A construction structure and construction method for treating soft foundation by polymer grouting

Abstract

This application relates to a construction structure for treating soft foundation by polymer grouting and its construction method. The solution includes setting up surcharge loading, polymer high-pressure jet grouting piles and polymer root steel pipe piles to improve the shear strength and bearing capacity of the soft foundation, reduce the compressibility and permeability characteristics of the foundation soil; through the cooperation of surcharge loading, drainage steel flower pipes, reticulated water collection pipes and pumps, the moisture in the foundation is discharged to eliminate or weaken the liquefaction characteristics of the foundation soil mass; by setting up a polymer gravel solidification layer, the cooperative working ability of the polymer high-pressure jet grouting piles and the soil between the piles is improved, deformation coordination is ensured, and uneven settlement is prevented. The grouting material uses a two-component quick-setting and expansive polymer material, with simple components and a fast setting time, which will not cause the consequence of sewage overflow and environmental pollution.

Description

Technical Field

[0001] This application relates to the technical field of foundation treatment, and specifically relates to a construction structure and a construction method for treating soft foundation by polymer grouting. Background Art

[0002] Foundation treatment refers to engineering technical measures taken to improve the bearing capacity of the foundation supporting a building, or to improve its deformation properties or permeability properties, which plays a crucial role in ensuring the smooth progress of subsequent project construction. Through foundation treatment, one or several of the following purposes need to be achieved:

[0003] 1) Improve the bearing capacity of the foundation soil. The specific manifestations of foundation shear failure include insufficient bearing capacity of the building foundation, structural instability due to eccentric load or lateral earth pressure; uplift of the adjacent foundation due to filling or building load; slope instability during earth excavation and bottom heave during foundation pit excavation. The shear failure of the foundation soil is mainly due to the insufficient shear strength of the foundation soil. Therefore, in order to prevent shear failure, certain measures need to be taken to improve the shear strength of the foundation soil.

[0004] 2) Reduce the compressibility of the foundation soil. The compressibility of the foundation is manifested in large settlement and differential settlement of the building, and the compressibility of the soil is related to the compression modulus of the soil. Therefore, measures must be taken to increase the compression modulus of the foundation soil to reduce the settlement and uneven settlement of the foundation.

[0005] 3) Improve the water permeability characteristics of the foundation. During the construction of foundation pit excavation, piping or quicksand occurs due to thin layers of silt or silty soil in the soil layer. These are all problems caused by the movement of groundwater in the soil. Therefore, measures must be taken to reduce the water permeability of the foundation soil or reduce its hydrodynamic pressure.

[0006] 4) Eliminate or weaken the liquefaction characteristics of the foundation soil. Saturated soil will liquefy under the action of earthquake or dynamic force, resulting in large deformation. Therefore, foundation treatment needs to remove the water in the foundation and eliminate or weaken the liquefaction characteristics of the foundation soil.

[0007] Currently, there is no systematic foundation treatment method that can comprehensively and efficiently solve the above various problems.

[0008] As the Chinese patent application number CN202110446411.3 proposes a construction method for treating soil landslides by high-polymer grouting emergency rescue and disposal, which uses the method of high-pressure grouting of two-component high polymers for landslide treatment. However, since it does not use the jet grouting method, but only sprays the slurry under high pressure, the penetration and flow of the high-pressure slurry are relatively random, and the reinforcement effect is lacking. Only by using the high-pressure jet grouting method and continuously rotating the drill while cutting the soil with high-pressure slurry can the slurry and the soil be more fully integrated, and a columnar solid with a certain diameter can be generated more evenly. Moreover, the ratio of the slurry to the soil can be adjusted, and the quality is easier to control.

[0009] As the Chinese patent application number CN201810614498.9 discloses a drainage board device and method with water-absorbing and swelling materials inside under surcharge preloading. However, it only improves the shear strength and bearing capacity of the foundation soil by absorbing water, and the reinforcement means are relatively insufficient. Moreover, the water remains in the water-absorbing and swelling materials and exists in the foundation, which is also a hidden danger.

[0010] Cement jet grouting piles are also a commonly used foundation treatment method. However, the setting time of conventional cement slurry is relatively long, which is difficult to meet the urgency of the project. Moreover, more importantly, cement consumes a large amount of energy, and sewage often overflows during the construction of cement jet grouting piles, which is easy to pollute the environment.

[0011] Therefore, there is an urgent need for a high-polymer grouting soft foundation treatment construction structure and its construction method to solve the above technical problems.

[0012] Application content

[0013] The purpose of this application is to provide a high-polymer grouting soft foundation treatment construction structure and its construction method for the above problems existing in the prior art.

