Electric vacuum-flocculation-rigid pile combined soft soil foundation reinforcing device and method

Abstract

The embodiment of the invention discloses an electric vacuum-flocculation-rigid pile combined soft soil foundation reinforcing device and method, by performing flocculation treatment on dredger fill sludge, a plurality of drainage piles are driven into the flocculated dredger fill sludge, the drainage piles are communicated with a water collector through a main drainage pipe, and the water collector is communicated with a rigid pile through a rigid pile. Connecting a water collector with a vacuum pump through a drainage connecting pipe, driving a steel sheet pile into the flocculated hydraulic reclamation sludge, connecting the steel sheet pile with a positive electrode of a direct-current voltage-stabilized power supply through a wire, connecting a drainage pile with a negative electrode of the direct-current voltage-stabilized power supply through a wire, and starting the vacuum pump to perform vacuum preloading drainage; if the water discharge amount at the current moment is lower than a preset water discharge threshold value, a direct-current stabilized power supply is started for electric vacuum water discharge, when water discharge is completed, the steel sheet piles are pulled out, cement mortar is poured into holes formed by the steel sheet piles, concrete is poured into the water discharge piles, and after the concrete is solidified, a rigid pile composite foundation is formed by the concrete and surrounding sludge; therefore, the bearing capacity and the stability of the soft soil foundation are improved.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of soft soil reinforcement, in particular to a soft soil foundation reinforcement device and method combined with electric vacuum-flocculation-rigid pile. BACKGROUND

[0002] Dredged fill is a common means of reclamation in coastal areas, which can effectively alleviate the realistic problem of land resource shortage. In actual engineering application, the dredged fill generally has inherent defects such as high water content, low permeability and insufficient bearing capacity, and needs to be treated by solidification to meet the engineering use requirements. At present, the soft soil improvement technologies such as high-pressure jet grouting pile, deep cement mixing pile, sand pile and plastic drainage board are generally used to treat the dredged fill. However, high water content will hinder the cement hydration reaction and reduce the reinforcement effect of high-pressure jet grouting pile and deep cement mixing pile. At the same time, fine particles in the dredged fill are easy to migrate with seepage, which can easily cause the blockage of drainage connection pipeline and restrict the drainage efficiency of plastic drainage board. The quality and efficiency of the solidification and drainage treatment of the dredged fill need to be improved. SUMMARY

[0003] The following is a summary of the subject matter of the detailed description of the present disclosure. This summary is not intended to limit the scope of protection of the claims.

[0004] The present disclosure provides a soft soil foundation reinforcement device and method combined with electric vacuum-flocculation-rigid pile, which can discharge free water and weakly bound water of the dredged fill through a vacuum pump and an electro-osmotic component, so that a rigid pile composite foundation is formed between the solidified concrete and the surrounding silt, thereby improving the bearing capacity and stability of the soft soil foundation.

[0005] In a first aspect, the present disclosure provides a soft soil foundation reinforcement device combined with electric vacuum-flocculation-rigid pile, comprising: a vacuum drainage device, the vacuum drainage device comprising a plurality of drainage piles, a water collector and a vacuum pump, the drainage piles being connected with the water collector, and the water collector being connected with the vacuum pump; an electro-osmotic component, the electro-osmotic component comprising an anode component, a cathode component and a direct current stabilized power supply.

[0006] According to certain embodiments of the first aspect of the present disclosure, the drainage pile is a metal pipe pile, which comprises a pile body, a pile cavity and a pile valve. The pile body is uniformly provided with a tapered hole, and the tapered hole is filled with a filter layer. A drainage branch pipe is arranged in the pile cavity, the lower end of the drainage branch pipe is communicated with the bottom of the pile cavity, and the upper end of the drainage branch pipe extends to the outside of the pile cavity. The pile valve is arranged at the bottom of the pile body.

[0007] According to certain embodiments of the first aspect of the present disclosure, upper ends of the drainage branch pipes of the plurality of drainage piles extend to the outside of the pile body to access a drainage main pipe, the drainage main pipe is in communication with the water collector, and the water collector is connected to the vacuum pump through a drainage connection pipe, so as to form a communication drainage passage between the drainage pile and the water collector.

