JP4734278B2 - Joining method for underground structures - Google Patents

Description

  The present invention relates to a method for joining underground structures.

  When joining existing or new underground structures such as shield tunnels on the side, auxiliary construction methods such as ground improvement were required. Typical examples of this auxiliary method include injection of water glass or cement into the ground to inject chemicals used for the purpose of securing water stoppage and increasing strength, and freezing of pore water in the ground. There is a freezing method that temporarily freezes the ground.

  However, the above auxiliary method is not only large-scale, but in the chemical injection method, if there are wells, rivers, fields, etc. in the vicinity, the effects on the water quality and water veins and deformations such as uplift in the surrounding ground and structures There is a risk of causing. In the freezing method, there is a problem that the surrounding ground due to freezing expansion and thawing has a great influence.

  The present invention has been made in view of the above problems, and its purpose is not a large-scale open-cut method, but a non-open-cut method for joining underground structures that can be joined side-by-side. Is to provide.

  The method of joining underground structures to solve the above problems is a method of joining underground structures built in parallel at the side, and the start side protective body is made of concrete on the inner side of the start side underground structure. The arrival side protection body is formed of concrete on the inner surface of the arrival side underground structure, and the parallel underground structures connected in parallel by connecting a connecting material over the start side protection body and the arrival side protection body. After that, after rotating the connecting steel pipe, cutting and propelling from the starting side protective body to the reaching side protective body to reach the reaching side protective body, the earth and sand in the cut connecting steel pipe is removed. . In addition, when propelling the connecting protective body, an entrance seal device in which an insertion port is formed by an outer entrance ring and a smaller inner entrance ring is installed in the start side protective body, and the entrance seal device is inserted into the insertion port of the entrance seal device. It includes cutting and propelling natural ground while inserting and rotating a connecting steel pipe. In addition, when the connecting steel pipe reaches the reaching-side protection body, the bent portion of the U-shaped cooling water circulation pipe whose one end is led out from the reaching-side protection body into the underground structure is cut, and the cut cooling water circulation The outer periphery of the joint between the connecting steel pipe and the arrival-side underground structure is filled with a water-stopping material, and at the start-side underground structure, the cooling steel injection pipe connected to the outer entrance ring is used to start the connection steel pipe. Filling the outer periphery of the joint with the side underground structure with a water-stopping material. Further, it includes that a steel pipe with a bit formed by assembling a plurality of divided pieces is connected to the front part of the connecting steel pipe. In addition, the inner and outer surfaces of the connecting steel pipe inserted into the insertion port of the entrance seal device include a seal installed on the outer entrance ring and the inner entrance ring to prevent the eruption of earth and sand.

  By piercing the connecting steel pipe, which plays the role of the tunnel lining body, directly into the side of the underground structure, this cutting steel pipe retains the defective part after the cutting is completed, thereby reducing the large-scale auxiliary construction method. Can do. In addition, since it is not necessary to open the ground, reducing the auxiliary construction method such as large-scale ground improvement can shorten the construction period, improve safety, and reduce the impact on the surrounding environment. Moreover, since the steel pipe for connection which is a tunnel lining body is integral, it is not necessary to take special measures against water leakage, and water leakage can be prevented. Further, since the connecting steel pipes are joined after connecting the parallel underground structures over the starting side protector and the arrival side protector, the collapse of the natural ground can be prevented. In addition, while the connecting steel pipe is inserted into the insertion port of the entrance seal device and rotated and cut and propelled, the underground structure is protected from being destroyed by the protective body. In addition, the inner and outer surfaces of the connecting steel pipe inserted into the insertion port of the entrance seal device are sealed with the seals installed on the outer entrance ring and the inner entrance ring, so that underground structures of groundwater and earth and sand during cutting can be obtained. The eruption into the inside can be prevented.

  Hereinafter, an embodiment of a method for joining underground structures according to the present invention will be described in detail with reference to the drawings. In the embodiments, the same components are described with the same reference numerals, and only different components are described with different reference numerals. This underground structure is a shield tunnel such as a road tunnel. When a new underground structure parallel to an existing underground structure is joined at the side, or when a new underground structure paralleled is joined at the side. Applicable.

