JP2021008725A - Construction method for soil retaining structure and pipe for soil retaining structure - Google Patents

Abstract

To improve water cut-off performance between pipes in a soil retaining structure.SOLUTION: A construction method for soil retaining structure comprises steps of: a first insertion step for inserting in the natural ground a first pipe 131 having a core member 132 and a cuttable section 133 arranged in the core member 132 and having lower hardness than that of the core member 132; and a second insertion step for inserting a second pipe 136 in the natural ground parallely to the first pipe 131 while cutting the cuttable section 133 of the inserted first pipe 131.SELECTED DRAWING: Figure 6

Description

The present invention relates to a method for constructing a retaining structure and a pipe for the retaining structure.

When forming a space inside the ground, a retaining structure may be constructed in the ground. Patent Document 1 discloses a method of constructing a pipe roof as an earth retaining structure prior to forming a continuous passage in the ground.

In the method disclosed in Patent Document 1, a pipe roof is constructed by sequentially inserting a plurality of pipes in parallel and substantially horizontally in parallel at a position above a position where a continuous passage is planned to be formed. .. When excavating the ground below the pipe roof to form a continuous passage, a refrigerant is flowed through the pipes provided in the pipes to freeze the ground between the pipes, or between the pipes provided in the pipes. Water is stopped between the pipes by injecting a chemical solution for water stopping into the ground.

Japanese Unexamined Patent Publication No. 2012-21502

In the method of constructing a soil retaining structure by inserting a plurality of pipes into the ground as disclosed in Patent Document 1, if the distance between adjacent pipes is wide, the entire area between the pipes may be frozen or the entire area between the pipes may be frozen. It becomes difficult to distribute the chemical solution for water stoppage to the pipes, and the water stoppage between the pipes is reduced. For this reason, it is required to narrow the distance between adjacent pipes to minimize the water blocking range and improve the water stopping property between the pipes.

In the method disclosed in Patent Document 1, in order to improve the water stopping property, it is conceivable to bring the trailing pipe closer to the leading pipe and insert it into the ground to minimize the water stopping range. However, since the pipe is inserted into the ground by the propulsive force applied to the rear end of the pipe, the trailing pipe may be unintentionally curved and inserted in the ground. If the trailing pipe is inserted close to the leading pipe and inserted into the ground, the trailing pipe may interfere with the leading pipe due to the curvature, making it difficult to insert the trailing pipe or damaging the leading pipe. .. Therefore, the trailing pipe must be inserted into the ground away from the leading pipe, and it is difficult to minimize the water blocking range and improve the water stopping property between the pipes.

Further, in the earth retaining structure constructed by the method disclosed in Patent Document 1, the strength of the structure is inferior because the distance between the trailing pipe and the leading pipe is relatively wide.

An object of the present invention is to improve the water-stopping property between pipes in a retaining structure and to improve the strength of the retaining structure.

The present invention is a method for constructing a soil retaining structure by inserting a plurality of pipes into a ground to construct a soil retaining structure, wherein the core material and a cuttable portion provided on the core material and having a hardness lower than that of the core material are formed. The first insertion step of inserting the first pipe having the above into the ground, and the second pipe being inserted into the ground in parallel with the first pipe while cutting the cuttable portion of the inserted first pipe. A second insertion step is provided.

Further, the present invention is a pipe for a soil retaining structure used by being inserted into a ground, and has a core material and a hardness higher than that of the core material provided in the core material before being inserted into the ground. It has a low machinable part.

According to the present invention, it is possible to improve the water stopping property between pipes in the earth retaining structure.

It is sectional drawing of the earth retaining structure which concerns on embodiment of this invention, and is the figure when seen in the direction of the tunnel axis. It is sectional drawing which follows the line II-II shown in FIG. It is a perspective view of the 1st pipe. It is a perspective view which shows the state which divided the 1st pipe. It is a perspective view of the 2nd pipe. It is a figure for demonstrating the construction method of the earth retaining structure, and is the enlarged sectional view of the VI part shown in FIG. It is a figure for demonstrating the procedure for inserting a 1st pipe into a ground, (a) shows a state in which an excavator and a propulsion machine are installed prior to insertion of a 1st pipe, and (b) is the 1st 1 Indicates the state in which the insertion of the pipe has started. It is a figure for demonstrating the procedure of inserting the 1st pipe into a ground, (a) shows the state which formed the space between the 1st pipe and a push ring, (b) shows the state which formed the 1st pipe, and is Indicates the state of addition. It is a figure for demonstrating the procedure for inserting the 1st pipe into a ground, and (a) shows the state which fixed the machinable part across the core material connected in the axial direction of the 1st pipe, and (a) b) shows a state in which the ground is further excavated and a hole is dug. FIG. 8 is a cross-sectional view taken along the line XX shown in FIG. 8A, showing a state in which the insertion of the first pipe has progressed. FIG. 8B is a cross-sectional view taken along the line XI-XI shown in FIG. 8B, showing a state in which the insertion of the first pipe has progressed. It is an enlarged sectional view of the side earth retaining structure constructed by using the 1st pipe which concerns on a modification. It is a perspective view which shows the state which disassembled the 1st pipe which concerns on another modification.

