JP3554698B2 - Grout method of tube bottom plate and tube form - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a grout method and a tube form of a sewer bottom plate, and in particular, draws a precast concrete box culvert to a predetermined connecting position, connects a plurality of units, constructs a sewer, and stabilizes a fixed sewer. The present invention relates to a method for grouting a sewer bottom plate and a tube form defining the range of grouting.
[0002]
[Prior art]
One of the applicants is one of the rational methods of laying precast concrete pipes used for sewage trunk lines constructed under narrow roads in urban areas, etc., as a rational method of laying using bearing balls as friction reducing means. A construction method has been developed (see Japanese Patent No. 2879021). According to this method, after the construction of the excavation tunnel section, a box culvert carry-in section as a unit pipe is provided in a small space above the ground, and the box culvert carried in from there is laterally drawn to a predetermined connection position, and these are laid. The connected sewer can be quickly constructed.
[0003]
FIG. 8 is a schematic side view showing a state of a horizontal pulling operation in the method of laying a sewer. As shown in the figure, a horizontal pulling rail 103 is laid along a direction in which a box culvert 102 extends on a foundation concrete 101 constructed in an open tunnel 100. As the horizontal pulling rail 103, a horizontal narrow H-shaped steel is used as shown in FIG. This narrow-width H-section steel is almost completely buried in the foundation concrete 101 in a buried state, and one side of the web 103a serves as a rail surface, and a flange 103b having a slightly exposed end portion serves as a side wall. Has become. Further, on the rail surface, bearing balls 104 as spherical bodies for reducing friction are arranged so as to be appropriately dispersed. For example, a steel ball having a diameter of about 11 mm is used for the bearing ball 104. On these bearing balls 104, a box culvert 102 having a guide plate 105 made of a thick steel plate fixed to the bottom surface is mounted. The box culvert 102 is point-supported by a number of bearing balls 104 via a guide plate 105.
[0004]
When the box culvert 102 is transported, as shown in FIG. 8, as the box culvert 102 is pulled in the direction of the arrow by a horizontal pulling device (not shown) such as a winch, a bearing ball 104 supporting the box culvert 102 is provided. Rolls. Thereby, the dynamic friction between the guide plate 105 and the rail 103 is greatly reduced. According to the experiment, the coefficient of kinetic friction is reduced to 1/4 as compared with the case of the horizontal drawing method such as warping. In FIGS. 8 and 9, the bearing ball 104 is enlarged for the sake of explanation.
[0005]
As described above, the box culverts 102 transported to the connection position are sequentially connected in a longitudinal direction of the sewer by a known connection means for each predetermined radix. In a state where this connection work is completed, the integrated box culvert 102 is placed on a bearing ball 104 which is a friction reducing means on a rail 103, and between the foundation concrete 101 and the bottom surface 102a of the box culvert 102. Has a gap 106 left open.
[0006]
Therefore, grouting is performed to close the gap 106. In the case of the conventional pipe laying method other than the horizontal drawing method, in laying the box culvert, after adjusting the level and gradient of the culvert, lay mortar between the bottom surface and the foundation concrete and place it on it Was. On the other hand, in the above-mentioned horizontal drawing method, since the sewer is placed on the rail, as shown in FIG. 10, grouting using the grout hole 107 provided in the bottom plate 102A of the box culvert 102 is performed. Is going. The two grout holes 107 are provided substantially at the center of the depth (1 m) of the box culvert 102 at a predetermined distance in the width direction.
[0007]
In the grouting operation, as shown in FIG. 10, a grout material 109 fed from a pump is filled through a grout hose (not shown) connected to a grout hole 107 at the installation position of the box culvert 102. Since the grout material 109 has high fluidity, it spreads so as to flow on the foundation concrete 101. The grout material 109 is temporarily dammed by the rail 103, but as the filling proceeds further, it passes over the upper surface of the rail 103 and passes through between the bearing balls 104. The filling range of the grout material 109 finally extends to a part of the bottom of the clearance 121 between the box culvert 102 and the retaining wall 120 outside the side wall 102b as shown in FIG. It is deposited on 121.
