A construction method for structural columns within a reserved soil platform

Abstract

The present application relates to the technical field of deep foundation pit construction, and provides a construction method for structural columns within a reserved soil platform, including: performing pile foundation construction of the structural columns within the reserved soil platform according to the preset positions of the structural columns; sinking a casing to the designed elevation of the pile foundation at the preset positions of the structural columns, and excavating the soil within the casing; prefabricating the steel bar formwork structure of the structural columns; opening a groove at the top of the pile foundation according to the preset positions of the structural columns, hoisting the steel bar formwork structure into the casing, and inserting one end of the steel bar formwork structure into the groove; pouring concrete into the steel bar formwork structure, and symmetrically backfilling the soil in sections between the steel bar formwork structure and the casing after the concrete strength meets the preset requirements; pulling out the casing. By constructing the structural columns within the reserved soil platform, the construction of the basement main structure can be achieved without excavating the reserved soil platform and ensuring the counterpressure effect of the reserved soil platform on the retaining piles, thus avoiding affecting the construction period of the basement main structure.

Description

Technical Field

[0001] This application relates to the technical field of deep foundation pit construction, and particularly to a construction method for structural columns within a reserved soil platform. Background Art

[0002] A deep foundation pit refers to a project where the excavation depth exceeds 5 meters (including 5 meters), or although the depth does not exceed 5 meters, the geological conditions, surrounding environment, and underground pipelines are extremely complex. When constructing the basement of a high-rise building, excavation of a deep foundation pit is required; during the excavation of a deep foundation pit, in order to protect the safety of the construction of the underground main structure and the surrounding environment of the foundation pit, a foundation pit support structure will be set up. After the foundation pit support structure is set up, the construction of the basement structure will be carried out; the most commonly used foundation pit support structure is the cable anchor support structure; the cable anchor support structure uses metal parts, wooden parts, polymer parts, or other materials to make rod columns, which are driven into pre-drilled holes in the surface rock mass or the rock mass around the chamber. Utilizing the special structure of its head, rod body, and the tail plate (which can also be not used), or relying on the bonding effect to combine the surrounding rock with the stable rock mass to achieve the purpose of support; for deep foundation pit excavation construction scenarios such as being close to the subway, having a developed groundwater system (close to lakes, rivers, seas), having many surrounding buildings (such as having a deep basement under the building), having complex surrounding underground pipe networks, or having a small construction land area, it is not suitable to drill holes in the wall surface around the foundation pit, and the cable anchor support structure is not applicable; a reserved soil platform can be used as backfill soil to replace the cable anchor support structure to achieve the support effect on the retaining piles.

[0003] In order to ensure that the reserved soil platform can effectively act as a counter-pressure on the retaining piles, the volume of the required reserved soil platform needs to be large enough so that the reserved soil platform invades the construction area of the basement main structure; therefore, during the construction of the basement, only part of the structure construction of the basement main structure can be completed first, and a temporary support system is installed to replace the reserved soil platform to support the retaining piles before the reserved soil can be excavated, and then the remaining part of the basement main structure can be constructed, which will seriously affect the construction period of the basement main structure.

[0004] Therefore, there are defects in the prior art and it needs to be improved and developed. Summary of the Invention

[0005] The technical problem to be solved by this application is that in the current construction of deep foundation pit basements, the reserved soil platform invades the construction area of the basement main structure. It is necessary to first complete part of the structure construction of the basement main structure and install a temporary support system to replace the reserved soil platform to support the retaining piles before the reserved soil can be excavated and the remaining part of the basement main structure can be constructed, seriously affecting the construction period of the basement main structure. In view of the above-mentioned defects in the prior art, a construction method for structural columns within a reserved soil platform is provided.

[0006] The technical solution adopted by this application to solve the technical problems is as follows: A construction method for structural columns in a reserved soil platform, including:

[0007] According to the preset position of the structural column, carry out the pile foundation construction of the structural column in the reserved soil platform;

[0008] At the preset position of the structural column, sink the casing to the designed elevation of the pile foundation, and excavate the soil inside the casing;

[0009] Prefabricate the steel bar formwork structure of the structural column;

[0010] According to the preset position of the structural column, open a groove at the top of the pile foundation, lift the steel bar formwork structure into the casing, and insert one end of the steel bar formwork structure into the groove;

[0011] Pour concrete into the steel bar formwork structure, and after the concrete strength meets the preset requirements, symmetrically backfill the soil in segments between the steel bar formwork structure and the casing;

[0012] Pull out the casing.

[0013] Optionally, before carrying out the pile foundation construction of the structural column in the reserved soil platform according to the preset position of the structural column, it further includes: Measuring and positioning on the reserved soil platform according to the preset position of the structural column and making marks.

[0014] Optionally, the step of sinking the casing to the designed elevation of the pile foundation and excavating the soil inside the casing at the preset position of the structural column specifically includes:

[0015] Sink the casing in segments at the marked position, and after sinking each segment of the casing, excavate the soil inside that segment of the casing, and then detect the verticality of that segment of the casing;

[0016] After the verticality of that segment of the casing meets the requirements, introduce the mark onto the inner wall of that segment of the casing;

[0017] Continue to sink the next segment of the casing until the designed elevation of the pile foundation.

[0018] Optionally, the steel bar formwork structure includes: a column formwork and a steel bar cage, the column formwork is sleeved on the steel bar cage, and both ends of the steel bar cage protrude from the column formwork.

[0019] Optionally, the step of opening a groove at the top of the pile foundation according to the preset position of the structural column, lifting the steel bar formwork structure into the casing, and inserting one end of the steel bar formwork structure into the groove specifically includes:

[0020] According to the position of the mark, a groove is opened at the top of the pile foundation, and positioning bars are vertically installed in the groove;

[0021] Insert one end of the steel reinforcement cage protruding from the column formwork into the groove, wherein the positioning bars are inserted into the steel reinforcement cage and abut against the corners of the steel reinforcement cage.

