JPH059926A - Sleeve-grouting method - Google Patents

Abstract

PURPOSE:To prevent generation of spring water from the mouth of a casing and flowing-out of sand and earth during the time from drilling of a hole to setting of a double pipe in foundation improvement work by a sleeve-grouting method by inserting the casing up to a specified depth of the ground through the mouth-sealing member, and so forth. CONSTITUTION:Water-stopping at the time that a casing 2 is inserted into the ground to be improved is performed by a mouth-sealing member, and a check valve in the nozzle hole of a front bit 12 detachably provided to the casing 2. In this case, water-stopping of a drilled hole mouth part 29a at the time that a double pipe is built up is performed by a seal grout poured and packed into the inside through a feed port 5. Water-stopping between the built-up double pipe and the casing 2 is performed by a water-stopping ring 12 which slides on the outer peripheral surface of the double pipe in the direction of pipe-axis as the casing is drawn out, in a state where it is firmly installed to the casing 2. Besides, drawing-out of the casing 2 is performed after the front bit 12 is disconnected by an external operation, and the front bit 12 is buried and dumped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sleeve injecting method which is useful for improving the ground by injecting a chemical solution, and particularly when applied to construction under pressurized water.

[0002]

2. Description of the Related Art The sleeve injection method is a method in which a double pipe and a double packer are used to inject a chemical solution to improve the ground, and many construction results have already been left. When such a sleeve pouring method is applied to construction under pressured water, it is necessary to take measures to prevent the outflow of spring water and earth and sand generated from the mouth between the drilling and the double pipe installation.

Conventionally, various measures have been taken as a measure for preventing the outflow of spring water and earth and sand, but there are merits and demerits in that the construction is complicated or a trouble is easily caused during the construction.

The present invention has been made for the purpose of eliminating such conventional problems.

[0005]

According to the present invention, a casing is penetrated into a ground for improvement to a predetermined depth of the ground through a mouth seal member attached to the mouth of the ground, and the penetration of the casing is the casing. Drilling guide of the tip bit mounted on the tip of the tip so that it can be detached by remote control, and drilling guide of drilling water ejected from the nozzle with check valve opening at the tip of the tip bit. Muddy water containing pressured water generated during work is discharged to the outside through the supply and discharge ports provided on the mouth seal member while backflowing the outside of the casing, and then the seal grout is pressed and filled from the supply and discharge ports. After sealing the base of the drilled hole with, the outer tube of the sleeve injecting double tube is inserted into the casing, and the circumferential gap generated between the casing and the outer tube is inserted by the insertion. Seal with a sealing member attached to the inner peripheral wall of the tip portion, and then through a pouring port provided at the tip of the outer pipe and a press-fitting pipe connected to the pouring port, insert a seal grout into the drilled hole from a deep portion. While press-fitting and filling toward the shallow part, the casing is pulled out from the inside of the drilling hole while leaving the tip bead separated by the external operation, and then the press-fitting pipe is pulled out from the outer pipe, and then the double packer is put in the outer pipe. The present invention relates to a sleeve injecting method, which is characterized in that an inner tube with a tube is inserted, and a medicinal solution is injected through the inner and outer tubes in the usual manner.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following will describe one embodiment of the method of the present invention with reference to the accompanying drawings.

To carry out the method of the present invention, a mouth seal member (1), a casing (2), and double pipes (3a) and (3b) as a sleeve injection device are used.

The mouth seal member (1) serves to insert and guide the casing (2) into the ground with the mouth sealed as shown in FIG. 1, for example.
An inlet seal portion (4) is provided on the inlet side, and a supply port (5) for press-fitting and filling the seal grout and an outlet port (6) for spring water and the like are provided on the side portions. The supply port (5) is connected to a press-fit filling section (not shown) of a seal grout through an opening / closing cock (7) and a conduit (8).
On the other hand, the discharge port (6) is provided with an opening / closing cock (9).

The casing (2) is provided with a tip bit (12) for ground excavation at the tip thereof, and the bit (12) has a nozzle (14) with a check valve (13) as shown in FIG.
Is provided.

It is necessary that the tip bit (12) provided at the tip of the casing (2) can be appropriately separated from the casing (2) by remote control.

In the embodiment shown in FIGS. 9 to 12, the tip bit (12) can be inserted into and removed from the shaft hole (2a) at the tip of the casing (2) in the hollow shaft (12a). Inserted,
In this inserted state, the casing (2) can be locked or unlocked by rotating the casing (2) forward or backward at a predetermined angle.

In order to construct the lock mechanism, as shown in FIG. 9, an arc-shaped detent protrusion (1) having an angular width of, for example, 60 ° is formed on the outer peripheral surface of the hollow shaft portion (12a) of the tip bit (12).
5) are formed at two places with the center of the shaft in between. On the front end face (15a) of each detent protrusion (15) in the excavation rotation direction, a locking protrusion (1) having a predetermined angle width, for example, an angle width of 15 °.
6) is projected. Uniform projection (15) and projection (1
The angular width of 6) is shown in detail in FIG.

