Chiseling-free method for interior of foundation pit latticed column

Abstract

A chiseling-free method for the interior of a foundation pit latticed column is characterized in that a bag is installed in the latticed column, after a stand column pile on the lower portion of the latticed column is poured with concrete, water is injected into the bag, then the space between the latticed column and a pile hole where the latticed column is located is filled with flow-state solidified soil, after a soil layer is excavated, a water outlet of the bag is opened, water is made to flow away, the bag is dismantled, and then the bag is installed in the latticed column. And chiseling-free removal of the latticed column is realized. The bag comprises a bag outer layer, a bag inner layer and a water inlet / outlet; the positions, provided with the bolt fixing holes, of the outer layer of the bag are connected with the angle steel of the latticed column through bolts; the inner layer of the bag is made of a deformable material and is expanded after being filled with water; and the number of the water inlets and outlets is determined by the water inlet and outlet speed. The bag designed by the invention can be connected in series and lengthened according to actual requirements, can be detached and reused, and has the characteristics of high engineering adaptability and reusability; the space between the latticed column and the pile hole is filled with the flow-state solidified soil, so that manual chiseling of gaps between the pile and the hole can be avoided; and a water filling manner is utilized, so that the concrete consumption is reduced, the ecological environment is protected, and the cost is greatly reduced.

Description

Technical Field

[0001] The invention relates to the field of foundation pit engineering, in particular to a method for chiseling out lattice columns in foundation pit engineering. Background Art

[0002] In underground engineering construction, excavation of foundation pits is inevitable. According to existing specifications, foundation pit projects with a single span greater than 20m need to be equipped with column piles to bear the deadweight of the support. The most common form of column piles is that the upper part is a lattice column and the lower part is reinforced concrete, and the upper and lower parts are connected by a lattice column inserted into the reinforced concrete at a certain depth. This form gives full play to the bearing function of the lower pile. The upper lattice column is a hollow steel structure, which can facilitate the passage of the steel bars of the concrete support to form a complete force node, and can also be welded on the lattice column for easy overlap. However, during the construction of column piles, plain concrete is often used to fill the entire pile hole superstructure, that is, the upper lattice column. After excavation, it is necessary to manually chisel the concrete inside and outside the lattice column to play the role of the lattice column. The chiseling process is time-consuming, which is one of the important reasons why the foundation pit support fails to play its role in time. In addition, the chiseling produces huge noise, which is one of the main noise sources in the construction of foundation pit projects, and has a very negative impact on the surrounding environment and the health of workers, affecting the personal safety of workers. In addition, the chiseling can only be done manually, and the chiseling cost is also very high. Therefore, it is urgent to improve the chiseling method of lattice columns.

[0003] At present, relevant technicians have proposed a method for lattice columns (CN 221461609 U) that is easy to clean quickly, which is to fill the inside of the lattice column with foam glue in order to reduce the need to chisel out the concrete. However, this method only fills the inside, and the concrete outside the pile still needs to be chiseled out. In addition, the filled foam glue still needs to be manually dug out, and there is also a major fire risk, because lattice columns often need to be welded during construction, and the high temperature of welding can easily cause the foam glue to catch fire. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a method for eliminating the need to chisel out lattice columns in foundation pit engineering, thereby avoiding the need to chisel out concrete and avoiding the shortcomings of existing methods. The present invention installs bags on the lattice columns, and after the lower column piles are poured with concrete, water is poured into the bags so that the lattice columns are filled with water, and then fluidized solidified soil is filled between the lattice columns and the pile holes to seal the holes. After the soil layer is excavated, the water inlet and outlet of the bags are opened to allow the water to flow away, and the bags are removed and reused. In this way, the lattice columns can be eliminated from chiseling out. The present invention has the advantages of low cost, reusability, and environmental protection, and is particularly suitable for situations where the lattice columns in foundation pit engineering do not need to be chiseled out of concrete.

[0005] The present invention provides a method for eliminating chiseling of lattice columns in foundation pit engineering. The core of the method is to install a bag in the lattice column, and after pouring concrete on the column piles at the bottom of the lattice column, water is injected into the bag, and then fluidized solidified soil is filled between the lattice column and the pile hole where the lattice column is located. After the soil layer is excavated, the water outlet of the bag is opened to let the water flow away, and the bag is removed to achieve eliminating chiseling of the lattice column. The method specifically includes the following steps:

[0006] Step 1, after completing the connection between the steel bars of the column pile and the lattice column, installing the bags in series on the lattice column; the number of the bags is greater than or equal to 2;

[0007] Step 2, hoisting the column piles and lattice columns into the pile holes;

[0008] Step 3, pouring concrete into the lower part of the column pile using a conduit;

[0009] Step 4, after the concrete has initially set, fill the bag with water;

[0010] Step 5, after the bag is filled with water, fluidized solidified soil is filled between the lattice column and the pile hole;

[0011] Step 6, excavating the soil at the first concrete support and constructing the first concrete support;

[0012] Step 7, excavating the first layer of soil, the first layer of soil is at the same height as the first concrete support; draining the bag water above the ground, and constructing the second concrete support according to the method of step 6;

[0013] Step 8, excavating the second layer of soil, the second layer of soil is at the same height as the second concrete support; draining the bag water above the ground, and constructing the third concrete support according to the method of step 6;

[0014] Step 9, refer to the methods of steps 6-8 to repeat the construction of concrete support, digging soil, and releasing the water in the bag to finally complete the foundation pit excavation.

