JP3485249B2 - Construction method of earth pressure wall - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming an earth pressure wall and a pipe for forming an earth pressure wall. More specifically, the present invention forms an earth pressure wall by pushing a large number of pipes one after another into the ground in a state where they are in close contact with each other.
How to do it. [0002] It is already known to construct an earth pressure wall by pushing a large number of pipes into the ground in close contact with one another. Generally, the earth pressure wall thus formed is called a pipe roof, and the method of forming the earth pressure wall in this way is called a pipe roof construction method. The pipe roof method is used to dig the ground located on one side of the earth pressure wall and then build a structure after digging. [0003] The pipes used in the pipe roof construction method are intended to constitute a wall that withstands the earth pressure. It must be able to withstand earth pressure. For this purpose, it is necessary for the tubes to be provided with a stop on the outer surface of the tube made of a hard material so that adjacent tubes can be connected to each other by the stop. [0004] As a tube made of a hard material, a steel tube having a circular cross section is often used. When a circular steel pipe is used, the locking portion has a structure as shown in FIG. 1, for example. FIG.
Shows a cross section of two tubes joined together. [0005] In FIG. 1, the tube 1 is provided with locking portions 11 and 12 at portions diametrically opposed to each other.
Each of the locking portions 11 and 12 is configured by facing a long body having an L-shaped cross section, but the locking portion 11 is configured such that the protruding pieces of the L shape are widely opened inward toward each other. On the other hand, the locking portion 12 has the L-shaped projecting piece slightly open outward. To this end, when a tube 2 having the same structure as the tube 1 is pushed in adjacent to the tube 1, the locking portion 1 of the tube 1
The tube 2 enters the engaging portion 21 of the tube 2 so that the tube 1 and the tube 2 are tightly integrated with each other. However, it is not easy to push the pipe as shown in FIG. 1 into the ground to form an earth pressure wall. This is because the tube 1 has the locking portions 11 and 12 having an L-shaped cross section projecting from the outer surface. That is, in order to push the pipe 1 into the ground to form an earth pressure wall, a disk with a cutting blade is rotated at the tip of the pipe 1 so that the ground is formed into a circle having a size substantially corresponding to the outer diameter of the pipe 1. Must be excavated and the excavated earth and sand discharged from the pipe, and the pipe must be propelled. At this time, the locking portions 11 and 12 having an L-shaped cross section project, and one piece of L This is because the locking portion hinders propulsion because it protrudes in the peripheral direction. More specifically, when hard soil or cobblestone-mixed soil is present at the place where the locking portion is provided, the locking portion hits the hard soil or boulder and the pipe cannot be propelled. On the other hand, when the place where the locking portion is attached is a gravel ground, the gravel is bitten into the locking portion and the propulsion resistance increases, and in this case, the pipe cannot be propelled. In addition, a tube having a circular cross section has a drawback that it is not suitable for forming an earth pressure wall due to a weak locking portion. Therefore, a rectangular steel pipe 3 as shown in FIG. 2 was used in place of the circular steel pipe. The use of the square steel pipe 3 eliminates the disadvantage that the locking portion is weak as in the case of a circular steel pipe, but it is difficult to excavate the ground so that the cross section becomes square. In particular, it becomes more difficult to excavate the portion where the locking portions 31 and 32 are additionally provided. For this reason, as in the case of the above-mentioned circular steel pipe, when there is hard soil, cobblestone-mixed ground or gravel soil at the place where the locking portions 31 and 32 are provided, propulsion becomes impossible. [0009] As described above, in the conventional pipe roof method, it is impossible to propel the pipe in the ground mixed with hard soil, cobblestone, or the ground of gravel soil. Therefore, there was a need to develop a method of constructing an earth pressure wall so that the pipe could be propelled on any ground. An object of the present invention is to provide a method for forming such an earth pressure wall. [0010] For this purpose, the soil of the present invention is used.
The construction method of the pressure wall made many pipes close to each other one after another
Construct an earth pressure wall by pushing it into the ground in the state
In the method, a part of an arc of a circular pipe having a circular cross section is used as the pipe.
Notch at a central angle of 60 to 120 degrees,
Weld the wall to form a depression in it, cut out the circular pipe
Near the end, weld a reinforcing piece between the partition and the
Use a hard material deformed pipe that penetrates in the pipe axis direction.
The notch end of the notch has a locking portion between an adjacent deformed pipe.
Profiled tube that acts as one of the
The other side of the locking part is a circular shape of a deformed pipe so that
The partition wall provided on the outer surface of the pipe portion and located in front of the deformed pipe
To make a hole in the part and push it into the ground,
Place the recess toward the deformed tube to be pushed in later,
Excavation of the ground in front of a circular shape, and the wall surface of the ground excavated in a circular shape
And the cavity formed between the recess of the deformed pipe,
Fill the filling material mainly composed of clay and water through
The gap is temporarily filled with filling material and drilled through the profiled pipe.
