TWI853491B - Anti-collapse continuous wall construction method for special geological layers - Google Patents

Abstract

A method for constructing a special geological layer anti-collapse continuous wall, comprising the following steps: using a full casing cutting method with anti-collapse measures to construct in the special geological layer composed of gravel, drilling or cutting a hole; backfilling the hole with low-strength solidifying material, and gradually removing the full casing to form an anti-collapse area while waiting for solidification; repeating the above steps in the anti-collapse area and the adjacent area that has not been drilled or cut, repeatedly drilling or cutting and backfilling low-strength solidifying material, and finally forming a construction area required for the construction of the continuous wall; and, according to the needs of the construction of the continuous wall, drilling a plurality of construction holes in the construction area, so that the size of the construction holes is smaller than the size of the construction area, so as to construct the continuous wall in the construction holes, and prevent collapse to improve construction safety.

Description

Anti-collapse continuous wall construction method for special geological layers

This creation belongs to the field of building construction methods, especially a kind of anti-collapse continuous wall construction method for special geological layers. It is specifically aimed at special geological layers such as gravel layers or soft soil layers. When carrying out continuous wall construction, it uses a full casing method to dig and then fill with appropriate consolidation materials, or improve the soil to improve the geology. It is a means of anti-collapse. It uses backfill materials with easy excavation and cutting characteristics to avoid collapse during construction, so as to facilitate the subsequent continuous wall construction.

According to the new buildings, they must be built higher and dug deeper to gain more space. The basement and foundation excavation cannot be done by open excavation, but must be done vertically downward. In order not to affect the structural safety of the neighboring houses and to maintain the construction safety of the new construction site, appropriate protective facilities such as continuous walls are installed to surround the basement area of the base to be excavated, thereby preventing the soil and water on the outside from collapsing and seeping into the base during construction, allowing the underground structure to be constructed smoothly and preventing groundwater from entering the underground structure. According to the current building foundation structure design specifications, it refers to "using sheet-like continuous walls as foundation piles, called wall piles". Generally, it is called a continuous wall. When it is constructed, first, it is placed on the ground downward. Drilling forms an installation hole, which is pre-filled with stabilizing fluid to prevent the hole wall from collapsing. However, the surface soil layer 1 to 2 meters below the ground cannot stand on its own and collapses under the additional load of heavy machinery approaching. Therefore, before construction, shallow excavation and reinforced concrete guide walls will be constructed in the surface soil layer with lighter machinery in the construction area and its surroundings. To prevent construction accidents caused by soil collapse caused by heavy machinery drilling for piles; furthermore, if the soil below the topsoil is loose sand, extremely soft sediment, soft clay or gravel, and the depth exceeds the reinforced concrete guide wall, but the stabilizer alone cannot prevent the hole wall from collapsing, the trench excavation of the continuous wall may fail to collapse or cause construction quality problems.

There are generally two methods to solve the above-mentioned ground collapse problem: the first method is to adopt large-scale slope excavation, and then build deep guide walls and backfill earth in sections. First, build the bottom guide wall and backfill the bottom earth, then build the second guide wall and backfill the second earth, and finally build the upper guide wall and backfill the upper earth, and finally build a pavement. For construction sites where slope excavation cannot be used, anti-collapse measures such as steel sheet piles are used instead, and then vertical excavation is carried out. After completion, , similarly construct the aforementioned guide walls and backfill the earth in stages, and finally remove the steel plate piles before constructing the pavement. The above anti-collapse method is too cumbersome and requires repeated backfilling of earth, which makes it difficult to improve construction efficiency; the second method is to solidify the site with high-pressure spraying cement piles, then conduct shallow excavation, and finally construct shallow guide walls. However, there are still some geological conditions and engineering conditions that cannot be completely solved by the above-mentioned deep guide wall construction or site solidification measures.

Therefore, in order to solve the situation where methods such as "deepening the guide trench" and "grouting geological improvement" are not applicable, the creator has designed the "anti-collapse continuous wall construction method for special geological layers", which is specifically aimed at the situation where the gravel layer or soft soil layer collapses during the excavation process due to loose structure or insufficient support of the stratum after excavation. For the gravel layer, full casing cutting and backfilling consolidation materials are adopted, or the geological improvement is carried out for the soft soil layer, so that a temporary and certain strength anti-collapse processing layer is formed in the construction area to avoid collapse during construction, and it has the characteristics of easy cutting and processing, which can indeed solve the construction of difficult situations such as "deepening the guide trench" and "grouting geological improvement".

