JPH03235811A - Continuous underground wall head portion processing work method - Google Patents

Abstract

PURPOSE:To prevent noise and vibration, by providing sinkingly within wall holes reinforced baskets fitted with partition plates and containers filled with a static breaking agent, and conducting expansion by making a stabilizing liquid absorbed into the breaking agent, and placing concrete into the insides of wall holes, and hardening it. CONSTITUTION:A static breaking agent is filled into containers such as spiral sheath pipes 4, 5, and containers are fitted to the continuous underground wall head portions of reinforced baskets 1. Next, partition plates 6 are fitted at continuous wall head portions at every predetermined interval, and then, the reinforced baskets 1 are provided sinkingly within continuous wall holes filled with a stabilizing liquid, and then, the stabilizing liquid is absorbed into the breaking agent through containers. Next, concrete is placed as far as above a breaking planning line 3, and also, curing is made. And the breaking agent generates a hydration reaction, and cracks are generated at continuous wall head portions by manifesting expansion pressure. In addition, cracked concrete is broken further into small pieces by the partition plates 6.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for treating the head of a continuous underground wall, and in particular a method for treating the head of a continuous wall by the hydration expansion action of a static crushing agent. This invention relates to a processing method for crushing and removing excess concrete.

[Conventional technology]

Generally, when constructing buildings, bridges, etc., a continuous underground wall is formed by drilling a continuous wall hole underground at the site and pouring ready-mixed concrete into the hole. Continuous cast-in-place walls are used. In this case, it is necessary to remove defective excess concrete that occurs at the head of the continuous underground wall, and conventionally, this excess concrete has been removed mainly using a breaker.

[Problem to be solved by the invention]

However, the conventional method of using breakers causes significant noise, vibration, and dust generation in the neighborhood.
In urban areas, it causes pollution and poses safety and health problems for workers.

Therefore, a technical object of the present invention is to provide a method for processing the head of a continuous wall that is quiet and safe without noise or vibration.

[Means to solve the problem]

In order to solve the above-mentioned technical problem, the present invention attaches a container filled with a static crushing agent to the head of the continuous wall of a reinforcing bar cage forming the framework of a continuous underground wall, and separates the head of the continuous wall at a predetermined interval. A reinforcing cage with the container and partition plate attached in this way is sunk into the wall hole, and the stabilizing liquid in the wall hole is absorbed by the static crushing agent to create a static crusher. The hydration expansion of the crushing agent is achieved, concrete is poured into the wall hole, and then it is cured and hardened, and the expansion pressure of the static crushing agent causes cracks to occur at the head of the continuous wall, causing the continuous wall to expand. The method used is a continuous wall head treatment method for continuous underground walls that crushes the excess concrete at the head.

The static crushing agent used in the present invention is calcium
Alumino ferrite [(CaOL・Al2O3・Fe
The basic components are 2031, free calcium oxide (Cab), and magnesium oxide (MgO), to which borate and the like are added as a retarder.

Note that the time for the hydration swelling pressure to develop can be adjusted by appropriately changing the type and amount of the retarder.

The properties of the static crushing agent are not limited, but especially when the static crushing agent is prepared in the form of granules, by maintaining voids between each particle, the stabilizing liquid can sufficiently envelop each particle. Therefore, even if a container filled with a static crushing agent is simply immersed in a stabilizing liquid, each particle is sufficiently hydrated and expansion pressure can be developed.

Methods for forming static crushing agents into granules include a method in which the dry powder of the crushing agent is continuously granulated into strong almond-shaped briquettes using a briquetting machine, and a method in which the dry powder of the crushing agent is continuously granulated into strong almond-shaped briquettes using a compacting machine. There are methods in which dry powder is compression-molded into a plate shape using a smooth roll, then crushed and granulated, and other dry compression-molding methods.

In addition, the size of the granules of the static crushing agent may be at least large enough to form voids between each particle.
For example, the particle size distribution shown in Table 1 below is suitable.

Table 1 Particle size distribution (wt%) The granular static crushing agent filled in the container absorbs water through the wall of the container made of permeable material, or the container is made of impermeable material. In the case of a granule, the openings at both ends are covered with a mesh net that is large enough to prevent the granules from falling out, and water is absorbed through this net.

On the other hand, the stabilizing liquid in the continuous wall hole is injected into the wall hole to prevent collapse of the surrounding surface of the wall hole during excavation of the continuous wall hole.For example, a bentonite solution or CMC or a dispersant is added to the bentonite solution. Added materials are used.

In actual water absorption, if the stabilizing liquid is sufficiently filled in the continuous wall hole, the stabilizing liquid will be absorbed when the reinforcing bar cage is sunk into the continuous wall hole, but if the stabilizing liquid is not sufficiently filled, the stabilizing liquid will be absorbed. When placing concrete, the water level of the stabilizing liquid is raised before it absorbs water. Note that the optimal hydration conditions for the static crushing agent can be adjusted by adjusting the immersion time in the stabilizing solution.