The first step is to propel the deformed pipe into the ground while discharging
Buried pipe, then a second with similar depressions and locking parts
The deformed pipe is placed in close proximity to the first buried pipe and the second
Aim the depression in the direction of the tube to be pushed later, and
The other of the locking portions of the deformed pipe is one of the locking portions of the first buried pipe.
, And the circular pipe part of the second deformed pipe is buried in the first
While drilling into the hollow of the pipe and digging the front ground circularly
Into the ground to form a second buried pipe ,
Repeatedly pushing deformed pipes into the ground one after another to remove the earth pressure wall
It is characterized by comprising. An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG.
It is sectional drawing of the modified pipe used by the method of this invention. FIG.
FIG. 3 is a sectional view of another modified pipe used in the method of the present invention. FIG. 5 is a sectional view of a tube showing a process of carrying out the method of the present invention. FIG. 6 is a schematic sectional view of a pipe showing another process of the method of the present invention. In FIG. 3, the deformed pipe 5 is originally a circular steel pipe 51, a part 52 of an arc is cut out, a partition wall 53 is newly welded inside the pipe, and a recess 54 is formed therein. The recess 54 is formed so as to penetrate the pipe 51 in the axial direction. Near the notch end of the circular steel pipe 51,
A reinforcing piece 55 is welded to the partition wall 53 to reinforce the notched end. The notch end projects from the reinforcing piece 55,
This serves as a locking portion 56 between adjacent deformed tubes. If the central angle α of the notch 52 is too small, the portion overlapping with the adjacent deformed pipe becomes small, and the coupling force between the adjacent pipes is weakened. On the other hand, if the central angle α is too large, the overlapping portion with the adjacent deformed pipe becomes large, and the number of necessary deformed pipes increases due to waste.
Therefore, the central angle α is preferably in the range of 120 to 60 degrees, and particularly preferably in the range of 90 to 70 degrees. The deformed pipe 5 shown in FIG. 3 has a locking portion 57 provided on a part of a circular steel pipe 51. The locking portion 57 is provided in a direction to come into contact with the same type of deformed pipe already pushed into the ground. That is, the deformed pipe 5 to be later pushed into the locking portion 56 of the deformed pipe already pushed into the ground.
The locking portion 57 is positioned so that the locking portion 57 of the
Is provided. However, as the starting pipe, that is, the deformed pipe to be pushed in first, when the earth pressure wall is formed only on one side from the deformed pipe, a pipe without the locking portion 57 is used. In the case of the starting pipe, in which earth pressure walls are formed on both sides from this pipe, a modified pipe 6 having the structure shown in FIG. 4 can be used. The deformed pipe 6 shown in FIG.
In the circular pipe 51, two portions are diametrically opposed to each other.
One cutout 52 is formed, and each cutout 52 is provided with a partition wall 53, a recess 54, a reinforcing piece 55, and a locking portion 56 provided in the deformed pipe 5. As the hard material constituting the deformed pipe, it is preferable to use metal, particularly steel, but in addition, synthetic resins such as hard vinyl chloride and polyester resin, concrete and the like can be used. Next, a method of forming an earth pressure wall using the deformed pipe 5 or 6 will be described. First, dig a shaft in the ground, make a guide for maintaining accuracy in the shaft, and then excavate the ground circularly, for example, with an ordinary auger or cutter with a cutter,
After excavation, the deformed pipe 5 or 6 shown in FIGS. 3 and 4 is pushed. At this time, the depression 54 included in the deformed pipe 5 or 6 is positioned with respect to the ground in the direction in which the deformed pipe to be pushed later is located. Thereafter, the ground in front of the deformed pipe is excavated in a circular shape, and while discharging the earth and sand generated by the excavation through the deformed pipe 5 or 6, the deformed pipe is propelled into the ground and pushed into the ground to form a first buried pipe. . At this time, as long as there is no landslide in the depression 54, there is no earth and sand, and a gap is formed between the wall surface of the ground and the deformed pipe. The deformed pipe 5 to be pushed next causes the locking portion 57 to enter the above-mentioned gap, engages with the locking portion 56 of the first buried pipe, and pushes the depression 54 later. And place it against the ground. After that, the first
Excavation of the front ground in a circular shape and discharge of the excavated earth and sand
The deformed tube is propelled to push the second tube into the ground. At this time, the second pipe connects the locking portion 57 to the locking portion 5 of the first buried pipe.