[0015] Preferably, the bladder bag includes an outer layer, an inner layer and water inlets and outlets; the outer layer of the bladder bag is installed with bolt fixing hole positions, and is connected to the angle steel of the lattice column through bolts; the inner layer of the bladder bag is a deformable material and is expanded after being filled with water; the water inlets and outlets are located at the upper and lower parts of the bladder bag, and the number of the water inlets and outlets is determined by the rate of water inlet and outlet.

[0016] Preferably, the plurality of bags are connected in series in such a manner that the water inlets and outlets of adjacent bags are interconnected.

[0017] Preferably, the compressive strength value of the filled fluidized solidified soil after solidification is lower than 4 MPa, so that the fluidized solidified soil can be directly excavated by an excavator during excavation, avoiding manual excavation.

[0018] Preferably, the water in the bag is discharged by digging a water inlet and outlet from the bottom, and the water flows out naturally.

[0019] Preferably, after the water in the bag is drained, the bolts are unscrewed, the emptied bag is removed, and it is pulled out from the gap between the lattice columns, thereby eliminating the need for manual chiseling and enabling the bag to be reused.

[0020] Preferably, the size of the outer layer of the bag matches the size of the space inside the lattice column; the inner layer of the bag is in a naturally contracted state when not filled with water, forming an inner hollow structure that fits the inner side of the lattice column, and can provide a lowering channel for the conduit for pouring concrete.

[0021] Preferably, the material of the outer layer of the bladder bag is high temperature resistant soil arch fabric; the material of the inner layer of the bladder bag is rubber with high deformation ability.

[0022] Preferably, after the bag is filled with water, the outer layer of the bag fits into the inner space of the lattice column, and the inner layer of the bag is compressed, thereby squeezing the reserved inner hollow structure to fill it.

[0023] The invention also provides application of the method in foundation pit engineering.

[0024] The present invention has the following technical effects:

[0025] 1. The pouches designed in the present invention can be connected in series and extended according to actual needs, and can be dismantled and reused, and have the characteristics of strong engineering adaptability and reusability.

[0026] 2. The present invention can avoid artificial chiseling of the gap between the pile and the hole by filling the fluidized solidified soil between the lattice column and the pile hole.

[0027] 3. The present invention utilizes water filling to reduce the amount of concrete used, is eco-friendly and environmentally friendly, and also greatly reduces costs.

[0028] 4. The present invention eliminates the need for manual chiseling of concrete, greatly reduces labor and improves efficiency; it avoids noise and improves the construction environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is the drawing of column pile hoisting.

[0030] Figure 2 Complete pouring concrete drawing for column piles.

[0031] Figure 3 The picture after filling the bladder with water.

[0032] Figure 4 This is the picture after the first support is constructed.

[0033] Figure 5 Complete the first soil map for excavation.

[0034] Figure 6 Complete the second soil map for excavation.

[0035] Figure 7 Complete the third soil map for excavation.

[0036] Figure 8 This is the lattice column diagram when not filled with water.

[0037] Fig. 9 This is the lattice column diagram after filling with water.

[0038] Fig.10 This is the AA cross-section diagram of the lattice column when it is not filled with water.

[0039] Fig.11 This is the AA section view of the lattice column after filling with water.

[0040] The reference numerals in the figure are: 1-ground; 2-pile hole; 3-crane; 4-column pile reinforcement; 5-lattice column; 6-concrete; 7-first concrete support; 8-second concrete support; 9-third concrete support; 10-fluidized solidified soil; 21-angle steel; 22-attachment plate; 30-bladder; 31-bladder outer layer; 32-bladder inner layer; 33-bolt; 34-water inlet and outlet; 35-water. Specific embodiments

[0041] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them.

[0042] Example 1

[0043] This implementation case is a foundation pit project of a shopping mall, with a depth of 12m, excavated in three layers, each layer is 4m. Because it is in a soft soil area, a support structure of three concrete supports + ground-connected walls is adopted. Among them, in order to avoid manual removal of column pile concrete, the method of the present invention is adopted. The total length of the column pile is 24m, and the lattice column adopts a 750mm×750mm square section steel lattice column. Each bag is 2m long, and a total of 8 bags are used in series to achieve the goal of avoiding the removal of lattice column concrete. The main steps for implementation include:

[0044] Step 1: After welding the column pile reinforcement and lattice column, install 8 bags in series on the angle steel of the lattice column.

[0045] Step 2: Use a crane to lift the entire column pile into the pile hole.

[0046] Step 3: Use a conduit to pour C35 concrete into the lower part of the column pile.

[0047] Step 4: After the concrete has initially set, fill the bag with water at a pressure of 150 kPa.