Hereinafter, the method for constructing the earth retaining structure and the pipe for the earth retaining structure according to the embodiment of the present invention will be described with reference to the drawings. Here, as shown in FIGS. 1 and 2, a method of constructing a retaining structure 100 that protects the ground when the tunnel 1 is expanded in the lateral direction, and a pipe 131 for the retaining structure 100 will be described.

The tunnel 1 is, for example, a shield tunnel constructed by a shield method. In the following, the direction along the central axis of the tunnel 1 will be referred to as the "tunnel axis direction", and the radial direction centered on the central axis of the tunnel 1 will be referred to as the "tunnel radial direction".

The tunnel 1 is expanded by excavating the ground in the radial direction of the tunnel. The earth retaining structure 100 is constructed inside the earth so as to surround the expansion area 2 prior to excavation of the earth for the expansion of the tunnel 1. 1 and 2 show a state after the earth retaining structure 100 is constructed and before the expansion area 2 is excavated.

First, the outline of the earth retaining structure 100 will be described.

The earth retaining structure 100 is provided with an upper earth retaining 110 extending diagonally upward from the tunnel 1, a lower earth retaining 120 provided below the upper earth retaining 110 and extending diagonally downward from the tunnel 1, and an interval from the tunnel 1 in the tunnel radial direction. The side retaining 130 is provided, and the front retaining 140 and the rear retaining 150 are provided between the tunnel 1 and the side retaining 130 at intervals in the axial direction. The side retaining 130, the front retaining 140, and the rear retaining 150 are provided between the upper retaining 110 and the lower retaining 120.

The upper earth retaining 110 is constructed by starting the excavator 111 diagonally upward from the inside of the tunnel 1 to form a hole 112 in the ground, and providing a lining body 113 on the inner surface of the hole 112. The lower earth retaining 120 is constructed by forming a hole 122 in the ground using an excavator 121 and providing a lining body 123 on the inner surface of the hole 122, similarly to the upper earth retaining 110. Although not shown, the cross sections of the holes 112 and 122 are substantially rectangular in which the longitudinal direction substantially coincides with the tunnel axial direction (the direction perpendicular to the paper surface in FIG. 1).

The side retaining 130, the front retaining 140 and the rear retaining 150 are constructed after the construction of the upper retaining 110 and the lower retaining 120. The construction method according to the present embodiment is used for constructing the side retaining 130, the front retaining 140, and the rear retaining 150.

The side retaining 130 includes a plurality of first pipes 131 and a plurality of second pipes 136 provided in parallel between the upper retaining 110 and the lower retaining 120. The first pipe 131 and the second pipe 136 are arranged alternately in the tunnel axial direction.

Similar to the side retaining 130, the front retaining 140 includes a plurality of first pipes 141 and a plurality of second pipes 146 provided in parallel between the upper retaining 110 and the lower retaining 120. The first pipe 141 and the second pipe 146 are arranged alternately in the tunnel radial direction. Similar to the front retaining 140, the rear retaining 150 is provided in parallel between the upper retaining 110 and the lower retaining 120, and a plurality of first pipes 151 and a plurality of second pipes alternately arranged in the tunnel radial direction. It is equipped with 156.

When excavating the expansion area 2, water is stopped between the first pipe 131 and the second pipe 136 in the side soil retention 130 by an auxiliary construction method. Specifically, a pipe (not shown) is fixed to the inner surface of the second pipe 136, and a refrigerant is allowed to flow through the pipe to freeze between the first pipe 131 and the second pipe 136 to stop water. The freezing location may be on the back side (ground side) with respect to the space between the first pipe 131 and the second pipe 136. Similarly, between the first pipe 141 and the second pipe 146 in the front retaining 140, and between the first pipe 151 and the second pipe 156 in the rear retaining 150, when excavating the expansion region 2, due to freezing. Stop the water.

When the water is stopped between the first pipe 131 and the second pipe 136, if the distance between the first pipe 131 and the second pipe 136 is wide, it becomes difficult to freeze the entire area of the distance, and the water is stopped. Decreases. For this reason, the distance between the first pipe 131 and the second pipe 136 should be narrowed to minimize the water stopping range, and the first pipe 131 and the second pipe 136 should be used to stop the water without using the auxiliary construction method. It is required to improve. Further, regardless of whether or not the auxiliary construction method is used, it is required that a stronger earth retaining structure is constructed by the first pipe 131 and the second pipe 136.

