JP2018150780A - Construction method of underground structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a construction method of an underground structure applicable to a water retaining layer through improving a construction method (SFT construction method) of an underground structure, which is to push out sediment in a working face together with box type roofs to advance a concrete box body after the box type roofs are pressed-in.SOLUTION: A construction method of an underground structure comprises: placing a friction cut plate on an outer side surface to apply its weight; assembling and positioning in rectangular arrays on a lower layer, side layers, and an upper layer corresponding to the outer configuration of a concrete box body of which box type roofs are advanced by pressed-in in the ground integrally with the friction cut plate; and pushing out sediment within rectangular arrays of box type roofs together with the rectangular arrays of box type roofs, remaining the friction plate as the box body advances and is tracked, which are positioned such that a tip of the box body is arrayed with an edge of the box type roof after the box type roofs are pressed-in to the ground, wherein a cut-off structure is configured by overlapping side ends of the corresponding friction cut plates.SELECTED DRAWING: Figure 1

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 the pipe roof was formed as a separate construction first, the underground structure was constructed as a box (box culvert) and propelled under the pipe roof, the earth covering would be as much as this pipe roof existed. Become thicker. 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.

  In order to promote the underground structure, it is advanced after excavating the face. Therefore, a process for excavating the face portion is required, which not only increases the construction cost, but also increases the construction period accordingly.

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

In order to eliminate such inconvenience, the present inventors, as shown in the following patent document, press the box-shaped roof and then propel the concrete box. Because it extrudes, it does not require additional work to excavate the face, reducing costs and shortening the work period.In addition, safety can be improved by eliminating the work of excavating the face with danger. By distributing the reaction force resistance for propelling the project, we applied for a construction method for an underground structure that does not require large-scale equipment and obtained a patent.
Japanese Patent No. 3887383 Japanese Patent No. 4134089 Japanese Patent No. 4317843

This construction method is named SFT construction method and is also published in Non-Patent Document 1 below. Note that the SFT method (Simple and Face-Less Method of Construction of Tunnel) is an abbreviation for “construction method of a tunnel that is simple and has no face”.
Homepage of Uemura Giken Co., Ltd. and the Underpass Technology Association of the Internet website http://www.uemuragiken.co.jp/tech/sft.html http://underpass.info/sft.html

  In the SFT method, as shown in FIG. 25, the earth retaining steel sheet pile 2 is placed beside the upper traffic (not shown) such as a railway as shown in FIG. The propulsion device 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 cut plate 7 is placed on the upper surface of the box-shaped roof 6 and extruded together with the box-shaped roof 6.

  The box-shaped roof 6 is a box-shaped cylindrical body having a rectangular cross section as shown in FIGS. 29 and 30, and has a bowl-shaped or flat-plate joint 6 a, 6 b formed continuously in the longitudinal direction on the side surface, and on the upper surface. A friction cut plate 7 made of a flat plate is attached. The box-shaped roof 6 has flanges for bolting at the front and rear ends and can be sequentially connected in the length direction to embed the required length, and further parallel in the vertical and horizontal directions via the joints 6a and 6b. Let

  Although the detailed illustration of the propulsion device 5 is omitted, the box roof 6 is dug out by pushing out the earth and sand discharge pipe with the main push jack as an extruded body. In addition to the case where a drilling mechanism such as an auger screw is provided.

  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, and a earth retaining member 19 is disposed on the face portion surrounded by the arrangement of the box-shaped roof 6.

  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. 26 in the second step, the concrete box 9 is installed in the start pit 3, and the main jack 10 and the 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 cut plate 7 is fixed to the start shaft 3 side by the stop member 14. The friction cut 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 as shown in FIG. The box 9 is pushed forward.

  Simultaneously with the extrusion of the concrete box 9, the box-shaped roof 6 is also extruded, and the face portion is not excavated. When the box-shaped roof 6 is extruded, the earth retaining member 19 disposed at the portion surrounded by the box-shaped roof 6 at the same time. By extruding (using a part of earth retaining steel sheet pile 2), the earth and sand α in front of it is also extruded. In this case, since the box-shaped roof 6 and the concrete box 9 and the surrounding earth and sand are cut off by the friction cut plate 7 as described above, the box-shaped roof 6 and the concrete box 9 are smoothly driven.

