JPH0718161B2 - Anchor method and casing pipe for anchor method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method of constructing an anchor formed in the ground for holding a retaining wall and the like, and a casing pipe for an anchor method used for the method.

[Conventional technology]

As is well known, the so-called anchor construction method is used to hold retaining walls and retaining walls during construction work.In this anchor method, a casing pipe is driven into the ground for a predetermined length from the outside of the retaining wall and the casing Anchor steel material made of steel wire or steel rod is inserted into the pipe, the solidification material is press-filled and the casing pipe is pulled out, and then the tensioned anchor steel material end is fixed to the pedestal outside the soil retaining wall. .

Then, in order to drive the casing pipe, a method in which a bit is provided at the tip of the casing pipe to cut the ground is usually performed, but a ring set is used for the bit in consideration of pulling out the casing pipe.

[Problems to be Solved by the Invention]

In such a method in which a bit is provided at the tip of the casing pipe for excavation, groundwater or earth and sand are ejected from the root of the casing pipe at the time of boring, which enables construction.

In order to prevent this, it is possible to use a bit with a check valve, but the presence of this check valve makes it impossible to pull out the casing pipe while leaving the anchor steel material and the solidifying material, and it is also necessary to check the bit. The presence of the valve may prevent drilling of hard ground.

The object of the present invention is to eliminate the inconvenience of the above-mentioned conventional example, and to effectively excavate even a hard ground with a bit at the tip to insert a casing pipe, and after inserting, while suppressing the inflow of groundwater and earth and sand at this bit part, other Since the work can be performed and the casing pipe can be pulled out without any trouble, it is an object of the present invention to provide an anchor construction method and a casing pipe for the anchor construction method suitable for construction under high water pressure.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the present invention drives a casing pipe having a bit at the tip into a predetermined length of ground from the outside of a soil retaining wall with a drilling hole machine, and inserts an anchor steel material by a steel wire or a steel rod into the casing pipe, In addition, in the anchor construction method in which the solidified material is press-fitted and the casing pipe is pulled out, the end of the anchor steel material is tensioned and fixed to the pedestal outside the soil retaining wall, the bit at the tip of the casing pipe is the Kronen bit in the ring bit. It is fitted and the ring bit and the Kronen bit are joined by a severable pin.In addition, a check valve is provided in the water passage hole that opens at the tip of the Kronen bit, and the ring bit is inserted when inserting the casing pipe. Cut with both bits of the Kronen bit to make a hole, then insert the inner rod into the casing pipe and hit it. Ete cutting the pin, after consolidating material injected into the casing, it is an gist pulling the casing pipe, leaving Kronenburg bit while holding the Kronenburg bit anchor steel inserted into the casing.

[Action]

According to the present invention, in addition to the ring bit, the Kronen bit is fitted in the ring bit at the tip of the casing pipe, so that not only the casing pipe can be rotated but also excavation can be performed by moving the casing pipe up and down, thus making it possible to perform hard ground excavation. Can drill holes effectively.

In addition, since the Kronen bit has a check valve inside the water passage hole that opens at the tip, high-pressure water can be jetted from this water passage hole during drilling, and also when the drilling is stopped Since it is closed, it is possible to prevent the inflow of groundwater and sediment into the casing pipe.

After that, insert the inner rod into the casing pipe, hit it to cut the pins, inject the solidifying material into the casing, and then pull out the casing pipe while pressing the Kronen bit with the tip of the anchor steel material inserted into the casing. For example, the Kronen bit and the casing pipe are separated and only the Kronen bit remains.

〔Example〕

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1 to 12 are side views of respective steps showing an embodiment of the anchoring method of the present invention, in which 1 is a retaining wall.

As shown in FIG. 1, a sleeve pipe 2 is embedded in the earth retaining wall 1 in advance, and a pedestal / water-stop box 3 is attached to the outside of the earth retaining wall 1 so as to be joined to the sleeve pipe 2.

FIG. 20 and FIG. 21 show the details of the water blocking box 3 which also serves as a pedestal. A joining plate 4 is embedded on the outer surface of the earth retaining wall 1 on the outer circumference of the sleeve tube 2.