In the earth retaining structure construction method according to the present embodiment, the first pipe 131 is inserted into the ground, and then the second pipe 136 is inserted into the ground in parallel with the first pipe 131 while cutting the first pipe 131. As a result, the side earth retaining 130 is constructed. Therefore, the second pipe 136 is arranged in the space formed by cutting the first pipe 131. Therefore, the distance between the first pipe 131 and the second pipe 136 can be narrowed to minimize the water stopping range, and the water stopping of the side soil retaining 130 can be improved. Further, the strength of the side retaining 130 as the retaining structure can be improved.

Hereinafter, the method of constructing the side retaining 130 will be described in detail with reference to FIGS. 3 to 9.

First, the structures of the first pipe 131 and the second pipe 136 suitable for the construction method according to the present embodiment will be described with reference to FIGS. 3 to 5.

As shown in FIG. 3, the first pipe 131 includes a hollow core material 132 and a pair of machinable portions 133 provided on the outer peripheral surface of the core material 132. The machinable portion 133 is fixed to the core material 132, and water is stopped between the core material 132 and the machinable portion 133. The core material 132 is made of a steel material, and the machinable portion 133 is made of a low-strength concrete material.

The materials of the core material 132 and the machinable portion 133 are not limited to the steel material and the low-strength concrete material, respectively, and may be selected so that the hardness of the machinable portion 133 is lower than the hardness of the core material 132, respectively. For example, the core material 132 may be formed of a steel material, and the cuttable portion 133 may be formed of a resin or the like. Further, it is preferable to form the cuttable portion 133 with a member that can be easily cut with a breaker, a cutter, a cutter bit or the like.

The core material 132 is formed in a drum shape. Specifically, the core material 132 includes a pair of first curved portions 132a that are curved along the circumferential direction of the first pipe 131, and a pair of second curved portions that are concavely curved inward in the radial direction of the first pipe 131. 132b and. The pair of first curved portions 132a are provided so as to be spaced apart from each other in the radial direction of the first pipe 131. The pair of second curved portions 132b are provided so as to be spaced apart from each other in the radial direction of the first pipe 131 and across the pair of first curved portions 132a. The internal space of the core member 132 is defined by a pair of first curved portions 132a and a pair of second curved portions 132b. The first curved portion 132a and the second curved portion 132b are connected to each other by welding, for example.

The machinable portion 133 is solidly formed and is provided on the second curved portion 132b. The outer peripheral surface of the machinable portion 133 is curved, and the outer shape of the first pipe 131 is formed in a circular shape by the first curved portion 132a of the core material 132 and the machinable portion 133.

As shown in FIGS. 3 and 4, the core material 132 is divided into a plurality of core material elements 132c in the axial direction of the first pipe 131 before being inserted into the ground. A pair of first curved portions 132a and a pair of second curved portions 132b are formed on each core material element 132c. The core material 132 is formed by connecting the core material elements 132c so that the first curved portions 132a of the plurality of core material elements 132c are continuous in the axial direction of the first pipe 131. Adjacent core material elements 132c are connected to each other by welding, for example.

The cuttable portion 133 includes an existing cuttable portion element 133a provided on the core material element 132c, a separate cuttable portion element 133b separated from the core material element 132c, and a separate cuttable portion element 133b before the core material elements 132c are connected to each other. It is divided in the axial direction of the first pipe 131. The existing machinable portion element 133a is molded in a state of being integrated with the core material element 132c in advance in, for example, a factory or the like. The separable cuttable element 133b is formed as a single member (block) in a factory or the like separately from the core material element 132c and the existing cuttable element 133a.

The axial height of the existing machinable portion element 133a is smaller than the axial height of the second curved portion 132b in the core material element 132c, and the existing cuttable portion element 133a sinks in the axial direction of the first pipe 131 with respect to both ends of the second curved portion 132b. The second curved portion 132b is provided so as to do so. In other words, the second curved portion 132b projects from the existing cuttable portion element 133a in the axial direction of the first pipe 131. Therefore, before the core material elements 132c are connected to each other, they are exposed from both sides of the existing cuttable element 133a.

The separable cuttable element 133b is arranged between the existing cuttable elements 133a provided on the core material elements 132c adjacent to each other in the axial direction of the first pipe 131, and is provided over the adjacent core material elements 132c. That is, the separate cuttable part elements 133b are arranged between the existing cuttable part elements 133a and arranged alternately in the axial direction of the first pipe 131, and the cuttable parts 133 are continuous.