[0008] According to certain embodiments of the first aspect of the present disclosure, the pile valve is a metal one-way valve that opens outwardly from the pile cavity.

[0009] According to certain embodiments of the first aspect of the present disclosure, the size of the tapered hole gradually increases from the pile cavity to the outside of the hydraulic fill.

[0010] According to certain embodiments of the first aspect of the present disclosure, the top of the drainage pile is provided with a sealing rubber plug for sealing the pile cavity, the upper end of the drainage branch pipe extends to the outside of the pile body through the sealing rubber plug, the top of the pile body is provided with a connecting piece, the connecting piece is a metal connecting piece, the connecting piece passes through the sealing rubber plug, and the connecting piece is connected to the negative electrode of the direct-current stabilized power supply.

[0011] According to certain embodiments of the first aspect of the present disclosure, the structure of the filter layer includes a large-pore metal mesh, a medium-pore metal mesh, a small-pore metal mesh, and a geotextile.

[0012] According to certain embodiments of the first aspect of the present disclosure, the anode component is a steel sheet pile connected to the positive electrode of the direct-current stabilized power supply, the cathode component is the drainage pile connected to the negative electrode of the direct-current stabilized power supply, and the steel sheet pile and the drainage pile are arranged in an alternating and spaced manner.

[0013] In a second aspect, the embodiments of the present disclosure further provide a method for reinforcing a soft soil foundation by using an electric vacuum-flocculation-rigid pile combination, which comprises the following steps: A calcium chloride solution and a polyacrylamide solution are obtained, the calcium chloride solution is mixed with the hydraulic fill for pretreatment, and the polyacrylamide solution is added to the hydraulic fill mixed with the calcium chloride solution for flocculation treatment. A plurality of drainage piles are driven into the flocculated hydraulic fill, the plurality of drainage piles are connected to a water collector through a drainage main pipe, and the water collector is connected to a vacuum pump through a drainage connection pipe. A steel sheet pile is driven into the flocculated hydraulic fill, the steel sheet pile is connected to the positive electrode of a direct-current stabilized power supply through a wire, and the drainage pile is connected to the negative electrode of the direct-current stabilized power supply through a wire, wherein the steel sheet pile and the drainage pile are arranged in an alternating and spaced manner. When the vacuum pump is started, vacuum preloading drainage is performed, the drainage amount of the vacuum pump at the current time is obtained, and if the drainage amount at the current time is lower than a preset drainage threshold, the direct-current stabilized power supply is started to perform electric vacuum drainage. When the drainage is completed, the steel sheet pile is pulled out, cement mortar is poured into the hole formed by the steel sheet pile, and concrete is poured into the drainage pile, so that the concrete is solidified to form a rigid pile composite foundation with the surrounding silt.

[0014] The soft soil foundation reinforcement device includes a vacuum drainage device and an electro-osmosis component. The vacuum drainage device includes a plurality of drainage piles, a water collector, and a vacuum pump. The drainage piles are connected to the water collector, and the water collector is connected to the vacuum pump. Negative pressure is applied to the hydraulic fill silt by the vacuum pump to accelerate the drainage of free water in the silt void. The electro-osmosis component includes an anode component, a cathode component, and a direct-current stabilized power supply. After being powered on, the calcium ions are adsorbed by the cathode component, and a large amount of water molecules are gathered to the drainage pile to further efficiently drain the weakly bound water in the hydraulic fill silt.