One of the purposes of this invention is to provide a method for anti-collapse continuous wall construction in special geological layers, which can be used for special geological layers such as gravel layers or soft soil layers, such as full casing cutting, filling with consolidation materials or using consolidation materials to improve the geological structure, so as to avoid collapse during drilling or installation during subsequent continuous wall construction, thereby improving construction quality and safety.

To achieve the above-mentioned purpose, the invention provides a method for constructing a special geological layer with an anti-collapse continuous wall, which can prevent the special geological layer from collapsing during excavation and thus affect the continuous wall constructor. The method includes the following steps: using a full casing cutting method with anti-collapse measures to construct the special geological layer composed of gravel, drilling or cutting a hole, using the full casing to form a support means to avoid collapse; backfilling the hole with a low-strength solidifying material, and waiting for solidification to form an anti-collapse area before removing the full casing; in the anti-collapse area and adjacent areas, Repeat the above steps in the undrilled or uncut area, repeatedly drill or cut and backfill the low-strength solidifying material using the full casing cutting method, and then form a construction area produced by the low-strength solidifying material inside the special geological layer; and drill multiple construction holes in the construction area according to the needs of constructing a continuous wall, so that the size of the construction holes is smaller than the size of the construction area, and place multiple steel cages in the construction holes in sequence and connect them, and finally perform grouting to form the continuous wall.

In one embodiment, when constructing a continuous wall with a thickness of 100 cm in the special geological layer, the invention first uses a full casing with a diameter of 250 cm and then drills the pilot holes, the depth of which needs to be slightly greater than or equal to the depth of the continuous wall to be constructed. The cutting holes are overlapped by drilling through the pilot holes, and the overlapping area width is 150 cm.

In another embodiment, the anti-collapse continuous wall construction method of the special geological layer of this invention, when the special geological layer is a mixture of gravel and soft soil, can be combined with a modifier mixed in the special geological layer, so that it solidifies to prevent the collapse of the special geological layer.

In addition, in the step of "drilling a plurality of construction holes in the construction area according to the needs of constructing the continuous wall, so that the size of the construction holes is smaller than the size of the construction area, and placing a plurality of steel cages in the construction holes in sequence and then connecting them, and finally performing a pouring project to form the continuous wall", the construction holes are combined with different continuous wall construction methods, and there are different setting methods such as setting the construction holes in an intermittent manner or setting the construction holes in a continuous manner.

S1~S4: Steps

1: Special geological layer

11: Holes

2: Continuous wall

3: Low strength solidifying material

31: Anti-collapse area

32: Construction area

33: Construction hole

4: Steel cage

Figure 1 is a flowchart of the steps in implementing the preferred embodiment of this invention.

Figure 2 is a schematic diagram of the state of the preferred embodiment of this invention corresponding to step S1 operation.

Figure 3 is a schematic diagram of the state of the preferred embodiment of this invention corresponding to step S2 operation.

Figure 4 is a schematic diagram of the state of the preferred embodiment of this invention corresponding to step S3 operation.

Figure 5 is a schematic diagram of the state of the preferred embodiment of this invention corresponding to step S4 operation.

In order to enable you, the review committee, to clearly understand the content of this work, please refer to the following description and diagram.

Please refer to Figures 1 and 2 to 5, which are the step flow charts of the preferred embodiment of the present invention, and the state diagrams of the corresponding steps. As shown in the above figures, the anti-collapse continuous wall construction method of the special geological layer of the present invention prevents the excavation work of the special geological layer 1 from causing continuous collapse during the construction process and making it impossible to construct the continuous wall 2, and includes the following steps:

S1: Use the full casing cutting method with anti-collapse measures to construct in the special geological layer 1 composed of gravel, and drill or cut a hole 11; it should be noted that the full casing cutting method can use the full casing to form a means of supporting the gravel in the hole, thereby avoiding the phenomenon of collapse, and using the full casing to separate the gravel to form the hole 11.

S2: Backfill a low-strength solidifying material 3 in the hole 11 and wait for it to solidify to form an anti-collapse area 31 before removing the entire casing; it should be noted that when the special geological layer is a mixture of gravel and soft soil, an improver can be mixed in the special geological layer to prevent the collapse of the special geological layer after the soft soil and the low-strength solidifying material solidify.

S3: Repeat the above steps in the anti-collapse area 31 and the adjacent area that has not been drilled or cut, forming a repeated drilling or cutting and backfilling of the low-strength solidifying material 3 using the full casing cutting method, thereby forming a construction area 32 generated by the low-strength solidifying material 3 inside the special geological layer 1; it should be noted that the diameter of the hole is about 250cm, and after several consecutive drillings or cuttings, a row of holes 11 of the same size can be generated, and a construction area 32 with a width greater than 100cm is formed.

