JPS59122620A - Ground improvement work by stabilizing material - Google Patents

Abstract

PURPOSE:To perform the improvement of the ground with good efficiency by a method in which the condition of the ground is detected during the period when a rotary shaft is penetrated to a given depth, the supply amounts of a stabilizing agent for every depth corresponding to the condition of the ground are memorized, and during the pulling up the rotary shaft, the stabilizing agent is injected correspondingly to the memorized amount. CONSTITUTION:In the course of the penetration of a rotary shaft 2 to a given depth into the ground while turning, the condition of the ground is surveyed for every depth. The condition (or behavior) of the ground is detected by a detector attached to the rotary shaft 2, the data are put in an arithmetical unit, and the supply amounts of the stabilizing agent, corresponding to the condition of the ground previously memorized, are calculated and set up for every depth and stored in a memory. After the rotary shaft is penetrated to a given depth, the stabilizing agent is injected through a supply tube 4 while pulling up the shaft 2 while turning. The supply amounts of the stabilizing agent in this case are based on the supply amounts of the stabilizing agent memorized.

Description

[Detailed Description of the Invention] The present invention relates to a method of improving the ground by stirring and mixing stabilizing materials (cement, lime, etc.) into soft ground. It has been proposed to control the amount of stabilizer input according to the properties of the original ground, but this is still at the conceptual stage and nothing concrete and practical has yet been developed.

By the way, there is a known construction method in which a rotating shaft equipped with stirring blades at the lower end penetrates soft ground to a predetermined depth, and then, while pulling up the rotating shaft, a stabilizing material is introduced and mixed. The rotating shaft reciprocates along the same path.

The present invention utilizes this point to rationally perform a series of operations to control the amount of stabilizing material added according to the properties of the ground. be.

During the process of penetrating soft ground at a predetermined depth with a rotating shaft equipped with stirring blades at the lower end, the properties of the original ground that affect the hardening strength of the stabilizer are investigated at each depth, and the results of this investigation are converted into a computer. By inputting the information, the amount of stabilizing material required to achieve the specified hardening strength based on the design is calculated and set for each depth, and this is stored in the storage device to stabilize it while raising the rotating shaft. A ground improvement method using a stabilizer, characterized in that in the process of adding the material and stirring and mixing, the amount of the stabilizer added is controlled based on the storage device ρ memory signal and the depth signal.

The present invention will be explained in detail below.

Figure 1 shows an example of a mixing treatment machine used in carrying out the present invention, in which 1 is a main body on the ground G, 2 is a rotating shaft suspended from the main body 1 so as to be able to move up and down, and 3 is a rotating shaft. 2 is a stirring blade protruding from the lower end; 4 is a stabilizer supply pipe that passes through the rotating shaft 2 and has its tip opened into the stirring blade 3; 5 is a stabilizer supply hose connected to the stabilizer supply pipe 4; In the construction method of the present invention, first, the properties of the ground are investigated at each depth while the rotary shaft 2 is being rotated and the ground G is purchased to a predetermined depth.

The hardening strength of the ground made by stirring and mixing a fixed amount of stabilizer varies depending on the water content ratio, sand content, etc. of the ground soil.For example, as shown in Figure 2, the strength decreases as the water content ratio increases. . Therefore, one or more of the ground properties that affect the hardening strength of the stabilizer can be determined by using the penetration method and penetration speed of the construction machine, or by using a detector attached to the rotating shaft 2. #) Conduct the survey, simultaneously measure the depth using the depth meter (position of the stirring blade 3), and input these data into the calculator.

For example, as shown in Fig. 5, the relationship between the ground properties (moisture content ratio in this case), the stable phase input amount, and the predetermined hardening strength q is preset and stored in the computing unit, and the ground properties are adjusted based on this. Correspondingly, the stabilizer input amount Q required to obtain q! is calculated and set for each depth.

If multiple ground properties are investigated, calculate the amount of stabilizer input required to obtain q for each property, and use the maximum value as the set value. Set the composite relationship between each property (water content ratio and sand content in the case of the figure) and the stabilizer input amount so that the hardening strength is q in the calculator, and input the measured values into this. Required amount of stabilizer input Q! Play and set.

The required stabilizing material input amount for each depth set as described above is stored in the storage device.

After the rotating shaft 2 has penetrated to a predetermined depth, the rotating shaft 2 is rotated and the stabilizing material is introduced while being pulled up, and stirring and mixing is performed. Control.

While measuring the depth again and sending the signal to the control panel,
A memory signal from the storage device is input to the control panel, and either or both of the stabilizing material supply mechanism and rotating shaft lifting mechanism are controlled for each depth using both signals, and the amount of stabilizing material input at each depth is controlled. Set it to the setting value at the time of penetration.

In this way, in the construction method of the present invention, the ground properties are investigated at each penetration depth at 9' when the rotating shaft enters, without affecting the hardening strength due to the stabilizer, and the required hardening strength is obtained based on the results of this investigation. The amount of stabilizing material required for each depth is calculated and set for each depth, and this is stored in a memory device. When stirring and mixing the stabilizing material while pulling up the rotating shaft along the same path, this memory is used. Since the amount of stabilizer added is controlled based on the memory signal and depth signal of the device, the stabilizer can be added efficiently and accurately in response to changes in ground properties.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of a mixing treatment machine for implementing the present invention, Fig. 2 is an explanatory diagram showing the relationship between soil properties and hardening strength, and Figs. 3 and 4 are explanatory diagrams regarding setting of required stabilizer input amount. . DESCRIPTION OF SYMBOLS 1... Mixing processing machine main body, 2... Rotating shaft, 3... Stirring blade, 4... Stabilizer supply pipe, 5... Stabilizer supply hose, q... Predetermined hardening strength. Patent Applicant Fudo Construction Co., Ltd. Representative Patent Attorney Hiroshi Sometani Figure 1 Ki Figure 3 Yasu Figure 4 Mourning\Mizhan.

Claims (1)

[Claims] In the process of penetrating soft ground to a predetermined depth with a rotating shaft equipped with stirring blades at the lower end, the properties of the original ground that affect the hardening strength of the stabilizer are investigated at each depth1, and the results of this investigation are converted into a computer. Based on the input and design, the input amount of stabilizer required to obtain a predetermined hardening strength is calculated and set for each depth, and this first value is stored in the storage device,
In the process of stirring and mixing by introducing stabilizer while pulling up the rotating shaft, the amount of stabilizer introduced is controlled based on the memory signal of the storage device and the depth signal. Improved construction method.