JPH0696859B2 - Construction method of earth retaining structure and reinforcing pipe used for it - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION This invention is arranged along the ground,
Earth retaining panels supported by anchors placed in the ground,
The present invention relates to a construction method for earth retaining structures such as sheet piles and piles, and also relates to a pipe for reinforcing an anchor in the construction.

[0002]

2. Description of the Related Art As shown in FIG. 6, a panel b is set up side by side with a predetermined distance from a natural ground a, and earth and sand c is filled between the natural ground a and the panel b to keep the soil in the middle of a slope. It has been adopted to build walls. Such earth retaining panel b
Are supported by anchors d placed on the ground a.
The anchor d is arranged in the excavation hole e excavated in the natural ground, and is filled with a hardening material f such as cement milk and hardened. The panel b is fixed to the tip of the anchor d, and the load is received by the anchor d.

[0003]

[Problems to be Solved by the Invention]
When the hardening material f is injected into the excavation hole e, the hardening material f is sufficiently filled in the excavation hole e, and all the water (breathing water) inside is discharged to the outside so that the quality of the hardening material f is high. There must be. For this purpose, the hole e to be excavated in the natural ground a is excavated at an angle so as to be inclined downward, and the hardening material f is sequentially filled from the bottom to push up the breathing water. Therefore, the anchor d in the excavation hole e is naturally driven in a downwardly inclined manner.

When the anchor d thus obliquely cast on the natural ground is extended as it is and the soil retaining panel b is fixed to the tip thereof, the portion protruding from the natural ground is also inclined. A problem when attaching the panel b to such an inclined anchor d is that the anchor head g attached to the panel b side must also be attached so as to be inclined with respect to the panel b. For this reason, as shown in FIG. 7, it is necessary to process a part of the panel b at an angle according to the inclination angle of the anchor d, which requires a large cost and time. Further, the work of connecting the anchor d and the panel b is also a very labor-intensive work.

On the other hand, a problem in the construction of the conventional earth retaining panel is that the downward force component i of the anchor d as shown by the arrow in the figure acts together with the load of the stacked panels b. This component force, together with the weight of the panel b, was concentrated on the ground immediately below it. In other words, all the loads act on the foundation directly underneath, causing a very large local stress, and there was concern that the slope would collapse due to this.

FIG. 8 shows a soil retaining method using steel sheet pile h. As in the case of FIG. 6, the tensile force of the anchor d that is diagonally driven into the soil as shown in the figure acts on the sheet pile h as a component force like the arrow in the figure. That is, since the downward component force i acts on the sheet pile h, the depth of the sheet pile h is deepened,
It is necessary to endure this component force by friction with the ground. This meant that it was necessary to lengthen the sheet pile h and carry out major construction work.
Further, as shown in the drawing, since the anchor head g connecting the anchor d to the sheet pile h is inclined, the bracket j to which the head g is attached becomes large. The larger the bracket j, the larger the construction work, and the higher the construction cost.

The present invention has been made to solve the above problems. The anchors can be easily attached to earth retaining structures such as panels, piles and sheet piles, and the risk of ground collapse is increased. An object of the present invention is to provide a method for constructing an earth retaining structure which is less in number and facilitates construction of piles, and a reinforcing pipe which makes the construction more effective in the construction.

[0008]

A method of constructing an earth retaining structure according to the present invention is to tilt a portion of an anchor disposed in a drill hole of a natural ground and to make a portion protruding from the natural ground substantially horizontal. Is. The excavation hole in the ground is inclined so that it becomes deeper toward the bottom, and the anchoring part of the anchor is placed in this hole, and a hardening material such as cement milk is injected and hardened. The portion of the anchor inside the excavation hole is bent at a predetermined angle with respect to the horizontal portion. This angle is 10 to 45 degrees. When fixing the panel to such a horizontal anchor, it is not necessary to correct the angle of the panel mounting part,
Construction is also significantly easier.

A reinforcing pipe of an anchor can be used as a means for making the construction method of the earth retaining structure function more effectively. The reinforcing pipe is a tubular body through which the anchor can be passed inside, and the middle part draws a gentle curve to
It is bent 45 degrees. Further, blades having a desired length are provided on the left and right sides of the outer circumference. The reinforcing pipe is put on the bent portion of the anchor so that there is no bent portion of the anchor. Moreover, the pressure receiving area is enlarged by the blades so that the anchor does not easily rotate in the ground.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on an embodiment shown in the drawings. 1 and 2 show the case where the earth retaining panel 7 is used as the earth retaining structure. In the figure, reference numeral 1 is a natural ground, and a plurality of excavation holes 2 are excavated in the natural ground 1. The drill hole 2 is inclined so that it becomes deeper toward the bottom. The anchor 3 is inserted into the excavation hole 2. The anchor 3 is formed by bundling a plurality of tensile materials such as steel stranded wires and arranging them in a straight free length sheath 4 and a fixing long sheath 5 having an uneven peripheral surface. The anchor 3 is inserted from the fixed long-sheath sheath 5 side and placed in the excavation hole 2. Cement milk 6, which is a hardening material, is injected into the excavation hole 2 and fixed. The breathing water in the drill hole 2 is pushed up by the cement milk 6 rising from the bottom and discharged to the outside of the drill hole 2.