  In this way, as shown in FIG. 28 as the fourth step, if the box roof 6 and the earth and sand that are simultaneously surrounded and pushed by the box roof 6 reach the access shaft 4, the box 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.

  In the conventional SFT method, it is necessary to perform construction by applying ground improvement such as chemical solution injection as a countermeasure against water under the ground condition having the stagnant ground so-called groundwater.

  An object of the present invention is to provide a construction method for an underground structure that can be constructed without using an expensive auxiliary construction method even in stagnant ground.

  In order to achieve the above object, the present invention according to claim 1 is directed to an outer shape of a concrete box in which a friction cut plate is placed on the outer surface, and a box roof is pressed into the ground together with the friction cut plate for propulsion. After the box-shaped roof is press-fitted into the ground, the box is placed by aligning the tip of the box with the end of the box-shaped roof. In the construction method of the underground structure that pushes the inner sand and sand in the rectangular arrangement of the box roof together with the rectangular arrangement of the box roof, leaving the friction cut plate together with the box propulsion and traction, the friction cut plate is The gist is to make the water-stopping structure by overlapping the ends.

  According to the present invention, since the friction cut plates arranged side by side form a water-stop structure, the groundwater to be invaded is stopped by the friction cut plates and does not flow into the concrete box.

  The gist of the present invention described in claim 2 is that the friction cut plate for overlapping the side ends has a water stop member interposed therebetween.

  According to this invention of Claim 2, it can be set as a reliable water stop structure by interposing a water stop member.

  The gist of the present invention described in claim 3 is that, in the access pit for extruding earth and sand together with the rectangular array of box-shaped roofs, a earth retaining jack is provided, and the earth retaining jack is reduced and extruded while suppressing the earth and sand pushed out by the earth retaining jack. To do.

  According to the third aspect of the present invention, since the inner earth and sand pushed out together with the rectangular array of the box-shaped roof is also water-based soft, the earth retaining jack is reduced and pushed out while suppressing the earth and sand pushed out by the earth retaining jack. Can be pushed out more safely.

  As described above, the construction method of the underground structure of the present invention can be constructed even on stagnant ground without using an expensive auxiliary construction method.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 3 to 8 are longitudinal side views of the respective steps showing the first embodiment of the construction method of the underground structure of the present invention. The same reference numerals are given to the same components as those in FIGS. 25 to 28 showing the conventional example. It is attached.

  This embodiment is a case where an underground structure is constructed on the water-resistant ground β.

  In the present invention, as in the conventional SFT method, as shown in FIG. 1, a temporary earth retaining pile made of earth retaining steel sheet piles 2 such as a sheet pile is placed next to an upper traffic such as a railway (not shown). The start pit 3 and the arrival pit 4 are constructed, and as shown in FIG. 2, the start pit 20 is formed on the start pit 3 by rubble and base concrete placement, and a propulsion device (not shown, see FIG. 25) Then, the box-shaped roof 6 that is a roof cylinder is press-fitted toward the access pit 4.

  Similarly, the arrival pit 4 is formed with rubble and base concrete placement.

  The box-shaped roof 6 is a box-shaped cylindrical body having a rectangular cross section as shown in FIGS. 29 and 30 as in the above-described conventional example, and is formed with flanges for bolt connection at the front and rear ends (not shown) in the length direction. The necessary length can be buried by connecting them sequentially.

  In addition, the box-shaped roof 6 used in the present invention has a flange-like or flat-plate joint 6a, 6b formed continuously in the longitudinal direction on the side surface, and a friction cut plate 7 placed on the upper surface.

  The friction cut plate 7 is a strip-shaped steel plate, but its end is welded and integrated with the end of the box-shaped roof 6 and the rest is simply placed. When sequentially connected in the vertical direction, the friction cut plates 7 themselves are also connected to each other by welding or the like to be continuous.

  In the present invention, as shown in FIGS. 20 and 21, the friction cut plate 7 has a width that protrudes to the left and right rather than the width of the box-shaped roof 6, and a water-stopping structure is formed by overlapping the side edges. .

  At the time of such superposition, one side end of the friction cut plate 7 is bent in the length direction to form a floating flange 7a, and one side end 7b of the adjacent friction cut plate 7 enters below. Like that.

  In this way, the friction cut plates 7 arranged side by side can be aligned without changing their level and can be firmly overlapped without being inclined.

