JPS5942768B2 - Ground reinforcement method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a soil strengthening method, and particularly to a reinforcing agent injection means.

Recently, a ground strengthening method using chemical injection has begun to be adopted in which two liquids, such as a sodium silicate solution and cement milk or slaked lime, are mixed and simultaneously injected into the ground before excavating a road.

This is an improved version of the conventional method, which had the disadvantage that the cement content was washed out by spring water etc. before it hardened when only cement milk or mortar was injected.It is based on a sodium silicate solution and is selected according to the soil condition. This is a method of solidifying in a relatively short time by mixing other chemical solutions, and the gelation time is sometimes as fast as several seconds.

Therefore, when injecting, the two liquids drawn in by separate pumps must be mixed at the bottom of a double pipe inserted into the ground and simultaneously pressurized into the ground. In order to reliably strengthen the ground, it is subject to various constraints, such as the need to know the amount of injection per unit time at all times.

Conventionally, two piston pumps with the same performance were typically used, but piston pumps require check valves such as ball pulp in the suction and discharge pipe communication parts, and solid foreign matter in the chemical solution is required. If the foreign substance is mixed in with the valve, there will be a difference in the discharge amount due to the blockage of the valve part, and due to the difference in liquid type, for example, slaked lime, cement milk, etc. cause much more wear on the pump equipment than sodium silicate solution. (As a result, the discharge volume gradually decreases during use, making it impossible to maintain the equivalence of the two liquids, causing an error in the gelation time, and not only failing to achieve the purpose of instant setting, but also reducing the injection volume.) It turns out (Naru).

Therefore, after a certain period of use, one or both of the pumps must be replaced, or the piston and cylinder litchi must be replaced, making it necessary to have a spare pump or downtime for parts replacement. There were various inconveniences, and urgent measures were required.

In view of the above-mentioned current situation, the present invention provides two roller drive shafts with a common roller drive shaft.
Using parallel roller rotary tube squeezing pumps with the same performance, two AsB liquids that are instantaneously solidified by mixing are sucked from separate storage tanks, and the same pulsation is carried out in underground pipes such as double pipes inserted into the destination ground. The invention relates to a ground reinforcement method characterized by being able to simultaneously discharge a certain amount of the two fluids into the ground at the same time, and the pumping part being only a rubber tube. Because it does not require any check valves for suction and discharge, the discharge performance is not only constant and stable at all times, but also has easy resistance to acids and other chemicals.Furthermore, it is resistant to wear caused by long-term use. There are various improvements in conventional piston pumps, such as the ability to restore pump performance to its original state very simply by shifting the tube position relative to the pump casing of only the worn pump or both pumps at the same time. It is possible to eliminate all defects.

To explain in detail with reference to the drawings as an example, 1 and 2 are respectively Aj B liquid storage tanks, and 3 is a roller rotary tube squeezing double pump consisting of two units 3a and 3b.
B is a pump of the same size, that is, the same performance, and rubber tubes 5a, 5 are arranged in a horizontal U shape in a common pump casing 4.
b is inscribed in the pump casing, and two aperture rollers 8 are pivotally supported at the ends of two arm members 7 which are fixed to a drive shaft 6 which is connected to a motor and a drive device (not shown) as appropriate. 4, the suction pipes 10a, IQb, and the discharge pipes 11a, 1 are connected by connecting fittings 9 at appropriate places on the suction side and the discharge side, respectively.
1b and a rubber tube 5a.

The support fitting 12 of the fastener, which is composed of a support fitting 12 and a restraining fitting 13 provided on the connection side with 5b, is swingably connected by an inverted U-shaped lever 14, and the inverted U-shaped lever 14
There are two support plates 15 protruding from the pump casing 4.
16, and a pin 17 at the intermediate portion between the support fittings 12.
It is supported by

Further, the support plate 15 is provided with an arcuate groove 15a centered around the pin 17 portion, and the lock bundle 18 is inserted through the groove.
The lever 14 is fixed by screwing it into the inverted U-shaped lever 14.