[0008]
[Problems to be solved by the invention]
As described above, in the grout method of the sewer bottom slab described above, since the grout material used has high fluidity, a part of the grout material filled between the bottom slab and the foundation concrete spreads to the retaining wall side. For this reason, a large amount of grout is required to reliably fill the space between the foundation concrete and the bottom slab of the sewer. Further, since sufficient injection pressure is not applied to the grout material to be injected, there is a possibility that the adhesion between the foundation concrete and the lower surface of the bottom slab cannot be ensured.
[0009]
Therefore, an object of the present invention is to solve the above-described problems of the conventional technology, and to surely place the box culverts which are carried to a predetermined position and connected by a horizontal drawing method using a bearing ball on foundation concrete. It is an object of the present invention to provide a method for grouting a sewer bottom plate and a tube form used for grouting.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, the present invention conveys a unit pipe constituting a sewer by connecting a plurality of pipes into a retaining space, and forms a spherical body on a rail surface laid on foundation concrete in the retaining space. Dispersed and arranged, in a state where the unit pipe is supported by the spherical body, transferred to a connecting position of the pipe, and a bottom plate of the pipe connected integrally in the pipe extending direction at the connecting position. In the grouting method of a sewer bottom slab in which a gap between the foundation concrete and the grout is filled with a grout material, an inflatable tubular tube is provided along the extension direction of the sewer at the lower end of the sewer wall that defines the sewer space . A tube form in which a wire is inserted along the extension direction while maintaining the airtightness at the end is disposed, and the unit pipe body carried in is transported to a predetermined connection position to transfer a pipe of a predetermined length. Connected as a culvert, and Along the extending direction is expanded into a cylindrical shape to close the gap between the concrete foundation from both sides of the sewer bottom plate, the grout was injected into the gap, the tubular frame after curing of the grout And recovering the wire from the installation position by winding the wire after deaeration .
[0011]
At the lower end of a retaining wall that defines a retaining space in which a sewer is connected and installed along the extension direction, the sewer is disposed along the extension direction, expands in a tubular shape, and extends from the side of the sewer bottom plate. A collection wire from the arrangement position is inserted into an inflatable tubular tube , which closes a gap between the bottom slab and the foundation concrete , along the extension direction thereof while maintaining the airtightness at the tube end. It is characterized by having been done .
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of a grout method and a tube form of a sewer bottom plate according to the present invention will be described with reference to the accompanying drawings.
FIG. 1 shows a lower half section of a box culvert 3 carried to a predetermined position by the above-described horizontal drawing method, and a side wall and a buckle of the box culvert 3 on a foundation concrete 2 at a bottom of a stake space 1 constructed by excavation. The figure shows a tube form 10 provided at the bottom of a clearance 8 between the wall 7.
[0015]
As shown in the figure, a guide rail 4 in which an H-shaped steel is placed horizontally is laid at a predetermined position on the foundation concrete 2 in the retaining space 1. In this guide rail 4, a number of bearing balls 5 are laid out and arranged in a concave groove having an H-shaped steel web as a bottom surface, and a box culvert 3 is mounted on the bearing balls 5 via a guide plate 9 attached to the bottom surface. It is to be placed. In this state, as described above, the gap 6 is formed between the bottom surface 3b of each box culvert 3 and the foundation concrete 2. A plurality of box culverts 3 are connected in the direction of extension of the sewer and are in a stable state as a whole. However, since they are actually mounted on rolling bearing balls 5, they are fixedly supported. Not in the state that was done. Therefore, grouting is performed as the next step, and the gap 6 is filled with a grout material and hardened to directly support the weight of the box culvert 3 and the overlaid load on the foundation concrete 2. At the time of grouting, by providing a tube form 10 which is used by being inflated as shown in the clearance 8 between the box culvert 3 and the mountain retaining wall 7 at the lower end of the side wall on both sides of the box culvert 3, It can be ensured that only the gap on the bottom surface is spread.
