Precipitation-support composite integrated enclosure structure system and design method

Abstract

The invention belongs to the technical field of building construction, and particularly relates to a precipitation-support composite integrated enclosure structure system and a design method.The enclosure structure system comprises a plurality of support units circumferentially arranged on the edge of a foundation pit to be excavated; the dewatering units are circumferentially arranged on the edge of the foundation pit to be excavated, and the dewatering units are arranged in the enclosure structure system at intervals and connected with the adjacent supporting units; the filtering assembly is arranged outside the precipitation unit; the sealing assembly is arranged at the bottom end in the precipitation unit; and the drainage assembly is arranged in the precipitation unit and used for draining accumulated water in the precipitation unit. The problems of complex construction procedures, long construction period, low precipitation efficiency, weak bearing capacity, large occupied space and high cost in the prior art are solved, the supporting unit and the precipitation unit are both located on the edge of the foundation pit, the requirement for the space in the foundation pit is lowered, the occupied area is reduced, and the foundation pit is not limited by the layout of a construction site; and meanwhile, the dewatering efficiency in the foundation pit can be guaranteed.

Description

Technical Field

[0001] The present invention belongs to the technical field of building construction, and in particular relates to a dewatering-supporting composite integrated enclosure structure system and a design method. Background Art

[0002] The rapid development of modern urban construction has driven the intensive implementation of projects such as underground space development, integrated pipeline corridors, and large-scale commercial complexes. As a core component in ensuring the safe construction of underground structures, the safety and stability of foundation pit engineering are directly related to the overall reliability and long-term durability of the project. Currently, commonly used foundation pit support methods include pile row support, underground diaphragm walls, soil nail walls, and steel sheet pile support. For example, pile row support uses multiple rows of piles to share soil pressure, underground diaphragm walls form a closed support system with continuous rigid walls, and soil nail walls enhance overall stability through the synergistic effect of soil nails and soil. Steel sheet piles are widely used in long foundation pits due to their high turnover rate and flexibility.

[0003] In traditional foundation pit projects, especially for areas with high groundwater levels, it is necessary to design a dewatering system at the same time as designing the support structure. The dewatering system and the support structure are set separately, which can easily lead to complicated construction procedures, extended construction periods, and increased costs. Moreover, when designing some narrow municipal foundation pits, due to the space limitations of excavation and structural construction in the pit, dewatering wells are generally set outside the pit, occupying the outer space of the foundation pit, restricting the layout of the construction site, and also greatly reducing the dewatering efficiency in the pit. In addition, the support structure and the dewatering system are functionally separated, making it difficult to dynamically adjust according to changes in stratum permeability or groundwater level fluctuations during excavation, which can easily lead to problems such as uneven force on the support structure and insufficient dewatering efficiency, thereby affecting the overall safety and economy of the foundation pit project. Although existing technologies have attempted to combine support and dewatering functions, they mostly adopt a simple superposition method. Currently, in existing specifications and standards, the design theory of a single form of retaining pile structure is relatively complete, but when different types of retaining piles are used in combination, there is currently a lack of a systematic collaborative design theory, which makes it difficult to scientifically guarantee the overall support and dewatering effects of the composite retaining structure, restricting the promotion of engineering applications.

[0004] Therefore, it is necessary to design a dewatering-support composite integrated enclosure structure system and design method to solve the above problems. Summary of the Invention

[0005] The purpose of the present invention is to provide a dewatering-support composite integrated enclosure structure system and design method, which integrates support and dewatering functions, improves construction efficiency and enhances adaptability.

[0006] To achieve the above-mentioned object, the present invention provides the following solution: a precipitation-support composite integrated enclosure structure system, comprising:

[0007] A plurality of supporting units are circumferentially arranged at the edge of the foundation pit to be excavated;

[0008] A plurality of dewatering units are circumferentially arranged at the edge of the foundation pit to be excavated, and are arranged at intervals in the supporting system and connected with adjacent supporting units, and the dewatering units are connected with the supporting units through buckles;

[0009] A filtering assembly is arranged outside the dewatering unit;

[0010] A sealing assembly is arranged at the bottom end of the dewatering unit, and is used for sealing the bottom end of the dewatering unit;

[0011] A drainage assembly is arranged inside the dewatering unit, and is used for draining the accumulated water inside the dewatering unit.

