 35 Main sheet, 36 Gap, 37 Joint sheet, 38 Partition plate, 39 Adhering means,
40 Concavity and convexity engagement part, 41 Seal member, 42 Bolt joint, 300 Friction reducing material layer A Air, G Ground, R Mud (earth), M Mound (substitution sand), W Groundwater,
a water-absorbing resin, b hydrophilic binder resin, c solvent, h additive,

Claims (10)

The caisson housing with the inner blade-shaped caisson blade tip formed at the tip is pressed and settled into the ground for each predetermined stroke, and the mud soil inside the caisson housing is excavated and discharged to the outside. The caisson housing used in the press-fitting caisson method for constructing a caisson shaft with a predetermined depth by adding and installing
A sheet accommodating portion is provided on the outer peripheral portion of the caisson housing, and a long friction reducing sheet having a friction reducing material layer applied or pasted on the inner surface of the sheet accommodating portion is wound and accommodated in a roll shape. and which, the friction reducing sheets are arranged in a state of being substantially connected over a plurality of locations along the outer circumferential surface of the caissons skeleton, caisson building frame is while holding the feeding tip of the friction reducing sheet on the ground by being pressed sedimentation, caisson skeleton, characterized by being configured to gradually unwound unwound is the friction reducing sheet along with the press-precipitation.   The caisson housing according to claim 1, wherein a friction reducing material layer is applied or pasted on an outer surface of the friction reducing sheet. 3. The friction reduction sheet according to claim 2, wherein the friction reduction sheet has a winding slit provided with a locking slit provided in a penetrating state in a direction perpendicular to the axis thereof, and the winding base end portion of the friction reduction sheet is placed on the locking slit. Is wound in a state of being inserted into
After the caisson housing is pressed and settled, the winding base end portion of the friction reducing sheet is rubbed through the locking slit to release the connection state with the winding shaft, and the friction reducing sheet can be pulled upward. The caisson enclosure characterized by being configured as follows.   4. The friction reducing material layer according to claim 1, wherein the friction reducing material layer is formed on the friction reducing sheet such that the thickness of the friction reducing material layer increases stepwise from the winding base end side toward the feeding leading end side of the friction reducing sheet. A caisson enclosure characterized by being applied or pasted in a laminated state. 5. The friction reducing sheet according to claim 1, wherein the friction reducing sheet is disposed in a gap between a main sheet provided in a substantially connected state along the outer peripheral surface of the caisson housing and an adjacent main sheet. It is configured by providing a joint sheet,
The main sheet and the joint sheet wound in a roll shape are provided so as to partially overlap when the main sheet and the joint sheet are unwound and fed out, and the roll-shaped main sheet the sheet accommodating portion for accommodating the sheets and the joint sheet, caisson skeleton, characterized in that said roll of said main sheet and the joint sheet is provided Rashi not vertically so as not to interfere with each other. According to claim 5, caisson skeleton, wherein the contact means are found provided that the main seat and the joint sheet in close contact in the use state to the bonding surface of the main seat and the joint sheet. The caisson housing with the inner blade-shaped caisson blade tip formed at the tip is pressed and settled into the ground for each predetermined stroke, and the mud soil inside the caisson housing is excavated and discharged to the outside. It is a press-in caisson method for constructing caisson shafts of a predetermined depth by adding and installing
A caisson housing having a long friction reducing sheet with a friction reducing material layer applied or pasted on its inner surface is used. The outer periphery of the caisson housing is initially wound in a roll shape. and mounted is accommodated in the sheet accommodating portion provided in, by press-fitting settle caisson precursor while holding the feeding tip of the friction reducing sheet on the ground, is the friction reducing sheet along with the press-precipitation The caisson housing or the subsequent housing added to the caisson housing is slidably contacted with the friction reducing sheet via the friction reducing material layer. Press-in caisson method using caisson housing. 8. The friction reducing sheet according to claim 7, wherein the friction reducing sheet has a winding base provided with a locking slit provided in a penetrating state in a direction perpendicular to the axis thereof, and the winding base end portion of the friction reducing sheet is placed on the locking slit. And a friction reducing material layer is applied to or pasted on the outer surface of the friction reducing sheet,
After the caisson housing is press-fitted and settled, the winding base end portion of the friction reducing sheet is rubbed through the locking slit to release the connection state with the winding shaft. The press-fitting caisson method using a caisson housing, wherein the engagement is released and the friction-reducing metal sheet is pulled upward.   It is a friction reduction sheet | seat used for the caisson housing | casing described in any one of Claim 1 to 6, Comprising: The friction reduction material layer is apply | coated or stuck, The friction reduction sheet | seat characterized by the above-mentioned.   A friction reducing sheet used in a press-fitting caisson method using the caisson housing according to claim 7 or 8, wherein a friction reducing material layer is applied or pasted.

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