JP6908666B2 - Construction method of underground structure - Google Patents

Description

The present invention relates to a method for constructing an underground structure that can be constructed without hindering upper traffic when excavating and constructing a large number of underground structures in the lower ground such as a railroad or a road in the transverse direction. be.

In order to dig a large number of underground structures in the lower ground such as railroads and roads in the crossing direction, protective work is required to support the upper traffic, and a pipe roof for horizontally paralleling steel pipes, etc. is required. Can be given.

However, if a pipe roof was formed as a separate work first and excavated under and inside to construct an underground structure, or if the underground structure was dug under the pipe roof, this pipe roof would be The overburden becomes thicker as much as it exists. Moreover, the protection work for the pipe roof construction is separate from the main work for burying the underground structure, and the construction cost and construction period are large.

In order to eliminate such inconvenience, the present inventors, as shown in the following patent documents, when the concrete box is propelled after the box-shaped roof is press-fitted, the earth and sand of the face portion is referred to as the box-shaped roof together with the propulsion of the box. Since it is extruded together, it is not necessary to excavate the face part separately, cost reduction and construction period can be shortened, and safety can be improved by omitting the dangerous excavation work of the face part. By distributing the reaction force resistance to propel the box, we applied for a construction method for underground structures that does not require large-scale equipment and obtained a patent right.
Japanese Patent No. 4134809

This method was named the SFT method (registered trademark). The SFT method (Simple and Face-Less Method of Construction of Tunnel) is an abbreviation for "a simple and face-less tunnel construction method."

In the SFT method, as shown in FIG. 2, as the first step, a retaining steel sheet pile 2 is placed beside the upper traffic such as a railroad to construct a starting pit 3 and a reaching pit 4, and the SFT method is propelled in the starting pit 3. The machine 5 is installed, and the box-shaped roof 6 which is a cylinder for the roof is press-fitted toward the reaching pit 4. A friction cutter plate 7 is attached to the upper surface of the box-shaped roof 6 as in the conventional case, and is extruded together with the box-shaped roof 6.

In this case, the box-shaped roof 6 is arranged in a square shape so as to correspond to the outer shape of the concrete box 9 to be propelled as shown in FIG. 7, and the retaining member is attached to the face portion surrounded by the box-shaped roof 6. 19 is arranged.

In the figure, 17 is fixed by a timber 18 that joins the abdominal raising material, the earth retaining steel sheet pile 2 on the starting pit 3 side, and the earth retaining steel sheet pile 2 on the reaching pit 4 side. 20 indicates a starting platform.

Further, a reaction force body 21 made of a ground is provided on the arrival shaft 4 side, a shaft is constructed by further excavating the front of the reaction force body 21, and a reaction force wall 23 is provided as a reaction force shaft 22 in the shaft.

Next, as shown in FIG. 4 of the second step, the concrete box 9 is installed on the starting platform of the starting pit 3, the towing jack 24 is attached to the rear part of the concrete box 9, and one end is attached to the towing jack 24. The other end of the cable 25 is fixed to the fixing device 26 fixed to the reaction force wall 23.

Then, the friction cutter plate 7 is fixed to the starting pit 3 side by the stopping member 14. The friction cutter plate 7 cuts the edges between the box-shaped roof 6 and the concrete box 9 and the surrounding earth and sand.

Next, the tip of the concrete box 9 is joined or brought into contact with the rear end of the box-shaped roof 6 extruded in advance, and as a third step, the towing jack 24 is operated as shown in FIG. 5 to operate the towing cable. At 25, the concrete box 9 is towed from the starting pit 3 toward the reaching pit 4.

The box-shaped roof 6 is also extruded at the same time as the concrete box 9 is towed, and the face portion is not excavated. By extruding the earth retaining member 19 which is connected to each other and fixed at the same time, the earth and sand in front of the earth retaining member 19 is also extruded at the same time. In this case, since the friction cutter plate 7 cuts the edges between the box-shaped roof 6 and the concrete box 9 and the surrounding earth and sand as described above, the box-shaped roof 6 and the concrete box 9 are towed smoothly.

In this way, as a fourth step, as shown in FIG. 6, when the box-shaped roof 6 and the earth and sand surrounded by the box-shaped roof 6 and extruded at the same time reach the reaching pit 4, the box-shaped roof is reached at the reaching pit 4. At the same time as removing 6, the earth and sand are excavated and discharged.

Then, the concrete box 9 is further towed until the tip of the concrete box 9 reaches the reaching pit 4, and the promotion of the entire length of the concrete box 9 is completed.

In the towing type by the conventional SFT method, the forward movement is performed by the towing jack 24 in which the reaction force body on the reaching side and the rear part of the box are connected by a towing cable 25 which is a PC steel wire.