[0014] To achieve the above application purpose, this application adopts the following technical solutions: A high-polymer grouting soft foundation treatment construction method includes the following steps:

[0015] S00. Clean the surface of the soft foundation and sort out the operation platform;

[0016] S10. Vertically drive drainage steel pipes with perforations on the operation platform and penetrate the soft foundation layer to be treated;

[0017] S20. Seal the drainage steel pipe with perforations and the drilling hole through a sealing ring sleeve, and press the sealing ring sleeve into the soft foundation;

[0018] S30. Lay a drainage gravel cushion on the ground surface and lay a vacuum film on the gravel cushion;

[0019] S40. Conduct surcharge on the gravel cushion, avoiding the reserved pile positions of the drainage steel pipes with perforations and the subsequent high-polymer high-pressure jet grouting piles;

[0020] S50. Connect all the drainage steel flower pipes through a reticulated water supply pipe and converge them into a single drainage main pipe, which is connected to a pump.

[0021] S60. Arrange the pile positions of the high-polymer high-pressure jet grouting piles in a designed formation among the drainage steel flower pipes, and ensure that the length of the pile body of the high-polymer high-pressure jet grouting pile penetrates the soft foundation layer to be treated.

[0022] S70. Use a high-polymer high-pressure jet grouting rig to drill and grout the soft foundation with high-polymer high-pressure jet grouting piles through a dual-channel high-pressure grouting pipe, so that the two-component grouting material contacts and reacts with each other, cuts the surrounding soil, and mixes with the soil to form a high-polymer high-pressure jet grouting pile. Stop the grouting operation when the bottom elevation of the dual-channel high-pressure grouting pipe reaches the ground elevation to complete the construction of the high-polymer high-pressure jet grouting pile.

[0023] S80. The two-component grouting material contacts and reacts with each other to heat the foundation, and use a vacuum pump to evacuate the foundation, so that the foundation temperature and the absolute pressure of the foundation are maintained within a preset range to promote the transformation of liquid water in the foundation into gas.

[0024] S90. Evacuate the drainage steel flower pipes, and cooperate with the vertical extrusion of the surcharge load and the lateral extrusion of the surrounding soil by the high-polymer high-pressure jet grouting piles to further promote the seepage of water in the soft foundation from the drainage steel flower pipes, and improve the consolidation degree and bearing capacity of the soft foundation.

[0025] S100. After the soft foundation drainage consolidation is completed, use the drainage steel flower pipe as a grouting pipe, and conduct high-polymer high-pressure grouting into the pipe, so that the grout penetrates into the surrounding soil through the holes of the drainage steel flower pipe to form a root-shaped high-polymer root steel pipe pile.

[0026] S110. Cut the overly high drainage steel flower pipes, and conduct high-polymer grouting on the gravel cushion to form a high-polymer gravel solidified layer, and use the high-polymer gravel solidified layer as the pile cap of the high-polymer high-pressure jet grouting pile.

[0027] S120. Demolish the construction equipment and clean the site to complete the construction.

[0028] Further, the designed formations in step S10 and step S60 are both square or plum blossom shape.

[0029] Further, in step S10 and step S60, the layout areas of the drainage steel flower pipes and the high-polymer high-pressure jet grouting piles are both greater than or equal to the area of the soft foundation to be treated.

[0030] Further, in step S70, the two-component grouting material is polyol and isocyanate.

[0031] Further, in step S70, the double-channel high-pressure grouting pipe includes a drill pipe and two independent nozzles disposed inside the drill pipe, and each nozzle extends from the side of the drill pipe.

[0032] Further, in step S70, after the drill tool of the high-polymer high-pressure jet grouting rig rotates and drills downward to the designed depth, it is then lifted at a predetermined speed while maintaining rotation, and at the same time, the double-channel high-pressure grouting pipe ejects polyol and isocyanate slurries at high speed respectively.

[0033] Further, in step S80, the foundation heating temperature is about 55°C, and the absolute pressure of the foundation is 5 - 15 kPa.

[0034] Further, in step S20, the sealing ring sleeve is sleeved on the outer circle of the drainage steel pipe with holes, and the protruding part at the bottom of the sealing ring sleeve is inserted into the soft foundation, and the downward flat part is closely attached to the surface of the soft foundation.

[0035] Further, in step S10, the top of the drainage steel pipe with holes exceeds the ground elevation by a certain height.