[0012] The dewatering unit is provided with an opening on the side wall facing the foundation pit, the opening is arranged along the depth direction of the foundation pit, the part of the side wall of the dewatering unit away from the foundation pit above the bottom of the foundation pit is a closed structure, the part of the side wall of the dewatering unit away from the foundation pit below the bottom of the foundation pit is provided with an opening, and the arrangement mode of the opening is one or more of a plum blossom shape and an equidistant rectangle.

[0013] The filtering assembly includes a filter screen, the filter screen is wrapped outside the dewatering unit, and sand filter material is filled between the filter screen and the hole wall of the mounting hole of the dewatering unit.

[0014] The sealing assembly includes a bottom cover, the bottom cover is arranged at the bottom end inside the dewatering unit, a support is fixedly connected to the top end of the bottom cover, the support is vertically arranged, a water-permeable supporting plate is fixedly connected to the top end of the support, and the drainage assembly is arranged at the top end of the water-permeable supporting plate.

[0015] The drainage assembly includes a water pumping pump, the water pumping pump is arranged at the top end of the water-permeable supporting plate, the outlet end of the water pumping pump is fixedly connected in communication with one end of a water outlet pipe, and the other end of the water outlet pipe extends out of the top end of the dewatering unit.

[0016] A design method of a dewatering-support composite integrated supporting system, comprising the following steps:

[0017] According to the geological conditions, the water inflow of the foundation pit is calculated ; According to the permeability of the aquifer and the structure of the dewatering unit, the flow of the dewatering unit is calculated ; According to the water inflow of the foundation pit and the precipitation unit flow Calculate the number of precipitation units ; According to the number of precipitation units Calculate the number of supporting units ; According to the calculated amount of water gushing from the foundation pit , the precipitation unit flow , the number of precipitation units , the number of supporting units The precipitation performance of the precipitation unit is calculated according to the data;

[0018] According to the selection parameters of the precipitation unit and the supporting unit, the data of the full-length equivalent bending stiffness, the full-length equivalent bending bearing capacity and the full-length equivalent shear bearing capacity of the composite integrated enclosure structure system are calculated, and the earth retaining performance of the composite integrated enclosure structure system is obtained according to the calculated data of the full-length equivalent bending stiffness, the full-length equivalent bending bearing capacity and the full-length equivalent shear bearing capacity.

[0019] According to the structure form of the composite integrated enclosure structure system, stability calculation is carried out, and after the stability meets the requirements, the precipitation unit and the supporting unit are installed to form the composite integrated enclosure structure system.

[0020] Based on the design method of the precipitation-supporting composite integrated enclosure structure system, the amount of water gushing from the foundation pit is calculated according to the geological conditions , comprising:

[0021] The amount of water gushing from the foundation pit of the phreatic complete well The calculation formula is:

[0022] ;

[0023] Among them, The total water consumption of the foundation pit precipitation is; The permeability coefficient is; The thickness of the phreatic aquifer is; The drawdown of the foundation pit water level is; The precipitation influence radius is; The equivalent circle radius of the area surrounded by the precipitation well group is;

[0024] The amount of water gushing from the foundation pit of the phreatic incomplete well The calculation formula is:

[0025] ;

[0026] ;

[0027] Among them, The thickness from the dynamic water level of the foundation pit to the surface of the aquifer is; The length of the effective working part of the precipitation unit is;

[0028] Water inflow from complete well foundation pit of pressurized water Calculation formula:

[0029] ;

[0030] in, is the thickness of the confined aquifer;

[0031] Water inflow from foundation pit of incomplete well of pressurized water Calculation formula:

[0032] ;

[0033] Water inflow from pressurized and submerged incomplete well foundation pit Calculation formula:

[0034] ;

[0035] Precipitation cell flow Calculation formula:

[0036] ;

[0037] in, is the radius of the precipitation unit. When the precipitation unit is square, , is the precipitation unit area;

[0038] Number of precipitation units Calculation formula:

[0039] ;

[0040] in, Take the integer;

[0041] Number of support units Calculation formula:

[0042] ;

[0043] in, is the length of the support unit; L is the total length of the support, and m is an integer.