As shown in FIG. 5, the second pipe 136 is made of a steel material and is formed in a cylindrical shape. That is, the second pipe 136 does not have a portion corresponding to the machinable portion 133 (see FIG. 3) in the first pipe 131.

The second pipe 136 is divided into a plurality of pipe elements 137 in the axial direction of the second pipe 136 before being inserted into the ground. Adjacent pipe elements 137 are connected, for example, by welding.

When constructing the side retaining 130 (see FIG. 1) using the first pipe 131 shown in FIG. 3 and the second pipe 136 shown in FIG. 5, first, as shown in FIG. 6 (a). , A plurality of first pipes 131 are inserted into the ground in parallel at intervals (first insertion step). At this time, the first pipe 131 is inserted into the ground so that the machinable portion 133 is arranged between the core members 132 of the adjacent first pipe 131. The details of the procedure for inserting the first pipe 131 into the ground will be described later.

Next, as shown in FIG. 6B, the ground is cut while cutting the second pipe 136 and the cuttable portions 133 of the adjacent first pipe 131 at the tip of the second pipe with a breaker, a cutter, or the like. Insert into (second insertion step). The second pipe 136 is formed of a steel material in a cylindrical shape, and has the same structure as a known pipe. Therefore, it is possible to insert the second pipe 136 into the ground by a known method. For example, it can be inserted into the ground by a known propulsion method or shield method. Here, the details of the procedure for inserting the second pipe 136 will be omitted.

When inserting the second pipe 136 into the ground, the earth retaining direction (up and down in FIG. 6 (b)) perpendicular to the arrangement direction of the first pipe 131 and the second pipe 136 (horizontal direction in FIG. 6 (b)). The second pipe 136 is inserted into the ground so that a part of the core material 132 of the first pipe 131 and a part of the second pipe 136 overlap each other with the machinable portion 133 in between.

With the above, the construction of the side soil retaining 130 (see FIGS. 1 and 2) is completed.

In the present embodiment, the second pipe 136 is inserted into the ground in parallel with the first pipe 131 while cutting the cuttable portion 133 of the first pipe 131 inserted into the ground. Therefore, the second pipe 136 is arranged at the same time as cutting in the space formed by cutting the cuttable portion 133 of the first pipe 131. Therefore, the distance between the first pipe 131 and the second pipe 136 can be narrowed to minimize the water stopping range, and the second pipe 136 is in close contact with the machinable portion 133 of the first pipe 131. Be placed. Therefore, the water-stopping property between the first pipe 131 and the second pipe can be improved, and the water-stopping property of the entire side soil retaining 130 is also improved.

Further, in the present embodiment, a plurality of first pipes 131 are inserted into the ground in parallel with each other, and then the second pipe 136 is used as the ground while cutting each cuttable portion 133 of the adjacent first pipe 131. insert. Therefore, the second pipe 136 receives the reaction force generated during cutting of the machinable portion 133 from both of the adjacent first pipes 131. Therefore, it is possible to prevent the second pipe 136 from being unintentionally curved and inserted so as to be biased toward one of the adjacent first pipes 131.

Further, in the present embodiment, a part of the core material 132 of the first pipe 131 and a part of the second pipe 136 overlap each other in the earth retaining direction perpendicular to the arrangement direction with the machinable portion 133 sandwiched between them. Therefore, the core material 132 of the first pipe 131 and the second pipe 136 are continuous in the arrangement direction when viewed from the soil retaining direction. Therefore, the flow of groundwater along the retaining direction can be received by at least one of the core member 132 of the first pipe 131 and the second pipe 136, and the earth pressure acting on the side retaining 130 can be received. Therefore, the water-stopping property of the side retaining 130 is improved, and the side retaining 130 as the retaining structure becomes stable and strong.

Although not shown, the front retaining 140 and the rear retaining 150 (see FIGS. 1 and 2) are also constructed in the same manner as the side retaining 130. Therefore, as with the side retaining 130, the water stopping properties of the front retaining 140 and the rear retaining 150 can be improved.

Next, the details of the procedure for inserting the first pipe 131 into the ground will be described with reference to FIGS. 7 to 11. Here, a case where the first pipe 131 is inserted into the ground from the upper soil retention 110 (see FIG. 1) toward the lower soil retention 120 (see FIG. 1) will be described.