[0036] A high-polymer grouting treatment soft foundation construction structure for strengthening the soft foundation, including:

[0037] An operation platform, which is arranged on the surface of the soft foundation for construction operations;

[0038] A gravel cushion layer, which is laid on the surface of the soft foundation for drainage and forming a high-polymer gravel solidified layer through high-polymer grouting in the final stage of construction, serving as the pile cap of the high-polymer high-pressure jet grouting pile;

[0039] A vacuum membrane, which is laid on the gravel cushion layer for draining water in cooperation with a vacuum pump for vacuum pumping;

[0040] A surcharge load, which is arranged on the gravel cushion layer and the vacuum membrane and avoids the positions of the drainage steel pipe with holes and the high-polymer high-pressure jet grouting pile for providing vertical pressure;

[0041] Drainage steel pipes with holes are evenly spaced and driven into the soft foundation, and the bottom penetrates the soft foundation layer, the top exceeds the ground elevation by a certain height, and the layout area is larger than the area of the soft foundation to be treated; for drainage and forming high-polymer root steel pipe piles after drainage is completed;

[0042] High-polymer high-pressure jet grouting pile positions are evenly spaced and driven into the soft foundation and are located between the drainage steel pipes with holes. The bottom of the high-polymer high-pressure jet grouting pile positions penetrates the soft foundation layer, and the layout area is larger than the area of the soft foundation to be treated; for grouting to form high-polymer high-pressure jet grouting piles;

[0043] A water pump for pumping water from the drainage steel pipes with holes;

[0044] A vacuum pump for vacuum pumping the soft foundation covered by the vacuum membrane;

[0045] A main drainage pipe, which is connected to the top of each drainage perforated steel pipe and is connected to a water pump for pumping water.

[0046] A sealing ring sleeve, which is used to seal the drainage perforated steel pipe and the soft foundation.

[0047] A temperature sensor, which is arranged in the soft foundation and is used to detect the temperature of the soft foundation.

[0048] Compared with the prior art, the present application has the following beneficial effects:

[0049] 1. Compared with the prior art (CN201410837193.6), in the present application, the foundation is preloaded first and then piles are formed, which can effectively prevent the pile body from being crushed or piercing into the foundation. Moreover, surcharge preloading can also improve the construction quality of the high-polymer high-pressure jet grouting piles and prevent the soil heave and damage under the condition of high-pressure grouting.

[0050] 2. Compared with the prior art (CN201410837193.6, which requires special hole forming and sand filling, is relatively inconvenient, and the diameter of the sand piles is generally at least 0.5 - 1 m, resulting in a huge consumption of sand and gravel), in the present application, high-polymer high-pressure jet grouting piles are used, which can make full use of the original soil in the soft foundation to form a reinforced body without additional sand and gravel filling.

[0051] 3. Compared with the prior art (after the sand piles in CN201410837193.6 are cemented by high polymers, the permeability will be greatly reduced, so the effect of "the pore water in the soil between piles 2 drains out along the drainage channels formed by the sand piles and the gravel cushion layer" may be very poor, seriously affecting the foundation treatment effect), in the present application, by driving the perforated steel pipes, different effects can be produced with the progress of the construction: first, it is specially used for drainage, then it is used as a high-polymer high-pressure grouting pipe, and finally it can form a root-shaped micro steel pipe high-polymer sand pile to improve the bearing capacity of the foundation. The function of the perforated steel pipe can be fully exerted under various working conditions, without causing the idle and waste of materials. Only by increasing the appropriate amount of materials can multiple purposes be achieved, with the effect of getting twice the result with half the effort and achieving multiple benefits at one stroke.

[0052] 4. The high-polymer grouting material used in the present application has the advantage of rapid setting, and it can solidify in as fast as 10 seconds at the fastest, greatly shortening the construction period and effectively solving the problem of the relatively long initial setting time of the conventional cement slurry existing in the prior art.

[0053] 5. The high-polymer grouting material has good expansibility. The high-polymer high-pressure jet grouting pile body formed can only expand violently horizontally due to the overlying load, thereby exerting a lateral pressure on the soil around the pile. Coupled with the overlying load, the soil is in a triaxial compression state, and the shear strength increases. At the same time, it is beneficial to extrude the water in the soil around the pile, so that the water in the soil around the pile can be more fully extruded into the perforated steel pipe and then discharged smoothly.

[0054] 6. In the past, special equipment or processes were required for heating the foundation. However, this application makes full use of the reaction of two-component polymers (isocyanate and polyol) to release a large amount of heat. It can not only form polymer jet grouting piles as reinforcement bodies, but also heat the soft foundation by the way. When the vacuum degree of the soft foundation reaches a certain level, it can promote the evaporation of water in the soft foundation and accelerate the consolidation of the soft foundation, achieving two goals with one action.