[0044] Based on the design method of a dewatering-supporting composite integrated enclosure structure system of the present invention, the full-length equivalent bending stiffness calculation formula of the enclosure structure system is:

[0045] ;

[0046] ;

[0047] ;

[0048] in, is the equivalent bending stiffness of the entire length of the enclosure structure system; is the flexural stiffness of the support unit; is the bending stiffness of the precipitation unit; is the elastic modulus of the support unit; is the elastic modulus of the precipitation unit; is the moment of inertia of the support unit; is the moment of inertia of the precipitation unit;

[0049] Calculation formula for the full-length equivalent bending bearing capacity of the enclosure structure system:

[0050] ;

[0051] ;

[0052] ;

[0053] in, is the equivalent bending bearing capacity of the entire length of the enclosure structure system; is the bending bearing capacity of the support unit; is the support bearing capacity of the precipitation unit; is the vertical displacement of the support unit; is the vertical displacement of the precipitation unit; is the axial coordinate position of the support unit; is the axial coordinate position of the precipitation unit;

[0054] Calculation formula for the shear bearing capacity of the equivalent section of the full length of the enclosure structure system:

[0055] ;

[0056] ;

[0057] ;

[0058] ;

[0059] in, is the equivalent section shear bearing capacity of the entire length of the enclosure structure system; is the shear force of the support unit; is the precipitation unit shear force; is the height of the web in the support unit and the precipitation unit; is the thickness of the web in the support unit and the precipitation unit; is the design value of steel shear strength.

[0060] Compared with the prior art, the present invention has the following advantages and technical effects:

[0061] 1. The present invention effectively improves the overall bending stiffness and bending bearing capacity of the enclosure structure system by combining the precipitation unit with the support unit, and reduces the deformation of the structure during the support process.

[0062] 2. The present invention solves the problem in the prior art that the dewatering wells set inside or outside the foundation pit occupy too much space by combining the dewatering unit with the support unit, so that the setting of the dewatering wells is not restricted by the layout of the construction site and is fully suitable for urban narrow foundation pit projects.

[0063] 3. The present invention combines the precipitation unit with the support unit to achieve simultaneous support and precipitation, effectively streamlining the construction process, reducing the construction period, and saving construction costs.

[0064] 4. By combining the dewatering unit with the support unit, the present invention can make dynamic adjustments according to the changes in stratum permeability or groundwater level fluctuations during excavation, thereby solving the problems of uneven force on the retaining structure and insufficient dewatering efficiency in the prior art.

[0065] 5. The present invention proposes a new quantitative design method for composite structures, enriches the content of composite pile design methods, and makes up for the shortcomings of current specifications. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive efforts.

[0067] Figure 1 This is a schematic diagram of the integrated enclosing structure system for precipitation support of the present invention;

[0068] Figure 2 Schematic diagram of a precipitation unit of the present invention;

[0069] Figure 3 This is a schematic diagram of the precipitation surface of the precipitation unit of the present invention;

[0070] Figure 4 This is a schematic diagram of the soil surface of the precipitation unit of the present invention;

[0071] Figure 5 This is a schematic diagram of the first connection between the precipitation unit and the support unit according to an embodiment of the present invention;

[0072] Figure 6 This is a schematic diagram of a second connection between a precipitation unit and a support unit according to an embodiment of the present invention;

[0073] Figure 7 Design a flow chart for the present invention.