Prior to the insertion of the first pipe 131, as shown in FIG. 7A, an excavator 3 for excavating the ground and a propulsion machine 4 for imparting propulsive force to the excavator 3 are placed in the upper earth retaining 110. Install. In the following, among the lining bodies 113 that define the internal space of the upper earth retaining 110, the lining body 113 located on the insertion direction side (lower side in FIG. 7A) of the first pipe 131 is referred to as “floor slab 113a”. The lining body 113 located on the side opposite to the insertion direction of the first pipe 131 (upper side in FIG. 7A) is referred to as a “top plate 113b”.

The excavator 3 includes a hollow body 3a having an outer diameter substantially equal to the outer diameter of the first pipe 131, and a cutter 3b rotatably provided at one end of the body 3a. A core element 132c of the first pipe 131 is connected to the other end of the body 3a, and a drive unit (not shown) for rotating the cutter 3b is housed inside the body 3a.

An entrance ring 6 for guiding the excavator 3 and the first pipe 131 is installed on the floor slab 113a of the upper earth retaining 110. The entrance ring 6 is formed in a cylindrical shape having an inner diameter substantially equal to or slightly larger than the outer diameter of the body 3a of the excavator 3 and the outer diameter of the first pipe 131.

The propulsion machine 4 inserts the push ring 4a arranged between the core material element 132c of the first pipe 131 and the top plate 113b and the push ring 4a in the insertion direction of the first pipe 131 (vertical direction in FIG. 7A). It includes a pair of hydraulic cylinders 4b that are moved along the line. The pair of hydraulic cylinders 4b are attached to the top plate 113b.

After the excavator 3 and the propulsion machine 4 are installed in the upper earth retaining 110, the insertion of the first pipe 131 into the ground is started.

First, as shown in FIG. 7B, the pair of hydraulic cylinders 4b are extended to move the push ring 4a in the insertion direction of the first pipe 131 (downward in FIG. 7B). As a result, propulsive force is applied to the excavator 3 through the core material element 132c of the first pipe 131, and the cutter 3b of the excavator 3 is pressed in the insertion direction of the first pipe 131. By rotating the cutter 3b in this state, the floor slab 113a is cut and the ground is excavated to form a hole 3c in the ground. The excavation slip is discharged to the upper earth retaining 110 through an earth removal pipe (not shown) provided inside the body 3a and the first pipe 131.

Next, as shown in FIG. 8A, the pair of hydraulic cylinders 4b are contracted, and the push ring 4a is moved in the direction opposite to the insertion direction of the first pipe 131 (upward in FIG. 8A). As a result, a space is formed between the core material element 132c of the first pipe 131 and the push ring 4a.

Next, as shown in FIG. 8B, a new core material element 132c is placed in the space between the core material element 132c connected to the excavator 3 and the push ring 4a, and the core material elements 132c are welded to each other. To concatenate. As a result, the core material 132 is extended.

The existing machinable portion element 133a of the first pipe 131 is provided in the core material element 132c so as to be submerged in the axial direction of the first pipe 131 with respect to both ends of the core material element 132c. Therefore, when welding the core material elements 132c to each other, a space is formed between the existing cuttable element 133a adjacent to each other in the axial direction of the first pipe 131, and the seam between the core material elements 132c is formed on the entire circumference. It is exposed over. Therefore, the entire circumference of the seam can be visually confirmed from the radial outside of the first pipe 131, and the core material elements 132c can be easily connected to each other.

Next, as shown in FIG. 9A, the separable cuttable part element 133b is arranged between the existing cuttable part elements 133a adjacent to each other in the axial direction of the first pipe 131, and extends over the adjacent core material elements 132c. To be provided. At this time, the space between the existing cuttable element 133a and the separable cuttable element 133b is sealed, and the space between the core material element 132c and the separate cuttable element 133b is sealed. As a result, the water stopping property between the existing cuttable part element 133a and the separate cuttable part element 133b and between the core material element 132c and the separate cutable part element 133b is improved.

Next, as shown in FIG. 9B, the pair of hydraulic cylinders 4b are extended, and the push ring 4a is moved in the insertion direction of the first pipe 131 (downward in FIG. 9B). As a result, the ground can be further excavated to excavate the hole 3c, and the first pipe 131 can be inserted into the hole 3c.

The step of digging the hole 3c, the step of connecting the core material elements 132c to each other, and the step of providing the separable cuttable part element 133b in the core material element 132c are performed by the lower end retaining 120 (see FIG. 1). ) Is repeated to complete the insertion of the first pipe 131.

FIG. 10 is a cross-sectional view taken along the line XX shown in FIG. 8A, showing a state in which the insertion of the first pipe 131 has progressed. As the excavation of the ground by the excavator 3 progresses, the groundwater in the ground flows into the hole 3c, and the pressure of the groundwater enters the cuttable portion 133 in the direction opposite to the insertion direction of the first pipe 131 (upper in FIG. 10). May work. In this case, when the pair of hydraulic cylinders 4b are contracted to move the push wheels 4a in order to extend the core material 132, the first pipe 131 inserted into the ground may be pushed back by the pressure of groundwater. ..