[0055] 7. In addition to using a vacuum pump to increase the vacuum degree of the soft foundation, this application also uses a water pump to directly extract air from the reticulated water collection pipes and perforated steel pipes, which can more straightforwardly discharge the water in the soft foundation without the problem of vacuum pressure loss.

[0056] 8. The polymer grouting material does not contain water and will not reduce the strength of the soft foundation at the initial stage of grouting, effectively solving the problem in the prior art that the cement slurry contains a large amount of water and is likely to reduce the overall strength of the already extremely weak site.

[0057] 9. Generally, the randomness of general high-pressure grouting is relatively large, and both the reinforcement range and quality are relatively uncontrollable. Therefore, in addition to randomly injecting high-pressure polymers through the holes of the perforated steel pipes to generate polymer root steel pipes as auxiliary reinforcement bodies, this application also generates polymer high-pressure jet grouting piles by means of high-pressure jet grouting. The quality of the pile body is more controllable, the strength and reinforcement range are more uniform, and the reinforcement effect is better than that of general high-pressure grouting with relatively large randomness.

[0058] 10. Based on the above advantages, this application has the advantages of simple process, portable equipment, easy operation, short construction period, and good effect, and is very suitable for working conditions with tight construction periods and high environmental protection requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 is a schematic diagram of the construction structure of this application;

[0060] Figure 2 is a schematic diagram during the construction process of this application;

[0061] Figure 3 is a schematic diagram of the installation of the sealing ring sleeve of this application;

[0062] Figure 4 is a flow chart of the construction method of this application;

[0063] Figure 5 is a schematic diagram of the structure of the double-channel high-pressure grouting pipe.

[0064] In the figure, 1 is the gravel cushion layer; 2 is the vacuum membrane; 3 is the surcharge; 4 is the drainage steel pipe with holes; 5 is the soft foundation; 6 is the position of the high-polymer high-pressure jet grouting pile; 7 is the water pump; 8 is the vacuum pump; 9 is the drainage main pipe; 10 is the temperature sensor; 11 is the high-polymer gravel solidified layer; 41 is the sealing ring sleeve; 42 is the high-polymer root-shaped steel pipe pile; 61 is the high-polymer high-pressure jet grouting pile; 62 is the double-channel high-pressure grouting pipe; 621 is the drill pipe; 622 is the drill bit; 623 is the nozzle. Specific Embodiment

[0065] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art belong to the scope of protection of the present application.

[0066] Those skilled in the art should understand that in the disclosure of the present application, the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limiting the present application.

[0067] Embodiment 1

[0068] As Figure 1 - Figure 2 shown, the high-polymer grouting soft foundation construction structure is used for reinforcing the soft foundation 5 and includes:

[0069] An operation platform is arranged on the surface of the soft foundation 5 for construction operations;

[0070] The gravel cushion layer 1 is laid on the surface of the soft foundation 5 for drainage and forming a high-polymer gravel solidified layer 11 through high-polymer grouting in the final stage of construction, serving as the pile cap of the high-polymer high-pressure jet grouting pile 61;

[0071] The vacuum membrane 2 is laid on the gravel cushion layer 1 for cooperating with the vacuum pump 8 to pump vacuum for drainage;

[0072] The surcharge 3 is arranged on the gravel cushion layer 1 and the vacuum membrane 2 and avoids the drainage steel pipe with holes 4 and the position of the high-polymer high-pressure jet grouting pile 6 for providing vertical pressure;

[0073] The drain steel pipe pile 4 is evenly spaced and driven into the soft foundation 5, penetrating the soft foundation 5 layer at the bottom, exceeding the ground elevation by a certain height at the top, and having a layout area larger than the area of the soft foundation 5 to be treated; it is used for drainage and grouting after drainage to form a polymer root pile 42;

[0074] The polymer high-pressure jet grouting pile position 6 is evenly spaced and driven into the soft foundation 5 and located between the drain steel pipe piles 4. The bottom of the polymer high-pressure jet grouting pile position 6 penetrates the soft foundation 5 layer, and the layout area is larger than the area of the soft foundation 5 to be treated; it is used for grouting to form a polymer high-pressure jet grouting pile 61;

[0075] The water pump 7 is used for pumping water from the drain steel pipe pile 4;

[0076] The vacuum pump 8 is used for vacuum pumping the soft foundation 5 covered by the vacuum film 2;

[0077] The drain main pipe 9 is connected to the top of each drain steel pipe pile 4 and connected to the water pump 7 for pumping water;

[0078] The sealing ring sleeve 41 is used for sealing the drain steel pipe pile 4 and the soft foundation 5;

[0079] The temperature sensor 10 is installed in the soft foundation 5 and used for detecting the temperature of the soft foundation 5.