[0074] Among them, 1. filter hole; 2. filter screen; 3. lock; 4. bottom seal; 5. bracket; 6. permeable support plate; 7. water pump; 8. opening; 9. sand filter material; 10. outlet pipe. DETAILED DESCRIPTION

[0075] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0076] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0077] Reference Figures 1 to 7 As shown, the present invention provides a precipitation-support composite integrated enclosure structure system, comprising:

[0078] Several support units are arranged circumferentially at the edge of the planned excavation pit;

[0079] The support unit is a retaining pile structure, and one or more of steel sheet piles, steel pipe piles, steel piles, and steel tube concrete piles can be selected; the support unit is installed by directly inserting into the stratum or drilling into it.

[0080] Several dewatering units are arranged circumferentially at the edge of the planned excavation pit. The dewatering units are arranged at intervals within the enclosure structure system and connected to adjacent support units. The dewatering units are connected to the support units via lock buckles 3.

[0081] The precipitation unit is a hollow structure, and one or more of round steel pipes, square steel pipes, and special-shaped steel pipes can be selected.

[0082] A filter assembly is arranged outside the precipitation unit;

[0083] A sealing assembly is provided at the bottom end of the precipitation unit, and is used to seal the bottom end of the precipitation unit;

[0084] The drainage component is arranged inside the precipitation unit and is used to drain the accumulated water inside the precipitation unit.

[0085] Furthermore, the precipitation unit is provided with openings 8 on the side wall facing the foundation pit, and the openings 8 are arranged along the depth direction of the foundation pit. The part of the precipitation unit's side wall away from the foundation pit and located above the bottom of the foundation pit is a closed structure, and the part of the precipitation unit's side wall away from the foundation pit and located below the bottom of the foundation pit is provided with openings 8. The arrangement of the openings 8 is one or more of a plum blossom shape, an equally spaced rectangle, etc.

[0086] The opening 8 is used to allow groundwater to seep into the interior of the dewatering unit before excavation of the foundation pit, thereby achieving dewatering of the stratum within the scope of the planned excavation pit; the closed structure of the dewatering unit can prevent groundwater outside the retaining structure from seeping into the interior of the dewatering unit.

[0087] Furthermore, the filter assembly includes a filter screen 2, which is coated on the outside of the precipitation unit, and a sand filter material 9 is filled between the filter screen 2 and the hole wall of the precipitation unit installation hole.

[0088] The filter screen 2 is made of metal or plastic.

[0089] Furthermore, the sealing assembly includes a bottom cover 4, which is arranged at the inner bottom end of the precipitation unit. The top of the bottom cover 4 is fixedly connected to a bracket 5, which is arranged vertically. The top of the bracket 5 is fixedly connected to a permeable support plate 6, and the drainage assembly is arranged at the top of the permeable support plate 6.

[0090] The bottom seal 4 prevents external soil particles from entering the precipitation unit along the bottom. The area between the permeable support plate 6 and the bottom seal 4 of the precipitation unit is a sand settling section for depositing and storing soil particles that penetrate into the precipitation unit during the precipitation process.

[0091] Furthermore, the drainage assembly includes a water pump 7, which is arranged at the top of the permeable support plate 6. The outlet end of the water pump 7 is fixedly connected to one end of the outlet pipe 10, and the other end of the outlet pipe 10 extends out of the top of the precipitation unit.

[0092] After the dewatering unit is installed, a water pump 7 is used inside the dewatering unit to pump water in the pipe. When the dewatering water level that meets the design dewatering level for the on-site foundation pit excavation is reached, the dewatering demand is met.

[0093] A design method for a dewatering-supporting composite integrated enclosure structure system includes the following steps:

[0094] Calculate the amount of water inflow from the foundation pit based on geological conditions ; Calculate precipitation unit flow based on aquifer permeability and precipitation unit structure ; According to the amount of water inflow from the foundation pit and precipitation unit flow Calculating the number of precipitation cells ; According to the number of precipitation units Calculate the number of support units ; According to the calculated foundation pit water inflow , precipitation unit flow , number of precipitation units , Number of support units The precipitation performance of the precipitation unit is calculated based on the data;

[0095] According to the selection parameters of the dewatering unit and the support unit, the full-length equivalent bending stiffness, full-length equivalent bending bearing capacity, and full-length equivalent cross-sectional shear bearing capacity data of the composite integrated retaining structure system are calculated, and the retaining performance of the composite integrated retaining structure system is obtained based on the calculated full-length equivalent bending stiffness, full-length equivalent bending bearing capacity, and full-length equivalent cross-sectional shear bearing capacity data;

[0096] The stability calculation is carried out according to the structural form of the composite integrated enclosure structure system. After the stability meets the requirements, the precipitation unit and the support unit are installed to form a composite integrated enclosure structure system.