[0016]
The overall configuration of the tube form 10 will be described with reference to FIGS. FIG. 2 is a vertical sectional view of the entire sewer schematically showing a state in which a predetermined number of box culverts 3 are connected and air is supplied to the tube formwork 10. In the present embodiment, the tube form 10 has a long tubular shape with a total length of about 50 m, and grouting of the gap between the bottom slabs of the plurality of box culverts 3 laid in this section and the foundation concrete 2 is performed at a stroke. . The length of the tube form 10 can be appropriately set in accordance with the planned range of the grout range of the sewer. Compressed air is supplied to an air tube of the tube form 10 from an air compressor 45 installed in a pit, and can be expanded into a cross-sectional shape as shown in FIG. FIG. 2 also shows a grout material supply line 40 for supplying grout material from a grout pump 43 to a grout hole 42 provided in the bottom plate of the box culvert 3. When the air is released, the tube form 10 is flattened toward the retaining wall 7 (see FIG. 3A). For this reason, there is no obstacle to the horizontal pulling operation of the box culvert 3.
[0017]
As the cross-sectional shape of the air tube 11 when inflated, in addition to a general circular cross-section, a horseshoe-shaped cross-section tube having a bottom width approximately equivalent to the width of the clearance 8 between the box culvert 3 and the retaining wall 7 (FIG. 3C) Reference) etc. can be adopted. In the case of a circular cross section, when the air tube 11 is inflated, the side portion 11a is sandwiched between the box culvert 3 and the retaining wall 7, and as shown in FIG. . For this reason, as described later, in a state where the grout material is injected into the gap and reaches the end, it is expected that the grout material will sink below the air tube 11 and the grout pressure acts on the air tube 11 upward. Is done. However, the air tube 11 is held at the illustrated position by frictional resistance generated between the box culvert 3 and the retaining wall 7. For this reason, the grout material injected between the bottom slab of the box culvert 3 and the foundation concrete 2 is dammed on the lower side of the tube form 10, and does not flow to the clearance 8 between the retaining wall 7. According to the horseshoe-shaped air tube 11 having a flat bottom portion 11b as shown in FIG. 3B, the grout pressure acts only on the air tube 11 as a side pressure, and no lifting occurs. The air tube 11 is securely held at the installation position.
[0018]
The detailed configuration in one embodiment of the tube form 10 will be described with reference to FIG. The tube form 10 has a cylindrical air tube 11 having a predetermined length, caps 12 and 13 for making both ends of the air tube 11 airtight, an air supply hose 14 for supplying compressed air into the air tube 11, and , And a wire 15 for removing the tube form 10. As the material of the air tube 11, a synthetic rubber hose is used in the present embodiment, but a resin hose, a resin-coated woven hose, or the like can be used in addition to the synthetic rubber hose. Normally, the entire cross section of the hose has a flat shape, and has a predetermined cross section when air is supplied (see FIGS. 3A and 3B). A resin-coated wire 15 is inserted into the air tube 11, and the distal end of the air tube 11 is sealed so as to maintain airtightness via a fastening base 12 </ b> A fixed to the wire 15 and a fastening ring 12 </ b> B. ing. An injection mouthpiece 13 is fitted to the mouth end of the air tube 11. The tip of an air supply hose 14 is attached to the inlet 13. As shown, the injection port 13 is held at a predetermined position of the wire 15 by a boss 13a, and an air supply hose 14 is fixed to a web 13c connecting the boss 13a and the outer ring 13b. An end 11c of the air tube 11 is housed and fixed in a recess between the boss 13a and the outer ring 13b so as to maintain airtightness. The compressed air supplied from the air supply hose 14 can expand the air tube 11 into a predetermined shape.
5 and 6 are cross-sectional views illustrating a configuration of a modified example of the tube form 10 and a method of collecting the air tube 11 when the tube form 10 is removed in this modified example. In this modification, the hose end caps 20A and 20B have the same shape at both ends, and the use thereof can be made different depending on whether the air supply hose 21 or the wire coupler 32 is screwed to the outer end of each hose end cap.