[0022] Optionally, after inserting one end of the steel reinforcement cage protruding from the column formwork into the groove, it further includes: according to the position of the mark, cross fixing bars are installed on the end face of the casing, and the cross fixing bars are connected and fixed to the steel reinforcement cage, and the cross position of the cross fixing bars corresponds to the corners of the steel reinforcement cage.

[0023] Optionally, the steel reinforcement formwork structure further includes: a pile cap reinforcement, the pile cap reinforcement is lapped on the steel reinforcement cage and passes through the column formwork, and the pile cap reinforcement is arranged adjacent to one end of the steel reinforcement cage protruding from the column formwork.

[0024] Optionally, according to the preset position of the structural column, opening a groove at the top of the pile foundation, hoisting the steel reinforcement formwork structure into the casing, and inserting one end of the steel reinforcement formwork structure into the groove specifically includes:

[0025] According to the position of the mark, a first - stage groove is opened at the top of the pile foundation, and a second - stage groove is opened at the bottom wall of the first - stage groove;

[0026] According to the position of the mark, determine the installation position of the steel reinforcement cage in the second - stage groove, and vertically install positioning bars in the second - stage groove, wherein the positioning bars correspond to the corners of the steel reinforcement cage;

[0027] Insert one end of the steel reinforcement cage protruding from the column formwork into the second - stage groove, wherein the positioning bars are inserted into the steel reinforcement cage and abut against the corners of the steel reinforcement cage, the end face of the column formwork abuts against the bottom wall of the first - stage groove, and the pile cap reinforcement is located in the first - stage groove.

[0028] Optionally, after inserting one end of the steel reinforcement cage protruding from the column formwork into the second - stage groove, it further includes: performing waterproof reinforcement at the connection position between the outer periphery of the column formwork and the first - stage groove.

[0029] Optionally, after sinking the casing to the design elevation of the pile foundation at the preset position of the structural column and excavating the soil inside the casing, it further includes: installing a rotary ladder on the inner wall of the casing, wherein the rotary ladder is spirally distributed on the inner wall of the casing.

[0030] In this application, a construction method for structural columns within a reserved soil platform is provided. By constructing the structural columns within the reserved soil platform, without excavating the reserved soil platform and ensuring the counter-pressure effect of the reserved soil platform on the retaining piles, the construction of the basement main structure can be achieved, avoiding the impact on the construction period of the basement main structure and facilitating the shortening of the construction period. Description of the Drawings

[0031] Figure 1 is the process flow chart of the structural column construction method provided in this application;

[0032] Figure 2 is the top view schematic diagram of the deep foundation pit in the structural column construction method provided in this application;

[0033] Figure 3 is the partial cross-sectional view schematic diagram of the deep foundation pit in the structural column construction method provided in this application;

[0034] Figure 4 is the cross-sectional view schematic diagram of the structural column in the structural column construction method provided in this application;

[0035] Figure 5 is the process flow chart of another implementation manner of the structural column construction method provided in this application;

[0036] Figure 6 is the cross-sectional view schematic diagram of the structural column in the structural column construction method provided in this application;

[0037] Figure 7 is the top view schematic diagram of the structural column in the structural column construction method provided in this application;

[0038] Figure 8 is the cross-sectional view schematic diagram of the structural column in the structural column construction method provided in this application;

[0039] Figure 9 is Figure 4 the enlarged schematic diagram of part A in

[0040] Figure 10 is Figure 4 the enlarged schematic diagram of part B in

[0041] Figure 11 is the process flow chart of another implementation manner of the structural column construction method provided in this application;

[0042] Figure 12 is the three-dimensional structure schematic diagram of the structural column in step S210 of the structural column construction method provided in this application;

[0043] Description of the Reference Numerals:

[0044] 10. Deep foundation pit; 11. Structural column; 12. Reserved soil platform; 13. Support pile; 14. Main structure of basement; 15. Casing; 16. Positioning steel bar; 17. Cross fixing steel bar; 18. Support rod; 191. Rotary climbing ladder; 192. Soft ladder; 111. Pile foundation; 112. Column body; 113. Steel bar formwork structure; 114. Raft foundation; 1111. Groove; 1112. First section of groove; 1113. Second section of groove; 1131. Column formwork; 1132. Steel reinforcement cage; 1133. Raft foundation steel bars; 1134. Through hole; 1135. Steel bar passing groove; 1136. Foam rubber; 1911. Tread board. Specific implementation manner

[0045] To make the purpose, technical solution and advantages of the present application clearer and more definite, the following further describes the present application in detail with reference to the accompanying drawings and by way of examples. It should be understood that the specific examples described herein are only used to explain the present application and are not used to limit the present application.

[0046] The purpose of the present application is to solve the problem that in the construction of the basement of the current deep foundation pit, the reserved soil platform invades the construction area of the main structure of the basement. It is necessary to first complete the construction of part of the structure of the main structure of the basement and install a temporary support system to replace the reserved soil platform to support the support piles before the reserved soil can be excavated and the remaining part of the main structure of the basement can be constructed, which seriously affects the construction period of the main structure of the basement. A construction method for the structural column in the reserved soil platform is provided. By constructing the structural column in the reserved soil platform, without excavating the reserved soil platform and ensuring the backpressure effect of the reserved soil platform on the support piles, the construction of the main structure of the basement can be realized, avoiding the impact on the construction period of the main structure of the basement and being beneficial to shortening the construction period. For details, please refer to the following examples.