The pedestal / water-stop box 3 is provided with right and left side wall plates 6a, 6b of substantially triangular shape which are erected so as to form a vertical open surface 5 to be welded to the joining plate 4, and the left and right side wall plates 6a, 6b are provided on one side thereof. , The swash plate 7 in the direction orthogonal to the sleeve pipe 2
The swash plate 7 is formed with a casing pipe insertion hole 8 for penetrating a casing pipe 13 described later.

The axial direction of the insertion hole 8 coincides with that of the sleeve tube 2.

Further, the side wall plates 6a and 6a,
A swash plate 9 was provided between b, and a discharge port 10 for removing water and debris and an injection port 11 for injecting a chemical solution were formed in this swash plate 9.

The open surface 5 is formed by being surrounded by the ends of the left and right side wall plates 6a and 6b, the end of the swash plate 9 and the end of the horizontal plate joined to the swash plate 7.

Also, in actual use, a fitting with a valve or the like is attached to the outlet 10 and the inlet 11.

As shown in FIG. 2, the casing pipe 13 set in the hole drilling machine 12 is inserted into the ground through the casing pipe insertion hole 8 of the pedestal-and-water-stop box 3 and the sleeve pipe 2 to drill a hole.

18 and 19 show the details of the tip portion of the casing pipe 13, the ring bit 14 in which the excavating blades 14a are arranged in a ring shape is attached to the inside of the tip portion of the casing pipe 13 by screwing.

Then, the Kronen bit 15 was fitted in the ring bit 14, and the ring bit 14 and the Kronen bit 15 were joined together by the pin 16 through the respective insertion holes. This pin 16
Is capable of being cut by striking as described later.

Further, the clonen bit 15 has a conical tip end surface on which the excavating blade 14a is formed, but a water passage hole 17 opening at the tip end surface is formed inside, and a ball valve is formed in the water passage hole 17. Built-in check valve 18 by.

The check valve 18 is biased by a spring 19 in the direction opposite to the front end surface of the Kronen bit 15.

Furthermore, a sleeve tube 20 is formed at the root of the Kronen bit 15, and this sleeve tube 20 is inside the ring bit 14
The end portion projects outside the ring bit 14 when the 15 is fitted, and an O-ring 21 is fitted on the outer periphery thereof.

For drilling with the casing pipe 13 having both the bit of the ring bit 14 and the bit of the Kronen bit 15 at its tip, the drilling machine 12 can add rotation, striking, and vertical movement.

Further, as shown in FIG. 13, water is fed into the casing pipe 13 at the time of drilling, and this water is passed through the water passage holes of the Kronen bit 15.
Discharge from the tip through 17 which facilitates drilling.

It should be noted that the casing pipe 13 is appropriately added by a unit pipe to have a predetermined length. At the time of this addition, the rotation, striking, vertical movement of the casing pipe 13 and water supply are stopped.

In that case, even if groundwater or earth and sand tries to enter the casing pipe 13 through the water passage hole 17, the check valve 18 is closed as shown in FIG. 14, so that backflow can be prevented.

In addition, since the mouth pre-bender 22 is interposed between the casing pipe 13 and the casing pipe insertion hole 8 of the pedestal water-stop box 3 to make it watertight, excess water and drilling scraps rising along the outer periphery of the casing pipe 13 are prevented. It collects in the pedestal and water blocking box 3 and does not come out from the outer periphery of the casing pipe 13.

Excavations in the water-stopping box 3 that also serves as a pedestal are drained.
Adjust the amount of water at 10 and discharge to the outside.

Furthermore, when the casing pipe 13 is completely inserted into the ground for a predetermined length and rotation, striking, vertical movement, or water supply is stopped,
Since the check valve 18 is closed, it is possible to prevent the backflow of groundwater and sediment.

Then, as shown in FIG. 3 and FIG. 15, the inner rod
23 is inserted into the casing pipe 13, and the boring machine 12 strikes the Kronen bit 15 through the inner rod 23 to cut the pin 16.

In this case, as shown in FIG. 16, the Kronen bit 15 advances a little, but the O-ring is placed between the sleeve tube 20 and the ring bit 14.
There are 21, so the water is stopped during that time.

After that, as shown in FIG. 4, the casing pull-out jack 24 is set in the pedestal / water-stop box 3, and then cement milk is primarily injected into the casing pipe 13,
As shown in the figure, a steel wire 25 as an anchor steel material is inserted into the casing pipe 13.