The tips of the suction pipes 10a and 10b are respectively A,
It communicates with the B liquid storage tanks 1 and 2, and also has a discharge pipe 11a.

The tip of 11b is connected to the inner pipe 19a and outer pipe 19b of the underground insertion pipe 19, which consists of an inner and outer double pipe, and the liquid discharged from both pipes is mixed at the bottom, and a small hole 19c is bored in the outer wall of the bottom.
Every time I take a bath.

However, after a long period of operation, in this type of pump, wear begins to occur in the tube at the position where the squeezing roller 8 begins to separate from the rubber tubes 5a and 5b on the discharge side (upper limit in Figure 3), and the degree of wear varies depending on the type of liquid. .

That is, at the upper and lower limit points of the squeezing rollers 8.8, the pressure in the chamber confined between the two squeezing rollers 8.8 is almost atmospheric, whereas the pressure on the discharge side is high, so the roller When the tube 8 rotates in the direction of the Z arrow to open the inside of the tube, a slight backflow occurs due to the pressure difference between the two, and the backflow causes the inner surface of the tube to wear out for a while, reducing the discharge amount.

Therefore, when the flow rate decreases due to wear, which has been measured in advance, when the lock bundle 18 is loosened and the pump is operated, the two tubes 5a are squeezed by the squeezing roller 8.
, 5b both move in the roller rotation direction.

When the operation is stopped at an appropriate amount of movement position (from the position shown in Figure 2, the tube moves sequentially to ■ and ■), and the lock bundle 18 is tightened, the tube movement is completed.

When the pumps are operated again, both pumps 3as3b are restored to their original predetermined pump performance.

In this case, if one of the pumps causes almost no wear depending on the type of liquid, an independent support fitting and a lever that can be changed in position for each individual tube may be used instead of the support fitting 12 and the inverted U-shaped lever 14. You can also use it as

As detailed above (according to the construction method of the present invention, the pump action part is only a rubber tube and does not require any suction/discharge check valves, so the discharge volume is not only constant and stable at all times, but also resistant to acids, etc.) In addition, the wear side pump can be used only for wear due to long-term use.
Alternatively, by simultaneously shifting the position of the rubber tube relative to the pump casing of both pumps, pump performance can be restored to its original state extremely easily, allowing simultaneous discharge of the same amount of two liquids, same pulsation, and always constant discharge. Since it is a positive displacement pump that can meet the strict constraints of volume, there is no need to measure the injection volume (it has the effect of having equal lengths that allow you to easily record the injection volume only by operating time). be.

[Brief explanation of the drawing]

The drawings show one embodiment of the chemical injection pump used in the construction method of the present invention. Fig. 1 is an external perspective view of the overall arrangement, Fig.
The figure shows a front view and a cross-sectional view of only the pump body, Fig. 4 is a perspective view showing the relationship between the rubber tube and the squeezing roller, Fig. 5 is a sectional view showing the connection between the rubber tube and the suction/discharge pipe, and Fig. FIG. 6 is a cross-sectional view showing a connecting portion between a double pipe for underground insertion and a discharge pipe. In the figure, 1 is a liquid A storage tank, 2 is a liquid B storage tank, 3 is a roller rotary tube squeezing twin pump, 5a and 5b are rubber tubes, 8 is a squeezing roller, 14 is an inverted U-shaped lever, and 19 is underground Insertion tube shown.

Claims (1)

[Claims] 1. Two roller rotary tube squeezing pumps of the same performance, which have a common roller drive shaft and are arranged in parallel, are used to suck two types of AlB fluids, which are instantaneously condensed by mixing, from separate storage tanks. A ground strengthening method characterized in that the two types of fluids can be mixed and injected into the ground at the same time by simultaneously discharging a constant and equal amount with the same pulsation in a double pipe inserted into the ground. Construction method. 2. The ground reinforcement construction method according to claim 1, wherein the pump can change the position of the tube relative to the casing either alone or at the same time.