JPH06228959A - Constructing method for underground structure - Google Patents

Abstract

PURPOSE:To enhance the efficiency of construction work by installing steel materials in parallel to a concrete box member in the longitudinal direction and filling up sand between the steel materials and reducing earth pressure- induced friction in an attempt to jack up the concrete box member when building a tunnel whose covering is shallow or the like. CONSTITUTION:Roof steel pipes 5 and concrete box members 9 are jacked up one after another while a friction cutter plate 6 is left over under ground. Rib-shaped steel materials 16 are installed to the concrete box members 9 in the front and the rear while sand is filled up between the steel materials 16 as a friction reducing material. In stead of the steel materials 16, preferably, projected strips be formed with the concrete box members in one piece. This construction makes it possible to enhance the efficiency of construction work without affecting the ground surface adversely.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is particularly intended to obstruct upper traffic when excavating a large number of underground structures in the transverse direction at a shallow depth of soil such as railways and roads. The present invention relates to a method for constructing an underground structure that can be constructed without any need.

[0002]

2. Description of the Related Art In order to dig a large number of reinforced concrete underground structures into the lower ground such as railways and roads in the transverse direction, a protective work for supporting upper traffic is required. It is possible to provide a pipe roof in which steel pipes are arranged in parallel. However, in such a conventional pipe roof protector, the work for constructing the pipe roof protector must be performed prior to the tunnel excavation work and the underground structure construction work. Since the construction is done separately, the construction period and construction cost are large, and the labor and financial loss are large.

Further, since a steel pipe as a pipe roof is buried in the ground to thereby support a railway and an overburden portion to construct a tunnel which serves as an underpass under the soil, the overburden portion and the steel pipe pipe. In addition to the diameter of the tunnel, a working space is required between the top of the tunnel and the pipe roof to create the top of the tunnel.

On the other hand, the applicant previously invented a method for constructing an underground structure as shown in FIG. 5, and named it the box roof construction method. According to this construction method, it is possible to perform several types of construction at the same time, because it is performed simultaneously with the excavation of the underground structure, without constructing the protection work for the underground structure to be excavated underground as a separate work. In addition, it can be constructed reliably and inexpensively, and it can be constructed with a shallow soil cover.

[0005] Soil retaining steel sheet pile 2 is driven beside an upper traffic 1 such as a railway to construct a starting pit 3 and a reaching pit 4, and a press-fitting machine (not shown) is installed in the starting pit 3 Then, the steel pipe for roof 5 having a box-shaped cross section is press-fitted toward the reaching pit 4. The press-fitting machine has an extruding mechanism such as a jack for the roof steel pipe 5 and an internal excavating mechanism for the steel pipe 5 such as an auger.

The roof steel pipe 5 is a box-shaped tubular body having a substantially square cross section, and has hook-shaped joints formed continuously on the left and right side surfaces in the longitudinal direction, and a friction cutter plate 6 made of a flat steel plate is mounted on the upper surface. It is location. Such roof steel pipe 5
Press-fits the unit cylinders one by one, but forms a box-extracting joint flange at the end, and by fastening the joint flanges with bolts and nuts, one piece is added in the length direction to bury the required length. The tip of the friction cutter plate 6 is fixed to the tip of the roof steel pipe 5 by welding or the like, but the other part than the tip is simply superposed on the upper surface of the roof steel pipe 5, and the roof steel pipe 5 is When connecting one by one, the friction cutter plate 6 is also lengthened by welding and the like for the length of the roof steel pipe 5.

The arrangement of the roof steel pipes 5 is to match the outer circumference of the section of the planned tunnel.
A concrete box 9 as an underground structure is set, a strut 14 and a push-push jack 10 are provided between the reaction wall 8 and the concrete box 9, and the concrete box 9
A blade 11 is provided at the tip of.

A small jack 12 for pushing the roof steel pipe 5 is arranged between the front end of the concrete box 9 and the rear end of the roof steel pipe 5, and the rear end of the friction cutter plate 6 is a stopper. * 13: Fix it to the starting pit 3 side, while installing the temporary support 15 on the reaching pit 4 side.

The fixation of the tip of the friction cutter plate 6 and the front end of the roof steel pipe 5 is released, and the propelling jack 10 is extended to apply a reaction force to the reaction force wall 8 to advance the concrete box 9. At that time, the steel pipe 5 for the roof is pushed forward by the small jack 12 prior to the concrete box 9. At this time, the friction cutter plate 6 is left in the ground.