  Further, as shown in FIGS. 22 to 24, the water blocking member 22 may be interposed between the overlapping portions of the friction cut plate 7 that overlaps the side ends.

  Various members can be used as the water stop member 22, but a molded synthetic rubber is preferable. FIG. 24 shows a sheet-like main body with projections and depressions as chevron stripes.

  As shown in FIG. 22, the water stop member 22 is attached to the back side of the raised flange 7a, and when the friction cut plates 7 are overlapped on the side ends, they are crushed to stop water.

  As shown in FIGS. 1 and 3, the box-shaped roof 6 on which the friction cut plates 7 are stacked is press-fitted from the starting pit 3 to the reaching pit 4 so as to correspond to the outer shape of the concrete box 9 to be propelled. The box-shaped roof 6 is assembled and arranged in a rectangular arrangement of the lower stage, the side part, and the upper stage.

  As shown in FIG. 4, the front end of the concrete box 9 installed on the start stand 20 in the start pit 3 is matched with the end of the box roof 6 arranged in the soil, and in front of the reaction wall 8 of the start pit 3. The main pushing jack 10 is installed on the rear side of the concrete box 9 and is brought into contact with the rear end of the concrete box 9 through the pushing angle 23.

  A pressing angle 24 made of an H-shaped steel material as a box connecting work is attached to the front end of the concrete box 9.

  The friction cut plate 7 is released from the end of the box-shaped roof 6 (release welding fixing) and fixed to the earth retaining sheet pile 2.

  As shown in FIG. 4, the front end of the concrete box 9 is joined or brought into contact with the rear end of the box-shaped roof 6, and the concrete box 9 is pushed out together with the box-shaped roof 6 by the main push jack 10. In the figure, 16 is a strut used for extrusion.

  The concrete box 9 can be pulled as well as being propelled. Towing, the front reaction force wall of the box is provided, a fixing device or a traction jack is attached to the rear of the box, and the other end of the traction cable with one end attached to the fixing device or the traction jack is fixed to the reaction force wall. Fix to the tow jack or fixing device and pull the tow jack. The concrete box 9 may be propelled or towed by either one or both propulsion and towing together.

  In this way, the concrete box 9 is propelled and towed, and the box-shaped roof 6 is extruded simultaneously with the propulsion and towing of the concrete box 9, and the box-shaped roof 6 is pushed out without excavating the face portion. Sometimes, when there is no earth and sand between the box-shaped roofs 6, the earth and sand are pushed out together with the box-shaped roof 6 to the reaching pit 4.

  A retaining member 19 is disposed on the face surrounded by the box-shaped roof 6 and is pushed out together with the box-shaped roof 6 while holding the earth and sand. The retaining member 19 mirror-opens the temporary retaining pile 2. An inner steel sheet pile surrounded by a box-shaped roof 6 can be used.

  Further, the friction cut plate 7 superimposed on the box-shaped roof 6 is stopped at the end near the wellhead when the box-shaped roof 6 is pushed out simultaneously with the propulsion and traction of the concrete box 9, and is left in the box shape. The roof 6 or the concrete box 9 and the natural ground can be cut.

  Since the friction cut plates 7 arranged side by side are stacked to form a water-stop structure as a cylinder, the groundwater to be invaded is stopped by the friction cut plate 7 and flows into the concrete box 9. Absent. Thereby, the concrete box 9 need not be backfilled.

  When the box-shaped roof 6 reaches the reaching pit 4 in this manner, the box-shaped roof 6 is sequentially removed at the reaching pit 4 one after another.

  FIG. 8 shows a state where the concrete box 9 has been press-fitted and the concrete box 9 has been installed.

  The earth and sand are also pushed out together with the box-shaped roof 6 to the access pit 4 and removed together with the removal of the box-shaped roof 6.

  FIGS. 9-15 shows 2nd Embodiment of this invention, the construction length of an underground structure is long, and the space | interval between the starting mine 3 and the arrival mine 4 is also large. The box-shaped roof 6 is also long.

  In such a case, as shown in FIGS. 11 to 15, if the box-shaped roof 6 reaches the arrival shaft 4, the box-shaped roof 6 is divided and removed at the arrival shaft 4.

  In this way, when the box-shaped roof 6 is divided and removed, as shown in FIGS. 16 to 18, the earth retaining jack 25 is provided in the reaching pit 4 that pushes earth and sand together with the rectangular array of the box-shaped roof 6.