Therefore, in the present embodiment, a pair of engaging members 5 that can be engaged with the existing machinable portion element 133a of the first pipe 131 are installed inside the upper earth retaining 110. The pair of engaging members 5 are swingably provided on the floor slab 113a, and are in an engaged state of engaging with the existing cuttable element 133a and a disengaged state of disengaging the existing cuttable element 133a. Can be switched to. FIG. 10 shows a state in which the engaging member 5 is switched to the engaged state.

When the engaging member 5 is switched to the engaging state, the engaging member 5 engages with the existing cuttable element 133a, and the first pipe 131 inserted into the ground is in the direction opposite to the insertion direction (upper in FIG. 10). Restrict movement to. By switching the engaging member 5 to the engaged state before contracting the pair of hydraulic cylinders 4b to extend the core material 132, it is possible to prevent the first pipe 131 from being pushed back by the pressure of groundwater. , A space can be formed between the first pipe 131 and the push ring 4a. Therefore, the core material 132 can be extended.

After extending the core material 132, as shown in FIG. 11, the pair of hydraulic cylinders 4b are slightly extended, and the first pipe 131 inserted into the ground is inserted in the direction opposite to the insertion direction by using the push ring 4a. Restrict movement (upward in FIG. 11). As a result, the engaging member 5 can be switched to the released state. After switching the engaging member 5 to the released state, the core material elements 132c are connected to each other, and the separable cuttable portion element 133b is provided over the adjacent core material elements 132c.

According to the above embodiment, the following effects are obtained.

In the construction method according to the present embodiment, the second pipe 136 is inserted into the ground while cutting the cuttable portion 133 of the first pipe 131. Therefore, the second pipe 136 is arranged in the space formed by cutting the machinable portion 133. Therefore, the water stopping range between the first pipe 131 and the second pipe 136 can be minimized, and the water stopping of the side soil retaining 130 can be improved. Further, the strength of the side retaining 130 as the retaining structure can be improved.

Further, in the present embodiment, a plurality of first pipes 131 are inserted into the ground, and then the second pipe 136 is inserted into the ground while cutting each cuttable portion 133 of the adjacent first pipe 131. Therefore, the second pipe 136 receives the reaction force generated during cutting of the machinable portion 133 from both of the adjacent first pipes 131. Therefore, it is possible to prevent the second pipe 136 from being unintentionally curved and inserted so as to be biased toward one of the adjacent first pipes 131.

Further, the core material 132 of the first pipe 131 is divided into a plurality of core material elements 132c in the axial direction of the first pipe 131 before being inserted into the ground, and the core material element is divided into a plurality of core material elements 132c in the first insertion step. 132c are connected to each other to extend the core material 132. Therefore, the core material 132 protruding from the ground into the upper earth retaining 110 can be shortened as compared with the case where the core material 132 of the first pipe 131 is not divided.

Further, the machinable portion 133 includes the existing machinable portion element 133a provided on the core material element 132c and the separable cuttable portion element 133b separated from the core material element 132c before the core material elements 132c are connected to each other. And, it is divided in the axial direction of the first pipe 131. The existing machinable portion element 133a is provided in the core material element 132c so as to sink in the axial direction of the first pipe 131 with respect to both ends of the core material element 132c. In the first insertion step, after the core material elements 132c are connected to each other, the separable cuttable part element 133b is provided over the adjacent core material elements 132c. Therefore, when the core material elements 132c are connected to each other, the seam between the core material elements 132c is not covered by the separable cuttable portion element 133b, and the entire circumference of the seam is exposed. Therefore, the entire circumference of the seam can be visually confirmed from the radial outside of the first pipe 131, and the core material elements 132c can be easily connected to each other.

Further, a part of the core material 132 of the first pipe 131 and a part of the second pipe 136 overlap each other in the earth retaining direction perpendicular to the arrangement direction with the machinable portion 133 sandwiched between them. Therefore, the core material 132 of the first pipe 131 and the second pipe 136 are continuous in the arrangement direction when viewed from the soil retaining direction. Therefore, the flow of groundwater along the retaining direction can be received by at least one of the core member 132 of the first pipe 131 and the second pipe 136, and the water stopping property of the side retaining 130 can be further improved. Further, the strength of the side retaining 130 as the retaining structure can be improved.