[0097] Furthermore, the amount of water inflow from the foundation pit is calculated based on the geological conditions. ,include:

[0098] Water inflow from the complete submersible well foundation pit Calculation formula:

[0099] ;

[0100] in, is the total water consumption for foundation pit dewatering; is the permeability coefficient m / d; is the thickness of the phreatic aquifer in m; The water level of the foundation pit is lowered in m; is the precipitation impact radius in m; The radius of the equivalent circle enclosed by the precipitation well group is m;

[0101] Water inflow from submerged incomplete well foundation pit Calculation formula:

[0102] ;

[0103] ;

[0104] in, The thickness from the dynamic water level of the foundation pit to the ground surface of the aquifer in m; is the length of the effective working part of the precipitation unit in m;

[0105] Water inflow from complete well foundation pit of pressurized water Calculation formula:

[0106] ;

[0107] in, is the thickness of the confined aquifer in m;

[0108] Water inflow from foundation pit of incomplete well of pressurized water Calculation formula:

[0109] ;

[0110] Water inflow from pressurized and submerged incomplete well foundation pit Calculation formula:

[0111] ;

[0112] Precipitation cell flow Calculation formula:

[0113] ;

[0114] in, is the radius of the precipitation unit. When the precipitation unit is square, , is the precipitation unit area;

[0115] Number of precipitation units Calculation formula:

[0116] ;

[0117] in, Take the integer;

[0118] Number of support units Calculation formula:

[0119] ;

[0120] in, is the length of the support unit in m; L is the total length of the support in m, where m is an integer.

[0121] Before calculating the number of support units, the drawdown and well spacing must be verified.

[0122] The dewatering-support composite integrated enclosure structure system has a total of n dewatering units and m support units along the entire support length.

[0123] Furthermore, the calculation formula for the full-length equivalent bending stiffness of the enclosure structure system is:

[0124] ;

[0125] ;

[0126] ;

[0127] in, is the equivalent bending stiffness of the entire length of the enclosure structure system; is the flexural stiffness of the support unit; is the bending stiffness of the precipitation unit; is the elastic modulus of the support unit; is the elastic modulus of the precipitation unit; is the moment of inertia of the support unit; is the moment of inertia of the precipitation unit;

[0128] Calculation formula for the full-length equivalent bending bearing capacity of the enclosure structure system:

[0129] ;

[0130] ;

[0131] ;

[0132] in, is the equivalent bending bearing capacity of the entire length of the enclosure structure system; is the bending bearing capacity of the support unit; is the support bearing capacity of the precipitation unit; is the vertical displacement of the support unit; is the vertical displacement of the precipitation unit; is the axial coordinate position of the support unit; is the axial coordinate position of the precipitation unit; d is the mathematical operation symbol;

[0133] Calculation formula for the shear bearing capacity of the equivalent section of the full length of the enclosure structure system:

[0134] ;

[0135] ;

[0136] ;

[0137] ;

[0138] in, is the equivalent section shear bearing capacity of the entire length of the enclosure structure system; is the shear force of the support unit; is the precipitation unit shear force; is the height of the web in the support unit and the precipitation unit; is the thickness of the web in the support unit and the precipitation unit; is the design value of steel shear strength; It means that the shear force of the support unit and the shear force of the precipitation unit need to satisfy the requirements of this inequality at the same time.

[0139] When the retaining structure system adopts a supporting retaining structure, it shall meet the requirements of embedded stability and pit bottom uplift stability.