[0015] The soft soil foundation reinforcement method includes the following steps. The calcium chloride solution and the polyacrylamide solution are obtained, the calcium chloride solution is mixed with the hydraulic fill silt for pretreatment, and the polyacrylamide solution is added to the hydraulic fill silt mixed with the calcium chloride solution for flocculation treatment. The permeability of the hydraulic fill silt is improved, and the drainage passage blockage problem is alleviated. On this basis, the plurality of drainage piles are driven into the flocculated hydraulic fill silt, the plurality of drainage piles are connected to the water collector through the drainage main pipe, the water collector is connected to the vacuum pump through the drainage connection pipe, the steel sheet pile is driven into the flocculated hydraulic fill silt, the steel sheet pile is connected to the positive electrode of the direct-current stabilized power supply through a wire, and the drainage pile is connected to the negative electrode of the direct-current stabilized power supply through a wire. The vacuum pump is started to perform vacuum preloading drainage, negative pressure is applied to the hydraulic fill silt by the vacuum pump to accelerate the drainage of free water in the silt void, and the drainage amount of the vacuum pump at the current time is obtained. If the drainage amount at the current time is lower than a preset drainage threshold, the direct-current stabilized power supply is started to perform electric vacuum drainage. Since the steel sheet pile and the drainage pile are staggered and spaced, the calcium ions migrate to the drainage pile and carry a large amount of water molecules to the drainage pile to further efficiently drain the weakly bound water in the hydraulic fill silt. When the drainage is completed, the steel sheet pile is pulled out, cement mortar is poured into the hole formed by the steel sheet pile, and concrete is poured into the drainage pile, so that the concrete is solidified to form a rigid pile composite foundation with the surrounding silt, thereby improving the bearing capacity and stability of the soft soil foundation.

[0016] Other features and advantages of the present disclosure will be set forth in the following description, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the present disclosure. BRIEF DESCRIPTION OF DRAWINGS

[0017] The accompanying drawings are used to provide a further understanding of the technical solutions of the present disclosure, and constitute a part of the specification, and are used to explain the technical solutions of the present disclosure together with the embodiments of the present disclosure, and do not constitute a limitation on the technical solutions of the present disclosure.

[0018] Figure 1 An optional cross-sectional structure schematic diagram of a drainage pile provided by the embodiments of the present disclosure; Figure 2 An optional cross-sectional structure schematic diagram of a filter layer provided by the embodiments of the present disclosure; Figure 3 An optional front view structure schematic diagram of a soft soil foundation reinforcing device provided by the embodiments of the present disclosure; Figure 4 An optional top view structure schematic diagram of a soft soil foundation reinforcing device provided by the embodiments of the present disclosure; Figure 5 An optional flow schematic diagram of a soft soil foundation reinforcing method of an electric vacuum-flocculation-rigid pile combination provided by the embodiments of the present disclosure; Figure 6 An optional schematic diagram of vacuum pressure strength of a vacuum drainage device provided by the embodiments of the present disclosure; Figure 7 An optional schematic diagram of concrete solidification provided by the embodiments of the present disclosure.

[0019] Reference signs: Drainage pile 100, pile body 110, pile cavity 120, pile valve 130, filter layer 140, sealing rubber plug 150, drainage branch pipe 160, connecting piece 170, geotextile 180, small-hole metal mesh 181, medium-hole metal mesh 182, large-hole metal mesh 183, water collector 200, vacuum pump 300, direct-current stabilized power supply 400, wire 410, wire 420, drainage main pipe 500, drainage connecting pipe 510, steel sheet pile 600, geomembrane 700. DETAILED DESCRIPTION

[0020] In order to make the objectives, technical solutions and advantages of the present disclosure clearer, the present disclosure is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present disclosure, and do not limit the present disclosure.

[0021] In the present application, unless specifically defined otherwise and limited, the terms "mount", "connect", "communicate", "fixed" and the like should be construed as broadly as possible, for example, it can be fixed communication, but also can be detachable communication, or integrated; can be mechanical communication, but also can be electrical communication; can be directly connected, but also through the intermediate medium indirectly connected, can be the internal communication of two elements or the interaction relationship of two elements, unless otherwise specifically limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0022] In the present application, unless specifically defined otherwise and limited, the first feature is "on" or "under" the second feature. The first and second features can be in direct contact, or the first and second features can be indirectly in contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be directly above or obliquely above the first feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be directly below or obliquely below the first feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0023] It should be noted that when an element is referred to as "fixed to" or "provided to" another element, it can be directly on another element or there can be a middle element. When an element is considered to be "connected" to another element, it can be directly connected to another element or a middle element can exist at the same time. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are for illustrative purposes only and are not the only embodiment.

[0024] In order to facilitate the understanding of the technical solutions provided by the embodiments of the present disclosure, some key terms used by the embodiments of the present disclosure are explained first: Dredged silt: refers to the silt soft soil dredged from the bottom of rivers, lakes, oceans and other water areas by hydraulic dredging process, which is transported to the designated area by hydraulic transportation, and then formed into an artificial remolded soft soil through sedimentation and consolidation.