The configuration of the hose end cap 20A will be described with reference to FIG. The hose end cap 20A is composed of an outer cylinder 23 whose inner peripheral surface is threaded, and a valve inner cylinder 24 which is screwed and housed inside the outer cylinder 23, and an outer side formed on the inner surface of the valve inner cylinder 24. The base 28 of the air supply hose 21 is screwed to the screw portion 24a. A check valve 27 that is normally closed by the action of a compression spring 26 is incorporated in the valve inner cylinder 24. As shown in FIG. 5A, when the base 28 of the air supply hose 21 is screwed into the valve inner cylinder 24 as shown in FIG. Is opened. As a result, the compressed air passes through the valve and is guided into the air tube 11.
[0020]
On the other hand, as shown in FIG. 5A, a wire coupler 31 to which an inner wire 35 is attached is screwed into an inner thread portion formed on the inner peripheral surface of the valve inner cylinder 24 inside the air tube 11. ing. The wire coupler 31 has a cup shape with a thread cut on the outer periphery, and the end of the inner wire 35 is fixed to the center of the plate 31a. Further, a large number of ventilation holes 33 are formed in the plate 31a, and the compressed air that has passed through the valve is supplied into the air tube 11 through the ventilation holes 33.
[0021]
The same configuration of the check valve 27 as described above is incorporated in the hose end cap 20B on the hose tip side. A wire coupler 32 for connecting an outer wire 36 is screwed to an outer thread portion 24 a formed on the inner surface of the valve inner cylinder 24. The wire coupler 32 also has a cup shape, and the rod 27a of the valve 27 enters the recess without interference. A wire coupler 31 having the same shape as the hose end cap 20A is screwed to the inner thread portion of the air tube 11 of the valve inner cylinder 24, and an inner wire 35 extending from the hose end cap 20A side is fixed to the wire coupler 31. I have.
[0022]
FIG. 5B is a cross-sectional view showing a state where the air tube 11 is completely inflated. As shown in the figure, when the air tube 11 is inflated, the base 28 of the air supply hose 14 is removed, and a wire coupler 32 as a fixing end of the outer wire 36 on the opposite side is screwed instead. ing.
[0023]
Next, a method of collecting the air tube 11 when removing the tube form 10 will be described with reference to FIG. First, the valve inner cylinder 24 screwed to the outer cylinder 23 of the hose end cap 20A on the mouth side is removed from the outer cylinder 23. At this time, since the inner wire 35 in the air tube 11 is connected to the other hose end cap 20B, the outer wire 36 connected to the inner cylinder 23 of the hose end cap 20A is wound up, so that the hose at the other end is wound. The end cap 20B enters the air tube 11. As a result, the entire length of the air tube 11 can be reduced and the air tube 11 can be sequentially collected from the installation position of the tube form.
[0024]
Referring to FIGS. 7A and 7B, a procedure for grouting a sewer bottom plate according to the present invention will be described.
In a state where a predetermined radix is arranged by the above-described box culvert 3 horizontal drawing method, the box culverts 3 are integrally connected in the vertical direction of the sewer by a fastening means (not shown) such as a PC steel rod. During this horizontal pulling operation, the tube form 10 is in a flat state where air is not supplied (see FIG. 3A), and is disposed along the retaining wall 7 side. The air tube 11 of the tube form 10 is inflated while the box culvert 3 is connected in the longitudinal direction. By inflating the air tube 11 sufficiently, both side surfaces of the air tube 11 sufficiently adhere to the side surface of the box culvert 3 and the retaining wall 7 (see FIG. 3B). In this state, the gap 6 between the box culvert 3 and the foundation concrete 2 can be completely closed using the grout hole 42 formed in the bottom plate of the box culvert 3. For the grout material 41, a filler such as cement mortar is suitable. In this case, it is also preferable to add a foaming agent such as aluminum powder to enhance the filling effect. The cement mortar for filling can be supplied by a concrete mixer truck. The grout pump 43 (see FIG. 2) may be easily pumped from the mixer truck to the filling position. At this time, the grout material 41 is filled in the range of the bottom surface 3b of the box culvert 3 while maintaining a predetermined grout pressure by the tube form 10 provided at the bottom of the clearance 8 on the side of the bottom surface 3b of the box culvert 3. You. It is confirmed that the grout material 41 flows out (returns) from the other grout hole 40 located in the front in the longitudinal direction, and grout work in the next section is sequentially performed.
