JPH0393920A - Reinforcing earthwork method - Google Patents

Abstract

PURPOSE:To improve workability and increase reinforcing effect by inserting a rod into a tubular reinforcing material, hitting the rod and reinforcing material alternately to intrude into natural ground, and pulling out the rod after hitting is completed. CONSTITUTION:A rod 4 provided with a tip bit 6 at the tip is inserted into a tubular reinforcing material 2, and the tip bit 6 and rod 4 intrude into a natural ground 8 by hitting the rear section of the rod 4 in prior to the reinforcing material 2. Next, the rear section of the reinforcing material 2 is hit to drive it up to the position of the tip bit 6. This is repeated several times as required to intrude the rod 4 and reinforcing material 2 into the natural ground 8 alternately and drive the reinforcing material 2 up to desired depth. Then, the rod 4 and tip bit 6 are pulled out of the reinforcing material 2 after hitting is completed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention uses small diameter pipes (length 3 to 5 m, diameter 40 to 100 mm) as reinforcing materials when reinforcing the ground to stabilize slopes.
Reinforced earthwork method for installing on the ground.

[Conventional technology]

Among the reinforced earthwork methods, there are the following two methods for installing reinforcing materials to reinforce natural ground.

(a) Pre-poling method (mouth) Direct driving method (b) The pre-poling method involves drilling a hole in the ground and inserting reinforcing material, using a poling machine, leg drill, etc. as the hole-drilling machine. Reinforced earth construction methods are often used in locations where workability is poor, and are characterized by short drilling lengths and a large number of holes. Therefore, ease of moving and installing the equipment is a factor that influences construction efficiency and economic efficiency. Hand-type drilling machines, such as leg drills, are easy to move and have sufficient drilling capacity depending on the soil type. However, in soils with gravel or scattered cobbles and boulders (typically talus deposits), it is often difficult to drill holes, so it is necessary to use a polling machine and, in some cases, casing excavation. There is.

Once the drilling is complete, reinforcing material is inserted. After insertion, grout immediately without disturbing the hole wall.

On the other hand, the direct driving method (mouth) includes a method of directly driving scalene angle steel, etc., and a method of using hollow reinforcing material and grouting from the hollow hole after driving.

As the driving machine, a polling machine with a percussion mechanism, a hand-type breaker, etc. are used. The driving method is very effective for ground where pre-poling is difficult, such as gravel-filled soil. [Problems to be Solved by the Invention] However, all of the pre-poling methods and some of the direct pouring methods require grouting work, resulting in complicated processes and problems in terms of workability.

On the other hand, in the direct driving method that does not require grout injection, there is a problem with the adhesion between the ground and the reinforcing material, and the reinforcing effect is generally low. The main reason for this is the reduction in the contact area between the reinforcement and the ground, which is caused by the "braking of the reinforcement" caused by hitting the reinforcement with low rigidity from the rear.
This is due to

The object of the present invention is to create a reinforcing material using the direct driving method that has excellent workability! [The purpose of the present invention is to provide a reinforced earth construction method that can provide reinforcement effects equal to or greater than installation using the pre-poling method.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a method for installing a tubular reinforcing material in the ground, in which a rod is inserted into the tubular reinforcing material, and after the rod is penetrated into the ground, the tubular reinforcing material is installed in the ground. This is a construction method in which the tubular reinforcing material is installed in the ground by penetrating the ground and then pulling out the rod.

and in particular, by penetrating a portion of the rod into the ground and then penetrating a portion of the tubular reinforcement, repeating this process alternately to penetrate the tubular reinforcement into the ground, and then withdrawing the rod to remove the tubular reinforcement. This is a method of installing in the ground.

In addition, the tip of the rod is made to protrude beyond the tip of the tubular reinforcing material, the rod tip penetrates into the ground first, and the tubular reinforcing material is penetrated together with the rod, and then the rod is pulled out and the tubular reinforcing material is installed in the ground. You can also. [Function] According to the above structure, there are the following effects.

(b) By inserting the rod into the hollow part and increasing its rigidity, the penetration energy from the rear can be smoothly transmitted to the reinforcing material and the tip of the rod without loss. Therefore, it is possible to suppress the "shaking of the reinforcing material" during driving, leading to an increase in the reinforcing effect. (Exposure) Penetrating the ground while pushing it apart is
The volume of the reinforcing material including the hollow portion is compressed, increasing the confining pressure of the ground around the reinforcing material. An increase in confining pressure increases the adhesion force between the ground and the reinforcing material, leading to an increase in the reinforcing effect.

〔Example〕

Some embodiments of the present invention will be described below.

In this example, the length is 3 to 5 m, the diameter is 40 to 100 m,
A tubular reinforcing material with a wall thickness of 2 to 4 m is used, and rods are inserted into this reinforcing material, and basically the rods and the reinforcing material are driven in alternately. The length of each drive is approximately several tens of centimeters, and the rod is driven in first. When driving the rod, the tubular reinforcing material acts as a guide to improve the straightness of the rod's penetration, and when driving the reinforcing material, the rod acts as a guide to prevent the reinforcing material from wobbling. In this embodiment, the gap between the inner circumferential wall of the tubular reinforcing material and the outer circumferential wall of the rod is made extremely small.

The following two embodiments will be explained using drawings depending on the type of rock.

