JPH03151411A - Method for placing plastic board drain - Google Patents

Abstract

PURPOSE:To prevent soil grain from entering a mandrel by providing a cardboard body formed by sealing the outside of a plastic core material with a nonwoven fabric as a filter in a mandrel, feeding compressed air thereto and pressurizing the same. CONSTITUTION:An apparatus for a plastic bond drain method comprises a mandrel 1, a cardboard 2, an exhaust pipe 5, an exhaust valve 6 and a pressure hose 7 and a winch 8. The cardboard 2 is formed on the outside of a core 4 in such a manner as to be sealed with a filter 3. An exhaust valve 6 is fitted to the upper portion of the mandrel 1 through a pressure hose 7 and an exhaust pipe 5, thereby preventing compressed air from diffusing from the upper end of the mandrel 1 into the air. Subsequently, the air pressure is put in a pressurized state by feeding the compressed air about 5-7kg/cm<2> into the mandrel 1. Thus, soil grain can be prevented from entering through an opening of the mandrel 1.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a construction method for improving soft ground for the purpose of promoting dewatering of cohesive soil, and particularly relates to a construction method for improving soft ground in the plastic board drain construction method. Regarding the installation method, it involves a method of installing a plastic core material in soft ground and a cardboard body having a shape that is sealed with a nonwoven fabric as a filter on the outside of the core material.

<Conventional technology and its problems> In the conventional plastic board drain construction method, after attaching an anchor plate to the tip of the cardboard, the mandrel 1 is pushed into the ground, and after driving to a predetermined depth, the Construction has been carried out by pulling out the mandrel l, and then cutting the cardboard at the appropriate position using a cutter when the pulling operation is completed. In such cases, a phenomenon was observed in which water or soil particles entered the mandrel through the opening at the tip of the mandrel 1 during the process of pushing or pulling the mandrel into the soil. In particular, if soil particles infiltrate during extraction, the filter of the cardboard body may be damaged, and in more serious cases, the entire filter located above the damaged part may become clogged in the opening at the tip of the mandrel 1. even occurs. As a result, the phenomenon in which the filter becomes clogged in the opening not only impairs the performance of the plastic drain construction method, but can even completely eliminate it, and this occurrence is extremely problematic. In particular, the above-mentioned phenomenon is likely to occur in the ground, which has alternating layers with sand layers, which is extremely worrying.

<Means for Solving the Problems> In order to achieve the above object, in the present invention, the inside of the mandrel 1 is filled with pressurized air or the inside of the mandrel 1 is filled with pressurized air, or water is poured into the inside of the mandrel 1. Fill the mandrel with water to a certain level to prevent surrounding soil particles from entering the mandrel through the opening.Especially when compressed air is used, a pressure regulator or flow regulator is required. By using an attached compressor, it is possible to appropriately control the desired pressure and flow rate.

<Example> Using a compressor, a discharge port of the compressor and a pressure hose are connected, and the pressure hose is connected to the upper end of the mandrel 1. By attaching a suitable exhaust valve to the uppermost end of the mandrel 1, the air compressed from the uppermost end of the mandrel 1 is prevented from dissipating into the atmosphere below a predetermined pressure.

Air pressure (air pressure should be approximately 5 to 7 kg/cm").

<Effects of the Invention> Since the present invention is configured as described above, the following effects can be achieved.

Since soil particles are less likely to enter through the opening at the tip of the mandrel, the filter material is less likely to be damaged by soil particles. Therefore, it becomes possible to drive the cardboard body into the ground in a predetermined condition, and a drain effect can also be expected.

[Brief explanation of the drawing]

Fig. 1 is a conceptual diagram showing all the equipment related to the plastic board drain construction method according to the present invention, Fig. 2 is a partially enlarged view of the tip of the mandrel shown in Fig. 1, and Fig. 2 is a perspective view of the cardboard body shown in FIG. 1. FIG. Mandrel Card Board Body Filter Core Exhaust Pipe Exhaust Valve Pressure Hose Winch

Claims (1)

[Claims] 1. A plastic board drain construction method characterized by applying fluid pressure inside the mandrel 1 to create a pressurized state to prevent external soil particles from penetrating into the mandrel. Board drain installation method 2 By filling the inside of the mandrel 1 with pressurized air or filling the mandrel 1 with liquid such as water to a certain height, soil particles are poured into the inside of the mandrel 1 from the tip of the mandrel 1. Claim 1: Preventing infiltration
How to install a plastic board drain in the described plastic board drain construction method