Anti-clogging drainage plate for soft soil foundation

Abstract

The utility model belongs to the soft soil foundation treatment technical field especially relates to a kind of anti-fouling drainage plate for soft soil foundation, including drainage plate, be equipped with a spiral air pipe on drainage plate, be equipped with Helmholtz resonance nozzle on spiral air pipe, the device is while effectively removing plastic drainage plate filter membrane fouling, promote the separation of combined water (or attached water) in silt, it is the key to improve drainage efficiency, guarantee consolidation quality, shorten the period of construction.

Description

Technical Field

[0001] This utility model belongs to the field of soft soil foundation treatment technology, and in particular relates to an anti-siltation and drainage board and method for soft soil foundations. Background Technology

[0002] Soft soil is widely distributed in my country, characterized by high water content, poor permeability, rheological properties, large void ratio, and low shear strength. Foundations composed of soft soil are generally weak, with poor permeability, low bearing capacity, weak strength, poor stability, and prone to uneven settlement, failing to meet engineering construction requirements. Therefore, construction on soft soil foundations requires pre-treatment for drainage. Traditional plastic drainage boards have long suffered from problems during the drainage consolidation process, including filter membrane clogging leading to obstructed drainage channels and difficulty in effectively removing bound water (or attached water) from the silt. This severely affects drainage efficiency and consolidation quality. Utility Model Content

[0003] The purpose of this invention is to provide a soft soil foundation anti-clogging drainage board with the synergistic effect of air jet and high-frequency sound waves. The device adopts an integrated design method of dredging, (sonic vibration) dewatering and drainage. While effectively removing the clogging of the plastic drainage board filter membrane, it promotes the removal of bound water (or attached water) in the sludge. It is the key to improving drainage efficiency, ensuring consolidation quality and shortening the construction period.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A drainage board for soft soil foundations, designed to prevent siltation, includes a drainage board with a spiral air pipe. A main air path is connected to the spiral air pipe via multiple branch paths. A Helmholtz resonant nozzle, made of 316L stainless steel, is mounted on the spiral air pipe. The nozzle body comprises an interconnected upstream nozzle, an oscillating chamber, and a downstream nozzle. A fixing rod is located at the connection between the upstream nozzle and the oscillating chamber. An inclined turbine blade is installed at the end of the fixing rod, inside the oscillating chamber. The central axes of the upstream nozzle, the inclined turbine blade, and the downstream nozzle are aligned. During operation, the boundary layer disturbance generated by the upstream nozzle is amplified by the oscillating chamber, forming a ring-shaped vortex. This vortex structure disrupts the continuity of the jet, generating a self-resonating pulse jet. This pulse jet generates a high-frequency sound wave at the downstream nozzle outlet. This high-frequency sound wave effectively strips bound water from the silt surrounding the drainage board. Simultaneously, under the action of the inclined turbine blade, the high-pressure airflow generates a swirling flow within the oscillating chamber. When this swirling flow leaves the nozzle outlet, it effectively removes the silt around the drainage board.

[0005] Furthermore, the spiral air tube is provided with a plurality of Helmholtz resonance nozzles in sequence along its length.

[0006] Furthermore, the drainage board includes a core board at its center, which is molded from a mixture of polypropylene and polyethylene. The core board has multiple longitudinal and lateral capillary pores, all of which are connected to drainage branches. The core board is wrapped with a filter membrane made of long-fiber thermally rolled nonwoven fabric, with pores no larger than 75 μm. In use, the plastic drainage board serves as the core vertical drainage component, inserted into soft soil foundations using an insertion machine. Its core board, made of a mixture of polypropylene (PP) and polyethylene (PE), combines the rigidity of polypropylene with the flexibility and weather resistance of polyethylene. The filter membrane wrapping the core board, made of long-fiber thermally rolled nonwoven fabric, has excellent water resistance and permeability. The pore size of this filter membrane can be adjusted and changed according to the particle size of the sludge; the equivalent pore size is generally less than 75 μm to achieve optimal mud-water separation. The interior of the board has longitudinal gaps and lateral holes to ensure smooth vertical drainage. The spiral air pipe tightly wraps around the outside of the plastic drainage board, and the high-pressure gas enters the spiral air pipe through the air passage and then reaches the nozzle.