[0080] Embodiment 2

[0081] Based on Embodiment 1, as Figure 4 shown, the construction method for treating soft foundation by polymer grouting includes the following steps:

[0082] S00. Clean the surface of the soft foundation 5 and arrange the working platform;

[0083] S10. Vertically drive the drain steel pipe pile 4 on the working platform according to the designed formation and penetrate the soft foundation 5 layer to be treated;

[0084] In this embodiment, the drain steel pipe pile 4 is vertically driven on the working platform, with a length penetrating the soft foundation 5 layer to be treated, arranged in a square or plum blossom shape. The top of the drain steel pipe pile 4 needs to exceed the ground elevation by a certain height to facilitate connecting the mesh water collection pipeline (drain main pipe 9) and the water pump 7. The layout area needs to be larger than the area of the soft foundation 5 to be treated to fully drain the excess water in the soft foundation 5 and eliminate the liquefaction characteristics; the soil strength of the soft foundation 5 is relatively low, which is convenient for driving the drain steel pipe pile 4.

[0085] S20. Seal the drain steel pipe pile 4 and the drilling hole through the sealing ring sleeve 41 and press the sealing ring sleeve 41 into the soft foundation 5;

[0086] In this embodiment, as Figure 3As shown in the figure, a rubber ring (sealing ring sleeve 41) is sleeved into the drainage perforated steel pipe 4 (the protruding part at the bottom of the sealing ring sleeve 41 is inserted into the soft foundation 5, and the downward flat part is closely attached to the surface of the soft foundation 5), and then pressed into the soft foundation 5 to fit the surface of the soft foundation 5, so as to ensure that there is no air leakage between the drainage perforated steel pipe 4 and the drilling hole as much as possible.

[0087] S30. Lay a drainage gravel cushion layer 1 on the ground surface, and lay a vacuum membrane 2 on the gravel cushion layer 1;

[0088] In this embodiment, a layer of drainage gravel cushion layer 1 is laid on the ground surface, and the water seeping out from the surface of the soft foundation 5 can be drained away horizontally through the gravel cushion layer 1; a vacuum membrane 2 is laid on the gravel cushion layer 1 for vacuum pumping to consolidate the soft soil and drain the water in the soft foundation 5.

[0089] S40. Conduct a surcharge 3 on the gravel cushion layer 1, and avoid the reserved pile positions of the drainage perforated steel pipe 4 and the high-polymer high-pressure jet grouting pile 61 in the subsequent steps;

[0090] In this embodiment, a surcharge 3 is conducted on the gravel cushion layer 1, and the load size is determined according to the design load, soil quality and required foundation bearing capacity. At the same time, the surcharge 3 needs to avoid the pile positions of the drainage perforated steel pipe 4 and the high-polymer high-pressure jet grouting pile 61, and the reserved gap should be slightly larger than the diameter of the jet grouting pile drilling hole; at this time, under the action of the surcharge 3, the foundation gradually begins to consolidate and settle.

[0091] S50. Connect all the drainage perforated steel pipes 4 through a mesh water supply pipeline and converge them into a drainage main pipe 9, and this drainage main pipe 9 is connected to a water pump 7;

[0092] In this embodiment, the tops of the respective drainage perforated steel pipes 4 are interconnected with a mesh water supply pipeline and finally merged into one pipe, which can be connected to a single water pump 7.

[0093] S60. Arrange the pile positions of the high-polymer high-pressure jet grouting piles 61 in a designed formation between the drainage perforated steel pipes 4, and make the pile body length of the high-polymer high-pressure jet grouting piles 61 penetrate the soft foundation 5 layer to be treated;

[0094] In this embodiment, the pile positions of the high-polymer high-pressure jet grouting piles 61 are arranged between the drainage perforated steel pipes 4, and the pile body length penetrates the soft foundation 5 layer to be treated, and is arranged in a square or plum blossom shape, and the arranged area needs to be not less than the area of the soft foundation 5 to be treated to fully reinforce the soft foundation 5.

