JPH09296463A - Construction method of L-shaped retaining wall corner - Google Patents

Abstract

(57) [Abstract] [Problem] (1) Work safety is improved by setting low-place work to tightly connect the front wall block and the bottom slab block, which was highly dangerous and involves a lot of work at high places. (2) Place the PC steel rod in a more effective position. (3) Prevent damage to the joints between the front wall blocks at the corners. In a method of constructing a corner portion of an L-shaped retaining wall by dividing a bottom slab and a front wall and connecting precast reinforced concrete products in which the bottom slab and the front wall are each divided into a plurality of blocks, (A) bottom side A precast reinforced concrete product with a nut embedded in it and a vertical through hole extending from the nut to the upper surface is used as a bottom slab block. (B) An overhanging portion is provided at the bottom of the earth pressure side, and a vertical through hole is provided in the overhanging portion. A precast reinforced concrete product is used as a front wall block (C) A tension is introduced by a PC steel rod between the embedded nut on the bottom slab block side and the upper end surface of the overhanging portion on the front wall block side for tight connection, and (D) Adjacent The front wall blocks are connected by straight parts that are not corners.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing a corner portion of a large L-shaped retaining wall used as a retaining wall.

[0002]

2. Description of the Related Art An L-shaped retaining wall used for a corner portion is inevitably wider in width than an L-shaped retaining wall used for a straight portion. Therefore, when the earth retaining height is low (3
It is possible to produce L-shaped retaining walls that are precast reinforced concrete products and transport them to the site for installation, but if the earth retaining height becomes high, the L-shaped retaining walls to be installed will suddenly become large. As a result, production becomes impossible in the factory, or even if production is possible, it becomes impossible to transport the product. For this reason, when the earth retaining height becomes higher, the front wall is divided into upper and lower parts, the bottom plate is divided into front and rear parts, or the front wall and the bottom plate are divided. Attempts have been made to connect and integrate by means of. If it is unavoidable, it is constructed of cast-in-place reinforced concrete.

FIG. 3 shows an example of a system in which a bottom plate and a front wall are divided. Further, the bottom plate is divided into three parts 2a, 2b and 2c, and correspondingly the front wall is also 3a, 3b and 3c. And 2a-3a, 2b-3b, 2c-3c as a pair to connect to the L-shape, and 3 pairs of L-shapes to each other to connect the corners of one large L-shaped retaining wall. To build. The through hole 5 for inserting the PC steel rod is provided in the center of the thickness of the front wall.

[0004]

In the conventional construction method as shown in FIG. 3, (1) the front wall and the bottom plate are connected to each other at a high position because the PC steel rod is tightly connected at the upper end of the front wall. Increase, the risk of construction increases and the construction cost rises.
(2) Since the PC steel rod is arranged at the center of the thickness of the front wall, the yield strength of the front wall against earth pressure is reduced. (3) Since the connecting positions of the front walls coincide with the corner portions, the connecting portions are easily broken by earth pressure. There is such a problem.

[0005]

According to the present invention, (1) the location of the PC steel rod is moved to the earth pressure side, (2) the location of the PC steel rod fixed to the front wall block is lowered, ( 3) Using the front wall block whose surface is bent to connect adjacent front wall blocks with a straight line part that is not a corner part. The purpose is to resolve.

That is, the present invention provides a method for constructing a corner portion of an L-shaped retaining wall by dividing a bottom slab and a front wall and connecting precast reinforced concrete products obtained by dividing the bottom slab and the front wall into a plurality of blocks. (A) A nut is embedded in the bottom surface side, and a precast reinforced concrete product having vertical insertion holes from the nut to the top surface is used as a bottom slab block. (B) An overhanging portion is provided in the lower portion on the earth pressure side.
A precast reinforced concrete product having a vertical through hole in the overhang is used as a front wall block. (C) A tension force is introduced by a PC steel rod between the embedded nut on the bottom slab block side and the upper end surface of the overhang part on the front wall block side. And (D) the adjacent front wall blocks are connected to each other by a straight line portion that is not a corner portion.