S4: Drill a plurality of construction holes 33 in the construction area 32 according to the requirements of constructing the continuous wall 2, so that the size of the construction holes 33 is smaller than the size of the construction area 32, and place a plurality of steel cages 4 in the construction holes 33 in sequence and then connect them, and finally perform grouting to form the continuous wall 2. It should be noted that the construction holes are matched with different continuous wall construction methods. For example, in the common continuous wall construction method, the C.W.S method (underground continuous wall high load-bearing lead joint method) (as shown in FIG. 4), the construction holes 33 of the present invention are arranged in an intermittent manner, that is, the two construction holes 33 are first constructed at intervals, and the two steel cages 4 are respectively placed therein and fixed, and finally the two construction holes 33 are dug through and the other steel cage 4 is placed therein and then connected to the first two steel cages 4 to form a whole. In addition, in the M.H.L method (Masago Hydraulic Long bucket, hydraulic longwall excavator excavation continuous wall construction method), the construction holes 33 of this invention are set in a continuous manner, that is, after each construction hole 33 is excavated, the steel cage 4 is immediately placed, and then the next construction hole 33 is excavated and the steel cage 4 is placed, and the two steel cages 4 are connected into one body. However, the above two construction methods are excavated or drilled within the construction area 32, so there will be no collapse.

According to this, the anti-collapse continuous wall construction method of the special geological layer of this invention uses different anti-collapse means to construct the construction area 32 and solidify it into an anti-collapse area. For example, for the special geological layer 1 composed of gravel or mixed with soft soil, anti-collapse means such as full casing cutting method and then filling mud or using mud to improve the geological conditions are used to form a supporting effect and easy to The processed strata are backfilled with segmented and overlapping drilling or cutting of the holes 11 to avoid collapse during drilling. Therefore, the construction area 32 processed by this invention can meet the requirements of various continuous wall construction methods on the market, which can ensure that the construction process will not be delayed due to collapse, or that the operators will not be in potential danger during the construction process.

However, the above is only the best implementation example of this creation, and is not used to limit the scope of implementation of this creation. Therefore, those who have common knowledge in the relevant technical field, or those who are familiar with this technology and make equivalent or easy changes, should be covered by the patent scope of this creation without departing from the spirit and scope of this creation.

S1~S4: Steps

Claims (5)

A method for constructing a special geological layer to prevent collapse of the continuous wall can prevent the special geological layer from collapsing during excavation and thus affect the continuous wall constructor. The method comprises the following steps: using a full casing cutting method with collapse prevention measures to construct the special geological layer composed of gravel, drilling or cutting a hole, using the full casing to form a support means to prevent collapse; backfilling a low-strength solidifying material in the hole, and waiting for solidification to form an anti-collapse area before removing the full casing; in the anti-collapse area and adjacent areas that have not been drilled or cut, Repeat the above steps in the area to be cut, repeatedly drill or cut and backfill the low-strength solidifying material using the full casing cutting method, and then form a construction area produced by the low-strength solidifying material inside the special geological layer; and drill a plurality of construction holes in the construction area according to the needs of constructing a continuous wall, so that the size of the construction holes is smaller than the size of the construction area, and place a plurality of steel cages in the construction holes in sequence and connect them, and finally perform grouting to form the continuous wall. For the anti-collapse continuous wall construction method for special geological layers as described in claim 1, when constructing a 100 cm thick continuous wall in the gravel layer, first use a full casing with a diameter of 250 cm and then drill the pilot hole. The depth must be slightly greater than or equal to the depth of the continuous wall to be constructed. Drill through the pilot holes so that the holes overlap each other, and the width of the overlapping area is 150 cm. For the anti-collapse continuous wall construction method for special geological layers as described in claim 1, when the special geological layer is a mixture of gravel and soft soil, an improver can be mixed in the special geological layer to prevent the collapse of the special geological layer after the soft soil and the low-strength solidifying material solidify. In the anti-collapse continuous wall construction method for special geological layers as described in claim 1, in the step of "drilling a plurality of construction holes in the construction area according to the needs of constructing the continuous wall, making the size of the construction holes smaller than the size of the construction area, placing a plurality of steel cages in the construction holes in sequence and connecting them, and finally performing grouting to form the continuous wall", the construction holes are arranged in an intermittent manner. In the anti-collapse continuous wall construction method for special geological layers as described in claim 1, in the step of "drilling a plurality of construction holes in the construction area according to the needs of constructing the continuous wall, making the size of the construction holes smaller than the size of the construction area, placing a plurality of steel cages in the construction holes in sequence and connecting them, and finally performing grouting to form the continuous wall", the construction holes are arranged in a continuous manner.

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