Further, the first pipe 131 according to the present embodiment includes a core material 132 and a machinable portion 133 provided on the core material 132 and having a hardness lower than that of the core material 132 before being inserted into the ground. Therefore, the cuttable portion 133 is inserted into the ground together with the core material 132. Therefore, the second pipe 136 can be inserted into the ground while cutting the cuttable portion 133 of the first pipe 131, and the water stop range between the first pipe 131 and the second pipe 136 is minimized. The water stopping property of the side soil retaining 130 can be improved. Further, the strength of the side retaining 130 as the retaining structure can be improved.

Further, the core material 132 is divided into a plurality of core material elements 132c that can be connected to each other in the axial direction of the first pipe 131 before being inserted into the ground, and the cuttable portion 133 is inserted into the ground. The existing cuttable element 133a provided on the core element 132c and the separate cuttable element 133b separated from the core element 132c are divided in the axial direction of the first pipe 131. The existing cuttable element 133a is provided in the core element 132c so as to sink in the axial direction of the first pipe 131 with respect to both ends of the core element 132c, and the separate cuttable elements 133b are connected to each other. It can be fixed over the core material element 132c. Therefore, when the core material elements 132c are connected to each other, the seam between the core material elements 132c is not covered by the separable cuttable portion element 133b, and the entire circumference of the seam is exposed. Therefore, the entire circumference of the seam can be visually confirmed from the radial outside of the first pipe 131, and the core material elements 132c can be easily connected to each other.

Although the embodiments of the present invention have been described above, the above embodiments are only a part of the application examples of the present invention, and the technical scope of the present invention is limited to the specific configurations of the above embodiments. Absent.

In the present embodiment, the core material 132 of the first pipe 131 is formed in a drum shape as shown in FIG. 3, but the present invention is not limited to this embodiment. For example, the first pipe 231 shown in FIG. 12A may be used. Specifically, in the first pipe 231 the core material 232 is formed in a cylindrical shape, and the machinable portion 233 is provided on the outer periphery of the core material 232. Further, the first pipe 331 shown in FIG. 12B may be used. Specifically, in the first pipe 331, the core material 332 is provided between the pair of curved portions 332a curved along the circumferential direction of the first pipe 331 and the flat plate portion 332b provided between the pair of curved portions 332a. The cuttable portion 333 is provided on the flat plate portion 332b.

The first pipe 131 shown in FIGS. 3 and 4 can have a larger space inside the core material 132 than the first pipes 231 and 331 shown in FIGS. 12A and 12B. Therefore, an excavation pipe (not shown) for discharging excavation scraps can be easily provided in the core member 132, which is preferable.

In the above embodiment, the case where water is stopped by freezing between the first pipe 131 and the second pipe 136 has been described, but a chemical solution is injected between the first pipe 131 and the second pipe 136. The water may be stopped. Even in this case, since the distance between the first pipe 131 and the second pipe 136 can be narrowed to minimize the water stopping range, the entire area between the first pipe 131 and the second pipe 136 is used for stopping water. The chemical solution can be easily distributed, and the water stopping property can be improved.

In the above embodiment, a plurality of first pipes 131 are inserted into the ground in parallel with each other, and then the second pipe 136 is grounded while cutting each cuttable portion 133 of the first pipes 131 adjacent to each other in the arrangement direction. Insert in. In the present invention, the first pipe 131 is inserted into one ground, and then the second pipe 136 is grounded in parallel with the first pipe 131 while cutting the machinable portion 133 of the inserted first pipe 131. It may be inserted into a mountain. Also in this case, the second pipe 136 is arranged in the space formed by cutting the machinable portion 133 of the first pipe 131. Therefore, the distance between the first pipe 131 and the second pipe 136 can be narrowed to minimize the water stopping range, and the water stopping of the side soil retaining 130 can be improved.

In the above embodiment, the cuttable portion 133 is divided into an existing cuttable portion element 133a and a separate cuttable portion element 133b before the core members 132 are connected to each other, as shown in FIG. It may be in the form. Specifically, before the core members 132 are connected to each other, the element corresponding to the existing machinable portion element 133a (see FIG. 4) is not provided in the core material element 132c, and after the connection, the existing machinable portion is provided. The core element 132c may be provided with a separable cuttable element 133c in which an element corresponding to the element 133a (see FIG. 4) and a separable cuttable element 133b (see FIG. 4) are integrated. That is, the cuttable portion 133 may be divided into a plurality of separate cuttable portion elements 133c separated from the core material element 132c in the axial direction of the first pipe. Even in this case, when connecting the core material elements 132c to each other, the joint between the core material elements 132c can be visually confirmed from the radial outside of the first pipe 131 over the entire circumference, and the core material element can be visually confirmed. The 132c can be easily connected to each other.