Although the bottom slab block used in the present invention is not much different from the conventional bottom slab block in shape, the position of the embedded nut and the insertion hole extending upward from the bottom nut block is higher than that of the conventional one.
Close to the earth pressure side. The front wall block is significantly different in shape and structure from the conventional one.

That is, the through hole for inserting the PC steel rod, which is conventionally provided at the center of the thickness of the front wall, is abolished, and instead, an overhanging portion is provided under the back surface (earth pressure side), and the overhanging portion is provided. A through hole is provided in the portion in the vertical direction. Furthermore, the front wall block installed at the corner of the corner is not flat in surface, but is bent corresponding to the bending of the corner.

The bottom slab block and the front wall block are transported to the site, and the L-shaped retaining wall at the corner is assembled as follows.

(1) A plurality of bottom slab blocks are installed at predetermined positions and the bottom slab blocks are connected to each other to form a bottom slab. (2) The lower end of the PC steel rod or the PC steel rod with the coupler is screwed to the embedded nut of the bottom plate. (3)
Each front wall block is hung on a predetermined position of the slab so that the front wall block for a corner with a bent surface is installed over two bottom slab blocks, and the PC steel is aligned and aligned. Insert the rod into the through hole in the front wall block. In the case of a PC steel rod with a coupler, the coupler is located at the lower end of the through hole, and the PC steel rod is inserted into the through hole and connected.
(4) A PC steel rod protruding above the through hole is pulled to introduce a tension force, and the upper end of the PC steel rod is fixed to the upper end surface of the overhang portion. (5) The front walls at the corners are formed by connecting the front wall blocks to each other.

By this assembling operation, the L-shaped retaining wall of the corner portion in which the bottom plate and the front wall are integrated is constructed. The slab block and the front wall block are connected to each other by bolting the end face steel plates, connecting bolts between the box punches, and connecting P between the box punches.
It is performed by an ordinary connecting method such as C steel rod connecting.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The structure and construction procedure of a slab block and a front wall block used in the present invention will be described below with reference to the drawings.

The illustrated example is an example in which three bottom slab blocks and four front wall blocks are assembled to construct an L-shaped retaining wall corner portion.

FIG. 1 is a plan view showing the arrangement of the bottom slab block and the front wall block, and FIG. 1 (a) is the arrangement of the bottom slab block.
(B) shows the arrangement of the front wall blocks, and (c) shows the arrangement of the front wall blocks on the slab block.

FIG. 2 shows P between the bottom block and the front wall block.
It is a longitudinal section showing connection by a C steel rod, (a) shows the case where a coupler is not used, and (b) and (c) shows the case where a coupler is used, respectively.

An embodiment of the present invention will be described in the order of construction with reference to FIGS. 1 and 2.

(1) The bottom plate block 2 is provided with a nut 6 embedded in the bottom surface side at the time of manufacture, and has a vertical insertion hole 7 extending from the nut 6 to the upper surface. At the time of manufacturing, the front wall block 3 is provided with an overhanging portion 4 at the lower portion on the earth pressure side, and the overhanging portion 4 is provided with a vertical through hole 5. (See FIG. 2) (2) The three bottom slabs 2a, 2b, 2c are shown in FIG.
The corner bottom slab 2 is formed by arranging as shown in (a), installing at a predetermined position, and connecting with each other.

(3) The lower end of the PC steel rod 8 is screwed onto the nut 6 embedded in the bottom plate 2 and is projected from the upper surface by a predetermined length.

(4) Four front wall blocks 3d, 3e, 3
1f and 3g are sequentially hung on the predetermined position of the bottom plate 2 according to the arrangement of FIG. 1 (b), and the protruding PC steel rod 8 is inserted into the through hole 5 of the front wall block and installed. As shown in the drawing, the front wall blocks 3d and 3e for corners whose surfaces are bent are bottom slab blocks 2a-2b and 2 respectively.
It is installed across a-2c.

