Layered sludge foundation deep-layer gas-driven grid type drainage and reinforcement method

Abstract

The invention discloses a layered sludge foundation deep-layer gas-driven grid type drainage and reinforcement method, which relates to the technical field of weak foundation drainage and reinforcement engineering, and comprises the following steps: step 1, laying geotechnical cloth; step 2, piling up a dividing embankment; 3, laying an air suction type vertical shaft; step 4, mounting a plug board; step 5, paving a gravel water filtering layer; step 6, loading and pre-pressing; and step 7, draining and settling. By the adoption of the layered sludge foundation deep gas drive grid type drainage and reinforcement method, water in the deep position of a soft foundation can be drained more efficiently, the drainage and reinforcement depth can be increased, the foundation reinforcement efficiency is improved, and the technical problems that an existing drainage method is low in drainage efficiency, high in cost and not ideal in effect are solved.

Description

Technical Field

[0001] The invention relates to the technical field of drainage reinforcement for weak foundations, and in particular to a deep gas-driven grid drainage reinforcement method for a layered silt foundation. Background Art

[0002] In the drainage construction of weak tailings ponds, layered silt foundations often need to be reinforced due to their low strength, high compressibility and poor drainage performance. Traditional reinforcement methods such as vacuum preloading, drainage consolidation, and pile preloading have long cycles, high costs, and poor results in some cases.

[0003] At present, the vacuum preloading reinforcement method is generally used for the reinforcement of silt foundation. my country began to study and apply this method in the 1980s, and has done a lot of work in construction technology and reinforcement theory. Practice has shown that although vacuum preloading technology is an economical and effective method for treating weak foundations, the vacuum degree decays rapidly along the plastic drainage board with depth. In silt with a small permeability coefficient, the treatment effect depth generally does not exceed 2m, that is, only a hard shell layer with a thickness of 0.5m-2m is formed, and the reinforcement effect below the hard shell layer is not obvious. Therefore, the application effect in large-area layered silt foundations is not ideal, so a more efficient, practical and economical reinforcement process method is needed. Summary of the invention

[0004] The purpose of the present invention is to provide a deep gas-driven grid-type drainage and reinforcement method for layered silt foundation, which can quickly discharge water and gas in silt of different depths by driving a gas-driven vertical shaft, increase the drainage and reinforcement depth, improve the foundation reinforcement efficiency, and lay the foundation for later heightening.

[0005] To achieve the above object, the present invention provides a deep gas drive grid drainage reinforcement method for layered silt foundation, comprising the steps of: first, laying a geotextile, dividing the entire silt area into a plurality of silt grids of appropriate size using the geotextile; Step 2: Build a grid embankment. The silt area is built on the geotextile in a grid form; Step 3: Laying an air suction vertical shaft: Laying an air suction vertical shaft for drainage on the grid dike; Step 5: Install the plug plate. Determine the installation location of the plug plate based on the solidification condition of the foundation in the sludge compartment. Step 6: Lay a gravel filter layer in the silt compartment; Step 7: Loading pre-pressure, using soil and stone to load on the gravel filter layer in the silt compartment; Step 8: Drainage and settlement: supply air to operate the air-suction shaft for drainage and monitor the settlement in real time.

[0006] Preferably, in step 2, the grid embankment forms a drainage prism, gravel is laid on the drainage prism, and the embankment material is a permeable material.

[0007] Preferably, in step three, compressed air is injected into the vertical shaft through the machine room and the air supply pipeline, and the water is sucked out through the vertical shaft by the negative pressure formed by the airflow.

[0008] Preferably, in step five, the silt layer, the plug plate and the gravel filter layer form a drainage channel.

[0009] Preferably, the drainage pipe and the machine room are both arranged at the ends of the grid dike.

[0010] Preferably, the air supply pipe is arranged on the drainage prism.

[0011] Preferably, the water discharged from the shaft is introduced into the drainage ditch through the drainage pipe, and is processed and recycled after passing through the drainage ditch.

[0012] Therefore, the present invention adopts the above-mentioned deep gas drive grid drainage reinforcement method for layered silt foundation, which has the following beneficial effects: (1) High reinforcement efficiency: The present invention can accelerate the discharge of water and gas in the sludge and improve the reinforcement efficiency through the driving effect of the air drive grid system.

[0013] (2) Reduce costs: Compared with traditional reinforcement methods, the materials and equipment required by the present invention are simpler, the construction efficiency is fast, safe and reliable, and the reinforcement cost is reduced.

[0014] (3) Wide applicability: The present invention is applicable to layered silt foundations of different thicknesses and properties and has wide applicability.

[0015] (4) Good economic benefits: During reinforcement, a large amount of water in the soft soil of the foundation is discharged, which increases the settlement and storage capacity, thus also having good economic benefits.

[0016] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is the plan layout of the pre-buried air suction drainage of the present invention; Figure 2 This is a schematic diagram of the pre-buried air suction drainage section of the present invention Figure 1 ; Figure 3 This is a schematic diagram of the pre-buried air suction drainage section of the present invention Figure 2 ; Figure 4 This is a schematic diagram of the pre-buried air suction drainage section of the present invention Figure 3 ; Reference numerals 1. Cell dike; 2. Drainage shaft; 3. Drainage plug plate; 4. Air supply pipeline; 5. Machine room; 6. Drainage channel; 7. Drainage ditch; 8. Gravel filter layer; 9. Geotextile; 10. Soil and stone. DETAILED DESCRIPTION

[0018] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0019] Unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0020] Example See also Figure 1-4 The present invention provides a deep gas drive grid-type drainage reinforcement method for layered silt foundation, comprising the following steps: Step 1: Lay geotextile 9. Divide the entire silt area into several silt cells of appropriate size with geotextile 9 to form a grid. Lay geotextile 9 at the bottom of the cell dike 1. Laying geotextile 9 at the bottom of the cell dike 1 can ensure the permeability of the cell dike 1 and prevent silt from clogging the drainage prism.