Since the concrete box 9 starts to move when the tension of the towing cable 25 exceeds the resistance of the concrete box 9 and the punched portion (the part surrounded by the box-shaped roof 6), the edge cutting and the box at the initial stage of towing the box When the resistance force is large, such as near the arrival point, a sudden movement may occur, and such a sudden movement may cause the following problems.
(1) Adverse effect on the area around the crossing point (especially the upper part) (2) Deterioration of box towing accuracy (3) Noise and vibration problems around the site

An object of the present invention is to solve the above-mentioned inconvenience of the conventional example, and to propel the concrete box body after press-fitting the box-shaped roof, an underground structure that pushes out the earth and sand of the face portion together with the box-shaped roof while propelling the box body. The purpose of the construction method is to provide a construction method for an underground structure that improves the accuracy of box towing, reduces the influence on the periphery of a crossing point, and improves noise and vibration on the periphery of the site.

In order to achieve the above object, the present invention according to claim 1 arranges box-shaped roofs in a rectangular arrangement in the lower, side and upper stages so as to correspond to the outer shape of the concrete box to be propelled, and arranges them in the ground. An underground structure that is press-fitted and the concrete box is placed behind the box-shaped roof and the earth and sand surrounded by the box-shaped roof as the punching part, and the punching part is pushed out together with the towing of the concrete box. In the construction method, it consists of a hydraulic jack and a spacer or strut made of steel material between the reaction force body or the ground and the punched part provided on the reaching side, and the hydraulic jack is made free and the cylinder of the hydraulic jack gradually contracts to buffer it. The purpose is to provide a shock absorber and operate this shock absorber when towing a concrete box.

According to the first aspect of the present invention, in order to suppress the sudden movement of the box body, a shock absorber is provided between the punched portion and the reaction force body (or the ground) on the reaching side, and the concrete box body. By activating this shock absorber during towing, the concrete box suddenly becomes sharp when the tension of the towing cable exceeds the resistance of the concrete box and the punched part (the part surrounded by the box-shaped roof 6). Even if it starts to move, the impact can be mitigated in front of the punched part, and noise and vibration to the surrounding part of the site can be prevented.

The shock absorber consists of a hydraulic jack and a spacer or strut made of steel, and the cylinder of the hydraulic jack is arranged in an extended state.

The cylinder of the hydraulic jack gradually contracts as the box body and the punching portion move forward, thereby serving as a buffering portion.

At this time, since the advance of the box is restricted by the oil pressure in the cylinder, sudden behavior can be suppressed.

When the hydraulic jack contracts by one stroke, the steel material (spacer strut) is recombined, the cylinder is placed in the extended state again, and the process is repeated until the box reaches the predetermined position.

As described above, in the construction method of the underground structure of the present invention, after the box-shaped roof is press-fitted, the concrete box is propelled, and the earth and sand of the face portion is pushed out together with the box-shaped roof while the box is propelled. In the construction method of the structure, the box body towing accuracy is improved, the influence on the area around the crossing is reduced, the noise and vibration on the area around the site are improved, and especially in the construction under the railway, the influence on the upper part (track) of the crossing. At the same time, it is effective to reduce noise and vibration to the surrounding environment during nighttime construction.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a vertical sectional side view showing one embodiment of the construction method of the underground structure of the present invention. In the figure, 6 is a box-shaped roof which is a cylinder for a roof, and 9 is a concrete box.

The box-shaped roof 6 is assembled and arranged in a rectangular arrangement in the lower, side, and upper stages so as to correspond to the outer shape of the concrete box 9 to be propelled, and press-fitted into the ground, and is surrounded by the box-shaped roof 6 and the box-shaped roof. A concrete box 9 is arranged behind the extruded portion 8 using the earth and sand that has been collected, and the extruded portion 8 is pushed out together with the towing of the concrete box 9.

As shown in FIGS. 2 to 6, the box-shaped roof 6 reaches the starting side 34 (may be the starting pit 3) by driving a retaining steel sheet pile 2 beside the upper traffic 1 of a railway or the like. A side 35 (which may be a reaching pit 4) is constructed, a propulsion device 5 is installed on the starting side 34, and a box-shaped roof 6 which is a roof cylinder is press-fitted toward the reaching side 15 to form a box shape. A friction cutter plate 7 is attached to the upper surface of the roof 6 and extruded together with the box-shaped roof 6.

In this case, the box-shaped roof 6 is arranged in a square shape so as to correspond to the outer shape of the concrete box 9 to be propelled as shown in FIG. 19 is arranged.

The earth retaining member 19 on the starting side 34 and the earth retaining member 19 on the reaching side 35 are fixed by the tie lot material 18. 20 indicates a starting platform.

Further, a reaction force body 21 made of a ground is provided on the reaching side 35, a shaft is constructed by further excavating the front of the reaction force body 21, and a reaction force wall 23 is provided in the shaft. The reaction force wall 23 may use the reaction force body 21 as it is, or may be constructed as a separate body from the reaction force body 21.

Further, the ground itself can be used as a reaction force body without being specially configured as a reaction force body 21.

Next, as shown in FIG. 4 of the second step, the concrete box 9 is installed on the starting platform 20, the towing jack 24 is attached to the rear part of the concrete box 9, and the towing cable 25 having one end attached to the towing jack 24. The other end is fixed to the fixing device 26 fixed to the reaction force wall 23.

