JPH10121557A - Method for reducing vertical earth pressure on culvert - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce construction costs by providing an elastic cushion material between a base concrete in the earth and a culvert and embedding the culvert. SOLUTION: An elastic cushion material 3 made of elastic material such as polystyrene or polyurethane is placed on a base concrete 2 in the earth. And a box culvert 1 is embedded on the material 3. Since the height of an embankment on the culvert is low, the magnitude of the settlement of the culvert 1 can be relatively reduced. Since the cushion material 3 contracts, the difference in the magnitude of settlement due to the difference between the height of the embankment on the culvert and that of the embankment where there is no culvert can be absorbed by the cushion material. Thus no excessive vertical earth pressure is applied onto the culvert 1, and hence economical design can be provided without increasing the thickness of the culvert 1 and construction costs can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION Culverts buried in the soil differ in the amount of settlement due to differences in the height of the embankment in the upper part of the culvert and the other parts, that is, the earth pressure. Therefore, extra earth pressure is applied to the culvert. The present invention relates to a method for reducing the vertical earth pressure of a culvert by making the settlement amount of the upper part of the culvert equal to that of the other parts.

[0002]

2. Description of the Related Art Generally, for a culvert buried in the ground, unless the culvert and the soil around the culvert are deformed, the vertical earth pressure acting on the culvert is equal to the weight of the embankment directly above the culvert itself. It is. However, in reality, the size of the settlement differs between the embankment directly above the culvert and the surrounding embankment. This causes the vertical earth pressure to be larger or smaller than the weight of the soil directly above the culvert. In the conventional method, when the culvert is buried in the soil, the height of the embankment to be settled differs between the upper part of the culvert and the other part, so the amount of settlement is naturally different and the amount of settlement of the culvert is relatively small Try to be.

FIG. 3 is a diagram showing a difference in height of an embankment to be subsided from a culvert buried underground.

Therefore, conventionally, not only the earth pressure of the embankment immediately above the culvert but also a wider range of earth pressure is applied to the culvert in cross section.

FIG. 4 is a cross-sectional view showing the state of earth pressure applied to a conventional buried culvert.
Should be applied only in the range of ???, but actually, the difference in the amount of settlement between the culvert and the part other than the culvert caused the earth pressure in the range of ABC'D '. Therefore, the culvert itself requires strength to withstand the earth pressure, and the thickness of the members constituting the culvert is increased, the weight is increased, the construction cost is increased, and it is uneconomical. The present invention has been made to solve such a problem.

[0006]

The present invention relates to a method for reducing vertical earth pressure of a culvert, in which an elastic cushioning material is laid between a base concrete and the culvert in the soil, and the culvert is buried on the cushion. The main purpose of this method is to reduce the vertical earth pressure of the culvert by absorbing the difference in the amount of settlement between the culvert part and the other part by shrinking the elastic cushioning material to reduce the vertical earth pressure of the culvert. And

Due to the low height of the embankment in the culvert portion, the amount of settlement of the culvert is relatively reduced. Here, when the elastic cushioning material arranged on the base concrete shrinks, the difference in the amount of settlement caused by the difference from the height of the embankment other than the culvert is absorbed. Therefore, it is possible to design an economical culvert without adding extra vertical earth pressure to the culvert and without increasing the thickness of the culvert.
The construction cost can be reduced by reducing the weight.

[0008]

FIG. 1 is a cross-sectional view in which an elastic cushioning material 3 is laid on a base concrete 2 and a box culvert 1 is buried thereon.

FIG. 2 shows an example in which an elastic cushion material 3 is laid on a base concrete 2 and an arch culvert 1 ′ is placed thereon.
FIG.

The material of the elastic cushion material may be any elastic material such as styrene or urethane, but the material and thickness of the cushion material are changed depending on the height and soil properties of the embankment.

[0011]

The present invention has the above configuration.

Due to the low height of the embankment at the culvert portion, the amount of settlement of the culvert is relatively reduced. Here, when the elastic cushioning material arranged on the base concrete shrinks, the difference in the amount of settlement caused by the difference from the height of the embankment other than the culvert is absorbed. Therefore, it is possible to design an economical culvert without adding extra vertical earth pressure to the culvert and without increasing the thickness of the culvert.
The construction cost can be reduced by reducing the weight.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view in which an elastic cushion material 3 is laid on a base concrete 2 and a box culvert 1 is buried thereon.

FIG. 2 is a cross-sectional view in which an elastic cushion material 3 is laid on a base concrete 2 and an arch culvert 1 ′ is buried thereon.

FIG. 3 is a view showing a difference in height of an embankment to be subsided by a culvert buried underground.

FIG. 4 is a cross-sectional view showing a state of earth pressure applied to a conventional buried culvert.

[Explanation of symbols]

 1 ... box culvert 1 '... arch culvert 2 ... base concrete 3 ... elastic cushioning material

Claims (1)

[Claims] 1. A method for reducing vertical earth pressure of a culvert,
An elastic cushioning material is laid between the base concrete and the culvert in the soil, and the culvert is buried thereon, and the elastic cushioning material shrinks due to earth pressure, so that the settlement amount in the culvert portion and other portions is reduced. A method for reducing the vertical earth pressure of a culvert, which absorbs the difference between the culverts and reduces the vertical earth pressure of the culvert.