6 and can be advanced in a state of complete close contact with the first tube. Thereafter, similarly, the third deformed pipe and the fourth deformed pipe are pushed into the ground, and a strong earth pressure wall can be easily formed here. Deformed tube 5 shown in FIG.
FIG. 5 shows a state in which a deformed pipe having no locking portion 57 is used as a starting pipe, and the deformed pipe 5 is pushed adjacently to form an earth pressure wall. In FIG. 5, reference numeral 7 denotes a deformed pipe having no locking portion 57. The deformed pipe 7 pushed into the ground
As described above, in the self-sustaining ground, the depression 54 does not reach the fullness of the earth and sand, and a gap exists there. Then, in the deformed pipe 5 to be pushed in next, the locking portion 57 projecting from the outer surface can be positioned in the gap. For this reason, the deformed pipe 5 can be pressed in close contact with the deformed pipe 7 even though the locking portion 57 protrudes from the outer surface. In addition, by previously providing the locking portion 57 at a position where the locking portion 57 meshes with the locking portion 56 of the adjacent deformed tube, the deformed tubes can be more securely brought into close contact with each other. In the method of the present invention, since there is a gap in the depression 54, there is a possibility that loose earth pressure may be generated on a ground that is not self-supporting. In such a case, the gap can be filled with a filling material to prevent loosening and earth pressure. Accordingly, the method of the present invention also includes a method of forming an earth pressure wall for pushing a deformed pipe into the ground while filling the above-mentioned space with a filling material. The filling material is a material in which solid fine powder is dissolved or dispersed in water or harmless oil and has fluidity or plasticity. It has the property of keeping. A typical filling material is a jelly-like, cream-like, or grease-like high-viscosity material that deforms when an external force is applied, but retains its shape without an external force. Such a filling material contains, for example, clay and water as main components, and a suspension stabilizer such as bentonite, CMC (sodium carboxymethylcellulose) or polyvinyl alcohol (povar) as an auxiliary component. In addition, as a filling material, a homogel having a short gel time or a sand gel (fly ash) having a low strength can be used in the ground where groundwater flows. In addition, bentonite mortar can be used. It is preferable that the filling material has a slight change in viscosity depending on the properties of the ground. When the ground has a small N value, in other words, when the ground has low self-sustainability and easily collapses, or when the ground has a high water permeability, it is preferable to increase the viscosity of the filling material. As the clay that can be used as the main component of the filling material, Kasaoka clay, Kibushi clay, kaolin clay, gairome clay and the like can be used. These clays are fine particles having a particle size of 5 μm or less and have large water absorption. When water is added thereto, the viscosity becomes high, but when water is further added, the viscosity decreases as the amount of water increases. According to the present invention, the viscosity when water is added is 8,000 to
It is preferable to use this as a filling material in the state of 30,000 mpa · s (millipascal · second). In order to fill the above-mentioned space with the filling material, a hole is made in a portion of the rear end of the excavator which is in contact with the space of the deformed pipe or a partition wall facing the depression of the deformed pipe, and the filling material is introduced into the space from the hole. inject. In the case where a hole is formed in the partition wall of the deformed pipe, it is preferable to make a hole in the partition wall portion located as forward as possible. FIG. 5 shows a state in which a hole 58 is made in the partition wall 53 of the deformed pipe 8, and the filling material is filled into the void, in other words, into the recess 54 from the hole 58. In FIG. 5, the filling portions are indicated by interspersed points. When the filling material is completely filled in the recess 54 in this manner, the injection pressure rises rapidly, and it can be known from the observation of the injection pressure that the filling has been completed. When the filling material is filled in the space,
Loose earth pressure can be prevented from being applied to the deformed pipe, and the slip of the deformed pipe is improved, so that the deformed pipe can be easily propelled. When an aqueous filler material mainly composed of, for example, clay and water is used as the filler material, since this filler material is only temporarily filled, it can be easily excavated to bury an adjacent deformed pipe. Can be removed. Therefore, the filling of the filling material does not hinder the pushing of the locking portion protruding from the outer surface of the next deformed pipe when propelling the next deformed pipe, but rather forms a depression. This helps the engagement with the locked portion with little creaking. FIG. 6 schematically shows an embodiment in which a deformed pipe having three recesses 54 is used as a starting pipe and an earth pressure wall is extended in three directions. Deformed tube 9 is recessed 54