  FIG. 1 shows underground structures 1 and 2 such as shield tunnels constructed in parallel, and newly installed underground structures 1 and 2 constructed with a natural ground 3 having an appropriate width are joined to each other on the side surface. First, as shown in FIG. 1, the start side protection body 4 is formed of concrete on the inner surface of the start side underground structure 1, and the arrival side protection body 5 is also formed of concrete on the inner surface of the arrival side underground structure 2. Form.

  These start side protector 4 and arrival side protector 5 prevent destruction of the underground structures 1 and 2 when passing through a connecting steel pipe, which will be described later. A set of three through holes 6 is formed in three stages by a rotary percussion or a boring machine over the body 5, and a tie rod 7 as a connecting material is disposed here. Then, a nut 8 and a support plate 9 are installed at the end of the tie rod 7 led out from the reaching-side protective body 5, and the support plate 9 is supported by two upper and lower fixing bases 10. Since the fixing base 10 is provided with an appropriate interval portion 11 so as to sandwich the through hole 6 between the upper and lower sides, the end portion of the tie rod 7 is inserted into the gap portion 11. The fixing of the end portion of the tie rod is not limited to the use of the two fixing bases 10 as described above, and the connecting material is not limited to the tie rod 7 but may be a PC bar or other bar. You can also.

  On the other hand, the end of the tie rod 7 led out from the starting side protective body 4 is also provided with the same nut 8 and supporting plate 9 as described above, and the supporting plate 9 is supported by two upper and lower fixing bases 10. Accordingly, a set of three tie rods 7 are arranged in an upper stage, a middle stage, and a lower stage across the starting side protective body 4 and the arrival side protective body 5, and these are tensioned and fixed by a predetermined force, so that The natural ground 3 between the structures 1 and 2 is tightened so as not to collapse. Moreover, these tie rods 7 not only prevent collapse due to the tightening of the natural ground 3, but also apply prestress to the start side protection body 4 and the arrival side protection body 5 to prevent the connection steel pipe from collapsing due to cutting and propulsion. is doing. In addition, the start side underground structure 1 and the arrival side underground structure 2 are connected by a tie rod 7, and the connecting steel pipe is cut and propelled in a state in which the ground 3 sandwiched between them is tightened, and thereby an entrance described later. Prevention of slipping out of the inner entrance ring 18 in the sealing device 16 and rotation of earth and sand in the connecting steel pipe cut by the connecting steel pipe (consisting of a cut start side protective body, start side underground structure, natural ground, etc.) prevent.

  In addition, a U-shaped cooling water circulation pipe 12 is embedded in the arrival side protective body 5 in a circular shape along the arrival point of the connecting steel pipe. The cooling water circulation pipe 12 is for preventing the bit 36 from becoming high temperature when a connecting steel pipe, which will be described later, cuts and propels the arrival-side protective body 5, and the U-shaped bent portion 13 is used for the connection. A portion cut by the steel pipe, that is, is buried so as to be orthogonal to the connecting steel pipe, and the end portions of the injection pipe 14 and the drain pipe 15 are led out from the reaching-side protective body 5 into the underground structure 2. Therefore, the connecting steel pipe from the starting side protection body 4 cuts the bent portion 13 and is propelled between the injection pipe 14 and the drain pipe 15.

  On the other hand, the entrance-side protective body 4 is provided with an entrance seal device 16 for preventing earth and sand and groundwater from being spouted by rotation and propulsion of the connecting steel pipe. As shown in FIGS. 2 and 3, the entrance seal device 16 includes an outer entrance ring 17 and a smaller inner entrance ring 18. The inner entrance ring 18 is installed inside the outer entrance ring 17. Between these, an insertion port 19 for inserting the connecting steel pipe is formed. The outer entrance ring 17 is formed in a L-shaped cross section by joining a seal case 20 and a bottom plate 21 projecting outside the seal case 20 with a reinforcing plate 22, and the bottom plate 21 is embedded in the start side protective body 4. The fixed plate 23 is fixed with bolts 24. A cooling water injection pipe 25 and a cooling water drain pipe 26 are installed in the outer entrance ring 17, and their tips are connected to the seal case 20.