[0025] Acrylamide-based anionic polyacrylamide (APAM) is a high molecular polymer. The APAM molecular chain has a large number of negative groups. The APAM molecular chain can be adsorbed on the surface of the silt fine particles pre-treated by calcium ions. Through the "bridging" effect, the dispersed particles are agglomerated into large particle size flocculation bodies. The stretched APAM molecular chain can entangle and wrap small particles, further increase the size of the flocculation body, improve the particle settling efficiency, and construct stable skeleton pores after the formation of the flocculation body, thereby enhancing the permeability of the silt and creating favorable conditions for subsequent vacuum drainage and electro-osmotic consolidation.

[0026] Rigid pile is a kind of vertical reinforcement in the field of foundation treatment, whose pile body stiffness is much greater than the stiffness of the soil around the pile. Its material strength is high, and the pile body deformation is small. Under the action of load, it mainly transmits the upper load through the pile end resistance and the pile side friction resistance, and can significantly improve the foundation bearing capacity and reduce the foundation settlement deformation.

[0027] Dredged fill is a common means of reclamation in coastal areas, which can effectively alleviate the realistic problem of land resource shortage. In practical engineering applications, the dredged fill generally has inherent defects such as high water content, high fine particle content, low permeability, and insufficient bearing capacity, and needs to be treated by solidification to meet the engineering use requirements. At present, high-pressure jet grouting pile, deep cement mixing pile, sand pile, plastic drainage board and other soft soil improvement technologies are generally used to treat the dredged fill. However, high water content will hinder the cement hydration reaction, and reduce the reinforcement effect of high-pressure jet grouting pile and deep cement mixing pile. At the same time, the fine particles in the dredged fill are easy to migrate with seepage, which is easy to cause the blockage of the drainage connection pipeline.

[0028] According to the above analysis, it can be seen that the water content has a significant effect on the shear strength of the dredged fill, so drainage and consolidation is the main way to improve the bearing capacity of soft soil. The vacuum preloading method increases the hydraulic gradient in the soil by applying negative pressure to accelerate the drainage of pore water, thereby realizing the consolidation of soft soil. However, the effect of this method in reinforcing the dredged fill is limited. On the one hand, it can only remove the free water in the soil pores, and cannot remove the weakly bound water which has a significant effect on the engineering properties of soft soil. On the other hand, the seepage force generated by vacuum drainage will promote the migration of fine particles, block the drainage channel and form a low-permeability soil column. These problems seriously hinder the transmission of vacuum pressure, and ultimately lead to the failure of the soft soil foundation reinforcement to meet the subsequent construction requirements.

[0029] Based on this, the electric vacuum-flocculation-rigid pile combined soft soil foundation reinforcement device and method provided by the embodiments of the present disclosure can discharge the free water and weakly bound water of the dredged fill through the vacuum pump and the electro-osmosis component, so that the concrete forms a rigid pile composite foundation with the surrounding silt after solidification, thereby improving the bearing capacity and stability of the soft soil foundation.

[0030] The following embodiments only express one embodiment of the present application, which is described in more detail and in detail, but it cannot be understood as a limitation on the scope of the patent. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the protection scope of the present application patent should be subject to the appended claims.

[0031] The following will be described in conjunction with the accompanying drawings Figures 1-4 The electric vacuum-flocculation-rigid pile combined soft soil foundation reinforcement device provided by the embodiments of the present disclosure will be further described.

[0032] The soft soil foundation reinforcing device comprises a vacuum drainage device and an electro-osmosis component, the vacuum drainage device comprises a plurality of drainage piles 100, a water collector 200 and a vacuum pump 300, and the electro-osmosis component comprises an anode component, a cathode component and a direct-current stabilized power supply 400.