[0007] Furthermore, the spiral air pipe is made of epoxy-coated carbon steel, which can withstand the pressure of 15m deep silt, and its epoxy coating has excellent corrosion resistance in soil environments with pH=3~11.

[0008] Furthermore, the inclined turbine blade is provided with a bearing and a bearing sleeve at its center, and blades are provided outside the bearing sleeve. The blades have an angle of attack of 22°, an inclination angle of 45°, and a total of 12 blades. The turbine is made of 316L stainless steel. The turbine is installed inside the oscillation chamber of the Helmholtz resonant nozzle and can generate a vortex with an angular velocity of ≥300rad / s under a working pressure of 2.0MPa. After being ejected from the nozzle, this vortex acts directly on the sludge to achieve efficient removal.

[0009] The advantages of this utility model are: 1. This novel soft soil treatment device utilizes the self-vibration of nozzles to generate high-frequency sound waves, which effectively promotes the desorption of bound water in sludge. It is particularly suitable for working conditions where the sludge has low moisture content and can significantly ensure the quality of drainage and consolidation of soft soil. 2. This novel soft soil treatment device generates high-speed swirling flow by setting inclined turbine blades inside the nozzle, which effectively removes the blockage of the filter membrane of the plastic drainage board, greatly improves the drainage efficiency of soft soil and significantly shortens the construction period; 3. This device has a simple and compact structure and a wide range of applications. It integrates sludge removal, (acoustic vibration) dewatering, and drainage. While effectively removing sludge from the plastic drainage plate filter membrane, it promotes the removal of bound water (or attached water) from the sludge and supports unmanned, fully automatic operation. Attached Figure Description

[0010] Figure 1 This is a front view structural diagram of the soft soil foundation anti-siltation drainage board of this utility model after being combined with water and air channels in its usage state.

[0011] Figure 2 This is a top view structural diagram showing the usage state of the soft soil foundation anti-siltation drainage board of this utility model after being combined with water and air channels.

[0012] Figure 3 Figure 1 is a structural schematic diagram of the drainage plate and the Helmholtz resonant nozzle in this utility model. Figure 2a is a structural diagram of the drainage plate and Figure 3b is a cross-sectional view of the Helmholtz resonant nozzle.

[0013] Figure 4 This is a schematic diagram of the oblique turbine blade structure in this utility model. Detailed Implementation