As shown in FIG. 4, in the form in which the machinable portion 133 is divided into the existing machinable portion element 133a and the separate machinable portion element 133b, a part of the machinable portion 133 before connecting the core material elements 132c to each other. The existing machinable portion element 133a can be provided in advance on the core material element 132c. Therefore, the time required to provide the separable cuttable part element 133b on the core material element 132c after connecting the core material elements 132c can be shortened, and the first pipe 131 can be efficiently inserted into the ground. ..

Further, in the example in which the existing cuttable part element 133a is provided in advance on the core material element 132c shown in FIG. 4, the separate cutable part element 133b does not have to be formed in advance in a factory or the like, and may be an early curing type mortar or spray. It may be formed by on-site construction using concrete or the like. In this case, after connecting the core material elements 132c to each other, an early curing type mortar or sprayed concrete may be sprayed to form the separable cuttable part element 133b on the core material element 132c.

130 ・ ・ ・ Side earth retaining (earth retaining structure)
131 ... 1st pipe 132 ... Core material 132a ... 1st curved part 132b ... 2nd curved part 132c ... Core material element 133 ... Movable part 133a ... Existing cutting possible Part element 133b ... Separately cuttable part Element 136 ... Second pipe 231 ... First pipe 232 ... Core material 233 ... Cuttable part 331 ... First pipe 332 ... Core Material 333 ・ ・ ・ Cuttable part

Claims (10)

It is a method of constructing a retaining structure by inserting multiple pipes into the ground.
A first insertion step of inserting a first pipe having a core material and a cuttable portion provided on the core material and having a hardness lower than that of the core material into the ground.
A second insertion step of inserting the second pipe into the ground in parallel with the first pipe while cutting the cuttable portion of the inserted first pipe.
A method of constructing a soil retaining structure. In the first insertion step, a plurality of the first pipes are inserted into the ground in parallel with each other.
The method for constructing a retaining structure according to claim 1, wherein in the second insertion step, the second pipe is inserted while cutting the cuttable portion of each of the adjacent first pipes. The core material is divided into a plurality of core material elements in the axial direction of the first pipe before being inserted into the ground.
The method for constructing a retaining structure according to claim 1 or 2, wherein in the first insertion step, the core material elements are connected to each other to extend the core material. The cuttable portion is formed on an existing cuttable portion element provided on the core material element and a separate cuttable portion element separated from the core material element before the core material elements are connected to each other. It is divided in the axial direction of the first pipe,
The existing machinable portion element is provided in the core material element so as to sink in the axial direction of the first pipe with respect to both ends of the core material element.
The method for constructing a retaining structure according to claim 3, wherein in the first insertion step, after the core material elements are connected to each other, the separable cuttable part element is provided over the adjacent core material elements. The cuttable portion is divided into a plurality of separable cuttable portion elements separated from the core material element in the axial direction of the first pipe before the core material elements are connected to each other.
The method for constructing a retaining structure according to claim 3, wherein in the first insertion step, after the core material elements are connected to each other, the separable cuttable part element is provided over the adjacent core material elements. In the second insertion step, a part of the core material and a part of the second pipe sandwich the cuttable portion in the soil retaining direction perpendicular to the arrangement direction of the first pipe and the second pipe. Insert the second pipe into the ground so that they overlap with each other.
The method for constructing a retaining structure according to any one of claims 1 to 5. The core material includes a first curved portion that is curved along the circumferential direction of the first pipe, and a second curved portion that is connected to the first curved portion and is concavely curved inward in the radial direction of the first pipe. Have,
The method for constructing a soil retaining structure according to any one of claims 1 to 6, wherein the cuttable portion is provided on the second curved portion. It is a pipe for the earth retaining structure that is inserted into the ground and used.
A pipe for an earth retaining structure including a core material and a machinable portion provided on the core material and having a hardness lower than that of the core material before being inserted into the ground. Before being inserted into the ground, the core material is divided into a plurality of core material elements that can be connected to each other in the axial direction of the pipe.
Before being inserted into the ground, the machinable portion is formed in the existing machinable portion element provided on the core material element and the separable cuttable portion element separated from the core material element in the axial direction. It is divided and
The existing machinable portion element is provided in the core material element so as to sink in the axial direction with respect to both ends of the core material element.
The separable cuttable element can be fixed over the core material element connected to each other.
The pipe for the earth retaining structure according to claim 8. Before being inserted into the ground, the core material is divided into a plurality of core material elements that can be connected to each other in the axial direction of the pipe.
The machinable portion is divided into a plurality of separable machinable portion elements separated from the core material element before being inserted into the ground.
The separable cuttable element can be fixed over the core material element connected to each other.
The pipe for the earth retaining structure according to claim 8.

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