[0033] In some embodiments, with reference to Figure 1 , Figure 1 An optional cross-sectional structure schematic diagram of the drainage pile provided by the embodiment of the present disclosure is shown, the drainage pile 100 is a metal pipe pile, comprising a pile body 110, a pile cavity 120 and a pile valve 130, a plurality of tapered holes are uniformly arranged around the pile body 110, the size of the tapered holes gradually increases from the pile cavity to the outside of the hydraulic fill, that is, the small-diameter end of the tapered hole is directed to the pile cavity 120, and the large-diameter end is directed to the hydraulic fill outside the pile body 110, and a filter layer 140 is filled in the tapered hole. A sealing rubber plug 150 is arranged at the top of the pile body 110, the sealing rubber plug 150 is used for sealing the pile cavity 120, a drainage branch pipe 160 is arranged in the pile cavity 120, the lower end of the drainage branch pipe 160 is communicated with the pile cavity 120 and maintains a certain distance from the bottom of the pile cavity 120, and the upper end of the drainage branch pipe 160 extends to the outside of the pile cavity 120 through the sealing rubber plug 150. A connecting piece 170 is arranged at the top of the pile body 110, the connecting piece 170 is a metal connecting piece, the connecting piece 170 is connected with the negative electrode of the direct-current stabilized power supply 400, so that the drainage pile 100 serves as the cathode component of the water permeation component. The pile valve 130 is a metal one-way valve, which is opened from the inside of the pile cavity 120 to the outside, and is arranged at the bottom of the pile body 110. The pile end is a solid cone.

[0034] In some embodiments, with reference to Figure 2 , Figure 2 An optional cross-sectional structure schematic diagram of the filter layer provided by the embodiment of the present disclosure is shown, the filter layer is composed of metal meshes with different pore sizes and geotextiles 180, the geotextiles 180, small-pore metal meshes 181, hollow metal meshes 182 and large-pore metal meshes 183 are arranged in sequence from the large-diameter end side to the small-diameter end side, the pore sizes of the metal meshes in each layer are gradiently increased, forming a reverse grading filter structure with the outside being fine and the inside being coarse, so as to avoid fine particles from entering the pile cavity. Even if a small amount of fine particles enter, they are not easy to accumulate in the large-pore metal meshes, reducing the probability of overall clogging of the filter layer, and the large-pore metal meshes on the inside can form a flow guide channel, allowing water molecules to quickly gather into the pile cavity, avoiding the retention of water molecules in the filter layer, thereby improving the drainage efficiency of the drainage pile.

[0035] In some embodiments, with reference to Figure 3 , Figure 3An optional front view structural schematic diagram of the soft soil foundation reinforcement device provided by the embodiment of the present disclosure is shown in the figure. In the vacuum drainage device, the upper end of the drainage branch pipe 160 of the plurality of drainage piles 100 extends to the outside of the pile body 110 to connect to the drainage main pipe 500, the drainage main pipe 500 is connected to the water collector 200, the water collector 200 is connected to the vacuum pump 300 through the drainage connecting pipe 510, and a communication drainage passage is formed between the drainage pile 100 and the water collector 200. In the electro-osmosis component, the anode component is a steel sheet pile 600, the steel sheet pile 600 is connected to the positive electrode of the direct current stabilized power supply 400 through the wire 410, the cathode component is the drainage pile 100, the drainage pile 100 is connected to the negative electrode of the direct current stabilized power supply 400 through the wire 420, and the steel sheet pile 600 and the drainage pile 100 are arranged in an alternating and spaced manner.

[0036] Referring to Figure 4 , Figure 4 An optional top view structural schematic diagram of the soft soil foundation reinforcement device provided by the embodiment of the present disclosure is shown in the figure. The soft soil foundation reinforcement device includes three drainage branches, each of which is provided with four drainage piles 100, and three steel sheet piles 600 are arranged between each two adjacent drainage branches. It can be understood that in actual application, the number of drainage branches, drainage piles and steel sheet piles needs to be determined according to the actual area and other actual physical properties of the soft soil foundation, and the embodiment of the present disclosure does not make specific limitation.

[0037] In addition, the embodiment of the present disclosure also provides a soft soil foundation reinforcement method combined with electric vacuum-flocculation-rigid pile, which can be applied to the reclamation scene or other soft soil reinforcement scene, referring to Figure 5 , Figure 5 An optional flowchart of the soft soil foundation reinforcement method combined with electric vacuum-flocculation-rigid pile provided by the embodiment of the present disclosure is shown in the figure, which can specifically include but not limited to the following steps S501-S505: Step S501: Obtain calcium chloride solution and polyacrylamide solution, mix and stir the calcium chloride solution with the hydraulic fill mud for pretreatment, and then add the polyacrylamide solution to the hydraulic fill mud mixed with the calcium chloride solution for flocculation treatment.