In the embodiment, the protruding portion of the anchor 3 from the natural ground 1 is bent by 10 degrees with respect to the portion arranged in the excavation hole 2 to be horizontal. It is preferable that the portion to be bent is bent so as to gently curve in an arc shape so as not to bend too much. Earth retaining panel 7 at the tip of this anchor 3.
To fix. The tension material of the anchor 3 is passed through a head 9 arranged in a notch portion 8 formed in the panel 7 and fixed by a wedge. At this time, since the anchors 3 are all horizontal, it is not necessary to correct the angle of the notch portion 8, and the labor of processing the panel 7 does not occur. Further, the work of attaching the anchor 3 can be performed extremely easily. Also, the work of attaching the anchor 3 to the panel 7 is significantly facilitated. Earth 10 is buried between the panel 7 and the natural ground 1.

In the construction as described above, the portion of the anchor 3 in the excavation hole 2 of the natural ground 1 and the portion protruding therefrom are bent at a predetermined angle. Due to the tensile force of the anchor 3, a downward component force is generated in the bent portion, and a force for pushing the component downward is exerted. However, since this is widely dispersed in the ground immediately below the bent portion, this downward component force does not serve as a load on the foundation portion 11. In other words, the downward component force of the anchor 3 is dispersed to the ground immediately below the bent portion, and the foundation 11
Only the load of panel 7 is applied. Therefore, a localized concentrated load is not generated on the foundation portion 11 directly below the panel 7, and an accident such as the ground collapse does not occur. The fact that such a downward component force does not act is the same even when it is applied to the construction of sheet piles or piles, and there is an effect that it is not necessary to deeply insert the sheet piles. It is also conceivable that concrete is placed on the ground directly below the bent portion of the anchor 3 or a precast member is placed to reinforce it and receive the component force downward of the anchor 3.

As described above, the portion of the anchor 3 inside the excavation hole 2 and the portion protruding from it are bent at an angle, but in order to prevent damage to this portion and to prevent friction between tension members, this portion is Reinforcement can be adopted.
For example, it is conceivable to multiplex the free length sheath 4 or to cover with a reinforcing sheath made of steel having a large diameter so as to have a predetermined length that extends from the portion inside the drill hole 2 to the protruding portion. Moreover, FIG.
As shown in FIG. 5, it is also possible to employ a reinforcing pipe 12 such as a reinforcing steel pipe in which blades 13, 13 protruding laterally are fixed. It is possible to cover the bending portion of the anchor 3 with this reinforcing pipe 12 so that the bending of the anchor 3 does not extend. Further, it is possible to prevent the anchor 3 from easily rotating in the earth and sand by increasing the pressure receiving area of the blades 13 and 13 in the earth and sand.

[0014]

The present invention has the above-mentioned structure and can obtain the following effects. Since the part protruding from the drill hole is made horizontal by making a certain angle with respect to the part inside the drill hole of the anchor, there is no need to correct the mounting part of the structure at all, and it is extremely easy to work and inexpensive to construct. Become. In addition, the entire construction can be performed extremely easily. Since the anchor is bent at a predetermined angle with respect to the horizontal portion extending from the excavation hole, a downward component force is generated in the bent portion, and this downward component force is dispersed to the ground immediately below the bent portion. In other words, the downward force component of the anchor does not act on the ground directly below the structure, does not become a localized concentrated load, and the ground does not collapse. Even in the case of construction on piles or sheet piles, downward component force does not act on the structure of piles or sheet piles, so it is not necessary to deepen the rooting and resist this due to the frictional force of the ground. Easy construction is possible with a short structure. The anchor head for fixing the anchor to the structure is not inclined with respect to the structure, and the bracket used especially for the construction of piles or sheet piles is small, which simplifies the construction and reduces the construction cost. By covering the bent portion of the anchor with the reinforcing pipe according to the present invention, it is possible to prevent the anchor from extending. Further, since the blades are provided so as to project, the pressure receiving area becomes large, and it is possible to prevent the anchor from rotating in the ground.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of a method of constructing an earth retaining panel according to the present invention.

FIG. 2 is a sectional view of a construction state.

FIG. 3 is a perspective view of an embodiment of a reinforcing pipe.

FIG. 4 is a perspective view of another embodiment of the reinforcing pipe.

FIG. 5 is a perspective view of another embodiment of the reinforcing pipe.

FIG. 6 is a cross-sectional view of a conventional construction method.

FIG. 7 is a partial cross-sectional view of a panel.

FIG. 8 is a cross-sectional view of construction of a steel sheet pile.

[Explanation of symbols]

 1 Ground 2 Drill hole 3 Anchor 4 Free length sheath 5 Fixed length sheath 6 Cement milk 7 Earth retaining panel 8 Cutout portion 9 Head 10 Earth and sand 11 Foundation portion 12 Reinforcement pipe 13 Blade

Claims (3)

[Claims] 1. An anchor placed in an excavation hole in a natural ground is fixed, and an earth retaining structure is erected at a position separated from the surface of the natural ground by a predetermined distance and fixed to the tip of the anchor, and the natural ground and the structure are secured. In the construction method of burying earth and sand between and, the ground excavation hole is inclined so that it becomes deeper as it goes to the bottom, and the part placed in the anchor's excavation hole is inclined and On the other hand, a method for constructing an earth retaining structure, characterized in that the portion inside the excavation hole is bent at a predetermined angle. 2. The method for constructing an earth retaining structure according to claim 1, wherein a portion of the anchor inside the excavation hole is bent by 10 to 45 degrees with respect to a horizontal portion extending from the excavation hole. . 3. A tubular body through which an anchor can be passed, the middle part of which is drawn in a gentle curve and has a diameter of 10 to 45.
A reinforcing pipe that is bent once and has blades of a desired length protruding on the left and right sides of the outer circumference.