[0140] Requirements for embedded stability of supporting retaining structures:

[0141] ;

[0142] Among them, K em is the embedded stability safety factor; E ak is the standard value of the active earth pressure outside the foundation pit (kN); E pk is the standard value of the passive earth pressure in the foundation pit (kN); a1 is the distance from the point of action of the active earth pressure outside the foundation pit to the bottom of the retaining member (m); p1 It is the distance (m) from the point of action of the resultant passive earth pressure measured in the foundation pit to the bottom end of the retaining structure.

[0143] Stability requirements for pit bottom uplift of supported retaining structure:

[0144] ;

[0145] ;

[0146] ;

[0147] Among them, K he is the anti-uplift safety factor; γ m1 is the weight of the soil above the bottom of the retaining structure outside the foundation pit (kN / m 3 );γ m2 The density of the soil above the bottom of the retaining structure in the foundation pit (kN / m 3 ); D is the thickness of the soil layer from the bottom of the foundation pit to the bottom of the retaining structure (m); h is the depth of the foundation pit (m); q0 is the uniformly distributed load on the ground (kPa); N c 、N q is the bearing capacity coefficient; c and φ are the cohesion (kPa) and internal friction angle (°) of the soil below the bottom surface of the retaining member.

[0148] When the enclosure structure system adopts a cantilever retaining structure, it shall meet the requirements of embedded stability and overall stability.

[0149] Embedded stability requirements for cantilever retaining structures:

[0150] ;

[0151] Among them, z a2 is the distance from the point of action of the active earth pressure outside the foundation pit to the bottom of the retaining member (m); p2It is the distance (m) from the point of action of the resultant passive earth pressure measured in the foundation pit to the bottom end of the retaining structure.

[0152] Overall stability requirements for cantilever retaining structures:

[0153] ;

[0154] ;

[0155] Among them, K s K is the overall stability safety factor of arc sliding; s,i is the ratio of the anti-sliding torque to the sliding torque of the i-th sliding arc; c j、 φ j is the cohesion (kPa) and internal friction angle (°) of the soil at the sliding arc surface of the jth soil strip; b j is the width of the jth soil strip (m); θ j is the angle between the normal line at the midpoint of the sliding arc surface of the jth soil strip and the vertical plane (°); l j is the length of the sliding arc section of the jth soil strip (m); q j is the standard value of the additional distributed load acting on the jth soil strip (kPa); ΔG j is the deadweight of the jth soil strip (kN); u j is the pore water pressure of the jth soil strip on the sliding arc surface (kPa).

[0156] Example:

[0157] This embodiment provides a dewatering and support integrated enclosure structure system. The dewatering units utilize φ325 steel pipe piles with a thickness of 20 mm. Filter holes are drilled on the dewatering surface of the steel pipe piles, with a diameter of 10 mm and a spacing of 20 mm between them, arranged in a quincunx pattern. The steel pipe piles are the same length as the steel sheet piles, with holes drilled on both sides below one-third of the way up. Larsen IV steel sheet piles are used as support units.

[0158] A 60-mesh (250-micron) filter screen 2 is placed in the opening of the steel pipe pile, then covered with a layer of wire mesh to hold it down. Steel strips are welded to the edges of the wire mesh to secure it. Filter screen 2 is made of stainless steel, and the wire mesh is 10-mesh stainless steel. A water pump 7 is mounted on a permeable support plate 6, which is mounted on the bottom cover 4.

