JPH01137012A - Light-weight banking work - Google Patents

Abstract

PURPOSE:To economically form a banking on soft ground by a method in which excavated soil of soft ground is mixed with water with stirring to slurry, and the slurry is mixed with a blowing agent and a cement-based solidifying material and piled up on the ground. CONSTITUTION:In forming banking for road, levee, etc., on soft ground, the ground is excavated and crushed, impurities are removed, and the soil is mixed with water with stirring to form slurried soil. The slurried soil is mixed with a bubbled cement paste composed of a cement-based solidifying material slurry and a blowing agent as void former and sent back and piled up on the field ground excavated to form a banking 1 using a formwork. The banking can thus be economically formed and the specific gravity and strength of the banking can also be regulated by adjusting the amounts of the blowing agent and the cement-based solidifying material.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a lightweight embankment construction method particularly suitable for creating an embankment on soft ground.

(Prior art) Conventionally, when constructing embankments for roads, embankments, etc. on soft ground, methods for supporting the embankment itself and the load of vehicles, buildings, etc. on it have been used. There are two methods: one method is to drain the water using a drain material, etc., and the other method is to inject and mix a cement-based hardening agent into the soft soil and harden it. There is a construction method that attempts to prevent subsidence by reducing weight.

(Problem to be solved by the invention) However, with methods of improving soft soil by compacting it or using cement-based hardeners, if the soft ground is deep, it is necessary to improve the ground to the depths. As the load on the upper part causes the building to sink, there are problems in that the construction work will be extensive, the construction period will be long, and the construction cost will be enormous.

On the other hand, the method of using styrofoam plates is advantageous compared to the above-mentioned ground improvement method when forming an embankment on soft ground that has a certain degree of bearing capacity because the entire structure is lightweight.

However, in this method, the styrofoam plate used needs to be manufactured at a factory, which is expensive.

Moreover, since it is lightweight and bulky, it costs a lot of money to transport, and the strength of styrofoam is 1 to 3 kg/aJ.
There are limits to its application. Furthermore, because the local soil cannot be used for embankment, there is still a problem that a large amount of embankment soil for use in the embankment attachment part and slope has to be brought in from other places.

In view of these conventional problems, the present invention is suitable for constructing a lightweight embankment on soft ground, and allows the use of local soft soil to create a lightweight embankment that is lightweight and has high strength. The purpose is to provide an embankment construction method.

(Means for Solving the Problems) The lightweight embankment construction method of the present invention, which solves these conventional problems and achieves the intended purpose, excavates the earth and sand at the construction site and uses the excavated earth and sand. Add water to make the water content ratio above the liquid limit, stir this to form a slurry, add a pore-forming agent such as a foaming agent or a foaming agent, and a cement-based solidifying agent, mix and stir, and stir this. It is characterized by mounding it up on the ground at the site and solidifying it to form an embankment.

(Function) This lightweight embankment construction method mixes a pore-forming agent and a cement-based solidifying agent to the soil at the site, hardens it, and uses this as embankment material. Moreover, the specific gravity of the embankment is significantly lower than that of an embankment made entirely of ordinary earth and sand, making it possible to create an embankment that is resistant to subsidence even when constructed on soft ground with low bearing capacity.

(Example) Next, embodiments of the present invention will be described with reference to the drawings.

In general, soft ground with low ground strength consists of fine-grained soil with high moisture content, such as silt, clay, and organic matter.

Such on-site earth and sand is excavated, pulverized and impurities are removed, water is added to it so that the water content ratio is higher than the liquid limit, and the mixture is mixed and stirred to form a slurry.

Separately, prepare a slurry of a cement-based solidifying agent (water-cement ratio W/C = 0.6 to 0.7) that has fluidity and maintains strength by reducing water content, and A foaming agent as a forming agent is added and left to foam for 30 to 60 minutes to create a cellular cement paste.

This aerated cement paste and the above-mentioned slurry are mixed and stirred to make embankment material, and this embankment material is backfilled into the excavated site ground as shown in Fig. 1 using appropriate formwork, and further on top of it. Stack and solidify to create embankment 1. - Note that instead of using a foaming agent, bubbles formed by mixing water and a foaming agent in advance or expanded styrene beads can be used as the void forming agent.

In addition to the above-mentioned pore forming agent and cement solidifying agent, a thickening agent is added to the site soil as necessary.

Thickeners are used to prevent sand from settling and separating from the slurry when the on-site soil contains about 40% or more of sand. Use about 0.5 to 1.0% of the water content.

In addition, if the on-site soil to be used is acidic, add a P, H regulator to adjust the pH, or use a solidifying agent for acidic soil.

The blowing agent is also called a gas generating agent, and powders of aluminum, magnesium, zinc, etc. can be used.

Further, the foaming agent is an admixture that is normally used to generate a large amount of foam in concrete, and proteins, saponins, resin-based surfactants, etc. can be used.

Next, Tables 1 and 2 show examples of formulations and test data for lightweight embankment materials according to the present invention.

Table 2 (Effects of the Invention) The lightweight embankment method of the present invention is constructed as described above, and the embankment material is prepared by mixing a gap-forming agent and a cement-based solidifying agent with earth and sand. However, since the earth and sand from the construction site can be used, there is no need to bring in large amounts of earth for embankment from elsewhere, and the amount of earth and sand brought in is significantly smaller than with conventional construction methods that use Styrofoam. There is no need to produce large structural materials in factories,
The work involved in transporting materials is extremely reduced, making construction more economical.Also, the embankment has a slurry-like embankment material that is solidified as a whole with a cement-based solidifying agent, which reduces the load-bearing capacity of the embankment. A large embankment will be created, and since the embankment is lightened by the use of a pore-forming agent, it can be carried out even on very soft and low-strength ground, and the strength and other properties of the soft ground can be improved. The amount of pore-forming agent and cement solidifying agent added can be adjusted according to the conditions, so the specific gravity and strength of the embankment can be adjusted to suit the soft ground at the construction site, allowing construction to be carried out over a wide range of areas. This made it possible to implement the project economically.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an example of a lightweight embankment according to the present invention. 1...Lightweight embankment.

Claims (1)

[Claims] The earth and sand at the construction site are excavated, water is added to the excavated earth and sand to bring the water content above the liquid limit, this is stirred to form a slurry, and this is mixed with a pore-forming agent such as a foaming agent or foaming agent and cement. A lightweight embankment construction method that is characterized by adding a solidifying agent, mixing and agitating the mixture, piling it up on the ground at the site, and solidifying it to form an embankment.