[0025]
FIG. 7B shows a state where the grouting is completed and the tube form 10 is removed after a predetermined curing period. As shown in the figure, the grout material 41 can be reliably filled only in the gap between the bottom surface of the box culvert 3 and the foundation concrete 2.
[0026]
FIG. 7C is a cross-sectional view showing a completed state of the sewer after the clearance 8 between the mountain retaining wall 7 is backfilled. As shown in the figure, since the grout material 41 does not adhere to the parent pile, the steel sheet pile, and the like that form the retaining wall 7, the temporary members such as the parent pile and the steel sheet pile can be easily removed.
[0027]
【The invention's effect】
As is apparent from the above description, according to the present invention, there is an effect that the grout of the culvert bottom plate for stabilizing the culvert can be efficiently performed and the cost for grouting can be significantly reduced. .
[Brief description of the drawings]
FIG. 1 is a partial front view showing an installed state of a tube form as an embodiment of a grout method of a sewer bottom plate according to the present invention.
FIG. 2 is an overall vertical sectional view of a sewer schematically showing a state where a tube formwork is set.
FIG. 3 is a partially enlarged cross-sectional view showing an air tube cross-sectional shape of a tube formwork.
FIG. 4 is a longitudinal sectional view showing an internal configuration according to an embodiment of the tube form.
FIG. 5 is a longitudinal sectional view showing an internal configuration according to another embodiment of a tube formwork.
FIG. 6 is a vertical cross-sectional view showing a configuration at the time of collecting the tube form shown in FIG. 5;
FIG. 7 is a construction sequence diagram showing a procedure for grouting a sewer bottom plate.
FIG. 8 is a side view showing an example of pipe laying work by a box culvert horizontal drawing method.
9 is a partial front view showing an example of the friction reducing means in the pipe laying work shown in FIG.
FIG. 10 is a partial front view showing a state of a bottom grouting work of the sewer shown in FIG. 9;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Mountain retaining space 2 Foundation concrete 3 Box culvert 5 Bearing ball 6 Clearance 7 Mountain retaining wall 8 Clearance 10 Tube form 11 Air tube 12 Tightening base 13 Injection base 14 Air supply hose 20, 20A, 20B Hose end base 35 Inner wire 36 Outer wire

Claims (2)

A plurality of unit pipes are connected to each other to form a unit pipe into a mountain retaining space, and the spherical body is dispersed and arranged on a rail surface laid on a foundation concrete in the mountain retaining space. With the spherical body supported, the pipe is transferred to the connection position of the pipe body, and the gap between the bottom slab of the culvert and the foundation concrete connected integrally in the culvert extension direction at the connection position is poured with grout material. In the grouting method of a closed bottom slab, a wire is provided at a lower end of a retaining wall defining the retaining space along an extending direction of the sewer and in an inflatable tubular tube along an extending direction. The tube form is inserted while maintaining the airtightness, and the unit pipe body is transferred to a predetermined connection position and connected as a pipe of a predetermined length, and the tube form is connected to the tube form. Inflate into a cylindrical shape along the extension of the sewer Closing the gap between the concrete foundation from both sides of the sewer bottom plate, the grout was injected into the gap, the tubular frame after curing of the grout, the by winding the wire after degassing A method of grouting a sewer bottom plate, wherein the grout is collected from an installation position . At the lower end of a retaining wall that defines a retaining space in which a sewer is connected and installed along the extension direction, the sewer is disposed along the extension direction, expands in a tubular shape, and extends from the side of the sewer bottom plate. A collection wire from the above-mentioned arrangement position is inserted into an inflatable tubular tube , which closes a gap between the bottom slab and the foundation concrete , along the extension direction thereof while maintaining airtightness at the tube end. Tube formwork characterized by being done .

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