[0095] S70. A high-polymer high-pressure jet grouting rig is adopted to drill and grout the high-polymer high-pressure jet grouting pile 61 in the soft foundation 5 through the double-channel high-pressure grouting pipe 62, so that the two-component grouting material (which can also be called the high-polymer grouting material) contacts and reacts with each other and cuts the surrounding soil mass, and is mixed with the soil mass to form the high-polymer high-pressure jet grouting pile 61. When the bottom elevation of the double-channel high-pressure grouting pipe 62 reaches the ground elevation, the grouting operation is stopped, and the construction of the high-polymer high-pressure jet grouting pile 61 is completed;

[0096] In this embodiment, the two-component grouting materials are polyol and isocyanate respectively, and the reaction between isocyanate and polyol is a violent exothermic reaction; the drill tool of the high-pressure jet grouting rig is composed of a drill bit 622, a drill pipe 621, a double-channel high-pressure grouting pipe 62 inside the drill pipe 621, and a nozzle 623. The drill tool rotates at a high speed and drills downward (at this time, grouting is not carried out temporarily). After reaching the designed depth, it is lifted at a set speed while maintaining rotation. At the same time, the double-channel high-pressure grouting pipe 62 sprays out polyol and isocyanate slurries at high speed respectively to cut the surrounding soil mass, and after the polyol and isocyanate are mixed, they react, expand and solidify rapidly, and release a large amount of heat, and are mixed with the soil mass to form a high-polymer high-pressure jet grouting pile 61 body with higher strength. At the same time, due to the overlying load, the high-polymer jet grouting pile body can only expand violently horizontally, thereby exerting a lateral pressure on the soil around the pile. Coupled with the overlying load, the soil mass is in a triaxial compression state, and the shear strength increases, and at the same time, it is beneficial to extrude the water in the soil around the pile.

[0097] Among them, when the double-channel high-pressure grouting pipe 62 is lifted at a set speed and grouting is carried out continuously, the soil mass of the soft foundation 5 cut by the high-speed slurry can be better combined with the high-polymer slurry, and the reinforcement effect is better; due to the existence of the surcharge 3, the formed expansive high-polymer high-pressure jet grouting pile 61 cannot expand axially and can only expand laterally. On the one hand, this improves the density and strength of the pile body. On the other hand, since the pile body can only expand laterally, the water in the soil around the pile can be more fully extruded into the perforated steel pipe and then discharged smoothly.

[0098] S80. The two-component grouting material contacts and reacts with each other to heat the foundation, and the foundation is evacuated by a vacuum pump 8, so that the foundation temperature and the absolute pressure of the foundation are maintained within a preset range to promote the transformation of the liquid water in the foundation into gaseous state;

[0099] In this embodiment, the foundation heating temperature (detected by the temperature sensor 10) and the absolute pressure of the foundation are matched according to Table 1 below. That is, when the foundation heating temperature is 50 °C, the absolute pressure of the foundation needs to be less than 12.34 kPa, and then water changes from liquid to gas; when the foundation heating temperature is 55 °C, the absolute pressure of the foundation needs to be less than 15.743 kPa, and then water changes from liquid to gas; when the foundation heating temperature is 60 °C, the absolute pressure of the foundation needs to be less than 19.923 kPa, and then water changes from liquid to gas; when the foundation heating temperature is 65 °C, the absolute pressure of the foundation needs to be less than 25.014 kPa, and then water changes from liquid to gas; when the foundation heating temperature is 70 °C, the absolute pressure of the foundation needs to be less than 31.164 kPa, and then water changes from liquid to gas. According to the current construction experience, the vacuum degree under the membrane of vacuum preloading can be maintained at about 85 - 95 kPa. Therefore, the absolute pressure of the foundation can be as low as 5 - 15 kPa (calculated with the atmospheric pressure of 100 kPa). That is, the foundation heating temperature only needs to be about 55 °C at most to promote the transformation of liquid water in the foundation into gas, accelerating the drainage and consolidation of the foundation moisture.

[0100] Table 1

[0101] Temperature (°C) 50 55 60 65 70 Absolute pressure (kPa) 12.34 15.743 19.923 25.014 31.164

[0102] S90. Exhaust air from the drainage perforated steel pipe 4, cooperate with the vertical extrusion of the surcharge 3 and the lateral extrusion of the high polymer high-pressure jet grouting pile 61 on the surrounding soil mass, further promote the seepage of moisture in the soft foundation 5 from the drainage perforated steel pipe 4, and improve the consolidation degree and bearing capacity of the soft foundation 5;

[0103] In this embodiment, exhaust air from the drainage perforated steel pipe 4 to increase the vacuum degree inside the pipe. Coupled with the vertical extrusion generated by the surcharge 3 and the lateral extrusion of the expansive high polymer high-pressure jet grouting pile 61 on the surrounding soil mass, the moisture in the deep part of the soft foundation 5 fully seeps out from the drainage perforated steel pipe 4, further improving the consolidation degree and bearing capacity of the soil mass of the soft foundation 5 and eliminating the liquefaction characteristics.

