JPH0114400B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a horizontal tunnel that can be constructed over a long span in the ground under existing structures such as railways and roads without causing any hindrance to the use of superstructures. This relates to a method of constructing a tunnel using steel pipe sheet pile shoring.

Conventionally, there is a pipe beam construction method in which a tunnel is constructed by excavating the ground under an existing structure using horizontal steel pipe sheet pile shoring, and then pouring concrete boxes into place in the excavated hole. Since there are no tunnels installed, the span length of tunnels that can be constructed by excavation is approximately 20 meters at most. In addition, as a similar method for constructing tunnels in the ground, after improving the ground and providing protection with a pipe roof in the ground, the precast concrete box frame installed at the departure base was installed using a frontage jack installed at the arrival base.
There is a frontage construction method in which a tunnel is constructed by drawing soil through prestressing steel and excavating the soil that enters the structure, but this method requires a large work area at the starting base, and while excavating the ground at the tip of the structure block, In order to pull it in, it is necessary to extensively improve the surrounding ground, and furthermore, towing the heavy frame block through the ground requires cost and advanced technology.

This invention was developed in view of the above circumstances,
This greatly increased the tunnel span length and made construction easier. The details will be explained below with reference to illustrated embodiments.

The example shows a case where a tunnel is constructed on the roadbed of track A. First, a trestle frame 1 is constructed using supports and beams at both ends of the excavated section (the first
(Fig. 5). Next, the steel pipe sheet piles 2 are pushed into the ground along the trestle frame 1 while being connected to each other at the joints 3, and the trestle frames 1 at both ends are pushed into the ground.
(Fig. 2, Fig. 6). In addition, when pushing, an auger can be inserted into the steel pipe sheet pile 2 and excavation can also be used. In addition, if the ground is soft, the steel pipe sheet piles 2 are also pushed into the bottom so as to surround the four peripheries. Also, if necessary, soil hardening agent will be injected into the excavated section and its surroundings.

Fill the joint 3 of the pushed steel pipe sheet pile 2 with mortar, and also fill the gap between the steel pipe sheet pile 2 and the pedestal frame 1 with concrete 4 for fixing the fulcrum part (Figures 7 and 8). Furthermore, if there is a risk that the steel pipe sheet pile 2 may locally buckle at an intermediate fulcrum, etc.
Fill the steel pipe with concrete.

Next, the entire excavation span is divided into several sections, and the ground surrounded by the steel pipe sheet piles 2 from one or both sides is excavated. At this time, the steel pipe sheet pile 2 is supported on one side by the frame frame and on the other side by the unexcavated ground 8 (FIG. 3).
In order to supplement the bearing capacity of the unexcavated ground 8, temporary supports 5 are sequentially installed in each required excavated section. Next, a concrete box 6, which will serve as the tunnel lining, is manufactured using on-site concrete in the excavation pit. Then, the gap between the concrete box 6 and the steel pipe sheet pile 2 is filled with non-shrinkable mortar or foam mortar 7 (fourth
Figure) Next, using the completed concrete box 6 as one fulcrum and the unexcavated ground as the other fulcrum, excavation is carried out in sequence while supporting the steel pipe sheet pile 2 with the temporary support 5 as the fulcrum in the middle, and the same procedure is repeated. The entire tunnel section will be completed.

This invention has the above-mentioned configuration. Prior to excavation, steel pipe sheet piles connected at joints are installed between the frame frames at both ends, and as the tunnel is excavated, one of the steel pipe sheet piles is placed in the unexcavated ground and temporarily installed. The tunnel is supported by pillars, and the other is supported by hardened concrete boxes constructed on site, and concrete is poured in sequence, so there is no problem in using the superstructure, and tunnels up to about 100 meters can be constructed quickly and easily. can.

[Brief explanation of drawings]

Figures 1, 2, 3, and 4 are longitudinal sectional views shown in the construction order; Figures 5 and 6 are side views of Figures 1 and 2; Figure 8 is a sectional view of the main part. A... Orbit. 1... Frame, 2... Steel pipe sheet pile, 3... Joint part, 4... Concrete, 5...
...Temporary support, 6...Concrete box, 7...
...Mortar, 8...Unexcavated ground.

Claims (1)

[Claims] 1. Construct a trestle frame at both ends of the excavation section, push the steel pipe sheet piles into the ground along the trestles while interconnecting them at their joints, bridge them between the two trestles, and then surround them with the steel pipe sheet piles. Partial sections of the ground are excavated, temporary supports are sequentially installed at required intervals, a concrete box is made to serve as the tunnel lining with cast-in-place concrete inside the excavation, and cast-in-place concrete is sequentially placed between the pedestal frames. A method for constructing a tunnel using horizontal steel pipe sheet pile shoring, which is characterized by manufacturing a concrete box and constructing a tunnel.