[0038] Specifically, the polyacrylamide solution is a flocculating agent. First, the calcium chloride solution is added to the hydraulic fill and stirred. The calcium ions dissociated from the calcium chloride solution can be adsorbed on the surface of the fine particles of the hydraulic fill, realizing the compression of the thickness of the particle double electric layer, increasing the free water content in the hydraulic fill, and increasing the vacuum drainage volume per unit time. After the calcium ions complete the pretreatment of the sludge particles, the polyacrylamide solution is added. At this time, the calcium ions adsorbed on the surface of the sludge particles and the polyacrylamide molecules produce a bridging effect, causing the dispersed sludge particles to agglomerate into flocculated bodies with larger size and more stable structure, thereby enhancing the flocculation effect. Through flocculation treatment, the flocculated bodies form larger pore channels with better connectivity, and water can flow quickly along the pores to the drainage pile, thereby improving the permeability of the hydraulic fill. At the same time, most of the flocculated bodies have a particle size much larger than the critical size of the pores of the filter layer, so the flocculated bodies cannot enter the filter layer, thereby alleviating the problem of drainage passage clogging.

[0039] Step S502: Drive a plurality of drainage piles into the flocculated hydraulic fill, connect the plurality of drainage piles to the water collector through the drainage main pipe, and connect the water collector to the vacuum pump through the drainage connection pipe.

[0040] Specifically, a plurality of tapered holes are uniformly formed in the pile body of the drainage pile, the filter layer is filled in the tapered holes, the drainage pile is uniformly driven into the flocculated hydraulic fill, the top of the pile body is kept level with the surface of the sludge layer, the connecting piece is welded on the top of the pile body, the drainage branch pipe is suspended in the pile cavity, and the lower end of the drainage branch pipe is kept a certain distance from the bottom of the pile cavity. Then, the rubber sealing plug is installed on the top of the drainage pile, the connecting piece and the drainage branch pipe are respectively inserted through the rubber sealing plug, the upper end of the drainage branch pipe inserted through the rubber sealing plug is connected to the drainage main pipe to ensure the sealing and unobstructed connection of the drainage passage, and the water collector and the vacuum pump are connected through the drainage connection pipe. Finally, the connecting piece inserted through the rubber sealing plug is connected to the negative electrode of the direct current stabilized power supply through the wire, thereby constructing the electro-osmotic passage.

[0041] Step S503: Drive the steel sheet pile into the flocculated hydraulic fill, and connect the steel sheet pile to the positive electrode of the direct current stabilized power supply through the wire, and connect the drainage pile to the negative electrode of the direct current stabilized power supply through the wire.

[0042] Specifically, the steel sheet pile is uniformly driven into the flocculated hydraulic fill, and the steel sheet pile and the drainage pile are arranged alternately and staggered. The steel sheet pile is connected to the positive electrode of the direct current stabilized power supply through the wire, thereby constructing a complete electro-osmotic passage. Then, the geomembrane is laid on the top of the hydraulic fill, the drainage main pipe is connected to the water collector, and the water collector is connected to the vacuum pump.

[0043] Step S504: Start the vacuum pump for vacuum preloading drainage, obtain the drainage volume of the vacuum pump at the current time, and if the drainage volume at the current time is lower than the preset drainage threshold, start the direct current stabilized power supply for electrokinetic vacuum drainage. Specifically, the vacuum pump is started to perform vacuum electric drainage, and the vacuum pressure strength is gradually increased in a stepwise manner, as shown in the following table: Figure 6 As shown, the water in the dredged sludge enters the pile cavity through the tapered hole of the pile body, enters the drainage main pipe through the drainage branch pipe, and is collected in the water collector. The drainage amount of the vacuum pump at the current time is obtained in real time, and if the drainage amount at the current time is lower than the set value, the direct current stabilized power supply is started to perform electric vacuum drainage. After the direct current stabilized power supply is started, the free calcium ions in the sludge migrate to the drainage pile (cathode) under the action of the electric field, and carry a large number of water molecules to the drainage pile to accumulate, and enter the pile cavity under the action of the vacuum suction force and are discharged outward along the drainage branch pipe, thereby improving the drainage efficiency. At the same time, the calcium ions migrated to the drainage pile react with hydroxyl ions and soluble calcium silicate to generate cementing materials, thereby enhancing the interaction between the drainage pile and the surrounding sludge.

