JPH0639798B2 - How to build a culvert - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a method for constructing a culvert embedded in an embankment.

[Prior Art] A conventional culvert construction method is a method in which a culvert is manufactured before embankment and then the culvert is buried and embanked.

If you build a culvert this way,
The amount of sediment on the top plate and the applied load due to the strain difference of the embankment act as a vertical load. For this reason, the culvert must increase its rigidity in proportion to the soil cover D.

[Problems to be Solved by the Invention] According to the conventional method, a culvert having a large overburden D requires a thick member and a large number of reinforcing bars to be arranged, resulting in high construction cost and poor workability.

The problem to be solved by the present invention lies mainly in what kind of method should be taken to reduce the construction cost and simplify the construction, in contrast with the culvert having a large overburden D.

[Means for Solving the Problems] In order to solve the above problems, the following method was invented.

That is, at the same time when the embankment 5 of the general part is constructed, the inner space 1 of the culvert, the peripheral wall 2 of the culvert, and the roadbed 4 are embanked by the following method, and then only 1 is excavated to construct the culvert.

Make the shape of 2 an arch.

To fill 2 in an arched shape, mark the line of intersection between the boundary surface of 1, 2, 2 and 3 and the embankment surface (M shown in FIG. 2) on the embankment surface and distinguish the embankment materials accordingly. The degree of compaction should be changed.

Further, in order to make the wall surface of the culvert smooth, a form K is provided at the boundary between 1 and 2, and a sheet S is stretched to embed 1 (3rd
(Fig.), K is removed to embed 2 (Fig. 4), except that from the side wall portion F to the invert portion E, 2 is placed before 1 is embeded.

For the embankment of 2, a material reinforced with cement-based solidifying material, lime or the like is used.

For the first embankment, use a material that is easy to excavate. In the past, in order to cross existing roads and new planned roads and waterways, there is an example of excavating a tunnel in an existing embankment and then winding up with concrete etc. to construct a culvert, but like this invention, There is no example of constructing a culvert by a method of embankment while reinforcing the peripheral wall 2 of the culvert together with the whole embankment and then excavating the inner space 1 of the culvert.

[Operation] If 1 is hollowed by excavating the embankment constructed by the method above,
In 2, a main stress almost parallel to the wall surface flows in an arch shape.

At this time, the degree of distortion greatly decreases near the wall surface and goes deeper. Since the physical properties of the embankment material are non-linear, the stress level does not become so high near the wall surface, and a gentle peak value appears at a point deeper than the wall surface.

In the case of an elastic material, the peak value of the stress appears on the wall surface, but in the case of a non-linear material, this is not the case,
The stress concentration is relaxed.

Therefore, the wall surface is stable even when 2 is a material having a relatively low strength.

In addition, if there are sharp irregularities on the wall after excavation,
The stress may be concentrated in the recesses and the wall surface may be missing,
If large irregularities are created, it is possible to prevent them from falling off by blasting them with sprayed concrete immediately after excavation.

Therefore, if the road surface is paved or a waterway is installed after excavating 1, it can be used as it is as a culvert, and it is not necessary to provide a rigid reinforced concrete wall unlike the conventional culvert.

Example An example is shown in FIG.

[Advantages of the Invention] When a culvert is constructed using the method of the present invention, it is not necessary to provide a concrete wall for supporting earth pressure unlike the conventional culvert, and therefore the construction cost is significantly reduced as compared with the conventional method.

Comparing a road culvert with an inner space width of 10 m and a height of 24 m from the road surface to the embankment Tenba, the construction cost of the culvert constructed by the method of the invention is about 56% of the conventional method, and the extension of 1 m is about 100 You can save 10,000 yen.

Further, when using the method of the present invention, when using the conventional method, must be constructed before embankment start,
The work process for supporting culverts (installation of support work → formwork / rebar assembly → concrete placement → training → removal of formwork / support work) is shortened.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an example (road culvert),
2, 3 and 4 are cross-sectional views for explaining the embankment construction method, 1 is the inner space of the culvert, 2 is the peripheral wall, 3 is the road surface of the road passing through the culvert, 4 is the same roadbed, and 5 is general. Embankment, 6 is the embankment top, D is the overburden, C is the crown, E is the invert, F is the side wall, M is the boundary between the embankment and 1 or 2, or 2 and 5 With the boundary surface, K is the form, S is the insulating sheet, and ΔE is the embankment height for each time.

Claims (1)

[Claims] Claims: 1. The inner space (1) of the culvert, the peripheral wall (2) of the culvert, the roadbed (4), and the general portion (5) are simultaneously embanked. At this time, in (2), a cement-based solidifying material, a material reinforced with lime or the like is used, and the shape of (2) is arched. After that, the method of excavating the sediment of (1) by the method of excavating the tunnel, and the method of constructing the culvert with the peripheral wall of (2).