At this time, if the casing pipe 13 is pulled out by the casing pull-out jack 24 while pressing the Kronen bit 15 with the tip of the steel wire 25, the Kronen bit 15 will be disengaged from the ring bit 14 as shown in FIG. Remain in.

When pulling out the casing pipe 13, it is necessary to close the root portion of the casing pipe 13.

22 and 23 show the water blocking packer 26 for such blockage, the water blocking packer 26 is a lump of elastic synthetic rubber or synthetic resin.

A rod 27 is constituted by the outer pipe 27a and an inner rod 27b whose root portion is screwed to the outer pipe 27a and whose tip projects from the tip of the outer pipe 27a, and a collar plate 28a is formed at the tip of the inner rod 27b. A collar plate 28b is provided at the tip of the outer pipe 27a, and the water blocking packer 26 having the inner rod 27b penetrating the center thereof is installed between the collar plate 28a and the collar plate 28b.

Then, when inserting the rod 27 into the casing pipe 13, the casing pre-bender 29 is attached to the root end of the casing pipe 13, and the rod 27 is inserted so as to penetrate the casing pre-bender 29.

Further, a rotating portion 30 having an insertion hole 30a such as a jig is provided at the root of the inner rod 27b.

As shown in FIG. 22, when the inner rod 27b is rotated through the rotating portion 30, the inner rod 27b moves with respect to the outer pipe 27a and the collar plate 28a.
And the collar plate 28b are shortened, and the water blocking packer 26 is crushed by the collar plates 28a and 28b and expanded outward to close the casing pipe 13.

Further, if the inner rod 27b is rotated in the opposite direction via the rotating portion 30, the gap between the collar plate 28a and the collar plate 28b is opened as shown in FIG. 23, the water blocking packer 26 is contracted, and the casing. It is not in contact with the inside of the pipe 13.

By the way, if the water pressure received by the water stop packer 26 at the time of expansion is high, the water stop packer 26 may move, so the end of the inner rod 27b and the earth retaining wall 1 are connected by the wire 32. Try to exert a reaction force on the wall 1.

The wire 32 connects the hole-in anchor provided on the earth retaining wall 1 and the insertion hole 30a of the rotating portion 30 of the inner rod 27b.

As described above, the casing pipe 13 has a predetermined length by adding the unit pipes, and the casing pipes 13 are sequentially pulled out while removing the unit pipes one by one.

The procedure for pulling out the casing pipe 13 is as follows.

The casing pre-bender 29 is set at the base end of the casing pipe 13, the water blocking packer 26 is inserted into the casing pipe 13, and the casing pipe 13 is pulled out by the casing pulling jack 24.

At this time, the water stop packer 26 is not expanded and only the casing pre-bender 26 prevents backflow of the cement milk.

After pulling out the casing pipe 13, pressure injection of cement milk is carried out.

At the time when the water blocking packer 26 is inserted from the joint between the last unit pipe of the casing pipe 13 and the unit pipe of the preceding stage, the water blocking packer 26 is expanded to close the inside of the casing pipe 13, and the casing Remove the pre-bender 29 and the last unit pipe.

In this state, the water stop packer 26 prevents backflow.

The removed casing pre-bender 29 is attached to the rearmost end of the casing pipe 13 again, and the water blocking packer 26 is contracted.

Hereinafter, the steps 1 to 3 are repeated by the number of unit pipes.

FIG. 6 shows a state where the cement milk is injected under pressure, and FIG. 7 shows the state when the casing is separated and the water-stopper packer 26 operates.

As shown in FIG. 8 and FIG. 24, before drawing out the final unit pipe and the unit pipe of the preceding stage, from the injection port 11 for injecting the liquid chemical of the pedestal / water shutoff box 3, the water stopping liquid 31
As LW (water glass + cement suspension) is injected.

At this time, the water stop packer 26 is inflated in the unit pipe of the preceding stage (the last unit pipe).

Since there is cement milk in the casing pipe 13 consisting of the final unit pipe and the unit pipe of the preceding stage, the water-stopping chemical solution 31 does not rotate.

After stopping the water in this way, the final casing (unit pipe) is removed as shown in FIG. 25. As shown in FIG.
Set the cloth packer 33 in a place that is a little deep from
The water-stopping chemical liquid 31 is injected into the cloth packer 33 to inflate it to stop the water.

