JPS6119769B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a method for injecting a ground hardening agent, which involves injecting a ground hardening liquid such as cement milk or water glass chemical into the soil in order to prevent soil collapse and stabilize the ground during foundation work construction. Regarding the method.

Injecting a soil hardening agent is conventionally done by inserting an injection pipe into a bored injection hole, injecting the hardening agent into the soil from an injection nozzle drilled at the tip of the injection pipe, and pulling it out while rotating the injection pipe to clean the surrounding ground. A hardened layer is created by crushing the particles and solidifying the ground. However, this hardening layer is formed by spraying from a nozzle composed of pores, that is, by a jet with a trajectory of dots. The distribution was not average but heterogeneous.

In view of the above, the present invention deals with this problem.The purpose of the present invention is to insert an injection pipe into a bored injection hole, and to spray a film of hardening agent from the periphery of the injection pipe on the distal end side. To provide an injection method capable of easily forming a homogeneous and stable hardened layer by raising an injection pipe and injecting the liquid. Embodiments of the present invention will be described below based on the accompanying drawings.

Reference numeral 1 denotes an injection tube, and a crown 2 is screwed onto the tip of the injection tube 1, and is moved up and down by the operation of a drive section 3. A swivel 4 introduces the curing agent in the tank 5 into the injection pipe 1.

The crown 2 has a conical recess 6 at its tip, and a cone 8 fitted into the recess with jet passages 7 at small intervals around the circumference.The cone 8 has a plurality of cutting blades 9 on its lower surface. A mounting screw shaft 10 is provided on the top of the crown 2 and is screwed onto a ring body 13 having a female hole 12 supported by a plurality of support pieces 11 at the top of the crown 2. Note that by providing a flow path 15 equipped with a differential pressure valve 14 in the conical body 8, downward injection can also be performed by adjusting the liquid feeding pressure. By doing so, the curing agent sent into the injection pipe 1 is extended into the jet flow path 7 formed by the outer periphery of the conical body 8 provided on the crown 2 and the conical gap on the inner periphery of the crown 2, and is spread to the lower end. The curing agent enters the target soil as a film jet while collapsing and agitating it through the annular spout 7'. In addition, if point-like protrusions 16 protruded in a dotted manner are appropriately arranged on the outer circumferential surface of the cone 8, the tips of the protrusions 16 will come into contact with the inner circumferential surface of the crown 2, supporting the gap in the jet channel 7, and the cone will In addition to increasing the strength of 8, when a two-component chemical solution is used, a stirring effect can be achieved when the chemical solution hits the dotted protrusions 16 that support the voids.

Since the present invention has the above-mentioned configuration, the injection pipe 1 is rotated and lowered to excavate, and when a specified depth is reached, the curing agent in the tank 5 is introduced into the injection pipe 1 via the swivel 4 and hardened. Once the agent is introduced,
The curing agent flows through a diagonal jet flow path 7 provided in the crown 2.
The injection tube 1 is raised as it is or while being rotated while jetting in a homogeneous film form around the injection hole from the annular injection port 7' passing through the injection hole. At this time, the hardening agent is injected into the surrounding soil as a two-dimensional jet, but if the injection tube is rotated while rising, the hardening agent breaks up the soil and mixes in the hardening agent. be. Therefore, unlike the conventional point injection which is ejected obliquely from a small-hole nozzle, the jet is jetted from the circumferential annular jet opening 7' in a film form over the entire circumference of the injection hole, so high pressure, medium pressure, and low pressure can be generated. It has the characteristic that it can create a homogeneous and stable hardened layer because it injects a jet evenly toward the soil regardless of the soil.

[Brief explanation of the drawing]

The drawings show an embodiment of an apparatus using the soil hardening agent injection method according to the present invention, and FIG. 1 is a front view;
Figure 2 is a partially enlarged cross-sectional view of the injection pipe, and Figure 3 is a partially enlarged sectional view of the injection tube.
FIG. 4 is an exploded perspective view of the tip of the injection tube. DESCRIPTION OF SYMBOLS 1... Injection pipe, 2... Crown, 3... Drive part, 4... Swivel, 5... Tank, 6... Conical recess, 7... Jet flow path, 7'... Spout nozzle, 8... Cone Body, 9...Drilling blade, 10...Spiral shaft, 11...branch, 12...female hole, 13...ring body, 14...differential pressure valve, 15...channel, 16...point projection .

Claims (1)

[Claims] 1. Insert the injection pipe into the ground, which has a swivel on the upper end, a conical recess and a conical body fitted on the tip, and a crown with an annular spout using the gap as a flow path, into the ground. A soil hardening agent injection method in which the hardening agent is introduced into the injection pipe through the injection pipe, and the injection pipe is raised while being jetted out in a film form from the annular spout at the tip to create a soil hardening layer.