[0047] Please refer to Figures 1 to 4 , in the first embodiment of the present application, a construction method for the structural column in the reserved soil platform is provided, including:

[0048] S100. According to the preset position of the structural column 11, construct the pile foundation 111 of the structural column 11 in the reserved soil platform 12;

[0049] Specifically, as Figure 2 and Figure 3As shown in the figure, before the excavation of the deep foundation pit 10, the construction of the retaining piles 13 will be carried out around the predetermined excavation area of the deep foundation pit 10. The retaining piles 13 can play a role in retaining soil, improving the stability of the foundation pit slope, and avoiding the deformation and collapse of the soil on the foundation pit slope during the excavation process; when excavating the soil in the deep foundation pit 10, a soil platform 12 is reserved in the deep foundation pit 10 without excavation. The soil platform 12 can play a role in backpressure on the retaining piles 13; in order to ensure that the soil platform 12 can effectively exert backpressure on the retaining piles 13, the volume of the required soil platform 12 needs to be large enough, so that the soil platform 12 invades the construction area of the basement main structure 14, affecting the construction of the basement main structure 14 and thus prolonging the construction period; the structural column 11 is located at the edge position of the basement main structure 14 and, as a supporting part of the basement main structure 14, plays a main supporting role for each floor slab in the basement main structure 14; generally, the structural column 11 includes a pile foundation 111 and a column body 112. The pile foundation 111 is located under the bottom slab of the basement main structure 14, that is, at the bottom surface position of the soil platform 12. The column body 112 is located on the pile foundation 111 and is connected to the floor slab of the basement main structure 14, playing a role in connecting and supporting the floor slab; the preset position of the structural column 11 refers to the construction position of the structural column 11 at the actual construction site corresponding to the design position of the structural column 11 on the construction design drawing. It needs to be determined by measurement and positioning at the actual construction site and marked (for example: punctuating, drawing lines) to facilitate the accurate construction of the structural column 11 according to the marked position.

[0050] S200. At the preset position of the structural column 11, sink the casing 15 to the design elevation of the pile foundation 111 and excavate the soil inside the casing 15.

[0051] As Figure 4As shown in the figure, the designed elevation of the pile foundation 111 refers to the top elevation of the pile foundation 111 determined by the construction drawings to ensure that the structural column 11 can play an effective supporting role in the main structure 14 of the basement; after the construction of the pile foundation 111 of the structural column 11 is completed, there is a certain distance from the pile foundation 111 to the top surface of the reserved soil platform 12. It is necessary to excavate the soil between the top surface of the reserved soil platform 12 and the pile foundation 111 to create space for the construction of the column body 112 of the structural column 11; when sinking the casing 15, the casing 15 is inserted into the reserved soil platform 12 until the designed elevation of the pile foundation 111, and the soil inside the casing 15 is excavated so that the construction workers can carry out the construction of the column body 112 inside the casing 15. The casing 15 has a soil retaining function, provides space for the construction of the column body 112, ensures the safety of the construction, and at the same time ensures the minimum disturbance of the counter-pressure soil of the deep foundation pit 10 during the construction of the column body 112; a vibratory hammer can be used to sink the casing 15, and the casing 15 can be made of a steel casing; before sinking the casing 15, it is necessary to determine the preset position of the structural column 11 on the reserved soil platform 12 according to the requirements of the drawing design, so that the casing 15 sunk in the reserved soil platform 12 is coaxial with the structural column 11, effectively ensuring the accuracy of the construction position of the subsequent structural column 11; the diameter size of the pile foundation 111 can be specifications such as 1800mm, 2000mm, 2400mm, 2800mm, etc. The outer diameter size of the casing 15 is slightly smaller than the diameter size of the pile foundation 111. Specifically, it can be 200mm smaller than the diameter of the pile foundation 111. Then the outer diameter size of the casing 15 corresponds to specifications such as 1600mm, 1800mm, 2200mm, 2600mm, etc.; after the casing 15 is sunk to the designed elevation of the pile foundation 111, the top surface of the casing 15 protrudes from the reserved soil platform 12 by a preset height, and the preset height can be 50cm; before sinking the casing 15, it is necessary to chisel off the concrete on the shotcrete surface of the slope protection of the reserved soil platform 12, level the site, and bend up the external anchor bars of the cast-in-place floor slab; if the construction height of the pile foundation 111 exceeds the designed elevation, it is necessary to break the pile head exceeding the designed elevation; when sinking the casing 15, if a pile head is encountered, after using a diamond drill to break the pile head for a certain distance, then press down the casing 15 for a certain distance; for each section of the pile head broken downwards, pressing down the casing 15 for a certain distance is a construction cycle, and the cycle construction is carried out until the designed elevation of the pile foundation 111 is reached;

[0052] S300, prefabricate the steel bar formwork structure 113 of the structural column 11;

[0053] As Figure 4As shown, the steel bar formwork structure 113 is an integrated structure of steel bars and formwork. The steel bars serve as the skeleton of the structural column 11, and the formwork is used to block the concrete to ensure its shaping after solidification. The steel bar formwork structure 113 of the structural column 11 is prefabricated. During use, it is directly lifted into the casing 15 for concrete pouring, eliminating the operation of workers installing the formwork in the casing 15. This ensures high construction quality, helps reduce the construction difficulty, improve the construction efficiency, and thus is conducive to shortening the construction period.

[0054] S400. According to the preset position of the structural column 11, a groove is opened at the top of the pile foundation 111. The steel bar formwork structure 113 is lifted into the casing 15, and one end of the steel bar formwork structure 113 is inserted into the groove.

[0055] As Figure 4 shown, the groove serves as the fixed position of the pile foundation 111. According to the preset position of the structural column 11, a groove is opened on the top surface of the pile foundation 111 to avoid the offset of the groove position, thereby ensuring that the installation position of the subsequent steel bar formwork structure 113 meets the requirements of design and construction specifications. After the construction of the pile foundation 111 and when the pile foundation 111 has cured to meet the strength requirements, a groove is opened on the top surface of the pile foundation 111 to facilitate the installation of the steel bar formwork structure 113 of the structural column 11. The depth of the groove is determined according to specific design requirements to ensure the reliability of the connection between the column body 112 and the pile foundation 111. When opening the groove, a water mill drill can be used. When inserting the steel bar formwork structure 113 into the groove, it should be lifted and placed into the hole, and forced impact into the hole is not allowed. When lifting and placing the steel bar formwork structure 113, a truck crane can be used for one-time hoisting. According to the specification requirements, the top surface elevation of the pile foundation 111 should be rechecked before lifting and placing the steel bar formwork structure 113, and the length of the lifting rope should be accurately calculated to ensure that the error is within the allowable range. After the steel bar formwork structure 113 is lowered in place, due to the incomplete coincidence of the lifting point position and the measuring point and the elongation of the lifting rope, etc., it will affect the elevation of the steel bar formwork structure 113. To ensure the elevation of the steel bar formwork structure 113, it should be adjusted according to the actual situation to adjust the elevation of the steel bar formwork structure 113 to the design elevation.