  Similarly to the above, the inner entrance ring 18 is formed in an L-shaped cross section by joining a seal case 20 and a bottom plate 21 projecting inside the seal case 20 with a reinforcing plate 22, and the bottom plate 21 is protected from the start side protection. The fixing plate 23 embedded in the body 4 is fixed with bolts 24. The inner entrance ring 18 is also provided with a cooling water injection pipe 25 and a cooling water drain pipe 26 as described above, and their tips are connected to the seal case 20.

  A seal 27 is installed in the seal case 20 forming the insertion port 19, and the tip of the seal 27 is bent to the back side so that the connecting steel pipe 35 can be easily inserted into the insertion port 19. It is in close contact with the inner and outer surfaces of the inserted connecting steel pipe 35.

  In this way, the cooling water circulation pipe 12 is embedded in the arrival side protection body 5 tightened by the tie rod 7, and the entrance side protection body 4 is provided with an entrance seal device 16 to prepare for starting the connecting steel pipe 35. It was.

  On the other hand, the connecting steel pipe 35 is composed of a steel pipe 33 with a bit and a plurality of additional steel pipes 34 joined thereto. This steel pipe 33 with a bit is an assembly of divided pieces divided into a plurality of pieces (for example, 4 divisions), which can be divided and transported, and assembled on site to improve transportation efficiency and economy. It is.

  Next, as shown in FIG. 4, a steel pipe excavator 30 is carried by a carriage 29 that runs on a rail 28 laid on the start side underground structure 1, and is raised by a hoisting jack 31, and then the start side protective body surface. To match. This is to rotate the connecting steel pipe 35 to cut the two protective bodies 4, 5 and the underground structures 1, 2 and the natural ground 3, and is installed on the starting side protective body 4 by the carriage 29. .

  Next, the connecting steel pipe 35 is placed on the placing portion 32 of the carriage. And while supplying cooling water to the cooling water injection pipe 25 and supplying grease from a grease nipple (not shown), the tip of the connecting steel pipe 35 is inserted into the insertion port 19 of the entrance seal device. Then, the connecting steel pipe 35 is propelled while being rotated by the steel pipe excavating propulsion device 30, and the starting side protection body 4, the starting side underground structure 1, and the ground 3 are sequentially cut, and the remaining length of the connecting steel pipe 35 is determined. When the number is reduced, the additional steel pipe 34 is connected. As the connecting steel pipe 35 is cut and propelled, cooling water is injected into the insertion port 19 and the excavation groove 37 from the cooling water injection pipe 25, and this cooling water and groundwater from the natural ground are stopped by the seal 27. Then, the water is drained by a cooling water drain pipe 26 located below the entrance ring inside and outside.

  Next, as shown in FIG. 6, when the connecting steel pipe 35 starts to cut the reaching-side underground structure 2, the cooling water is supplied to the U-shaped cooling water circulation pipe 12 in the reaching-side protective body 5 and circulated. Then, when the bent portion 13 of the cooling water circulation pipe 12 is cut, the rotation, cutting and propulsion are stopped. The cutting of the bent portion 13 of the cooling water circulation pipe is confirmed by detecting a pressure change of the water circulated through the cooling water circulation pipe 12 with a pressure gauge (not shown). When the rotation, cutting and propulsion of the connecting steel pipe 35 are stopped, the injection of cooling water from the cooling water injection pipe 25 is also stopped.

  At this time, the connecting steel pipe 35 is located between the injection pipe 14 and the drain pipe 15 of the cooling water circulation pipe 12, and the cut injection pipe 14 of the cooling water circulation pipe 12 is located outside the connecting steel pipe 35, The drain pipe 15 is located inside the connecting steel pipe 35. As a result, the start side undercarriage 4, the start side underground structure 1, the ground 3, the arrival side guard 5 and the arrival side underground structure 2 are cut, and the start side underground structure 1 and the arrival side underground structure 2 are cut. Are connected by a connecting steel pipe 35.

  Next, as shown in FIG. 7, a water stop material 38 is filled from the cooling water injection pipe 25 of the outer entrance ring 17 in the entrance seal device 16 to the outer periphery of the joint portion between the connecting steel pipe 35 and the underground structure 1. Stop water on the side. On the other hand, from the injection pipe 14 of the cooling water circulation pipe cut by the connecting steel pipe 35, the outer periphery of the joint portion between the connecting steel pipe 35 and the underground structure 2 is filled with a water stop material 38 in the same manner as described above. Stop water. After stopping the water, the earth and sand 39 (including the cut start side guard, the start side underground structure, the ground, the reaching side underground structure and the reaching guard) 39 and the like in the connecting steel pipe 35 are removed. Then, when the lining 40 is applied to the inner surface side, an underground structure in which the parallel underground structures 1 and 2 are joined by the connecting steel pipe 35 as shown in FIG. 8 is constructed.