By advancing the roof steel pipe 5 and the concrete casing 9 while leaving the friction cutter plate 6 in this manner, the roof steel pipe 5 and the concrete casing 9 advance with their edges cut off from the ground. ,
It does not suffer from frictional resistance due to earth pressure. Further, in order to advance the concrete box 9, the front part of the blade opening 11 is excavated, but this work is protected by the steel pipe 5 for the roof, and it is possible to perform safely without the risk of soil collapse. While receiving the tip of the roof steel pipe 5 that has come out of the reaching pit 4 on the temporary support 15, the fastening with bolts and nuts is released and the pieces are sequentially removed one by one.

Regarding the method of propelling the concrete box 9, a reaction force receiving material and a center-hole type towing jack are provided on the side of the reaching pit 4 and one end of which is fixed to the underground structure by a fixing tool. It is also possible to pull the underground structure 9 from the reaching pit 4 side by pulling the towing member made of C steel wire with this towing jack. It is also possible to directly push the roof steel pipe 5 at the front end of the concrete box 9 without providing the small jack 12.

[0012]

Since the friction cutter plate 6 is provided as described above, the steel pipe 5 for the roof and the concrete case 9 advance with the edge cut off from the ground, and are subjected to frictional resistance due to earth pressure. Although it is unnecessary, it is difficult to directly and completely join the friction cutter plate 6 to the upper surface of the concrete box 9 depending on the mutual positional relationship between the concrete box 9 and the roof steel pipe 5. .

In order to completely match the friction cutter plate 6 and the upper surface of the concrete box 9, it is necessary to match the upper surface of the roof steel pipe 5 with the upper surface of the concrete box 9. Because it is easy to shift as shown.

If a gap is created between the friction cutter plate 6 and the upper surface of the concrete box 9, the soil above the friction cutter plate 6 may wrap around the gap and adversely affect the ground surface due to a phenomenon such as depression. There is.

The object of the present invention is to eliminate the disadvantages of the conventional example, to dispose the friction cutter plate first, and to push the concrete box under the friction cutter plate, the friction cutter plate and the concrete box are combined. It is an object of the present invention to provide a method for constructing an underground structure that can be engaged with no gap between the concrete boxes and in a state where the concrete box can easily advance with low friction.

[0016]

In order to achieve the above-mentioned object, the present invention has a structure in which steel pipes for roofs having a cross-section box type having a friction cutter plate on the upper surface thereof are juxtaposed in parallel from the starting pit side to the reaching pit side. In the method of constructing an underground structure, in which the roof steel pipe and the concrete box for the underground structure behind it are sequentially pushed in while the friction cutter plate is left under pressure, The steel material is arranged in a rib shape so as to extend in the direction of the ribs, sand is filled between the steel materials as a friction reducing material to form a bed, or the concrete box has an integrally formed ridge so as to extend in the front-rear direction on the outer peripheral surface. The crevice between the ridges is filled with sand as a friction reducing material to form a bed as a whole, and the bed is contacted with the friction cutter plate from below. It is an gist thereby.

[0017]

According to the present invention, the outer peripheral surface of the concrete box is filled with sand to prepare a bed, and the friction cutter plate is engaged with the concrete box through the bed, so that a gap is generated between them. Sediment does not enter. Furthermore, since this bed is filled with sand as a friction reducing material, it promotes the effect of the friction cutter plate, and the concrete box advances with the edge completely cut off from the ground, and Avoids frictional resistance.

[0018]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a vertical sectional front view of a main part showing a first embodiment of the method for constructing an underground structure of the present invention, FIG. 2 is a vertical sectional side view of the same as above, and the main part of the construction method is the same as the conventional example described in FIG. , The cross-section box-shaped steel pipes for roof 5 having the friction cutter plate 6 on the upper surface thereof are arranged in parallel and pressed into the ground from the starting pit 3 side to the reaching pit 4 side, and the friction cutter plate 6 is left in the ground. While roof steel pipe 5
And a method for constructing an underground structure in which the concrete box 9 for the underground structure behind it is sequentially propelled, and the detailed description is omitted because it is the same as the conventional example.

In the present invention, the concrete box 9 has an outer peripheral surface,
For example, an H-shaped steel material 16 that extends in the front-rear direction of the concrete box 9 is provided on the upper surface so that the flanges thereof are located above and below. The H-shaped steel materials 16 are arranged side by side in a rib shape with an interval equal to or less than the width of the friction cutter plate 6.

The H-shaped steel material 16 may be provided integrally with the concrete box 9 such that the lower flange thereof is embedded when the concrete box 9 is manufactured. further,
Instead of the H-shaped steel material 16, another shaped steel material such as another T-shaped steel material or an I-shaped steel material may be used.