[0056] S500. Pour concrete into the steel bar formwork structure 113, and after the concrete strength meets the preset requirements, symmetrically backfill the soil in sections between the steel bar formwork structure 113 and the casing 15.

[0057] Concrete is poured into the steel bar formwork structure 113 to form the entire column body 112; the concrete pouring must be completed at one time, and the top elevation of the column body 112 is controlled. The elevation control points can be marked on the casing 15 to control the top elevation of the column body 112; after the concrete is poured into the steel bar formwork structure 113 and solidifies to form the column body 112, the earthwork backfilling operation between the steel bar formwork structure 113 and the casing 15 needs to be carried out after the concrete strength reaches the preset requirements, so as to avoid the pressure generated by the backfilled earthwork causing deformation or position inclination of the steel bar formwork structure 113. At the same time, it can also avoid the infiltration of the earthwork into the steel bar formwork structure 113 in rainy weather, resulting in quality problems; the preset requirement can be 30%, that is, after the concrete strength of the column body 112 reaches 30%, the earthwork backfilling operation between the steel bar formwork structure 113 and the casing 15 is carried out; after the concrete strength of the column body 112 reaches the preset strength, earthwork is backfilled between the inner wall of the steel bar formwork structure 113 and the casing 15. The earthwork can provide a supporting effect on the steel bar formwork structure 113, so that the steel bar formwork structure 113, the casing 15 and the reserved soil platform 12 form an integral structure, which is beneficial to enhancing the stability of the structure, ensuring the counterpressure effect of the reserved soil platform 12 on the retaining pile 13, and being able to avoid deformation or position inclination of the steel bar formwork structure 113; when backfilling the earthwork between the steel bar formwork structure 113 and the casing 15, the method of symmetric segmented backfilling is adopted; segmented backfilling means that the entire depth from the bottom end to the top end of the casing 15 is divided into multiple depths for backfilling, so as to avoid excessive unilateral earthwork outside the steel bar formwork structure 113 during the earthwork backfilling process, forming a unilateral pressure on the side of the steel bar formwork structure 113, causing the steel bar formwork structure 113 to incline and affecting the pouring quality; by adopting the method of segmented backfilling, the single-segment depth is limited, which can effectively avoid excessive pressure generated when the unilateral earthwork is too much, ensure the uniform backfilling of the earthwork, and avoid generating unilateral pressure on the side of the steel bar formwork structure 113; symmetric backfilling means that the earthwork is backfilled on both sides in the symmetric direction of the outer periphery of the entire steel bar formwork structure 113, or one side is backfilled first and then the other side, and it is required that the height difference between the backfilled earthwork on both sides does not exceed 30 cm, so as to effectively avoid excessive pressure generated when the unilateral earthwork is too much; a flexible hose can be used to extend the flexible hose into the side of the steel bar formwork structure 113 and fill the earthwork.

[0058] S600. Remove the casing 15. When removing the casing 15, the concrete strength of the column body 112 also needs to meet the preset requirements, which can avoid disturbing the steel bar formwork structure 113 during the removal process of the casing 15, and thus cause deformation of the column body 112; the preset requirement can be 50%, that is, after the concrete strength of the column body 112 reaches 50%, the casing 15 outside the column body 112 is removed.

[0059] It can be understood that in order to ensure that the reserved soil platform 12 can effectively counter-pressure the retaining pile 13, the volume of the reserved soil platform 12 needs to be large enough. The reserved soil platform 12 invades the construction area of the basement main structure 14, affecting the construction of the basement main structure 14 and thus prolonging the construction period. The construction method of the structural column 11 in the reserved soil platform 12 provided in this application constructs the structural column 11 in the reserved soil platform 12. Without excavating the reserved soil platform 12 and ensuring the counter-pressure effect of the reserved soil platform 12 on the retaining pile 13, the construction of the basement main structure 14 is realized, avoiding the impact on the construction period of the basement main structure 14 and being beneficial to shortening the construction period. Among them, when constructing the structural column 11, a steel bar and formwork integrated installation steel bar formwork structure 113 is adopted, which can be directly used, avoiding the operation of installing the formwork in the casing 15, being beneficial to reducing the construction difficulty and improving the construction efficiency, and thus being beneficial to shortening the construction period. When constructing multiple structural columns 11, the casings 15 can be recycled, that is, the casings 15 of the constructed structural columns 11 are used for the construction of the unconstructed structural columns 11. When the construction of the structural column 11 is completed in the reserved soil platform 12, the construction of other parts of the basement main structure 14 can be carried out simultaneously. Connect the floor slab and the structural column 11 in the basement main structure 14 and construct them together. After the basement main structure 14 is completed and the support system is installed for replacement bracing, the reserved soil platform 12 can be excavated.

[0060] Please refer to Figure 5 , in some embodiments, before the step S100, it further includes:

[0061] S10. According to the preset position of the structural column 11, measure and position on the reserved soil platform 12 and make marks.