(5) The PC steel rod 8 protruding from the through hole 5 is pulled to introduce a tension force, and the upper end of the PC steel rod 8 is fixed to the upper end surface of the overhanging portion 4.

(6) Front wall block 3d, 3e, 3f, 3
g are interconnected to form the corner front wall 3.

In this manner, the three bottom slab blocks 2 and the four front wall blocks 3 are assembled to construct the L-shaped retaining wall 1 at the corner.

In the example of FIG. 2 (a), the PC steel rod 8 was penetrated through the through hole 5 at the same time when the front wall block 3 was installed.
As shown in (b) and (c), the PC steel rod 8b having the coupler 10 attached to the upper end is screwed to the nut 6 and the front wall block 3 is installed. Alternatively, the PC steel rod 8c may be connected to the PC steel rod 8b via the coupler 10.

The layout of the bottom slab 2 in FIG. 1 (a) is an example in which three trapezoidal bottom slabs 2 are arranged symmetrically. However, depending on the shape of the corners, the number of the bottom slabs 2 may be different. There are cases where the number is two or there are cases where the number is four or more, and the shape is not limited to a trapezoid but may be a rectangle or a triangle.

Similarly, for the front wall block 3, a number other than four may be used, and the front wall block 3 may be arranged asymmetrically on the left and right.

[0026]

According to the construction method of the present invention, the following effects can be obtained.

(1) Compared with the conventional divided block assembling method, (1) most of the assembling work is performed at a low place and the work at a high place is reduced, so that the safety is improved. (2) Since the position of the PC steel material is arranged close to the earth pressure side, the tensile stress due to the earth pressure effectively acts on the front wall concrete, and it becomes possible to reduce the diameter of the PC steel material and reduce the number thereof. .

(3) Since the corner portion of the front wall is the front wall block and the connecting portion is a straight portion, there is no fear of breaking the connecting portion of the corner portion due to earth pressure. (4) Since the connecting surfaces of the bottom slab blocks and the connecting surfaces of the front wall blocks are separate vertical surfaces, stress is smoothly transmitted and stress concentration on the connecting surfaces is avoided.

[Brief description of drawings]

FIG. 1 is a plan view showing the arrangement of bottom slab blocks and front wall blocks, (a) is the arrangement of bottom slabs, (b) is the arrangement of front wall blocks, and (c) is the front wall block on the bottom slab block. Shows the arrangement of.

FIG. 2 is a vertical cross-sectional view showing a connection between a bottom slab block and a front wall block by a PC steel rod, (a) shows a case where a coupler is not used, and (b) and (c) show a case where a coupler is used. Show.

FIG. 3 shows an example of a conventional method of assembling divided blocks, (a) is a plan view and (b) is a longitudinal sectional view.

[Explanation of symbols]

1 ... Corner L-shaped retaining wall, 2, 2a, 2b, 2c ...
Bottom block, 3,3a, 3b, 3c, 3d, 3e, 3
f, 3g ··· Front wall block, 4 · · Overhanging part, 5 · · Through hole, 6 · · Nut, 7 · · Insertion hole, 8, 8b, 8c ·
・ PC steel rod, 10 ・ ・ Coupler.

Claims (1)

[Claims] 1. A method for constructing a corner portion of an L-shaped retaining wall by dividing a bottom slab and a front wall and connecting precast reinforced concrete products in which the bottom slab and the front wall are each divided into a plurality of blocks, wherein (A) bottom surface A precast reinforced concrete product in which a nut is embedded in the side and a vertical through hole extending from the nut to the upper surface is used as a bottom slab block. The precast reinforced concrete product provided is used as a front wall block, and (C) a tension is introduced by a PC steel rod between the embedded nut on the bottom slab block side and the upper end surface of the overhanging portion on the front wall block side, and (D) adjacent A method for constructing a corner portion of an L-shaped retaining wall, characterized in that the front wall blocks are connected by a straight portion that is not a corner portion.