JPH0530924B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a lightweight reinforced soil block for use in various locations such as the foundations of embankments and slopes by hardening earth and sand. (Prior art) Conventionally, when constructing roads, railways, etc. on soft ground, water in the soft soil has been used as a method to support the load of the embankment itself and the loads of vehicles and buildings on it. There are two methods: one method is to discharge and consolidate the soil using a drain material, and the other 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 from the upper part causes subsidence, 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 1.
It is about 3Kg/cm ² , and there are limits to its application. Furthermore, since the local earth and sand cannot be used for embankment, there were still problems such as a large amount of earth and sand for embankment had to be brought in from other places to be used for the embankment attachment parts and slopes. In view of such conventional problems, the present invention is suitable for constructing lightweight embankments on soft ground,
The purpose is to provide a lightweight reinforced soil block that is lightweight and has high strength, which can use local soft soil. (Means for Solving the Problems) In order to solve these conventional problems and achieve the intended purpose, the lightweight reinforced soil block of the present invention is designed to solve the problems of the conventional art and to achieve the intended purpose. Alternatively, it is characterized in that a synthetic resin reinforcing net is provided inside the hardened soil block body, which is made by hardening mixed soil mixed with a pore-forming agent such as a foaming agent, using cement. (Function) This lightweight reinforced soil block has a large amount of deformation because it is hardened by mixing a void forming agent and a cement-mixing polymer into the earth and sand. The tensile stress is borne by the synthetic resin reinforcing net disposed inside. (Example) Next, an example of implementation of the present invention will be described with reference to the drawings. FIG. 1 shows a cross section of a lightweight reinforced earth block according to the present invention, and numeral 1 in the figure is the main body of the hardened block. This hardened block body 1 is obtained by mixing a cement-mixing polymer and a foaming agent or a pore-forming agent such as a foaming agent into soft earth and sand at a construction site, and at the same time, mixing cement and hardening the mixture. Polymer for cement admixture is 5% for cement.
Use ~30% amount. The blowing agent is also called a gas generating agent, and powders of aluminum, magnesium, zinc, etc. can be used. Foaming agents are admixtures that are normally used to generate a large amount of foam in concrete. Proteins, saponins, resin-based surfactants, etc. can be used, and the foaming agent is created by adding raw materials into a mixer. Alternatively, pre-foamed beads may be used. Also, when mixing cement and other admixtures,
Water is added to the mixed earth and sand so that the water content exceeds the liquid limit to form a slurry, which is then poured into a mold and formed into a predetermined shape. During this molding, a reinforcing net made of synthetic resin is previously housed in the mold and buried within the hardened soil block. As the synthetic resin reinforcing net, a polymer grid 2 is installed horizontally at the bottom of the hardened earth block body 1, and a plastic net 3 is placed above the polymer grid 2 in a trapezoidal configuration. Further, a hanging ring 4 is connected to the polymer grid 2 at its lower end and protrudes from the upper surface of the hardened block body 1. The polymer grid 2 is a lattice-like net made by punching holes in a thick sheet made of polypropylene or high-density polyethylene and stretching it in one or two axes while heating to orient the molecules of the sheet. A material with a ratio ε of about 7 to 10% is used. When using the lightweight reinforced soil blocks A formed in this way, for example, when forming an embankment 6 on soft ground 5 as shown in FIG. Although it is not shown in the diagram, it can be laid at the bottom of the embankment as a foundation. Next, Table 1 shows the formulation and test data of the lightweight reinforcing block according to the present invention. Note that Case 1 in the table shows a target example, and Cases 2 and 3 show examples of the present invention.

[Table] Fig. 3 is a graph showing the relationship between strain and compressive strength of the target examples and examples in Table 1. According to this, the examples of the present invention are compared to the target examples. It can be seen that the compressive strength is small, but the strain is extremely large. Figure 4 shows the combination of case 3 in Table 1.
It shows the relationship between the load and the amount of deformation when using a synthetic resin reinforcing net. In the figure, A is when the synthetic resin reinforcing net is not used, and B is when the polymer grid 2
C shows the case where only the polymer grid 2 and the plastic net 3 are used, respectively. According to this, it can be seen that when a synthetic resin reinforcing net is used, both the deflection and the load capacity are significantly different. In addition, in the above-mentioned embodiment, an example is shown in which both the polymer grid 2 and the ordinary plastic net 3 are used as the synthetic resin reinforcing net.
In the present invention, it is sufficient that at least the polymer grid 2 is used. (Effects of the Invention) The lightweight reinforced soil block of the present invention is constructed as described above, and since the hardened soil block body is hardened by blending a cement-mixing polymer and a pore-forming agent, it is lightweight and has flexibility itself. It has a high tensile stress and has a high overall strength because it is combined with a synthetic resin reinforcing net, making it suitable as a foundation for lightweight embankments and as a slope material. Since it can be used, the material cost and the cost required for transporting the material are low, and it has the effect of being economical.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing an example of the implementation of the lightweight reinforced earth block of the present invention, Fig. 2 is a cross-sectional view showing an example of the use of the same lightweight reinforced earth block, and Fig. 3 is a cross-sectional view showing an example of the use of the lightweight reinforced earth block. FIG. 4 is a graph showing the relationship between compressive strength and strain, and FIG. 4 is a graph showing the relationship between load and deformation of the embodiment and target example of the present invention. 1...hardened soil block, 2...polymer grid, 3...plastic net.

Claims (1)

[Claims] 1 A synthetic resin reinforcing net is placed inside the hardened soil block body, which is made by mixing earth and sand with a cement-mixing polymer and a foaming agent or a pore-forming agent such as a foaming agent. A lightweight reinforced soil block.