[0044] It can be understood that, in addition to using the drainage amount at the current time to determine whether to start the direct current stabilized power supply, the vacuum drainage efficiency can also be used to determine whether to start the direct current stabilized power supply.

[0045] Step S505: When the drainage is completed, the steel sheet pile is pulled out, cement mortar is poured into the hole formed by the steel sheet pile, and concrete is poured into the drainage pile, so that the concrete is solidified to form a rigid pile composite foundation with the surrounding sludge.

[0046] Specifically, after the drainage is completed, the steel sheet pile is pulled out, cement mortar is poured into the hole left by the steel sheet pile, and the cement mortar is solidified to be tightly bonded with the surrounding sludge. Then, the drainage branch pipe is pulled out, the connecting piece and the sealing rubber plug are removed, and concrete is injected into the pile cavity of the drainage pile. The concrete fills the pile cavity and penetrates into the opening (tapered hole) of the pile body, and the concrete is solidified to form a rigid pile body. The pile valve is opened outward under the pressure of the self-weight of the concrete, the concrete enters the dredged sludge, and is solidified to form an enlarged pile head, further improving the bearing capacity of the pile foundation. Referring to Figure 7 , Figure 7 An optional schematic diagram of concrete solidification provided by the embodiment of the present disclosure. During the entire soft soil reinforcement process, the drainage pile can not only drain water, but also serve as a permanent foundation reinforcement, greatly improving the construction efficiency. After the construction is completed, the drainage pile can also be tightly bonded with the surrounding sludge to form a rigid pile composite foundation structure, effectively improving the bearing capacity and stability of the soft soil foundation.

[0047] In summary, the electric vacuum-flocculation-rigid pile combined soft soil foundation reinforcement device and method provided by the embodiments of the present disclosure can enhance the flocculation effect of polyacrylamide by using calcium chloride solution, can improve the permeability of the hydraulic fill mud, and can relieve the problem of drainage channel blockage. On this basis, the free water in the mud is first discharged by using the vacuum drainage device, and then the direct current stabilized power supply is started to perform electric vacuum drainage, the calcium ions are promoted to migrate to the drainage pile by the electric field effect, and a large amount of water molecules are carried to the drainage pile to further efficiently discharge the weakly bound water of the hydraulic fill mud, and at the same time, the calcium ions participate in the synthesis reaction to generate cementing materials to form a reinforcement body around the drainage pile, thereby enhancing the interaction between the drainage pile and the surrounding mud. Finally, the perforated metal pipe pile is used as the drainage pile to avoid the bending problem of the traditional plastic drainage board, and in addition, after the drainage is completed, the concrete is injected into the drainage pile, the concrete enters the top mud through the one-way mechanism of the pile valve, and after solidification, the expanded head rigid pile is formed, thereby further enhancing the interaction between the drainage pile and the surrounding mud, forming a rigid pile composite foundation, and improving the bearing capacity and stability of the soft soil foundation.

[0048] It should also be understood that various embodiments provided by the embodiments of the present disclosure can be combined arbitrarily to achieve different technical effects. The preferred embodiments of the present disclosure are specifically described above in combination with the drawings, but the present disclosure is not limited to the above embodiments, and those skilled in the art can make various equivalent modifications or replacements without departing from the spirit of the present disclosure. These equivalent modifications or replacements are all included in the scope defined by the claims of the present disclosure.

Claims

1. An electric vacuum-flocculation-rigid pile combined soft ground reinforcement device, characterized by, The application relates to a vacuum drainage device and an electro-osmosis device. The vacuum drainage device comprises a plurality of drainage piles, a water collector and a vacuum pump, the drainage piles are connected with the water collector, and the water collector is connected with the vacuum pump. The electro-osmosis device comprises an anode component, a cathode component and a direct-current stabilized power supply.