Then, the friction cutter plate 7 is fixed to the starting side 34 side by the stopping member 14. (See FIG. 5) The friction cutter plate 7 cuts the edges between the box-shaped roof 6 and the concrete box 9 and the surrounding earth and sand.

Next, the tip of the concrete box 9 is joined or brought into contact with the rear end of the box-shaped roof 6 extruded in advance, and as a third step, the towing jack 24 is operated as shown in FIG. 5 to operate the towing cable. At 25, the concrete box 9 is towed from the starting side 34 toward the reaching side 35.

The earth and sand surrounded by the box-shaped roof 6 and the box-shaped roof 6 is used as the punching portion 8, and the punching portion 8 is pushed out at the same time as the concrete box 9 is towed.

In this way, before pushing out the punched portion 8 at the same time as towing the concrete box 9, a shock absorber 30 is provided between the reaction force 21 provided on the reaching side 35 or the ground and the punched portion 8, and the concrete box is provided. At the time of towing of 9, the shock absorber 30 is operated.

The shock absorber 30 includes a hydraulic jack 31 and a spacer or strut 33 made of a steel material.

The spacer or strut 33 is assembled in a horizontal frame shape from a steel material such as H-shaped steel, and its length can be increased as appropriate by assembly.

Although not shown, the hydraulic jack 31 is connected to the operation panel and the pump, and a plurality of hydraulic jacks 31 are arranged in the horizontal direction (the width direction of the concrete box 9).

It is desirable that the shock absorber 30 abuts between the reaction force 21 or the ground and the punching portion 8 at a lower position, for example, the tip of the box-shaped roof 6 located at the lower stage.

When the punching portion 8 is pushed at the same time as the towing of the concrete box 9, the box-shaped roof 6 and the edge of the concrete box 9 and the surrounding earth and sand are cut by the friction cutter plate 7 as described above. 6 and the concrete box 9 are towed smoothly.

The hydraulic jack 31 makes the hydraulic jack 31 free of hydraulic pressure, and the cylinder of the hydraulic jack 31 does not extend due to the hydraulic pressure, but gradually contracts as the concrete box 9 and the punching portion 8 move forward to serve as a cushioning portion.

At this time, since the advance of the concrete box 9 is restricted by the oil pressure in the cylinder, abrupt behavior can be suppressed.

When the hydraulic jack 31 contracts by one stroke, the steel material (spacer or strut 33) is recombined, the hydraulic jack 31 (cylinder) is placed again in an extended state, and the process is repeated until the concrete box 9 reaches a predetermined position.

In this way, as a fourth step, as shown in FIG. 6, when the box-shaped roof 6 and the earth and sand surrounded by the box-shaped roof 6 and extruded at the same time reach the reaching pit 4, the box-shaped roof is reached at the reaching pit 4. At the same time as removing 6, the earth and sand are excavated and discharged.

Then, the concrete box 9 is further towed until the tip of the concrete box 9 reaches the reaching pit 4, and the promotion of the entire length of the concrete box 9 is completed.

It is a longitudinal side view which shows one Embodiment of the construction method of the underground structure of this invention. It is a vertical sectional side view of the 1st process of the SFT method. It is a longitudinal side view of the 2nd process of the SFT method. It is a longitudinal side view of the 3rd process of the SFT method. It is a longitudinal side view of the 4th process of the SFT method. It is a longitudinal side view of the 5th process of the SFT method. It is a front view which shows the arrangement state of a box-shaped roof. It is a front view which shows the arrangement state of a box-shaped roof.

1 Upper traffic 2 Retaining steel sheet pile 3 Starting pit 4 Reaching pit 5 Propulsion machine 6 Box-shaped roof 6a, 6b Joint 7 Friction cutter plate 8 Punching part 9 Concrete box 10 Earth and sand 13 Support material 14 Stopping member 15 Cradle 16 Strut 17 Raising material 18 Tylot material 19 Retaining member 20 Starting platform 21 Reaction force body 22 Reaction force pit 23 Reaction force wall 24 Towing jack 25 Towing cable 26 Fixing device 30 Buffering device 31 Hydraulic jack 33 Spacer or strut 34 Starting side 35 Reaching side

Claims (1)

The box-shaped roofs are assembled and arranged in a rectangular arrangement on the lower, side and upper stages so as to correspond to the outer shape of the concrete box to be propelled, and press-fitted into the ground, surrounded by the box-shaped roof and the box-shaped roof. In the construction method of the underground structure where the concrete box is placed behind the punched part and the punched part is pushed out together with the towing of the concrete box, the reaction force body or the ground provided on the reaching side It consists of a hydraulic jack and a spacer or strut made of steel material between the punched part, and a shock absorber is provided to buffer the concrete box by gradually shrinking the cylinder of the hydraulic jack as a free hydraulic jack. A construction method for underground structures characterized by operating the device.

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