JP3887383B2 - Construction method for underground structures - Google Patents

Description

  The present invention relates to a method for constructing an underground structure that can be constructed without hindering the upper traffic when excavating and constructing a significant underground structure in a lower ground such as a railway or a road. is there.

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

  However, if a pipe roof is first formed as a separate construction and an underground structure is constructed by excavating the pipe roof, or if the underground structure is advanced under the pipe roof, this pipe roof exists. The soil cover becomes thicker by the amount Moreover, the protective work for pipe roof construction is separate from the main construction for underground structure burial, and the construction cost and construction period are large.

  Conventionally, there is a construction method for an underground structure as shown in FIG. 7 to FIG. As shown in FIG. 7, the earth retaining steel sheet pile 2 is placed on the side of the upper traffic 1 such as a railroad, the start pit 3 and the arrival pit 4 are constructed, and the propulsion device 5 is installed in the start pit 3. The box-shaped roof 6, which is a cylinder for roofing, is press-fitted toward the access pit 4.

  FIG. 10 is a front view of the box-shaped roof 6, which is a box-shaped cylinder having a substantially square cross-section, with flange-shaped joints 6 a and 6 b formed continuously in the longitudinal direction on the side, and a friction consisting of a flat plate on the upper surface. A cutter plate 7 is attached. The box-type roof 6 can be sequentially connected in the length direction to embed the required length, and is further juxtaposed in parallel in the vertical and horizontal directions via hook-shaped joints 6a and 6b. FIG. 11 shows a case in which they are arranged in a square shape.

  The propulsion unit 5 includes an extrusion mechanism using a jack of the box-type roof 6 and an internal excavation mechanism of the box-type roof 6 using an auger.

  Next, as shown in FIG. 8, an underground structure with a reaction wall 8 and a concrete box 9 is set in the start pit 3, and a main jack 10 is provided between the reaction wall 8 and the concrete box 9. A blade 11 is provided at the tip of the concrete box 9 and a small jack 12 is interposed between the tip of the concrete box 9 and the box roof 6.

  In the figure, reference numeral 13 denotes a support material for the box-type roof 6, and 14 denotes a stop member for the friction cutter plate 7, which are provided on the start pit 3 side, while a cradle 15 is provided on the arrival pit 4 side.

  The small jack 12 is extended and the box box 6 is pushed forward one by one while leaving the friction cutter plate 7 using the concrete box 9 as a reaction force. When the box roof 6 moves forward, the small jack 12 is retracted. This time, the original pushing jack 10 is extended to dig the concrete box 9.

  In the figure, reference numeral 16 denotes a strut interposed between the main pushing jack 10 and the concrete box 9.

  In this manner, the box-shaped roof 6 that has come out to the reaching pit 4 is sequentially removed while alternately repeating the advance of the box-shaped roof 6 and the advance of the concrete box 9.

And if the front-end | tip of the concrete box 9 reaches the arrival mine 4, the blade edge 11 etc. will be removed and backfill grout will be performed suitably and construction will be completed.
JP-A-55-19312

  In the construction method described above, after the box-shaped roof 6 is advanced, the face section is excavated and then the concrete box 9 is advanced. Therefore, a step of excavating the face portion is inserted between the advance of the box-type roof 6 and the advance of the concrete box 9, and an excavation work is required as a separate thing from the propulsion work of the concrete box 9. For this reason, not only the construction cost increases, but also the construction period becomes longer.

  Moreover, the excavation work of the face part involves danger such as the face collapsing, and the work for ground improvement such as a stabilization process for stabilizing the face face is also required.

  The object of the present invention is to eliminate the inconvenience of the conventional example, and when a concrete box is propelled after press-fitting a box-type roof, the work of excavating the face portion is not required separately, and cost reduction and construction period can be reduced. Another object of the present invention is to provide a construction method for an underground structure that can improve safety by omitting excavation work of a face part that is dangerous.

  In order to achieve the above-mentioned object, the present invention is characterized in that the present invention according to claim 1 is a method in which a box-shaped roof is assembled and arranged so as to correspond to the outer shape of a box to be propelled and press-fitted into the ground from a starting pit. The gist of the invention is to dispose the tip of the box at the end of the box-type roof and push the earth and sand of the face portion together with the box-type roof as the box is propelled.

  According to the first aspect of the present invention, since the earth and sand of the face portion is pushed out together with the box-type roof at the tip of the box, the box-type roof and the box can be simultaneously propelled. It is possible to omit the existing excavation process of the face part during the process of promoting the body, thereby reducing the construction cost and the construction period. In addition, the safety of construction is improved by eliminating the excavation work of the dangerous face part.

  The gist of the present invention described in claim 2 is that a retaining member is disposed on the face part, and the pushing out of the sand and sand in the face part is performed by pushing out the retaining member at the tip of the box. .

  According to the second aspect of the present invention, since the earth and sand in the face portion is pushed out through the earth retaining member, the earth and sand in the box roof can be easily pushed out.