2. The electrodynamic vacuum-flocculation-rigid pile combined soft ground reinforcement device according to claim 1, characterized in that, The drainage pile is a metal pipe pile, the drainage pile comprises a pile body, a pile cavity and a pile valve, the pile body is uniformly provided with a tapered hole, the tapered hole is filled with a filter layer, the pile cavity is provided with a drainage branch pipe, the lower end of the drainage branch pipe is communicated with the bottom of the pile cavity, the upper end of the drainage branch pipe extends to the outside of the pile cavity, and the pile valve is arranged at the bottom of the pile body.

3. The electrodynamic vacuum-flocculation-rigid pile combined soft ground reinforcement device according to claim 2, wherein the drainage piles are a plurality of, The upper ends of the drainage branch pipes of the plurality of drainage piles extend to the outside of the pile body and are connected with a drainage main pipe, the drainage main pipe is communicated with the water collector, the water collector is connected with the vacuum pump through a drainage connecting pipe, and a communication drainage passage is formed between the drainage piles and the water collector.

4. The electrodynamic vacuum-flocculation-rigid pile combined soft ground reinforcement device according to claim 2, characterized in that, The pile valve is a metal one-way valve and is opened from the inside to the outside of the pile cavity.

5. The electrodynamic vacuum-flocculation-rigid pile combined soft ground reinforcement device according to claim 2, characterized in that, The size of the tapered hole gradually increases from the pile cavity to the outside of the hydraulic fill.

6. The electrodynamic vacuum-flocculation-rigid pile combined soft ground reinforcement device according to claim 2, characterized in that, A sealing rubber plug is arranged at the top of the drainage pile, the sealing rubber plug is used for sealing the pile cavity, the upper end of the drainage branch pipe extends to the outside of the pile body through the sealing rubber plug, a connecting piece is arranged at the top of the pile body, the connecting piece is a metal connecting piece, the connecting piece passes through the sealing rubber plug, and the connecting piece is connected with the negative electrode of the direct-current stabilized power supply.

7. The electrodynamic vacuum-flocculation-rigid pile combined soft ground reinforcement device according to claim 2, characterized in that, The structure of the filter layer comprises a large-pore metal mesh, a medium-pore metal mesh, a small-pore metal mesh and a geotextile. 8.The electric vacuum-flocculation-rigid pile combined soft soil foundation reinforcement device according to claim 1, characterized in that, The anode component is a steel sheet pile, the steel sheet pile is connected with the positive electrode of the direct-current stabilized power supply, the cathode component is the drainage pile, the drainage pile is connected with the negative electrode of the direct-current stabilized power supply, and the steel sheet pile and the drainage pile are arranged in an interlaced and spaced mode.

9. A method for reinforcing soft ground foundation by electrodynamic vacuum-flocculation-rigid pile combination, applied to the soft ground foundation reinforcing device according to any one of claims 1 to 8, characterized in that, The application relates to a vacuum drainage device and an electro-osmosis device. Calcium chloride solution and polyacrylamide solution are obtained, the calcium chloride solution is mixed with hydraulic fill to perform pretreatment, and the polyacrylamide solution is added into the hydraulic fill mixed with the calcium chloride solution to perform flocculation treatment. A plurality of drainage piles are driven into the flocculated hydraulic fill, the plurality of drainage piles are communicated with a water collector through a drainage main pipe, and the water collector is connected with a vacuum pump through a drainage connecting pipe. A steel sheet pile is driven into the flocculated hydraulic fill, the steel sheet pile is connected with the positive electrode of a direct-current stabilized power supply through a wire, and the drainage pile is connected with the negative electrode of the direct-current stabilized power supply through a wire, wherein the steel sheet pile and the drainage pile are arranged in an interlaced and spaced mode. The vacuum pump is started to perform vacuum prepressing drainage, the drainage amount of the vacuum pump at the current time is obtained, if the drainage amount at the current time is lower than a preset drainage threshold value, the direct-current stabilized power supply is started to perform electric vacuum drainage. When the drainage is completed, the steel sheet pile is pulled out, cement mortar is poured into the hole formed by the steel sheet pile, and concrete is poured into the drainage pile, so that the concrete is solidified and forms a rigid pile composite foundation together with the surrounding hydraulic fill.

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