(1) is a cross-sectional view of tie rods laid over parallel underground structures, (2) is a cross-sectional view along line AA in (1), (3) is a cross-sectional view of the end of the tie rod, and (4) is cooling It is sectional drawing of the arrival side protection body with which the water circulation pipe was embed | buried. (1) is the BB sectional drawing of FIG. 1, (2) is a front view of an entrance seal apparatus. (1) is an abbreviated sectional view of the entrance seal device, (2) is a sectional view taken along the line CC of (1), and (3) is a sectional view taken along the line DD. It is sectional drawing of the underground structure which set the propulsion machine for steel pipe excavation. It is sectional drawing of the underground structure which propels the steel pipe for connection. (1) is a cross-sectional view in which connecting steel pipes are stretched over parallel underground structures, (2) is a cross-sectional view taken along line EE of (1), and (3) is a cross-sectional view taken along line FF. It is sectional drawing of a starting side protection body and an arrival side protection body. (1) is a cross-sectional view in which parallel underground structures are joined by a connecting steel pipe, (2) is a cross-sectional view taken along the line GG of (1), and (3) is a cross-sectional view taken along the line H-H.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Start side underground structure 2 Arrival side underground structure 3 Ground mountain 4 Start side protective body 5 Arrival side protective body 6 Through hole 7 Tie rod 8 Nut 9 Supporting plate 10 Fixing base 11 Gap part 12 Cooling water circulation pipe 13 Bending part 14 Injection Pipe 15 Drain pipe 16 Entrance seal device 17 Outer entrance ring 18 Inner entrance ring 19 Insert port 20 Seal case 21 Bottom plate 22 Reinforcement plate 23 Fixing plate 24 Bolt 25 Cooling water injection pipe 26 Cooling water drain pipe 27 Seal 28 Rail 29 Bogie 30 Steel pipe Propulsion machine for excavation 31 Unraveling jack 32 Mounting part 33 Steel pipe with bit 34 Additional steel pipe 35 Steel pipe for connection 36 Bit 37 Excavation groove 38 Water stop material 39 Earth and sand 40 Lining

Claims (5)

  This is a method of joining underground structures built side by side on the side, forming a start-side protective body with concrete on the inner side of the starting side underground structure, and reaching the inner side of the reaching side underground structure with concrete After forming the side armor and connecting the parallel structures between the starting side armor and the arrival side armor by connecting the connecting materials in parallel, rotate the steel pipe for connection from the starting armor to the reaching side A method for joining underground structures, characterized by removing the earth and sand in the connecting steel pipe after cutting and propelling the protective body to reach the arrival side protective body.   When propelling a connecting steel pipe, an entrance seal device with an insertion port formed by an outer entrance ring and a smaller inner entrance ring is installed on the start side protective body, and connected to the insertion port of the entrance seal device. The method for joining underground structures according to claim 1, wherein the ground is cut and propelled while inserting and rotating the steel pipe.   When the connecting steel pipe reaches the reaching-side protective body, the bent portion of the U-shaped cooling water circulation pipe whose one end is led out from the reaching-side protective body into the underground structure is cut, and the cut cooling water circulation Fill the outer periphery of the joint between the connecting steel pipe and the arrival side underground structure with a pipe with a water-stopping material, and use the cooling water injection pipe connected to the outer entrance ring in the starting side underground structure to connect the connecting steel pipe and the starting side The method for joining underground structures according to claim 1 or 2, wherein the outer periphery of the joint with the underground structure is filled with a water stop material.   The method for joining underground structures according to any one of claims 1 to 3, wherein a steel pipe with a bit formed by assembling a plurality of divided pieces is connected to a front portion of the connecting steel pipe.   The seal installed in the outer entrance ring and the inner entrance ring is in intimate contact with the inner and outer surfaces of the connecting steel pipe inserted into the insertion port of the entrance seal device to prevent eruption of earth and sand. The joining method of the underground structure in any one of -4.

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