[0062] It can be understood that before the construction of the structural column 11, it is necessary to convert the designed position of the structural column 11 on the construction design drawing into the construction position of the corresponding structural column 11 at the actual construction site; at the actual construction site, the construction position of the structural column 11 is determined by means of measurement and positioning, including the central position, corner position, etc. of the structural column 11, and marks are made (for example: setting pile positions, punctuation marks, drawing lines, etc.) to facilitate the accurate construction of the structural column 11 according to the marked positions; tools such as total station and steel ruler can be used for measurement and positioning; the column body 112 of the structural column 11 is a rectangular structure, and there are four points corresponding to the four corners of the column body 112; for example, four pile positions can be set, and the four pile positions are used as marks, and the lines are connected with the four pile positions as endpoints, and the lines intersect to form a "×" shape, and the four corners of the column body 112 are all located on the lines, and the intersection point of the lines is used as the center point of the structural column 11; during the subsequent construction of the pile foundation 111, sinking of the casing 15, opening of the groove, and hoisting of the steel bar formwork structure 113, the intersection point of the lines can be used as the center point for construction, which can ensure the proper construction of the structural column 11; specifically, surveying and mapping are pre-conducted at the construction site of the deep foundation pit 10 to determine the building baseline dimensions, each axis, and set control piles; during the construction of the structural column 11, first, check and review each point of the control piles to check whether their building baseline dimensions conform to the points; secondly, according to the relevant coordinates and level points, measure the positions of each axis and the site elevation; for the positions of each axis, axis numbers are set and marked, and temporary protection measures are taken to avoid damage; finally, use a total station and a steel ruler to determine each pile position according to each axis, which can be marked on the cushion layer with red paint, and after the casing 15 is sunk and the soil inside the casing 15 is excavated during the construction of the casing 15, it is introduced onto the hole wall and marked with red paint or cement nails as the positioning basis for the groove opening.

[0063] In some embodiments, the step S200 specifically includes:

[0064] S20. Sink the casing 15 in sections at the marked positions, and after each section of the casing 15 is sunk, excavate the soil inside the section of the casing 15, and then detect the verticality of the section of the casing 15.

[0065] According to the position of the mark, the center of the structural column 11 can be determined. When sinking the casing 15, the position of the mark is used as the positioning reference, so that the center of the casing 15 corresponds to the center of the structural column 11, ensuring that the center of the casing 15 meets the requirements. For example, the deviation between the center of the casing 15 and the center of the structural column 11 does not exceed 50 mm. When sinking the casing 15, the casing 15 is inserted into the reserved soil platform 12. When the distance from the top surface of the reserved soil platform 12 to the design elevation of the pile foundation 111 is too long, directly sinking the casing 15 in place cannot control the deviation between the center of the casing 15 and the center of the structural column 11 and the verticality of the casing 15. When the difference is large, it will affect the subsequent construction of the groove 1111 and the steel bar formwork structure 113. The method of segmentally sinking the casing 15 is adopted. The distance from the top surface of the reserved soil platform 12 to the design elevation of the pile foundation 111 is segmented into multiple segments. When sinking the casing 15, the sinking depth of the casing 15 corresponds to the multiple segments. The casing 15 only sinks a distance of one segment each time. After the casing 15 sinks a distance of one segment each time, the soil inside the casing 15 is excavated, which is beneficial to reducing the resistance during the subsequent sinking process of the casing 15 and also facilitates the construction personnel to enter the casing 15 to detect the verticality of the casing 15. By detecting the verticality after each sinking of the casing 15, the verticality of the casing 15 can be effectively guaranteed, avoiding affecting the subsequent construction of the groove 1111 and the steel bar formwork structure 113, and ensuring that the verticality of the structural column 11 meets the requirements of the design and construction specifications.

[0066] S21. After the verticality of the casing 15 in this section meets the requirements, introduce the mark onto the inner wall of the casing 15 in this section.

[0067] During the construction of sinking the casing 15, there are specific requirements for the verticality of the casing 15 after sinking to ensure the subsequent construction of the groove 1111 and the steel bar formwork structure 113. For example, the verticality deviation does not exceed 1%. After ensuring the verticality of the casing 15, introduce the mark on the reserved soil onto the inner wall of the casing 15 as the positioning reference for the subsequent construction of the groove 1111 and the installation of the steel bar formwork structure 113, ensuring the in-place construction of the structural column 11. Marks can be made on the inner wall of the casing 15 with red paint or cement nails.

[0068] S22. Continue to sink the next section of the casing 15 until the design elevation of the pile foundation 111 is reached. The bottom end of the casing 15 sinks to the design elevation of the pile foundation 111, and the bottom end of the casing 15 contacts the top surface of the pile foundation 111. Jin Tang waterstop can be applied at the contact position to block groundwater.

[0069] In some embodiments, detecting the verticality of the casing 15 in this section specifically includes:

[0070] S201. Design several measuring points in advance for the distance from the top surface of the reserved soil platform 12 to the design elevation of the pile foundation 111.

[0071] S202. Install attitude angle sensors on the inner wall of the casing 15 corresponding to several of the measurement points.

[0072] S203. Receive the data from the attitude angle sensors and calculate and determine the verticality deviation of the casing 15.

[0073] It can be understood that during the entire process of the casing 15 sinking from the top surface of the reserved soil platform 12 to the designed elevation of the pile foundation 111, the verticality is detected. By setting several measurement points and installing attitude angle sensors corresponding to each measurement point respectively, through the supporting software, the verticality deviation value of the casing 15 can be dynamically displayed in real time. Based on this during the construction process, the sinking position and angle of the casing 15 are adjusted to ensure that after construction, the verticality of the casing 15 meets the requirements, avoiding affecting the subsequent construction of the groove and the steel bar formwork structure 113. At the same time, it is convenient for construction workers to introduce marks onto the inner wall of the casing 15, providing a reliable positioning reference for the subsequent construction of the groove and the steel bar formwork structure 113, and ensuring that the verticality of the structural column 11 meets the requirements of the design and construction specifications; the attitude angle sensor can adopt a portable suction-attached attitude angle sensor, which is convenient for installation; in addition, a total station can be used simultaneously for re-measuring and correcting the verticality to ensure the accurate sinking of the casing 15.

[0074] Please refer to Figure 4 and Figure 6 , in some embodiments, the steel bar formwork structure 113 includes a column formwork 1131 and a steel reinforcement cage 1132. The column formwork 1131 is sleeved on the steel reinforcement cage 1132, and both ends of the steel reinforcement cage 1132 protrude from the column formwork 1131.