[0159] The first construction plan is as follows: (1) Clean the locks of the steel sheet pile and the steel pipe pile, then tightly engage the locks of the steel sheet pile and the steel pipe pile on the ground, and then weld the steel pipe pile and the steel sheet pile 1 at the lock 3 position; (2) On-site personnel select the steel pipe pile position and mark it, and then use a drilling rig to drill a hole with a hole diameter of 650mm. Then use the slurry replacement and hole cleaning method to clean the hole; (3) Drive the steel sheet pile 1, and the steel pipe is passively sunk into the borehole through the welded lock 3. Then drive the steel sheet pile 2, ensuring that the lock 3 is tightly connected. Before driving the steel pipe pile, fill the lock 3 with butter asphalt mixture. When driving the steel sheet pile, use the pile driver to hang the steel pipe pile to prevent it from sinking, and use a level to observe and correct it to ensure that the inclination meets the requirements; (4) Fill the space between the steel pipe pile and the borehole with medium and coarse sand filter material 9 as a filter layer; (5) Hang a water pump 7 in the steel pipe pile to pump water. Ensure that the water pump 7 is 0.5-1m away from the bottom of the well.

[0160] The second construction plan is as follows: (1) Extend and weld the lock buckle 3 on one side of the steel pipe pile. The length of the extended lock buckle should be no less than 200mm and the thickness should be no less than 15mm. (2) Sink the steel sheet pile 1 and then drill a hole with a diameter of 650mm on the right side of the steel sheet pile 1. Then use the slurry replacement and hole cleaning method to clean the hole. (3) Slowly press the steel pipe pile into the hole with a pile driver. Ensure that the long lock buckle of the steel pipe pile is tightly connected to the steel sheet pile 1. (4) Fill the space between the steel pipe pile and the drill hole with medium and coarse sand filter material 9 as a filter layer. (5) Drive the steel sheet pile 2 into the side of the short lock buckle of the steel pipe pile and ensure that the lock buckle is tightly connected. When the steel sheet pile is driven in, the steel pipe pile is suspended by the pile driver to prevent it from sinking. During the pile driving process, a level ruler is used to observe and correct to ensure that the inclination meets the requirements. (6) Hang a water pump into the steel pipe pile to pump water. Ensure that the water pump is 0.5-1m away from the bottom of the well.

[0161] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention, 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, and therefore cannot be understood as a limitation on the present invention.

[0162] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the scope of protection of the present invention.

Claims

1. A precipitation-support composite integrated enclosure structure system, characterized in that: include: Several support units are arranged circumferentially at the edge of the planned excavation pit; A plurality of dewatering units are circumferentially arranged at the edge of the planned excavation pit, the dewatering units are arranged at intervals within the retaining structure system, and are connected to adjacent support units; A filter assembly is arranged outside the precipitation unit; A sealing assembly is provided at the bottom end of the precipitation unit, and is used to seal the bottom end of the precipitation unit; A drainage component is arranged inside the precipitation unit, and is used to drain the accumulated water inside the precipitation unit.

2. The dewatering-supporting composite integrated enclosure structure system according to claim 1 is characterized in that: The side wall of the precipitation unit facing the foundation pit is provided with openings (8), and the openings (8) are arranged along the depth direction of the foundation pit. The part of the side wall of the precipitation unit facing away from the foundation pit and located above the bottom of the foundation pit is a closed structure. The part of the side wall of the precipitation unit facing away from the foundation pit and located below the bottom of the foundation pit is provided with openings (8), and the arrangement of the openings (8) is one or more of a plum blossom shape, an equidistant rectangle, etc.

3. The dewatering-supporting composite integrated enclosure structure system according to claim 1 is characterized in that: The filter assembly comprises a filter screen (2), the filter screen (2) being wrapped around the outside of the precipitation unit, and a sand filter material (9) being filled between the filter screen (2) and the wall of the installation hole of the precipitation unit.

4. The dewatering-supporting composite integrated enclosure structure system according to claim 1, characterized in that: The sealing assembly comprises a bottom seal (4), the bottom seal (4) being arranged at the inner bottom end of the precipitation unit, the top end of the bottom seal (4) being fixedly connected to a bracket (5), the bracket (5) being arranged vertically, the top end of the bracket (5) being fixedly connected to a permeable support plate (6), and the drainage assembly being arranged at the top end of the permeable support plate (6).

5. The dewatering-supporting composite integrated enclosure structure system according to claim 4 is characterized in that: The drainage assembly comprises a water pump (7), which is arranged at the top of the permeable support plate (6), and the outlet end of the water pump (7) is fixedly connected to one end of a water outlet pipe (10), and the other end of the water outlet pipe (10) extends out of the top of the precipitation unit.