  The earth retaining member 19 is pushed by the earth retaining jack 25, and the earth retaining jack 25 is reduced and pushed out while suppressing the earth and sand to be pushed out.

  Extruded earth and sand are removed except for the retaining member 19.

It is explanatory drawing which shows arrangement | positioning of the box-shaped roof of the construction method of the underground structure of this invention. It is a front view which shows the concrete box of the construction method of the underground structure of this invention. It is a vertical side view of the 1st process which shows 1st Embodiment of the construction method of the underground structure of this invention. It is a vertical side view of the 2nd process which shows 1st Embodiment of the construction method of the underground structure of this invention. It is a vertical side view of the 3rd process which shows 1st Embodiment of the construction method of the underground structure of this invention. It is a vertical side view of the 4th process which shows 1st Embodiment of the construction method of the underground structure of this invention. It is a vertical side view of the 5th process which shows 1st Embodiment of the construction method of the underground structure of this invention. It is a vertical side view of the 6th process which shows 1st Embodiment of the construction method of the underground structure of this invention. It is a vertical side view of the 1st process which shows 2nd Embodiment of the construction method of the underground structure of this invention. It is a vertical side view of the 1st process of the 1st system of division removal of a box-shaped roof which shows a 2nd embodiment of a construction method of an underground structure of the present invention. It is a vertical side view of the 2nd process of the 1st system of division removal of a box-shaped roof which shows a 2nd embodiment of a construction method of an underground structure of the present invention. It is a vertical side view of the 2nd process of the 2nd system of the division removal of the box-shaped roof which shows 2nd Embodiment of the construction method of the underground structure of this invention. It is a vertical side view of the 3rd process of the 2nd system of the division removal of the box-shaped roof which shows 2nd Embodiment of the construction method of the underground structure of this invention. It is a vertical side view of the 1st process of the 3rd system of division removal of the box-shaped roof which shows a 2nd embodiment of the construction method of the underground structure of the present invention. It is a vertical side view of the completed form which shows 2nd Embodiment of the construction method of the underground structure of this invention. It is a side view of the 1st process of using the arrival side earth retaining jack. It is a side view of the 2nd process of using the arrival side earth retaining jack. It is a side view of the 3rd process of using the arrival side earth retaining jack. It is an image figure of a box-shaped roof and a concrete box connection. It is an end view of a box-shaped roof and a friction cut plate. It is explanatory drawing of the superimposition of a friction cut plate. It is explanatory drawing of a water stop member intervention. It is explanatory drawing of a water stop member intervention. It is an end view of a water stop member. 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 vertical side view which shows the 3rd process of the construction method of the conventional underground structure. It is a front view of an example of a box-shaped roof. It is a front view of the other example of a box-shaped roof.

2 Steel retaining sheet pile 3 Start pit 4 Arrival pit 5 Propeller 6 Box roof 6a, 6b Joint 7 Friction cut plate 7a Flange 7b Side end 8 Reaction force wall 9 Concrete box 10 Main push jack 14 Stopping member 16 Strut 17 Raising Material 18 Tylot material 19 Earth retaining member 20 Start stand 21 Arrival base 22 Water stop member 23 Push angle 24 Push angle 25 Dome jack

Claims (3)

  Friction cut plates are placed on the outer surface, and a box-shaped roof is press-fitted into the ground together with the friction cut plates to form a rectangular array of lower, side, and upper stages to correspond to the outer shape of the concrete box to be propelled. After assembling and pressing the box roof into the ground, align the tip of the box with the box roof end and place the box to leave the friction cut plate along with the box propulsion and traction, In the construction method of the underground structure where the inner soil in the rectangular array of the box-shaped roof is pushed out together with the rectangular array of the box-shaped roof, the friction cut plate has a water-stop structure by overlapping the side edges. Construction method for underground structures.   The construction method for an underground structure according to claim 1, wherein a water cut-off member is interposed between the friction cut plates that overlap the side ends.   The underground pit according to claim 1 or 2, wherein a earth retaining jack is provided in a pit that extrudes earth and sand together with a rectangular array of box-shaped roofs, and the earth retaining jack is reduced and pushed out while suppressing the earth and sand pushed out by the earth retaining jack. Construction method.