JP2765324B2 - Embankment method on soft ground - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an embankment method for soft ground using a water-permeable and pressure-resistant drainage material instead of a sand mat.

[0002]

2. Description of the Related Art Generally, in the embankment method on soft ground, the ground consolidates and sinks due to the earth pressure of the embankment, and the soil water exudes to the ground surface. First, a sand mat having a predetermined thickness is laid on the surface of the soft ground, and an embankment is formed above the sand mat. Alternatively, prior to the embankment formation, the above-described formation may be performed in a state where a drain material is previously poured into soft ground and drainage of groundwater is promoted. According to these construction methods, the water that has oozed to the soft ground surface penetrates between the sand particles of the sand mat layer, and is drained to the bottom periphery of the embankment due to the permeation pressure caused by the consolidation of the ground.

[0003]

As a material for the sand mat, it is necessary to use high-quality sand having good drainage properties. However, in fact, high quality sand of this kind is hard to obtain at present, and the material cost is basically high,
Also, depending on the construction site, transportation costs are high, especially when the embankment area is large, a considerable amount of sand is required, so not only the construction cost rises drastically, but also the construction method can not be adopted. . As a countermeasure, for example, it is conceivable to use a water-permeable sheet such as a nonwoven fabric instead of a sand mat and drain the water by capillary action.However, since a large earth pressure is applied to the water-permeable sheet itself, when the embankment area is large, There is a high possibility that the drainage function will be insufficient only by the capillary phenomenon.

An object of the present invention is to solve the above-mentioned problem, and an object of the present invention is to provide an embankment method on soft ground which can provide a sufficient drainage function without using a sand mat.

[0005]

In order to achieve the above-mentioned object, the present invention provides a method for embankment in soft ground in which a drainage layer is provided on soft ground and embankment is formed on the drainage layer. Occupies a certain space against the earth pressure, and has a water permeable material having a through hole communicating with each other therein, and a water permeable sheet arranged to surround the water permeable material, and the water permeable material is Multiple bars to bear the earth pressure
Support members, and each support member at both ends of the support members.
It consists of a connecting member that connects the
It is characterized by exhibiting a shape of a metal .

[0006]

[0007]

According to the present invention having the above-described structure, the drainage layer occupies a certain space against the earth pressure, and has a through-hole communicating with each other inside the drainage layer. consists of a water-permeable sheet disposed so as to, in particular as a water-permeable material, from a support member of a plurality of rod-shaped to bear earth pressure, the connecting member in the both end portions connecting between each of the support members of the support members Therefore , the surface pressure due to the earth pressure of the embankment is applied to the connecting members disposed on the front and back surfaces of the supporting member, which has a hollow mattress shape. Retains a large hollow shape , thereby crushing to strong earth pressure
Secure large drainage space without waste
Becomes

[0008] The water-permeable sheet disposed so as to surround the water-permeable material prevents permeation of soil particles into the water-permeable material and allows seepage water to permeate into the water-permeable material. The water that has penetrated into the permeable material is drained from the end face opening of the permeable material. Such a drainage layer does not need to be spread all over the surface as compared with the sand mat, and can be arranged in an area and a pattern according to the drainage plan.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a drainage mat applied to the construction method according to the present invention. The drainage mat 1 is formed of a plastic molded body, and a space between a rectangular top plate 2 and a bottom plate 3 as connection members disposed on the front and back surfaces of the drainage mat 1 is supported by four support legs 4 as support members. It is formed integrally every other one so as to be located alternately on the front and back, is formed as a continuous three-dimensional checkerboard pattern as a whole, and holds a hollow shape with a thickness corresponding to the height of the support leg 4 .

The drainage mat 1 has pressure resistance in accordance with the pressure resistance of the support legs 4 and has sufficient flexibility in the bending direction corresponding to the flexibility of the support member.

[0011] The pattern shape of the drainage mat 1 as possible out to give a variety of shapes not limited to a checkered pattern illustrated in FIG.