6. A design method for a water-reduction-support composite integrated enclosure structure system according to any one of claims 1 to 5, characterized in that: The following steps are involved: Calculate the amount of water inflow from the foundation pit based on geological conditions ; Calculate precipitation cell flow based on aquifer permeability and precipitation cell structure ; According to the amount of water inflow from the foundation pit and precipitation unit flow Calculating the number of precipitation cells ; According to the number of precipitation units Calculate the number of support units ; According to the calculated foundation pit water inflow , precipitation unit flow , number of precipitation units , Number of support units The precipitation performance of the precipitation unit is calculated based on the data; According to the selection parameters of the dewatering unit and the support unit, the full-length equivalent bending stiffness, full-length equivalent bending bearing capacity, and full-length equivalent cross-sectional shear bearing capacity data of the composite integrated retaining structure system are calculated, and the retaining performance of the composite integrated retaining structure system is obtained based on the calculated full-length equivalent bending stiffness, full-length equivalent bending bearing capacity, and full-length equivalent cross-sectional shear bearing capacity data; The stability calculation is carried out according to the structural form of the composite integrated enclosure structure system. After the stability meets the requirements, the precipitation unit and the support unit are installed to form a composite integrated enclosure structure system.

7. The design method of a dewatering-supporting composite integrated enclosure structure system according to claim 6 is characterized in that: The calculation of foundation pit water inflow according to geological conditions ,include: Water inflow from the complete submersible well foundation pit Calculation formula: ； in, is the total water consumption for foundation pit dewatering; is the permeability coefficient (m / d); is the thickness of the phreatic aquifer (m); is the depth of foundation pit water level drop (m); is the precipitation impact radius (m); is the radius of the equivalent circle enclosed by the precipitation well group (m); Water inflow from submerged incomplete well foundation pit Calculation formula: ； ； in, is the thickness from the dynamic water level of the foundation pit to the ground surface of the aquifer (m); is the length of the effective working part of the precipitation unit (m); Water inflow from complete well foundation pit of pressurized water Calculation formula: ； in, is the thickness of the confined aquifer (m); Water inflow from foundation pit of incomplete well of pressurized water Calculation formula: ； Water inflow from pressurized and submerged incomplete well foundation pit Calculation formula: ； Precipitation cell flow Calculation formula: ； in, is the radius of the precipitation unit. When the precipitation unit is square, , is the precipitation unit area; Number of precipitation units Calculation formula: ； in, Take the integer; Number of support units Calculation formula: ； in, is the length of the support unit (m); L is the total length of the support (m), where m is an integer.

8. The design method of a dewatering-supporting integrated enclosure structure system according to claim 6 is characterized in that: Calculation formula for the full-length equivalent bending stiffness of the enclosure structure system: ； ； ； in, is the equivalent bending stiffness of the entire length of the enclosure structure system; is the flexural stiffness of the support unit; is the bending stiffness of the precipitation unit; is the elastic modulus of the support unit; is the elastic modulus of the precipitation unit; is the moment of inertia of the support unit; is the moment of inertia of the precipitation unit; Calculation formula for the full-length equivalent bending bearing capacity of the enclosure structure system: ； ； ； in, is the equivalent bending bearing capacity of the entire length of the enclosure structure system; is the bending bearing capacity of the support unit; is the support bearing capacity of the precipitation unit; is the vertical displacement of the support unit; is the vertical displacement of the precipitation unit; is the axial coordinate position of the support unit; is the axial coordinate position of the precipitation unit; Calculation formula for the shear bearing capacity of the equivalent section of the full length of the enclosure structure system: ； ； ； ； in, is the equivalent section shear bearing capacity of the entire length of the enclosure structure system; is the shear force of the support unit; is the precipitation unit shear force; is the height of the web in the support unit and the precipitation unit; is the thickness of the web in the support unit and the precipitation unit; is the design value of steel shear strength.

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