(First example) This example is a method that can be called a tip bit removal type, and is used for ordinary earth, with the outside diameter of the bit at the rod tip being about the same as the rod diameter, and the tip bit being removed together with the rod after casting is completed. This is also a method of recovering waste.

Figure 1 is an explanatory diagram showing the construction procedure of this example.
Construct in the order of (A), (B), (C), and (D).

In Fig. 1, (A) shows the reinforcing material partially attached to the ground, but a rod 4 is inserted inside the tubular reinforcing material 2, and the tip of the rod 4 is inserted into the reinforcing material 2. The tip bit 6 has sufficient rigidity to push apart and penetrate the soil.
is installed. From this state, the rear part of the rod 4 is struck to cause the tip bit 6 and the rod 4 to penetrate the ground 8 ahead of the reinforcing material 2, resulting in the state shown in (B) in the figure.

Next, from this state, the rear part of the reinforcing member 2 is struck to approximately the position of the tip bit 6. In this way, the rod 4 and the reinforcing material 2 are alternately struck and driven to a predetermined depth.
) Finish pouring as shown.

After completion of pouring, as shown in (D) in the figure, the rod 4 and tip bit 6 are pulled out from the reinforcing material 2, and the ground 8 of the reinforcing material 2 is removed.
8 installation is completed.

In this embodiment, since a tip bit having higher rigidity than the rod is used, the tip bit 6 is connected to the rod 4 by a threaded portion 1o. If the rod has sufficient rigidity, the tip bit may be omitted and the rod may be inserted directly.

(Second Example) This example is a method that can be called the tip bit-remaining type, which is used for relatively hard ground, and uses a tip bit larger than the inner diameter of the reinforcing material to reduce the resistance when penetrating the reinforcing material. There is.

That is, FIG. 2 shows the construction procedure of this embodiment, and the tip of the tip bit 12 is formed with a large diameter portion 14 that is larger than the inner diameter of the reinforcing material 2. 1
2 is attached to the tip of the reinforcing material 2.

The casting procedure is exactly the same as in the first embodiment, but after finishing the casting, in this embodiment, only the rod is pulled out, leaving the tip bit 12 in the soil.

According to this embodiment, it is possible to drill a hole approximately equal to the outer diameter of the reinforcing material, so there is little resistance when the reinforcing material penetrates even in hard ground.

Note that if this outer diameter portion is configured to be able to be reduced in diameter, the tip bit can be pulled out together with the rod after finishing the casting.

In these examples, the rod and the reinforcing material are struck alternately, but as another example, a two-step driving method may be used in which the rod is first driven to the length of the reinforcing material, and then the reinforcing material is driven to the full length. In addition, the tip of the rod is made to protrude from the reinforcing material, and a locking part is provided on the reinforcing material and the rod to lock each other,
Simultaneous driving is also possible in which the reinforcing material is penetrated at the same time as the rod is penetrated.

Further, in these embodiments, penetration energy is applied by a simple impact, but by rotating the tip bit, efficient driving becomes possible even in hard ground.

Note that the reinforcing material is not limited to steel pipes, but may also be made of plastic or resin as long as it has rigidity.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to install a reinforcing material with a high reinforcing effect by a simple method, and it is possible to provide a reinforced earth construction method that is economical and has excellent workability for stabilizing the ground.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the construction of the first embodiment of the present invention, and Fig. 2 is an explanatory diagram of the construction of the second embodiment. 2... Tubular reinforcement material, 4
... Rod, 6, 12 ... Tip bit, 8 ... Earth, 14 ... Large diameter part.

Claims (1)

[Claims] 1. A construction method for installing a tubular reinforcing material in the ground, in which a rod is inserted into the tubular reinforcing material, the rod is penetrated into the ground, and then the tubular reinforcing material is penetrated, A reinforced earthwork method in which the rod is then pulled out and the tubular reinforcing material is installed in the ground. 2. A method of installing a tubular reinforcing material in the ground, in which a rod is inserted into the tubular reinforcing material, a part of the rod is penetrated into the ground, and then a part of the tubular reinforcing material is penetrated, This is a reinforced earthwork method in which this process is repeated alternately to penetrate the tubular reinforcing material into the ground, and then the rod is pulled out to install the tubular reinforcing material into the ground. 3. A method of installing a tubular reinforcing material in the ground, in which a rod is inserted into the tubular reinforcing material, the tip of the rod protrudes from the tip of the tubular reinforcing material, and the tip of the rod is placed in front of the reinforcing material. A reinforced earthwork method in which the tubular reinforcing material is penetrated into the ground at the same time as the rod, and then the rod is pulled out and the tubular reinforcing material is installed in the ground. 4. The reinforced earth construction method according to claim 1, 2 or 3, wherein the rod and the tubular reinforcing material penetrate the ground by hitting the rear part thereof. 5. The reinforced earth construction method according to claim 1, 2 or 3, wherein the rod rotates and penetrates the ground while pushing it apart. 6. The reinforced earth construction method according to claim 1, 2, 3, 4, or 5, wherein the rod is equipped with a tip bit having an outer diameter larger than the inner diameter of the tubular reinforcing material at its tip. 7. A tubular reinforcing material used in the reinforced earth construction method according to claim 1, 2, 3, 4, 5 or 6. 8. A rod for use in the reinforced earth construction method according to claim 1, 2, 3, 4, 5 or 6.