[0104] S100. After the drainage consolidation of the soft foundation 5 is completed, using the drainage perforated steel pipe 4 as the grouting pipe, conduct high polymer high-pressure grouting (two-component grouting material) into the pipe, so that the grout penetrates into the surrounding soil mass through the holes of the drainage perforated steel pipe 4, forming a root-shaped high polymer root steel pipe pile 42;

[0105] In this embodiment, after the soft foundation 5 is drained and consolidated, the drainage steel flower pipe 4 is used as a grouting pipe, and high-pressure polymer grouting is performed into the pipe, so that the slurry penetrates into the surrounding soil through the holes of the drainage steel flower pipe 4 to form a tree root-shaped polymer reinforcement body, and finally forms a polymer root steel pipe pile 42, which works together with the aforementioned tree root-shaped polymer reinforcement body to further improve the bearing capacity of the foundation; at the same time, the polymer reaction releases a large amount of heat, which reinforces the foundation again, promotes the transformation of liquid water in the foundation into gas, and accelerates the drainage and consolidation of the foundation.

[0106] S110, cutting the over-high drainage steel pipe 4, and performing polymer grouting on the gravel cushion layer 1 to form a polymer gravel solidification layer 11, and using the polymer gravel solidification layer 11 as the pile cap of the polymer high-pressure rotary jet pile 61;

[0107] In this embodiment, the excessively high drainage steel pipe 4 is cut off, and polymer grouting is performed on the gravel cushion layer 1 to glue the originally loose gravel together to form a polymer gravel solidification layer 11 with certain strength and flexibility, which can be directly used as the pile cap of the polymer high-pressure rotary jet pile 61, improve the collaborative working ability of the polymer high-pressure rotary jet pile 61 and the soil between the piles, ensure deformation coordination, and prevent uneven settlement.

[0108] S120. Dismantle construction equipment, clean up the site and complete the construction.

[0109] The parts not described in detail in this application are prior art, so this application does not describe them in detail.

[0110] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0111] Although the present invention uses more terms such as crushed stone cushion 1, vacuum membrane 2, heap load 3, drainage steel flower pipe 4, soft foundation 5, polymer high pressure rotary jet pile position 6, pump 7, vacuum pump 8, drainage main pipe 9, temperature sensor 10, polymer crushed stone solidification layer 11, sealing ring sleeve 41, polymer tree root steel pipe pile 42, polymer high pressure rotary jet pile 61, double channel high pressure grouting pipe 62, drill rod 621, drill bit 622, nozzle 623, etc., it does not exclude the possibility of using other terms. The use of these terms is only for more convenient description and explanation of the essence of this application; interpreting them as any additional restrictions is contrary to the spirit of this application.

[0112] This application is not limited to the above-mentioned best implementation modes. Any person can obtain other various forms of products under the inspiration of this application. However, no matter what changes are made in its shape or structure, as long as there are technical solutions that are the same as or similar to this application, they all fall within the protection scope of this application.

Claims

1. A construction method for treating soft foundation by polymer grouting, characterized in that, It includes the following steps: S00. Conduct surface cleaning on the soft foundation and arrange a working platform. S10. Vertically drive drainage steel-pipe piles on the working platform in a designed formation and penetrate the soft foundation layer to be treated. S20. Seal the drainage steel-pipe piles and the drill holes through a sealing ring sleeve and press the sealing ring sleeve into the soft foundation. S30. Lay a drainage gravel cushion layer on the ground surface and lay a vacuum film on the gravel cushion layer. S40. Conduct surcharge loading on the gravel cushion layer, avoiding the reserved pile positions of the drainage steel-pipe piles and the high-polymer high-pressure jet grouting piles in the subsequent steps. S60. Connect all the drainage steel-pipe piles through a mesh water supply pipeline and converge them into a single drainage main pipe, which is connected to a pump. S70. Arrange the pile positions of the high-polymer high-pressure jet grouting piles in a designed formation between the drainage steel-pipe piles, and make the pile body length of the high-polymer high-pressure jet grouting piles penetrate the soft foundation layer to be treated. S80. Use a high-polymer high-pressure jet grouting rig to drill and grout the soft foundation through a double-channel high-pressure grouting pipe, so that the two-component grouting materials contact and react with each other, cut the surrounding soil, and mix with the soil to form the high-polymer high-pressure jet grouting piles. Stop the grouting operation when the bottom elevation of the double-channel high-pressure grouting pipe reaches the ground surface elevation to complete the construction of the high-polymer high-pressure jet grouting piles. Among them, the two-component grouting materials are polyols and isocyanates; the double-channel high-pressure grouting pipe includes a drill pipe and two independent nozzles arranged inside the drill pipe, and each nozzle extends from the side of the drill pipe. S90. The two-component grouting materials contact and react with each other to heat the foundation, and perform vacuum pumping on the foundation through a vacuum pump, so that the foundation temperature and the absolute pressure of the foundation are maintained within a preset range to promote the transformation of liquid water in the foundation into gaseous state. S100. Exhaust air from the drainage steel-pipe piles, cooperate with the vertical extrusion of the surcharge loading and the lateral extrusion of the surrounding soil by the high-polymer high-pressure jet grouting piles, further promote the seepage of water in the soft foundation from the drainage steel-pipe piles, and improve the degree of consolidation and bearing capacity of the soft foundation. S110. After the soft foundation is drained and consolidated, use the drainage steel-pipe piles as grouting pipes, and conduct high-polymer high-pressure grouting into the pipes, so that the grout penetrates into the surrounding soil through the holes of the drainage steel-pipe piles to form tree-root-shaped high-polymer tree-root steel pipe piles. S120. Cut the overly high drainage steel-pipe piles, and conduct high-polymer grouting on the gravel cushion layer to form a high-polymer gravel solidified layer, and use the high-polymer gravel solidified layer as the pile cap of the high-polymer high-pressure jet grouting piles. S130. Demolish the construction equipment and clean the site to complete the construction.