And three deformed pipes 61, 62, and 63 are provided to extend the earth pressure wall from the deformed pipe 9 in three directions. These modified tubes 61, 62 and 63 have the same structure as the modified tube 5 shown in FIG. The present invention also includes such a modified tube 9. According to the present invention, a deformed pipe made of a hard material, in which a part of the circular arc of a circular pipe is depressed and the depression penetrates in the pipe axis direction, is formed as an earth pressure wall. Since it is used as a pipe for use, although there is a depression in part, it will use a circular pipe as a whole, so there is little deformation even under a large external pressure, so it is possible to construct a strong earth pressure wall it can. In addition, such a deformed tube can be easily manufactured. According to the present invention, a deformed pipe having the above-described depression is used. When the deformed pipe is pushed into the ground, the deformed pipe is placed toward the pipe into which the depression is to be pushed later. Since the front ground of the deformed pipe is excavated in a circular shape and the excavated earth and sand is discharged through the pipe and the deformed pipe is propelled into the ground to be a buried pipe, the deformed pipe can be easily buried. Further, since the deformed pipe buried in this way has a space without soil at the pipe to be pushed later, the circular pipe portion of the deformed pipe to be pushed later can be easily inserted into this gap. Therefore, the deformed pipe which is pushed in later is firmly and securely connected in close contact with the already buried deformed pipe. As a result, a strong earth pressure wall can be easily formed. In particular, as the deformed pipe, one in which a locking portion extending in the pipe axis direction is provided in the recess, and the other of the locking portion which meshes with the locking portion protrudes from the outer surface of the circular pipe portion is used. ,
When carrying out the above-mentioned method, when the deformed pipe is pushed into the ground, the locking portion projecting from the outer surface will advance in the recess of the already buried deformed pipe, so the progress is not There is no hindrance, and it can be engaged without any squeezing between the locking portion formed in the recess. Therefore, the configuration of the earth pressure wall is more reliably and easily made. According to the present invention, the modified pipe 5 shown in FIG.
As shown in the figure, the locking portion 57 provided on the outer surface of the circular tube portion
Is shifted from a position diametrically opposed to the recess 54, whereby the deformed pipe 8 to be pushed in later can be attached to a bent portion. Therefore, it becomes easy to bend the earth pressure wall. Further, when the deformed pipe is propelled into the ground while filling the recess 54 with the filling material, not only the loose earth pressure can be prevented as described above, but also the propulsion becomes easy. The construction of the earth pressure wall is further facilitated. The present invention provides such benefits.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a pipe used for a conventional earth pressure wall configuration. FIG. 2 is a cross-sectional view of another pipe used in the construction of the conventional earth pressure wall. FIG. 3 is a cross-sectional view of a pipe used in the construction of an earth pressure wall according to the present invention. FIG. 4 is a cross-sectional view of another pipe used in the construction of the earth pressure wall according to the present invention. FIG. 5 is a cross-sectional view of a part of an earth pressure wall configured according to the present invention. FIG. 6 is a cross-sectional view of a part of another earth pressure wall configured according to the present invention. DESCRIPTION OF THE SYMBOLS 1, 2, 3, 4 Conventional earth pressure wall forming pipes 11, 12, 21, 22, 31 Locking portions 5, 6, 7, attached to conventional earth pressure wall forming pipes 8, 9 Deformed pipe (pipe for earth pressure wall formation according to the present invention) 51 Circular pipe 52 Notch 53 Partition wall 54 Depression 55 Reinforcement piece 56, 57 Locking part 58 Hole 61, 62, 63 Deformed pipe

Claims (1)

(57) A method for constructing an earth pressure wall by pushing a large number of pipes one after another into the ground in a state where they are in close contact with each other, wherein the pipe has an arc of a circular pipe having a circular cross section. Is a central angle of 60 ~
Notch in the range of 120 degrees, weld the partition wall inside,
A recess is formed there, near the notch end of the circular tube,
A reinforcing piece is welded between the partition wall and a deformed pipe made of a hard material having a hollow penetrating in the pipe axis direction, and the notch of the notch is used.
Notched end acts as one of the locking parts between adjacent deformed pipes
So that the deformed tube that is later pushed into this locking part engages
Position of the locking part on the outer surface of the circular pipe part of the deformed pipe.
And a hole is provided in the partition wall located in front of the deformed pipe.
When pushing into the ground, place the above-mentioned depression toward the deformed pipe to be pushed in later, excavate the ground in front of the deformed pipe in a circular shape, and
Between the clay and water through the pores of the bulkhead
Fills voids temporarily by injecting a filling material containing
The deformed pipe is filled with a material and excavated through the deformed pipe to discharge the excavated earth and sand into the ground to form a first buried pipe.
Placed close to the buried pipe, with direct in the direction of the tube to push the recesses of the second profiled tube later, engagement of the second profiled tube
While the engagement of the locking portion of the other of the stop portion first buried pipe
Then, the circular pipe portion of the second deformed pipe is inserted into the depression of the first buried pipe, and is pushed into the ground while excavating the front ground in a circular shape to form the second buried pipe. And a deformed pipe is pushed into the ground to form an earth pressure wall.