[0075] It can be understood that the steel bar formwork structure 113 is an integrated structure of the steel reinforcement cage 1132 and the column formwork 1131. The steel reinforcement cage 1132 serves as the skeleton of the column body 112, and the column formwork 1131 is used to separate the concrete to ensure its shaping after solidification; the steel reinforcement cage 1132 is pre-tied, and the column formwork 1131 is assembled outside the steel reinforcement cage 1132. Both ends of the steel reinforcement cage 1132 protrude from the column formwork 1131 and are respectively used to connect the pile foundation 111 and the floor slab; concrete cushion blocks or other effective measures can be set on the outer side of the steel reinforcement cage 1132 to ensure that the thickness of the steel bar protection layer meets the requirements of relevant specifications; adopting the integrated structure of the column formwork 1131 and the steel reinforcement cage 1132 avoids the operation of assembling the formwork inside the casing 15, which is beneficial to reducing the construction difficulty and improving the construction efficiency, that is, shortening the construction period.

[0076] Please refer to Figure 5 , Figure 6 and Figure 7 , in some embodiments, the step S400 specifically includes:

[0077] S40A. According to the position of the mark, a groove 1111 is opened at the top of the pile foundation 111, and positioning bars 16 are vertically installed in the groove 1111;

[0078] As Figure 6 and Figure 7 shown, the steel reinforcement cage 1132 is of a rectangular structure, and the positioning bars 16 play a role in positioning the steel reinforcement cage 1132. Specifically, two, three or four positioning bars 16 can be installed, corresponding to the respective corners of the steel reinforcement cage 1132. Preferably, four positioning bars 16 are used. The length and width dimensions between the four positioning bars 16 are slightly smaller than the length and width dimensions of the four corners of the steel reinforcement cage 1132, so that the positioning bars 16 can be inserted into the four corners of the steel reinforcement cage 1132 to form a connection. After measuring, positioning and making marks on the reserved soil platform 12, a "well"-shaped or "cross"-shaped bracket can be installed at the orifice of the casing 15 corresponding to the position of the mark, and a plumb bob is connected at the intersection of the brackets. The positions of the respective corners of the steel reinforcement cage 1132 are determined in the groove 1111 through the plumb bob, and then the positioning bars 16 can be installed at the corresponding positions of the respective corners; or the positions of the four corners of the column body 112 in the groove 1111 can be determined through the marks introduced from the inner wall of the casing 15, and then the positioning bars 16 can be installed at the corresponding positions of the respective corners;

[0079] S41A. Insert the end of the steel reinforcement cage 1132 protruding from the column formwork 1131 into the groove 1111, wherein the positioning bars 16 are inserted into the steel reinforcement cage 1132 and abut against the corners of the steel reinforcement cage 1132.

[0080] As Figure 6 and Figure 7 shown, the positioning bars 16 correspond to the four corners of the steel reinforcement cage 1132. The length and width dimensions between the positioning bars 16 are slightly smaller than the length and width dimensions of the four corners of the steel reinforcement cage 1132, so that the steel reinforcement cage 1132 is inserted into the groove 1111, and the positioning bars 16 are inserted into the four corners of the steel reinforcement cage 1132 to form a connection, enhancing the connection reliability between the steel reinforcement cage 1132 and the groove 1111 before pouring, ensuring that the steel reinforcement cage 1132 is installed in place, and effectively guaranteeing the verticality of the steel reinforcement cage 1132; when the steel reinforcement cage 1132 is inserted into the groove 1111, the column formwork 1131 is in contact with the top surface of the pile foundation 111 or slightly higher than the top surface of the pile foundation 111.

[0081] It can be understood that through the above steps, the steel reinforcement cage 1132 in the structural column 11 can be accurately installed in place on the pile foundation 111, and the verticality of the steel reinforcement cage 1132 can be guaranteed, improving the construction quality of the structural column 11.

[0082] Please continue to refer to Figure 5 , in some embodiments, after the step S41A, it further includes:

[0083] S42A. According to the position of the mark, install the cross fixing bars 17 on the end face of the casing 15, and connect and fix the cross fixing bars 17 to the reinforcement cage 1132. The cross position of the cross fixing bars 17 corresponds to the corners of the reinforcement cage 1132.

[0084] It can be understood that as Figure 6 shown, the cross fixing bars 17 can be set in a "well" shape or a "cross" shape. According to the position of the mark, install the cross fixing bars 17 at the mouth of the casing 15 so that the cross position of the cross fixing bars 17 corresponds to the corners of the reinforcement cage 1132; connect and fix the cross fixing bars 17 to the reinforcement cage 1132, and connect the cross position of the cross fixing bars 17 to the corners of the reinforcement cage 1132, which can effectively ensure that the installation position of the reinforcement cage 1132 does not deviate, ensure the verticality of the structural column 11, and at the same time provide a supporting effect for the reinforcement cage 1132 to avoid deformation and position deviation during the concrete pouring process.

[0085] Please continue to refer to Figure 5 , in some embodiments, after the step S42A, it further includes:

[0086] S43A. Install a support rod 18 between the column formwork 1131 and the casing 15.

[0087] It can be understood that as Figure 6 and Figure 7 shown, install a support rod 18 between the column formwork 1131 and the casing 15. The two ends of the support rod 18 abut against the inner walls of the column formwork 1131 and the casing 15, which has a supporting effect on the column formwork 1131 and can avoid the deformation of the column formwork 1131 during the subsequent concrete pouring process and ensure the construction quality of the structural column 11.

[0088] Please refer to Figure 4 , Figure 6 , Figure 8 , Figure 9 and Figure 10 , in some embodiments, the steel bar formwork structure 113 further includes a bearing platform bar 1133. The bearing platform bar 1133 overlaps on the reinforcement cage 1132 and is arranged through the column formwork 1131. The bearing platform bar 1133 is adjacent to one end of the reinforcement cage 1132 protruding from the column formwork 1131.