2. The construction method for treating soft foundation by polymer grouting according to claim 1, characterized in that The designed formations in steps S10 and S60 are both square or plum blossom shapes.

3. A construction method for treating soft foundation by polymer grouting according to claim 1, characterized in that, In steps S10 and S60, the layout areas of the drainage steel-pipe piles and the high-polymer high-pressure jet grouting piles are both greater than or equal to the area of the soft foundation to be treated.

4. A construction method for treating soft foundation by polymer grouting according to claim 1, characterized in that, In step S70, after the drill tool of the high-polymer high-pressure jet grouting rig rotates and drills downward to the designed depth, it is then lifted at a predetermined speed while maintaining rotation, and at the same time, the double-channel high-pressure grouting pipe respectively sprays out polyol and isocyanate slurries at high speed.

5. A construction method for treating soft foundation by polymer grouting according to claim 1, characterized in that, In step S80, the heating temperature of the foundation is about 55°C, and the absolute pressure of the foundation is 5 - 15 kPa.

6. A construction method for treating soft foundation by polymer grouting according to any one of claims 1-5, characterized in that, In step S20, the sealing ring sleeve is sleeved on the outer circle of the drainage steel pipe with holes. The protruding part at the bottom of the sealing ring sleeve is inserted into the soft foundation, and the downward flat part is closely attached to the surface of the soft foundation.

7. A construction method for treating soft foundation by polymer grouting according to any one of claims 1-5, characterized in that, In step S10, the top of the drainage steel pipe with holes exceeds the ground elevation by a certain height.

8. A high-polymer grouting soft foundation construction structure applying the high-polymer grouting soft foundation construction method according to any one of claims 1-7, which is used for reinforcing a soft foundation, and is characterized in that It includes: An operation platform, which is set on the surface of the soft foundation for construction operations; A gravel cushion layer, which is laid on the surface of the soft foundation, used for drainage and forming a polymer gravel solidified layer by polymer grouting in the final stage of construction, serving as the pile cap of the polymer high-pressure jet grouting pile; A vacuum membrane, which is laid on the gravel cushion layer, used for draining water in cooperation with a vacuum pump to extract vacuum; A surcharge load, which is set on the gravel cushion layer and the vacuum membrane and avoids the positions of the drainage steel pipe with holes and the polymer high-pressure jet grouting piles, used for providing vertical pressure; Drainage steel pipes with holes, which are evenly spaced and driven into the soft foundation, and the bottom penetrates the soft foundation layer, the top exceeds the ground elevation by a certain height, and the layout area is larger than the area of the soft foundation to be treated; used for drainage and forming polymer root steel pipe piles by grouting after drainage is completed; Polymer high-pressure jet grouting pile positions, which are evenly spaced and driven into the soft foundation and are located between the drainage steel pipes with holes. The bottom of the polymer high-pressure jet grouting pile positions penetrates the soft foundation layer, and the layout area is larger than the area of the soft foundation to be treated; used for forming polymer high-pressure jet grouting piles by grouting; A water pump, used for pumping water from the drainage steel pipes with holes; A vacuum pump, used for extracting vacuum from the soft foundation covered by the vacuum membrane; A drainage main pipe, which is connected to the top of each drainage steel pipe with holes and is connected to the water pump for pumping water operation; A sealing ring sleeve, used for sealing the drainage steel pipe with holes and the soft foundation; A temperature sensor, which is set in the soft foundation, used for detecting the temperature of the soft foundation.

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