[0048] Step 5: After the bag is filled with water, the fluidized solidified soil is filled between the lattice column and the pile hole, and the final compressive strength of the fluidized solidified soil is controlled within 4 MPa.

[0049] Step 6: Dig out the soil at the first concrete support to a depth of 1m and construct the first concrete support with a cross-sectional size of 1m high and 0.8m wide.

[0050] Step 7, excavate the first layer of soil with a thickness of 4m; dig the water inlet and outlet from the bottom to drain the bag water above the ground; after the water in the bag is drained, unscrew the bolts, remove the emptied bag, and pull the lattice column out of the lattice column air attack; and construct the second concrete support with a cross-sectional size of 1m high and 0.8m wide.

[0051] Step 8, excavate the second layer of soil with a thickness of 4m; dig the inlet and outlet from the bottom to drain the bag water above the ground; after the water in the bag is drained, unscrew the bolts, remove the emptied bag, and pull the lattice column out of the lattice column air attack; construct the third concrete support with a cross-sectional size of 1m high and 0.8m wide.

[0052] Step 9, excavate the third layer of soil with a thickness of 4m; dig the water inlet and outlet from the bottom to drain the bag water above the ground; after the water in the bag is drained, unscrew the bolts, remove the emptied bag, and remove the lattice column from the lattice column air attack; finally complete the foundation pit excavation.

[0053] The specific positions of the various parts and their interconnected relationships can be clearly seen through the accompanying drawings. These illustrations provide visual support for the specific embodiments of the present invention and are helpful for understanding its technical principles and practical applications.

[0054] Based on the embodiments of the present invention, all other implementations obtained by ordinary technicians in this field without making any creative work are within the scope of protection of the present invention.

Claims

1. A method for eliminating chiseling in a lattice column of a foundation pit, characterized in that: Install the bag in the lattice column, and after pouring concrete on the column piles at the bottom of the lattice column, inject water into the bag, and then fill the fluidized solidified soil between the lattice column and the pile hole where the lattice column is located. After the soil layer is excavated, open the water outlet of the bag to let the water flow away, and remove the bag to achieve the lattice column without chiseling. The specific steps include: Step 1, after completing the connection between the steel bars of the column pile and the lattice column, installing the bags in series on the lattice column; the number of the bags is greater than or equal to 2; Step 2, hoisting the column piles and lattice columns into the pile holes; Step 3, pouring concrete into the lower part of the column pile using a conduit; Step 4, after the concrete has initially set, fill the bag with water; Step 5, after the bag is filled with water, fluidized solidified soil is filled between the lattice column and the pile hole; Step 6, excavating the soil at the first concrete support and constructing the first concrete support; Step 7, excavating the first layer of soil, the first layer of soil is at the same height as the first concrete support; draining the bag water above the ground, and constructing the second concrete support according to the method of step 6; Step 8, excavating the second layer of soil, the second layer of soil is at the same height as the second concrete support; draining the bag water above the ground, and constructing the third concrete support according to the method of step 6; Step 9, refer to the methods of steps 6-8 to repeat the construction of concrete support, digging soil, and releasing the water in the bag to finally complete the foundation pit excavation.

2. The method according to claim 1, characterized in that: The bladder bag includes an outer layer, an inner layer and water inlets and outlets; the outer layer of the bladder bag is installed with bolt fixing holes and is connected to the angle steel of the lattice column through bolts; the inner layer of the bladder bag is a deformable material and is expanded after being filled with water; the water inlets and outlets are located at the upper and lower parts of the bladder bag, and the number of the water inlets and outlets is determined by the rate of water inlet and outlet.

3. The method according to claim 2, characterized in that The plurality of bags are connected in series in such a manner that the water inlets and outlets of adjacent bags are interconnected.

4. The method according to claim 1, characterized in that: The compressive strength value of the filled fluidized solidified soil after solidification is lower than 4MPa, so that the fluidized solidified soil can be directly excavated by an excavator during excavation, avoiding manual excavation.

5. The method according to claim 2, characterized in that: The way to drain the water in the bag is to dig a water inlet and outlet from the bottom, and the water flows out naturally.

6. The method according to claim 5, characterized in that After the water in the bag is drained, the bolts are unscrewed, the emptied bag is removed, and it is pulled out from the gap between the lattice columns, thus eliminating the need for manual chiseling and enabling the bag to be reused.

7. The method according to claim 6, characterized in that The outer layer size of the bag matches the inner space size of the lattice column; the inner layer of the bag is in a naturally contracted state when not filled with water, forming an inner hollow structure that fits the inner side of the lattice column, and can provide a lowering channel for the conduit for pouring concrete.

8. The method according to claim 2, characterized in that: The material of the outer layer of the bladder bag is high temperature resistant soil arch fabric; the material of the inner layer of the bladder bag is rubber with high deformation ability.

9. The method according to claim 2, characterized in that: After the bag is filled with water, the outer layer of the bag fits into the inner space of the lattice column, and the inner layer of the bag is compressed, thereby squeezing the reserved inner space structure to fill it up.

10. Application of the method according to any one of claims 1 to 9 in foundation pit engineering.

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