[0089] It can be understood that the structural column 11 includes a pile foundation 111 and a column body 112. A bearing platform 114 is also provided at the connection position between the pile foundation 111 and the column body 112. The bearing platform 114 is connected to the pile foundation 111 and the column body 112. By providing the bearing platform reinforcement 1133, when the subsequent construction of the bearing platform 114 is carried out, the column body 112 is lapped with the bearing platform 114 through the bearing platform reinforcement 1133. The bearing platform reinforcement 1133 is lapped with the steel reinforcement cage 1132, passes through the column formwork 1131, and is located at an adjacent position to one end of the steel reinforcement cage 1132 inserted into the groove 1111. Specifically, as Figure 6 shown, the bearing platform reinforcement 1133 passes through the side surface and the end of the column formwork 1131. As Figure 9 and Figure 10 shown, through holes 1134 are correspondingly provided on the side surface of the column formwork 1131, and reinforcing bar grooves 1135 are correspondingly provided on the end face of the column formwork 1131 for the bearing platform reinforcement 1133 to pass through. A foam rubber 1136 is provided at the connection position between the bearing platform reinforcement 1133 and the column formwork 1131, that is, the foam rubber 1136 is provided in the through holes 1134 and the reinforcing bar grooves 1135 of the column formwork 1131 to block the gap positions between the through holes 1134 and the bearing platform reinforcement 1133 and between the reinforcing bar grooves 1135 and the bearing platform reinforcement 1133 to prevent slurry leakage during concrete pouring.

[0090] Please refer to Figure 6 and Figure 11 . In some embodiments, the step S400 specifically includes:

[0091] S40B. According to the marked positions, a first-section groove 1112 is opened at the top of the pile foundation 111, and a second-section groove 1113 is opened at the bottom wall of the first-section groove 1112;

[0092] Specifically, the first - section groove 1112 is used to reserve the space for post - embedded bars for the subsequent construction of the bearing platform 114. The depth of the first - section groove 1112 is the depth of the bearing platform 114. The bearing - platform bars 1133 are located in the first - section groove 1112 and are used for the lap joint between the bearing platform 114 and the column body 112. It can be set that the diameter of the first - section groove 1112 is a certain distance outward from the outside of the structural column 11. The distance can be 300 mm. The bearing - platform bars 1133 protrude a certain length outside the formwork. The length can be 250 mm. After the construction of the basement main structure 14 is completed and the reserved soil excavation is carried out, when constructing the bearing platform 114, the outer wall of the first - section groove 1112 can be chiseled to expose the steel bars of the pile foundation 111 and the bearing - platform bars 1133, so as to facilitate the post - embedded bar and pouring of the bearing platform 114. The second - section groove 1113 is opened on the bottom wall of the first - section groove 1112 and is used to accommodate one end of the steel - reinforcement cage 1132 that protrudes from the column formwork 1131. The opening position of the second - section groove 1113 is determined according to the marked position to ensure the construction of the structural column 11 and ensure that the installation position of the subsequent steel - reinforcement cage 1132 meets the requirements of the design and construction specifications. The diameter of the second - section groove 1113 is equal to or slightly larger than the size of the structural column 11. After the first - section groove 1112 and the second - section groove 1113 are opened, the pile slag is cleaned and transported outside the site.

[0093] S41B. According to the marked position, determine the installation position of the steel - reinforcement cage 1132 in the second - section groove 1113, and vertically install positioning bars 16 in the second - section groove 1113, wherein the positioning bars 16 correspond to the corners of the steel - reinforcement cage 1132.

[0094] Specifically, the positioning bars 16 play a role in positioning the steel - reinforcement cage 1132. Specifically, two, three or four positioning bars 16 can be installed, corresponding to the respective corners of the steel - reinforcement cage 1132. Preferably, four positioning bars 16 are used. The length and width dimensions between the four positioning bars 16 are slightly smaller than the length and width dimensions of the four corners of the steel - reinforcement cage 1132, so as to facilitate the insertion of the positioning bars 16 into the four corners of the steel - reinforcement cage 1132 to form a connection. After measuring and marking on the reserved soil platform 12, corresponding to the marked position, an "X" - shaped or "cross" - shaped support can be installed at the orifice of the casing 15. A plumb bob is connected at the intersection of the support. Through the plumb bob, the positions of the four corners of the steel - reinforcement cage 1132 are determined in the groove 1111, and then the positioning bars 16 can be installed at the corresponding positions of each corner. It is also possible to determine the positions of the four corners of the column body 112 in the groove 1111 through the marks introduced from the inner wall of the casing 15, and then the positioning bars 16 can be installed at the corresponding positions of each corner.

[0095] S42B. Insert one end of the steel reinforcement cage 1132 protruding from the column formwork 1131 into the second section of the groove 1113. Among them, the positioning bars 16 are inserted into the steel reinforcement cage 1132 and abut against the corners of the steel reinforcement cage 1132. The end face of the column formwork 1131 abuts against the bottom wall of the first section of the groove 1112, and the pile cap reinforcement bars 1133 are located in the first section of the groove 1112. The positioning bars 16 correspond to the four corners of the steel reinforcement cage 1132, and the length and width dimensions between the positioning bars 16 are slightly smaller than the length and width dimensions of the four corners of the steel reinforcement cage 1132, so that the steel reinforcement cage 1132 is inserted into the second section of the groove 1113, and the positioning bars 16 are inserted into the four corners of the steel reinforcement cage 1132 to form a connection, enhancing the connection reliability between the steel reinforcement cage 1132 and the second section of the groove 1113 before pouring, ensuring that the steel reinforcement cage 1132 is installed in place, and effectively ensuring the verticality of the steel reinforcement cage 1132; the steel reinforcement cage 1132 is inserted into the groove 1111, and the end face of the column formwork 1131 abuts against the bottom wall of the first section of the groove 1112, which can avoid the phenomenon of slurry leakage during concrete pouring.

[0096] It can be understood that through the above steps, the steel reinforcement cage 1132 in the structural column 11 can be accurately installed in place on the pile foundation 111, and the verticality of the steel reinforcement cage 1132 can be ensured, improving the construction quality of the structural column 11. At the same time, it also reserves the space for post-inserting steel bars and the accommodating space for the pile cap reinforcement bars 1133 for the subsequent construction of the pile cap 114, ensuring the connection reliability between the pile cap 114, the pile foundation 111, and the column body 112.

[0097] Please refer to Figure 4 、 Figure 10 and Figure 11 , in some embodiments, after the step S42B, the following steps are further included:

[0098] S43B. Perform waterproof reinforcement at the connection position between the outer periphery of the column formwork 1131 and the first section of the groove 1112.