In this way, when the concrete box 9 is installed in the starting pit, sand 17 as a friction reducing material is filled between the H-shaped steel materials 16 to make a bed 18. This sand 17
May be raised above the H-shaped steel material 16 so as to be connected between the adjacent H-shaped steel materials 16 beyond the H-shaped steel material 16.

In the present invention, the rear end of the friction cutter plate 6 is not fixed to the starting pit 3 side by a stopper member,
The concrete box 9 is extended to a position overlapping with the concrete box 9, and the lower side of the rear end of the friction cutter plate 6 is brought into contact with the bed 18. In that case, the friction cutter plate 6 is arranged so that both sides are placed between the H-shaped steel materials 16.

When the concrete box 9 is pushed forward while leaving the friction cutter plate 6, the concrete box 9 advances with its edge completely cut off from the ground, and does not receive frictional resistance due to earth pressure.

FIGS. 3 and 4 show a second embodiment of the present invention, in which a concrete box 9 is integrally provided with a ridge 19 on the outer peripheral surface, for example, the upper surface, so as to extend in the front-rear direction. A recess 20 is formed between the projections 19.
The projections 19 and the recesses 20 may be formed at the same time when the concrete box 9 is formed.

Sand is used as a friction reducing material in the recess 20.
Filling 17 and making bet 18 as a whole, this bet
The 18 is brought into contact with the friction cutter plate 6 from below. The width of the recess 20 is slightly smaller than the width of the friction cutter plate 6, and the friction cutter plate 6 is arranged so that both sides are placed between the projections 19 as in the conventional example.

In the case of the second embodiment, since the concrete box 9 can be directly filled with the sand 17, the cost is lower than that of the first embodiment using the H-shaped steel material 16.

[0027]

As described above, according to the method for constructing an underground structure of the present invention, steel pipes for roofs having a box-shaped cross section having a friction cutter plate arranged on the upper surface thereof are arranged in parallel to each other from the starting pit side to the reaching pit side. In a construction method for an underground structure, in which a roof steel pipe and a concrete box for an underground structure behind the roof steel tube are sequentially pushed while being pressed into the ground and the friction cutter plate is left in the ground, a friction cutter plate and a concrete box are used. And there is no gap between
The concrete box can be engaged in a state where it can easily proceed with low friction, and there is no fear of adversely affecting the ground surface.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view of a main part showing an embodiment of a method for constructing an underground structure of the present invention.

FIG. 2 is a vertical cross-sectional side view of essential parts showing one embodiment of the method for constructing an underground structure of the present invention.

FIG. 3 is a vertical cross-sectional front view of essential parts showing an embodiment of the method for constructing an underground structure of the present invention.

FIG. 4 is a vertical cross-sectional side view of essential parts showing one embodiment of the method for constructing an underground structure of the present invention.

FIG. 5 is a vertical sectional front view of a conventional method in which the present invention is not used.

FIG. 6 is a vertical cross-sectional front view of a main part of a conventional method that does not use the present invention.

[Explanation of symbols]

 1 ... Upper traffic 2 ... Domechi steel sheet pile 3 ... Starting pit 4 ... Destination pit 5 ... Roof steel pipe 6 ... Friction cutter plate 8 ... Reaction wall 9 ... Concrete box 10 ... Pushing jack 11 ... Blade 12 ... Small Jack 13 ... Stopper 14 ... Strut 15 ... Temporary cradle 16 ... H-shaped steel 17 ... Sand 18 ... Bed 19 ... Convex ridge 20 ... Recess

Claims (2)

[Claims] 1. A steel pipe for roof having a box-shaped cross section having a friction cutter plate arranged on the upper surface thereof is arranged in parallel and press-fitted into the ground from the starting pit side to the reaching pit side, while leaving the friction cutter plate in the ground. In a method of constructing an underground structure in which a roof steel pipe and a concrete box for an underground structure behind it are sequentially promoted, the concrete box is provided with steel members arranged in a rib shape so as to extend in the front-rear direction on the outer peripheral surface, and The method for constructing an underground structure is characterized in that a bed is prepared by filling sand as a friction reducing material, and the bed is brought into contact with the friction cutter plate from below. 2. A cross-section box-shaped steel pipe for roof having a friction cutter plate arranged on the upper surface thereof is arranged in parallel and press-fitted into the ground from the starting pit side to the reaching pit side, while leaving the friction cutter plate in the ground. In the method of constructing an underground structure for sequentially propelling a concrete pipe for a roof steel pipe and an underground structure behind the roof, the concrete casing is integrally provided with a ridge so as to extend in the front-rear direction on the outer peripheral surface,
A method for constructing an underground structure, characterized in that the recesses between the ridges are filled with sand as a friction reducing material to produce a bed as a whole, and the bed is brought into contact with a friction cutter plate from below.