Next, an embankment method using the drain mat 1 will be described with reference to FIGS. First, as shown in FIG. 2A, a nonwoven fabric 5 as a water-permeable sheet is laid at a planned embankment position on the soft ground E, and the drainage mat 1 is laid on the upper surface thereof. Next, the nonwoven fabric 5 is placed on the drainage mat 1.
And cover both sides in the width direction. By covering the upper and lower opening surfaces and both side surfaces formed between the top plates 2 and the bottom plates 3 with the nonwoven fabric 5, soil particles can be prevented from entering from the upper and lower surfaces and both side openings, and especially laid on the bottom side. The nonwoven fabric 5 assured has a water permeability to seepage water rising from the ground E. The drain mat 1 may be wrapped by covering the upper and lower surfaces and both side surfaces in the width direction with the nonwoven fabric 5 in advance.

The drainage mat 1 is not laid uniformly in accordance with the construction area, but as shown in a cross-sectional view in the width direction in FIG. Can be arranged. Also, various arrangement patterns can be given as well as a single horizontal line as shown in FIG.

It is to be noted that a drain material may be cast in the soft ground E before the above-mentioned laying work. In this case, if the drain mat 1 is arranged at the place where the drain material is placed, the drainage efficiency is extremely high. Becomes

Next, as shown in FIG. 2B, an embankment 6 is formed on the drainage mat 1. Surface pressure due to the earth pressure of the embankment 6 is applied to the drainage mat 1.
The thickness is kept constant in accordance with the pressure resistance of the substrate, and the hollow shape is maintained.

After the embankment 6 is completed, the soft ground E undergoes consolidation settlement as shown in FIG. 2C according to the earth pressure of the embankment 6 with time. Since the drainage mat 1 has flexibility in the bending direction, it can follow this ground deformation.
In addition, soil water that oozes to the ground surface due to the consolidation of the ground E oozes into the hollow inside of the drainage mat 1 through the nonwoven fabric 5, and goes out through both end surface openings 1 a of the drainage mat 1 that opens on both sides of the bottom of the embankment 6. It is drained.

[0017]

As described in detail in the above embodiments, in the embankment method for soft ground according to the present invention, the drainage layer occupies a certain space against the earth pressure and has a mutual inside. A water-permeable material having a communicating hole,
A water-permeable sheet is arranged to surround the water-permeable material. In particular, as the water-permeable material , a plurality of rod-shaped support members that bear earth pressure are connected to each other at both ends of the support members. to consists of a connecting member, so used that exhibit a hollow mattress shape, but the surface pressure due embankment soil pressure is applied to the connecting member disposed on the front and back surfaces, of the support member for connecting between the connecting members the size with sufficient pressure resistance
Holding such a hollow shape, thereby pushing the mighty earth pressure
Secure and large drainage space without crushing
As well as being possible, the water permeable sheet arranged to surround the water permeable material prevents the soil particles from entering the water permeable material and allows the seepage water to penetrate inside the water permeable material, so that it can penetrate inside the water permeable material. The drained water is drained from the end face opening of the drainage layer, and exhibits a sufficient drainage function.

Further, since the drainage layer can be arranged with an area and a pattern according to the drainage plan, material costs and transportation costs are particularly large when embankment having a large area is formed as compared with the case where the conventional sand mat is spread all over. However, there are various excellent effects such as low cost and simple construction work.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a drainage mat used in the present invention.

2 (a) to 2 (c) are cross-sectional views showing a construction procedure of embankment using the drainage mat.

FIG. 3 is a sectional view taken along line AA of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Drain mat 2 Top plate (as a connection member) 3 Bottom plate (as a connection member) 4 Support leg (as a support member) 5 Nonwoven fabric (a water-permeable sheet) 6 Embankment E Soft ground

──────────────────────────────────────────────────続 き Continuation of the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) E02D 3/00 102 E02D 17/18

Claims (1)

(57) [Claims] An embankment method in soft ground, wherein a drainage layer is provided on soft ground and an embankment is formed on the drainage layer.
The drainage layer occupies a certain space with respect to the earth pressure, and a water permeable material having through holes communicating with each other inside thereof,
Permeable sheet disposed so as to surround the translucent waterstops and Tona
And the water permeable material has a plurality of rod-shaped supports that bear the earth pressure.
Holding members and supporting members at both ends of these supporting members.
Hollow mattress type consisting of connecting members that connect between materials
Embankment method on soft ground characterized by exhibiting a shape .