On the other hand, the shaft hole (2a) at the tip of the casing (2)
On the side, an anti-rotation groove (17) having an angle width slightly exceeding the sum of the angle widths of the protrusion (15) and the protrusion (16), for example, an angle width of 90 °, sandwiches the shaft center. Are formed in two places by the above-mentioned projection ((1
5) and the protrusion (16) are fitted. A locking recess (18) that locks with the locking projection (16) is formed so as to open to the front end surface (17a) of the recess groove (17) in the excavation rotation direction. Although the locking recess (18) is formed over the entire length between the recessed grooves (17) and (17) in FIG. 9, it may have at least an angular width corresponding to the locking protrusion (16). ..

10 to 11 show the state of the locked state,
In this state, the locking projection (16) is engaged in the locking recess (18) and is prevented from coming off. In addition, the protrusion for stopping rotation (15)
The front end face (15a) in the excavation rotation direction of the above contacts the front end face (17a) in the same direction of the concave groove (17), so that the casing (2) and the tip bit (12) rotate integrally to enable excavation of the ground. become. As shown in FIG. 11, in the locked state, the locking projection (15) is locked between the rear end surface (15b) and the rear end surface (17b) of the concave groove (17). There is an interval (19) (see FIG. 10) having an angular width of, for example, 30 ° that exceeds the angular width of the projecting portion (16).

In FIG. 11, when the casing (2) is rotated in the direction opposite to the excavation rotation direction indicated by the arrow (20), 1
The rotation of 5 ° to 30 ° causes the locking protrusion (16) to move into the locking recess (1
8) It comes off and the lock is released. Then, in this state, as shown in FIG. 12, the tip bit (12) can be separated.

A water stop ring (21) is mounted on the inner peripheral surface near the tip of the casing (2), and the ring (21) is attached.
The inner diameter of is approximately equal to or smaller than the outer diameter of the outer pipe (3a) of the sleeve pipe, and if smaller, it is made of an elastic member such as rubber.

The outer tube (3a) which constitutes one part of the sleeve injection device has an injection port (22) as shown in FIG.
And a flexible sleeve (2) that covers the outside of the mouth (22).
3) and an injection part (24), and the injection part (2
4) are provided at a plurality of positions at appropriate intervals in the pipe axis direction. Further, the tip is provided with a tip cone (25) with an inlet (26) as shown in an enlarged manner in FIG.

On the other hand, the inner pipe (3b) is provided with a double packer portion (27) as shown in FIG. 8, and a strainer portion (not shown) is formed between the packers.

In carrying out the method of the present invention, the mouth seal member (1) is attached at a predetermined position on the ground surface to be improved according to a conventional method, and then the casing (2) is attached to the mouth seal portion (1) of the member (1). It passes through 4) and is inserted up to the core boring mark (28) on the ground surface.

Next, when the rotation imparting device (not shown) is operated with the cock (7) closed and the cock (9) opened, the rotation is made in the direction indicated by the arrow (20) in FIG. The tip bit (12) rotates integrally with the casing (2) as shown in FIGS. When the casing (2) is inserted into the ground in this state, the casing (2) guides the drilling of the tip bit (12) and the tip nozzle (1) as the casing (2) is inserted.
The ground is drilled by the drilling guide of the drilling water ejected from 4), and this drilling is continued until the predetermined depth is reached while adding the casing (2). Casing (2)
Outflow of spring water from the inside of the casing (2), which may be a concern at the time of replenishment, is prevented by the check valve (13) provided in the injection port (14).

The situation during the drilling operation is shown in FIG. At the time of drilling operation, drilling water, groundwater under pressure, etc. intensively flow back outside the casing (2) and are discharged from the discharge port (6). In FIG. 2, reference numeral (32) is the casing (2).
It is a jack for pulling out.

After finishing the drilling by the casing (2), as shown in FIG. 3, after closing the valve (9) of the discharge port (6), the drilling ( A water blocking agent (30) is press-fitted into the mouth portion (29a) of 29). Any water-stopping agent may be used as long as it has water-stopping properties, and for example, a cement-milk-based or water-glass-based water-stopping agent is suitable.

Next, the outer tube (3a) of the sleeve injecting device is inserted into the casing (2), and the casing (2) is rotated in the reverse rotation direction, for example, 1
The tip bit (12) is rotated by an angle of 5 ° to 30 °, and by this reverse rotation operation, the tip bit (12) is unlocked as apparent from FIG. 11, and the tip bit (12) is separated by pulling out the casing (2). Ready to get.