[0014] like Figure 1-4 As shown, a drainage board for soft soil foundations is provided, comprising a drainage board with a spiral air pipe on it. The spiral air pipe is made of epoxy-coated carbon steel. The main air path is connected to the spiral air pipe through multiple branches. Multiple Helmholtz resonant nozzles are sequentially arranged along the length of the spiral air pipe. The Helmholtz resonant nozzles are made of 316L stainless steel. The main body of the Helmholtz resonant nozzle includes an upstream nozzle, an oscillation chamber, and a downstream nozzle that are interconnected. A fixing rod is provided at the connection between the upstream nozzle and the oscillation chamber. An inclined turbine blade is installed at the end of the fixing rod, i.e., inside the oscillation chamber. The turbine blades and downstream nozzles are aligned along their central axes. The drainage plate includes a central core plate made of a mixture of polypropylene and polyethylene. The core plate contains multiple longitudinal and lateral capillary pores, all connected to drainage branches. A filter membrane, made of long-fiber hot-rolled nonwoven fabric, is wrapped around the core plate. The filter membrane has pores no larger than 75 μm. The inclined turbine blades have a bearing and bearing sleeve at their center. Blades are mounted outside the bearing sleeve. The blades have an angle of attack of 22° and an inclination angle of 45°, with 12 blades made of 316L stainless steel. In practical use, this drainage board needs to be used in conjunction with water and air systems to achieve the best sludge removal and drainage effect, such as... Figure 1-2The core components of the operating device include: air compressor 1, main intake valve 2, drainage channel 3, air passage 4, gas-liquid dual-purpose pump 5, water collection well 6, fully automatic anti-siltation drainage plate 7, spiral air passage 8, Helmholtz resonance nozzle 9, plastic drainage plate 10, upstream nozzle inlet 11, upstream nozzle outlet 12, oscillation chamber 13, inclined turbine blade 14, fixing rod 15, downstream nozzle 16, bearing 17, bearing sleeve 18, and inclined turbine blade 19. First, use a drilling rig to drill to the designed depth in the soft soil foundation to be treated. Install the anti-siltation drainage plate 7 according to the predetermined arrangement and connect it to the drainage channel 3 and air passage 4. Turn on air compressor 1 and set parameters, setting the system working pressure threshold to 10MPa: when the pressure is higher than 10MPa, the air compressor stops working; when the pressure is lower than 10MPa, the air compressor automatically starts pressurizing. Keep air compressor 1 running continuously, injecting gas into air passage 4. High-pressure gas flows through the anti-siltation drainage board 7 and enters the spiral air passage 8, then into the Helmholtz resonant nozzle 9. The gas is continuously accelerated to supersonic speed within the nozzle. Upon reaching the oscillation chamber 13 inside the Helmholtz resonant nozzle 9, resonance occurs, generating a circumferential air jet within the oscillation chamber 13 under the action of the inclined turbine blades 14. This jet, after leaving the nozzle, efficiently flushes away the silt around adjacent drainage boards. Simultaneously, under the resonance of the Helmholtz resonant chamber 13, high-frequency ultrasonic waves are generated at the nozzle outlet, effectively stripping bound water from the silt around adjacent drainage boards. The gas-liquid pump 5 is activated to apply negative pressure, rapidly discharging groundwater, pore water in soft soil foundations, and bound water detached from the silt under ultrasonic action. The discharged water is collected in the collection well 6. The above process is automatically cyclical. Using this method and device for drainage consolidation successfully solves the problems of filter membrane clogging and low drainage efficiency faced by traditional plastic drainage boards in soft soil foundation treatment. Even under low moisture content conditions, it can achieve efficient dredging and significantly improve the quality and efficiency of drainage consolidation in soft soil foundations.

Claims

1. A drainage board for soft soil foundations to prevent siltation and blockage, characterized in that: It includes a drainage plate, a spiral air pipe on the drainage plate, and a Helmholtz resonant nozzle on the spiral air pipe. The Helmholtz resonant nozzle is made of 316L stainless steel. The main body of the Helmholtz resonant nozzle includes an upstream nozzle, an oscillation chamber and a downstream nozzle that are interconnected. A fixing rod is provided at the connection between the upstream nozzle and the oscillation chamber. An inclined turbine blade is installed at the end of the fixing rod, which is inside the oscillation chamber. The central axes of the upstream nozzle, the inclined turbine blade and the downstream nozzle are coincident.

2. The anti-siltation and drainage board for soft soil foundations as described in claim 1, characterized in that: Multiple Helmholtz resonance nozzles are sequentially arranged along the length of the spiral tube.

3. The anti-siltation and drainage board for soft soil foundations as described in claim 1, characterized in that: The drainage board includes a core board located at the center. The core board is made of polypropylene and polyethylene mixed and molded. The core board has multiple longitudinal capillary pores and lateral capillary pores inside. The longitudinal capillary pores and lateral capillary pores are all connected to the drainage branches. The core board is wrapped with a filter membrane. The filter membrane is made of long-fiber hot-rolled non-woven fabric and has a pore size of no more than 75μm.

4. The anti-siltation and drainage board for soft soil foundations as described in claim 1, characterized in that: The spiral air tube is made of epoxy-coated carbon steel.

5. The anti-siltation and drainage board for soft soil foundations as described in claim 1, characterized in that: The inclined turbine blade is provided with a bearing and a bearing sleeve at its center, and blades are provided outside the bearing sleeve. The blades have an angle of attack of 22° and an inclination angle of 45°. There are 12 blades, which are made of 316L stainless steel.

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