Partition plates that divide the head of a continuous wall at predetermined intervals are used to break the head of the continuous wall into small pieces. As long as it is a partitioning board, there are no restrictions on the material.

Next, the treatment method of the present invention will be explained based on FIG.

First, a granular static crushing agent is filled into a container such as a spiral sheath pipe, and the container is attached to a predetermined location on the head of a continuous wall between reinforcing bars framed to a predetermined size (processing step 100).

Furthermore, after installing partition plates at predetermined intervals at the head of the continuous wall,
The reinforcing bars are placed in a continuous wall hole filled with a stabilizing liquid (processing step 101).

At this time, the stabilizing liquid enters through the entire container or through the nets at both ends and is absorbed by the static crushing agent (processing step 10).
2). Next, concrete is placed above the crushing plan line while replacing with a stabilizing liquid, and is cured until the concrete develops its strength (processing step 103). Static crushing agent
Water absorption of the stabilizing liquid gradually causes a hydration reaction, and after the concrete has sufficiently hardened after curing, expansion pressure is developed and cracks are generated at the heads of the continuous walls (processing step 104).

Then, since the cracked and crushed concrete is further crushed into smaller pieces by the partition plate, this excess concrete is removed block by block to complete the treatment of the continuous wall head (processing step 105).

(Example) CAB (product name manufactured by Sumitomo Cement Co., Ltd.), which is a type of static crushing agent, is molded into granules, and the granules are molded into a flat spiral sheath tube with a horizontally oblong cross section (maximum diameter 45 mm, length 50 cm).
m) and a round spiral sheath tube with a circular cross section (diameter 4
0 mm and length 50 cm). Then, both ends of these spiral sheath tubes are closed with nets, and the second
As shown in the figure and FIG. 3, it was arranged in a box-shaped reinforcing bar 1 with a width dimension W = 1.5 m and a length dimension J2 = 6 m. In this arrangement, the flat spiral sheath pipe 4 is placed on the fracture plan line 3 set at the head of the continuous wall along the main reinforcement 2 of the reinforcing bar 1.
and the round spiral sheath tube 5 at a position slightly above it.
are arranged respectively, and are fixed to the main reinforcing bars 2 of the reinforcing bar cage 1 with binding wires. In addition, the round spiral sheath tube 5
The racks are passed in the width direction of the reinforcing bar cage 1 every 1.5 m along the length direction of the reinforcing bar cage 1 at the same height position as above. Further, a tin plate 6 having a height dimension is disposed adjacent to the round spiral sheath pipe 5 above the planned fracture line 3.

Next, the reinforcing cage to which the spiral sheath pipe 4.5 and the tinplate plate 6 are attached is placed in the continuous wall hole, and the spiral sheath pipe is submerged in the stabilizing liquid. Concrete was then poured while replacing the stabilizer with a stabilizing solution.

When the head of the continuous wall was dug up after curing for 7 days, cracks with a width of 1 to 2 cm were found along the fracture plan line 3, and the cracks caused by the round spiral sheath pipe 5 were caused by the flat spiral sheath pipe 4. In the excess concrete portion above the horizontal cracks that occur, cracks were generated in all directions from the round spiral sheath pipe 5 without having a fixed directionality. Furthermore, since the head of the continuous wall was partitioned by a tin plate, the crushed blocks caused by cracks were broken into small pieces, and these crushed blocks could be easily removed.

〔effect〕

As explained above, according to the method for treating the head of a continuous underground wall according to the present invention, by using the hydration expansion pressure of a static crushing agent and the partition plate, continuous ground It is now possible to easily process the continuous wall head of the middle wall without vibration or noise.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the processing steps of the continuous wall head treatment method according to the present invention, FIG. 2 is a front view of a reinforcing bar corner in which a spiral sheath pipe is arranged, and FIG. 3 is a plan view of a reinforcing bar corner. 1... Rebar cage 2... Main reinforcement 3... Fracture plan line 4... Flat spiral sheath pipe 5... Round spiral sheath pipe 6... Partition plate

Claims (1)

[Claims] A container filled with a static crushing agent is attached to the head of a continuous wall of a reinforcing bar cage forming the framework of a continuous underground wall, and partitions are attached to the head of the continuous wall in a vertical direction at predetermined intervals. A reinforcing cage with a container and a partition plate attached is placed inside the wall hole, and the static crushing agent absorbs the stabilizing liquid in the wall hole, allowing the static crushing agent to hydrate and expand. , After concrete is poured into the wall hole, it is cured and hardened, and the expansion pressure of the above-mentioned static crushing agent causes cracks to occur at the head of the continuous wall, and the excess concrete at the head of the continuous wall is crushed. A continuous wall head treatment method for continuous underground walls.