In addition, cement milk is re-injected from a grout hose (not shown) attached to the steel wire 25 in order to increase the reliability of the fixing portion.

After this, the final casing (unit pipe) is removed, and as shown in FIG. 10, the tension jack 34 is set on the pedestal and water blocking box 3 to tension and fix the steel wire 25 after curing.

Then, as shown in FIG. 11, the steel wire 25 is cut, and as shown in FIG. 12, the protective cap 25 is attached as a final step, or the water-stopping chemical solution 31 is injected again into the pedestal / water-stop box 3. The anchor head is then treated with water to complete the construction.

〔The invention's effect〕

As described above, the anchor construction method and the anchor casing pipe of the present invention can effectively excavate the casing pipe even with hard ground with a bit at the tip, and after the insertion,
This bit part is suitable for construction under high water pressure because it can perform other work while suppressing the inflow of groundwater and earth and sand, and can also pull out the casing pipe without any problems.

[Brief description of drawings]

1 to 12 are side views of each step showing one embodiment of the anchoring method of the present invention, and FIGS. 13 to 17 are side views of each step showing the state of the bit at the tip of the casing pipe, 18th step. Figure is a vertical sectional side view of the tip of the casing pipe, Figure 19 is a front view of the same as above, Figure 20 is a front view of a water-stopping box that also serves as a pedestal, Figure 21 is a sectional view taken along the line AA of Figure 20, and Figure 22 is A side view showing the water-stopper pack when inflated, and FIG. 23 is a side view showing the same when it contracts.
FIG. 24 is a side view showing a step before the final step of drawing the casing pipe, and FIG. 25 is a side view showing a final step of drawing the casing pipe. 1 …… Soil retaining wall 2 …… Sleeve tube 3 …… Stand-stop water box 4 …… Joining plate 5 …… Opening surface 6a, 6b …… Sidewall plate, 7,9 …… Swash plate 8 …… Casing Pipe insertion hole 10 …… Discharge port, 11 …… Injection port 12 …… Driller, 13 …… Casing pipe 14 …… Ring bit, 14a …… Drilling blade 15 …… Kronen bit, 15a …… Drilling blade 16 ...... Pin, 17 …… Water hole 18 …… Check valve, 19 …… Spring 20 …… Sleeve tube, 21 …… O ring 22 …… Mouth pre-bender, 23 …… Inner rod 24 …… Casing extraction jack 25 …… Steel wire, 26 …… Water stop packer 27 …… Rod, 27a …… Outer tube 27b …… Inner rod, 28a, 28b …… Crim plate 29 …… Casing pre-bender 30 …… Rotating part, 30a …… Insertion hole 31 …… Still water solution, 32 …… Wire 33 …… Cloth packer, 34 …… Tension jack 35 …… Protective cap

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Masayuki Komaki 1-6-4 Moto-Akasaka, Minato-ku, Tokyo Within Chemical Grout Co., Ltd. (72) 1-6-6 Moto-Akasaka, Minato-ku, Tokyo Issue Chemikaru Grout Co., Ltd. Examiner Kaname Ichino

Claims (2)

[Claims] 1. A casing pipe having a bit at its tip is driven into the ground for a predetermined length from the outside of the earth retaining wall by a boring machine, and an anchor steel material made of a steel wire or a steel rod is inserted into the casing pipe, and a solidifying material is also used. In the anchor construction method that press-fits and fills the casing pipe, then tightens the end of the anchor steel material to fix it to the pedestal outside the soil retaining wall,
The bit at the tip of the casing pipe fits the Kronen bit into the ring bit, and the ring bit and the Kronen bit are joined by a severable pin.
A check valve is provided in the water passage opening at the tip of the Kronen bit, and when inserting the casing pipe, cut with both bits of the ring bit and the Kronen bit to make a hole, then insert the inner rod into the casing pipe. The anchor construction method is characterized in that the pin is cut by hitting and the solid material is injected into the casing, and then the casing pipe is pulled out while leaving the Kronen bit while pressing the Kronen bit with the anchor steel material inserted into the casing. . 2. A ring bit provided with a ring bit at the tip and a check valve provided in a water passage opening at the tip is fitted into the ring bit, and the ring bit and the Kronen bit can be cut by striking. A casing pipe for the anchor construction method, characterized by being joined with different pins.