  As described above, in the construction method of the underground structure of the present invention, when a concrete box is propelled after press-fitting a box roof, the earth and sand in the face part is pushed out simultaneously with the extrusion of the box roof. There is no need for excavating the face part inside, and there is no need to improve the ground for stable treatment of the face part, which can reduce costs and construction time, and excavate the face part with danger. Safety can be improved by omitting work.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a longitudinal side view of a state before propelling a concrete box showing an embodiment of a construction method of an underground structure of the present invention, FIG. 2 is a front view of the same, and the conventional examples shown in FIGS. The same components as those in FIG.

  The construction method of the underground structure of this invention is demonstrated based on process drawing of FIGS. In the same way as in the past, as the first step, as shown in FIG. 3, the earth retaining steel sheet pile 2 is placed beside the upper traffic (not shown) such as a railway, and the start pit 3 and the arrival pit 4 are built. Then, the propulsion unit 5 is installed in the start pit 3, and the box-shaped roof 6, which is a roof cylinder, is press-fitted toward the arrival pit 4. A friction cutter plate 7 is attached to the upper surface of the box-shaped roof 6 in the same manner as in the prior art, and is extruded together with the box-shaped roof 6.

  In this case, the box-shaped roof 6 is arranged in a quadrangular shape so as to correspond to the outer shape of the concrete box 9 to be propelled as shown in FIG. 2, and the earth retaining member is placed on the face surrounded by the box-shaped roof 6. 19 is disposed.

  In the figure, reference numeral 17 denotes a bellows material, and a tie-lot material 18 that joins the earth retaining steel sheet pile 2 on the start pit 3 side and the earth retaining steel sheet pile 2 on the arrival mine 4 side. Reference numeral 20 denotes a starting stand.

  Next, as shown in FIG. 4 in the second step, a concrete box 9 is installed in the start pit 3, and a main jack 10 and a strut 16 are installed as propulsion equipment between the concrete box 9 and the reaction wall 8 behind the concrete box 9. Arrange.

  Then, the friction cutter plate 7 is fixed to the start shaft 3 side by the stop member 14. The friction cutter plate 7 cuts the box roof 6 and the concrete box 9 and the surrounding earth and sand.

  Next, the leading end 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 the main jack 10 is extended as shown in FIG. The box 9 is pushed forward.

  Simultaneously with the extrusion of the concrete box 9, the box roof 6 is also extruded, and the face face portion is not excavated. When the box roof 6 is pushed out, the earth retaining member 19 disposed in the portion surrounded by the box roof 6 at the same time. The soil in front of it is also extruded at the same time. In this case, since the edge of the box-shaped roof 6 and the concrete box 9 and the surrounding earth and sand is cut by the friction cutter plate 7 as described above, the box-type roof 6 and the concrete box 9 are smoothly driven.

  In this way, as shown in FIG. 6, as the fourth step, if the box-shaped roof 6 and the earth and sand that are simultaneously pushed and surrounded by the box-shaped roof 6 reach the access shaft 4, the box-shaped roof is formed in the access shaft 4. At the same time as 6 is removed, the soil is excavated and discharged.

  Further, the concrete box 9 is further propelled until the tip of the concrete box 9 reaches the reaching pit 4, and the propulsion of the full length of the concrete box 9 is completed.

It is a vertical side view of the state before the concrete box promotion showing the embodiment of the construction method of the underground structure of the present invention. It is a front view of the state before concrete box promotion showing the embodiment of the construction method of the underground structure of the present invention. It is a vertical side view of the 1st process which shows embodiment of the construction method of the underground structure of this invention. It is a vertical side view of the 2nd process which shows embodiment of the construction method of the underground structure of this invention. It is a vertical side view of the 3rd process which shows embodiment of the construction method of the underground structure of this invention. It is a vertical side view of the 4th process which shows embodiment of the construction method of the underground structure of this invention. It is a vertical side view which shows the 1st process of the construction method of the conventional underground structure. It is a vertical side view which shows the 2nd process of the construction method of the conventional underground structure. It is a vertical side view which shows the 3rd process of the construction method of the conventional underground structure. It is a front view of a box-type roof. It is a front view which shows the arrangement | positioning state of a box-type roof.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Upper traffic 2 Earth retaining sheet pile 3 Starting pit 4 Arrival pit 5 Propulsion machine 6 Box-type roof 6a, 6b Hook-shaped joint 7 Friction cutter plate 8 Reaction force wall 9 Concrete box 10 Original push jack 11 Blade edge 12 Small jack 13 Support material 14 Stopping member 15 Receiving base 16 Strut 17 Waist-raising material 18 Tylot material 19 Earth retaining member 20 Starting stand

Claims (2)

  A box-shaped roof is assembled and arranged so as to correspond to the outer shape of the box to be propelled, and after press-fitting into the ground from the starting pit, the box-shaped roof end is disposed at the box-shaped roof end. A construction method for underground structures characterized by pushing the earth and sand of the face together with the box-type roof as well as propulsion.   The construction method for an underground structure according to claim 1, wherein a earth retaining member is disposed on the face portion, and the earth and sand of the face portion is pushed out by pushing the earth retaining member at a tip portion of the box.

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