Therefore, in this state, as shown in FIGS. 4 to 5, the press-fitting pipe (31) is inserted into the outer pipe (3a), and the tip of the press-fitting pipe (31) is connected to the tip cone of the outer pipe (3a). (25)
Connection to the inlet (26).

In the state shown in FIGS. 4 to 5, the press-fitting pipe (3
When the jack (32) is actuated and the casing (2) is gradually pulled out while press-fitting the seal grout through the inlet (26) connected to the outer pipe (3a), the casing (2) is gradually pulled out. A seal grout is injected and filled in the hole (29) around the hole. The tip bit (12) is in a separable state and does not accompany the casing (2) withdrawn. This seal grout is press-fitted into the hole (2
It is carried out with a pressure that pushes the remaining mud in 9) into the ground. Outer tube (3a) during press-fit filling operation of seal grout
The outflow of the seal grout from between the casing and the casing (2)
It is prevented by the water stop ring (21) provided in the casing (2).

Seal grout (33) in the drilled hole (29)
Since the casing (2) is pulled out while injecting and filling, the pulling resistance is small and the pulling out work is easy.

After the operation of drawing the casing (2) to the mouth and injecting and filling the seal grout (33) into the drilled hole (29) are completed, the press-fitting rod (31) is extracted and recovered, as shown in FIG. As shown in FIG. 3, the inner pipe (3b) and the existing outer pipe (3a) are utilized to make a mouth portion (29) of the hole (29).
The water-stopping agent (30) was again injected and filled in a), and the mouth portion (29
Strengthen the waterproofness of a). This waterproofing enhancement is necessary for removing the equipment such as the mouth seal member (1) and the jack (32).

Grouting agent (33) filled in the hole (29)
After the curing and solidification of the outer tube is completed, as shown in Fig. 7, the outer tube (3
After removing all the equipment except a) and installing the seal flange (34) at the mouth instead, as shown in FIG. 8, using the inner pipe (3b), cracking and water pushing as usual. After that, ground improvement by grout injection is performed.

After the ground improvement, the inner pipe (3b) is pulled out and recovered, and the outer pipe (3a) is buried.

As shown in FIG. 7, when the outer pipe (3a) is projected to the ground longer than necessary, the unnecessary portion may be cut and removed.

In the embodiment, the ground improvement from the vertical direction is explained, but even if it is applied to the ground improvement from the horizontal direction,
The substantially same effect is obtained.

[0032]

[Effect] According to the method of the present invention, the spring water (including pressurized water) is completely stopped during the process from drilling to installation of the outer pipe, and the seal grout is drilled in the drilling hole. Since the casing is pulled out while pouring and filling from the deep part to the shallow part, the pulling resistance is much smaller than the case where the casing is pulled out after the filling and filling of the seal grout, and the pulling work becomes easier, and the seal grout layer There is no risk of breaking the seal and a good quality seal grout layer can be formed.

[Brief description of drawings]

FIG. 1-8 is an explanatory view showing the method of the present invention in order of steps.

FIG. 9 is a perspective view of a lock mechanism applied to the tip bit.

FIG. 10 is a vertical cross-sectional view when locked.

11 is a cross-sectional view taken along line 11-11 of FIG.

FIG. 12 is a vertical cross-sectional view when unlocking.

FIG. 13 is a partial vertical sectional view of an outer tube.

[Explanation of symbols]

 1 mouth seal member 2 casing 3a outer pipe 3b inner pipe 4 mouth seal part 5 supply port 6 discharge port 7 cock 8 conduit 9 cock 12 tip bit 13 check valve 14 check nozzle

Claims (1)

Claims: 1. A casing penetrates into a target ground for improvement to a predetermined depth of the ground through a mouth seal member attached to the mouth of the ground, and the penetration of the casing is made at the tip of the casing. It is performed by remote control of the drill bit of the tip bit that is detachably attached, and the guide of drilling water ejected from the nozzle with check valve that opens at the tip of the tip bit. The mud water containing the pressurized water is discharged to the outside from the supply / exhaust port provided in the mouth seal member while backflowing the outside of the casing, and then the press-filling of the seal grout from the supply / exhaust port is performed. After sealing the mouth of the
The outer tube of the heavy tube is inserted into the free tube, and the peripheral gap generated between the casing and the outer tube by this insertion is sealed by the seal member attached to the inner peripheral wall of the tip portion of the casing, and then the tip of the outer tube. Through the injection port provided in the, and the press-fitting pipe connected to the injection port, while press-filling the seal grout into the drilled hole from the deep part to the shallow part, the casing,
After pulling out from the inside of the drilled hole while leaving the tip bead separated by the external operation, and then removing the press-fitting pipe from the outer pipe, insert the inner pipe with the double packer into the outer pipe,
The sleeve injection method is characterized in that the chemical solution is injected through the inner and outer tubes in the usual manner.