JPS63308108A - Underwater construction of gravity type retaining wall - Google Patents

Abstract

PURPOSE:To construct a retaining wall by using sheet piles having a comparatively small rigidity by a method in which joint parts are projected from the inside of a sheet pile, a partition wall is formed of the sheet piles, and a hardening material is placed in a multi-layer up to a given height in contact with the inner surface of the partition wall. CONSTITUTION:A partition wall 1 is formed, and a hardening material 3 is placed up to a given height in contact with the inner wall of the wall 1 on the bottom under water inside of the wall 1. Many joint parts 2, e.g., dowel beam, etc., are projected at given intervals vertically from the inner face of the sheet pile of the wall 1. The material 3 placed is cured for a fixed period of time, and the material 3 is likewise placed on the cured material 3 to form a multi-layer stepwise. Cross sectional force and displacement which occur in the wall 1 can thus be relieved.

Description

[Detailed Description of the Invention] "Industrial Application Field" This invention is a method for constructing retaining walls such as sea walls by pouring hardened materials such as concrete in stages on the inside of partition walls established underwater. It is related to construction methods.

``Prior art, problems to be solved by invention'' In the past, it was difficult to assemble formwork in deep water such as the sea, so no bank protection structure using retaining walls was constructed, and only caissons or caissons were used. Currently, bank protection construction is carried out using sheet piles with high support rigidity.

However, in construction using caissons or highly rigid sheet piles, large-scale machinery is required, resulting in large-scale construction, resulting in problems such as large construction costs and long construction times.

"Means for Solving the Problems" In order to solve the above-mentioned conventional problems, the present invention establishes a partition wall on the underwater ground, and protrudes joint materials at predetermined intervals vertically on the inner surface of the partition wall. A hardened material is placed at a predetermined height on the bottom of the water inside the partition wall in contact with the inner surface of the partition wall, and after curing for a certain period of time, it is partially integrated with the partition wall using joint material. After that, the hardened material is poured in the same way on top of the first stage hardened material, and the same steps are repeated step by step while curing sequentially, and the hardened material is poured in multiple layers to a predetermined height. Each part of the hardened material is partially integrated into the partition wall, and each part supports the lateral pressure acting on the partition wall by the hardened material cast in the next process, reducing the cross-sectional force and displacement generated in the partition wall. This paper proposes a construction method that makes it possible to construct retaining walls using sheet piles, etc., which are not very rigid, as partition walls.

"Embodiments" Below, embodiments of the present invention shown in the drawings will be described.
As shown in FIG. 1, a partition wall 1 is established by continuously driving sheet piles or the like into the underwater ground on a floating work boat.

On the inner surface of the sheet piles etc. that make up this partition wall l, a large number of joint materials 2 such as dowel bars are placed at predetermined intervals vertically.
Set it up.

Next, as shown in FIG. 2, a hardening material 3 such as concrete or soil cement is placed on the bottom of the water inside the partition wall
The concrete is placed at a predetermined height in contact with the inner surface of the concrete.

Then, this first stage hardened material 3 is cured for a certain period of time, and after it has hardened, the second stage hardened material 3 is placed on top of it as shown in FIG. Meanwhile, as shown in Fig. 4, hardened material 3 is poured in multiple layers in stages until the desired height is reached, and the rear portion is reclaimed 4 to create a retaining wall (such as a sea wall).

The hardened material 3 of each layer cast and hardened in one step in this way is integrated by the joint material 2 at the end that contacts the inner surface of the partition wall 1, as shown in FIG.
As shown in FIG. 6, the moment acting on the partition wall 1 due to the gravitational force of is distributed to each layer, and can be suppressed to a low value.

Therefore, if the bearing capacity of the ground can be obtained, it is possible to reduce the height of pouring to a low level so as to reduce the cross-sectional force and displacement acting on the partition wall 1, without using particularly large sheet piles with high rigidity. It is impossible to construct the seawall up to a height of approximately 30m.

Incidentally, if an error occurs during construction with respect to the design value of the final displacement amount, it can be corrected by adjusting the casting height of the -times hardened material 'I43.

``Effects of the Invention'' As described above, according to the present invention, a partition wall is established on the underwater ground, and joint materials are provided protruding from the inner surface of the partition wall at predetermined intervals vertically. A hardened material is placed at a predetermined height on the inner water bottom in contact with the inner surface of the partition wall, cured for a certain period of time, and partially integrated with the partition wall using joint material, and then poured onto the first stage of hardened material. The hardening material is poured in the same way over the top layer, and the same process is repeated step by step while curing sequentially, and the hardening material is poured to a predetermined height.This allows each layer to harden while keeping the casting height low. Each material is partially integrated into the partition wall using a joint member, and the lateral pressure acting on the partition wall is supported by the hardened material cast in each part in the next process, thereby reducing the cross-sectional force and displacement generated in the partition wall. As a result, even in deep water sites, it is possible to construct a retaining wall using sheet piles, etc., which are not very rigid, as a partition wall, reducing construction cost and construction period, making it possible to construct economically. becomes.

[Brief explanation of the drawing]

fJS1 to 4 are vertical cross-sectional views sequentially showing the construction process according to the present invention, and FIG. 5 is a vertical cross-sectional view of the main parts of the construction according to the present invention.
FIG. 6 is a diagram showing the relationship between bending moments generated in the partition wall during construction according to the present invention. ■...Partition walls, 2.Joint materials, 3.Hardened materials, 4.Reclamation. Figure 1 Figure 2 Figure 5 Figure 3 Fourth cause Sixth cause

Claims (1)

[Claims] A partition wall such as a sheet pile with joint materials protruding from the inner surface at predetermined intervals vertically is established on the underwater ground, and a hardened material is applied to the required height on the underwater bottom inside the partition wall in contact with the inner surface of the partition wall. This is then cured for a predetermined period of time to be integrated into the partition wall using the joint material, and then a hardened material is placed over the first stage of hardened material in the same way, and gradually cured. An underwater construction method for gravity retaining walls, which is characterized by repeating the same process and pouring hardened material to a predetermined height.