[0021] Step 2: Build the lattice dike 1. Use permeable materials to build the lattice dike 1 to form a drainage prism, improve the permeability around the shaft, and lay gravel on the drainage prism.

[0022] Step three: Lay an air-suction shaft. Lay an air-suction drainage shaft 2 on the grid dike 1. The air-suction drainage shaft 2 is evenly arranged on the grid dike 1 to ensure balanced drainage and stable sedimentation in the entire silt area. Compressed air is injected into the drainage shaft 2 through the machine room 5 and the air supply pipe 4, and the water is sucked out through the shaft through the negative pressure formed by the airflow.

[0023] The air-suction vertical drainage system can be put into operation right after installation. It is not restricted by the process of drainage boards and sand cushion layers. It can realize rapid, automatic and intelligent suction of deep pore water in sludge, form a vacuum environment at the bottom of the well, and accelerate the drainage and consolidation of middle and deep sludge. It can avoid water accumulation in the construction area, make the sludge change from a fluid plastic state to a hard plastic state, accelerate the consolidation of sludge, and provide a stable working platform for subsequent drainage plugs. After the construction of the drainage board is completed, two-way drainage of the sludge layer can be achieved.

[0024] Step 4: Install the plug plate. Determine the installation of the plug plate according to the solidification condition of the foundation in the silt compartment to form the plug plate drainage 3.

[0025] Step 5: Lay a gravel filter layer 8 in the silt compartment, guide the pore water in the silt layer into the gravel filter layer 8, form an effective drainage channel 6, accelerate the rapid consolidation of the silt layer, and guide the water discharged from the plug board into the air-suction drainage shaft 2 through the filter layer.

[0026] Step 6: Loading pre-pressure, in the silt area of ​​the silt grid where the crushed stone filter layer 8 is laid, use soil and stone 10 to load pressure to make the silt drain quickly and reduce sedimentation.

[0027] Step 7: Drainage and sedimentation. The uninterrupted suction of the air-suction vertical drainage can continuously discharge the squeezed water generated by the later loading, reduce sedimentation, and continuously observe the consolidation degree and sedimentation of the sludge after drainage.

[0028] The entire silt area is divided into multiple small silt areas by the gravel grid dike 1 to form a grid. The water discharged from the air-suction shaft in the entire silt area is introduced into the drainage ditch through the drainage channel 6, and then processed and recycled after passing through the drainage ditch 7. Therefore, the present invention adopts the above-mentioned deep gas-driven grid drainage reinforcement method for layered silt foundation, and the reinforcement efficiency is high: the present invention can accelerate the discharge of moisture and gas in the silt and improve the reinforcement efficiency through the driving action of the gas-driven grid system. Reduce costs: Compared with traditional reinforcement methods, the materials and equipment required by the present invention are simpler, the construction efficiency is fast, it is safe and reliable, and the reinforcement cost is reduced. Wide applicability: The present invention is suitable for layered silt foundations of different thicknesses and properties and has a wide range of applicability. Good economic benefits: While reinforcing, due to the discharge of a large amount of water in the soft soil of the foundation, the settlement amount is increased, the storage capacity is increased, and therefore it also has good economic benefits.

[0029] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A deep gas drive grid drainage reinforcement method for layered silt foundation, characterized in that: The following steps are involved: Step 1: Lay the geotextile and divide the entire silt area into several silt compartments according to the appropriate size; Step 2: Build a grid embankment. The silt area is built on the geotextile in a grid form; Step 3: Laying an air suction vertical shaft: Laying an air suction vertical shaft for drainage on the grid dike; Step 5: Install the plug plate. Determine the installation location of the plug plate based on the solidification condition of the foundation in the sludge compartment. Step 6: Lay a gravel filter layer in the silt compartment; Step 7: Loading pre-pressure, using soil and stone to load on the gravel filter layer in the silt compartment; Step 8: Drainage and settlement: supply air to operate the air-suction shaft for drainage and monitor the settlement in real time.

2. A deep gas drive grid drainage reinforcement method for layered silt foundation according to claim 1, characterized in that: In step 2, the grid embankment forms a drainage prism, and gravel is laid on the drainage prism. The embankment material is a permeable material.

3. A deep gas drive grid drainage reinforcement method for layered silt foundation according to claim 2, characterized in that: In step three, compressed air is injected into the shaft through the machine room and the air supply pipeline, and the water is sucked out through the shaft by the negative pressure formed by the airflow.

4. A deep gas drive grid drainage reinforcement method for layered silt foundation according to claim 3, characterized in that: In step five, the silt layer, the plug plate and the gravel filter layer form a drainage channel.

5. A deep gas drive grid drainage reinforcement method for layered silt foundation according to claim 4, characterized in that: The drainage pipes and machine rooms are both located at the ends of the grid dikes.

6. A deep gas drive grid drainage reinforcement method for layered silt foundation according to claim 5, characterized in that: The air supply pipeline is arranged on the drainage prism.

7. A deep gas drive grid drainage reinforcement method for layered silt foundation according to claim 6, characterized in that: The water discharged from the shaft is introduced into the drainage ditch through the drainage pipe, and then processed and recycled after passing through the drainage ditch.

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