[0099] It can be understood that performing waterproof reinforcement at the connection position between the outer periphery of the column formwork 1131 and the bottom wall of the first section of the groove 1112 can block groundwater and soil from entering the column formwork 1131, and block the leakage of the poured concrete; specifically, foam glue 1136 can be used to set a whole circle of fixed foam glue 1136 on the outer periphery of the connection position between the column formwork 1131 and the first section of the groove 1112 to effectively prevent slurry leakage or water leakage.

[0100] Please refer to Figure 12 , in some embodiments, after the step S200, the following steps are further included:

[0101] S210. Install a rotating ladder 191 on the inner wall of the casing 15, where the rotating ladder 191 is spirally distributed on the inner wall of the casing 15.

[0102] It can be understood that a spiral rotating ladder 191 is installed on the inner wall of the casing 15, enabling construction workers to enter the bottom of the casing 15 via the rotating ladder 191 for construction operations such as earthwork removal and groove 1111 excavation, thus enhancing the convenience of construction; during the process of excavating the earthwork inside the casing 15, a long-arm excavator can be used for soil extraction. When the long-arm excavator is unable to operate after reaching a certain depth, construction workers can use the rotating ladder 191 to go up and down to complete pile head breaking and earthwork and stonework removal; when opening the groove 1111 on the pile foundation 111, a soft ladder 192 can be set up. The soft ladder 192 is installed on the rotating ladder 191 and extends into the groove 1111 to facilitate the construction workers to open the groove 1111; after implanting the positioning bars 16, the rotating ladder 191 and the soft ladder 192 are removed to make room for hoisting the steel bar formwork structure 113.

[0103] Please continue to refer to Figure 12 In some embodiments, the rotating ladder 191 includes a plurality of treads 1911. The plurality of treads 1911 are spaced at intervals along the extending direction of the casing 15 and are distributed in a spiral shape. One end of each of the plurality of treads 1911 is connected to the inner wall of the casing 15, and the other ends are spaced apart and enclose a construction passage.

[0104] It can be understood that by setting a plurality of treads 1911, construction workers can step on the treads 1911 in the casing 15 and ascend and descend along the spiral direction, and remove earthwork, pile slag or hoist tools in the construction passage, effectively enhancing the convenience of construction for the construction workers.

[0105] Please continue to refer to Figure 12 In some embodiments, the plurality of treads 1911 are evenly spaced. The spacing can be set to 30 cm to better assist construction workers in ascending and descending in the casing 15.

[0106] In some embodiments, for any two adjacent treads 1911 among the plurality of treads 1911, one tread 1911 rotates a preset angle around the center of the casing 15 relative to the other tread 1911, so that the treads 1911 can be evenly distributed on the inner wall of the casing 15, better assisting construction workers in ascending and descending in the casing 15.

[0107] Please continue to refer to Figure 12 In some embodiments, the value range of the preset angle is 10 - 30°, and the specific value can be adjusted and selected according to the aperture and depth of the casing 15.

[0108] In summary, the present application provides a construction method for structural columns within a reserved soil platform, including: conducting pile foundation construction for the structural columns within the reserved soil platform according to the preset positions of the structural columns; sinking a casing to the designed elevation of the pile foundation at the preset positions of the structural columns and excavating the soil within the casing; prefabricating the steel bar formwork structure of the structural columns; opening a groove at the top of the pile foundation according to the preset positions of the structural columns, hoisting the steel bar formwork structure into the casing, and inserting one end of the steel bar formwork structure into the groove; pouring concrete into the steel bar formwork structure, and symmetrically and segmentally backfilling soil between the steel bar formwork structure and the casing after the concrete strength meets the preset requirements; and pulling out the casing. By constructing the structural columns within the reserved soil platform, the construction of the basement main structure can be achieved without excavating the reserved soil platform and ensuring the counterpressure effect of the reserved soil platform on the retaining piles, avoiding affecting the construction period of the basement main structure and being beneficial to shortening the construction period.

[0109] It should be understood that the application of the present application is not limited to the above examples. For those of ordinary skill in the art, improvements or transformations can be made according to the above description, and all such improvements and transformations shall fall within the protection scope of the appended claims of the present application.

Claims

1. A construction method for structural columns within a reserved soil platform, characterized in that, it includes: According to the preset position of the structural column, measure and mark the position on the reserved soil platform, and carry out the pile foundation construction of the structural column within the reserved soil platform; At the preset position of the structural column, sink the casing to the design elevation of the pile foundation, and excavate the soil within the casing; Prefabricate the steel bar formwork structure of the structural column. The steel bar formwork structure includes a column formwork, a steel bar cage, and a pile cap steel bar. The column formwork is sleeved on the steel bar cage. Both ends of the steel bar cage protrude from the column formwork. The pile cap steel bar is lapped on the steel bar cage and passes through the column formwork. The pile cap steel bar is adjacent to the end of the steel bar cage that protrudes from the column formwork; According to the preset position of the structural column, open a groove at the top of the pile foundation, hoist the steel bar formwork structure into the casing, and insert one end of the steel bar formwork structure into the groove. Specifically, it includes: According to the marked position, open the first section of the groove at the top of the pile foundation, and open the second section of the groove at the bottom wall of the first section of the groove; According to the marked position, determine the installation position of the steel bar cage in the second section of the groove, and install positioning steel bars vertically in the second section of the groove. Among them, the positioning steel bars correspond to the corners of the steel bar cage; Insert the end of the steel bar cage that protrudes from the column formwork into the second section of the groove. Among them, the positioning steel bars are inserted into the steel bar cage and abut against the corners of the steel bar cage. The end face of the column formwork abuts against the bottom wall of the first section of the groove, and the pile cap steel bar is located in the first section of the groove; Pour concrete into the steel bar formwork structure, and after the concrete strength meets the preset requirements, symmetrically backfill the soil in sections between the steel bar formwork structure and the casing; Pull out the casing.

2. The structural column construction method according to claim 1, characterized in that, The step of sinking the casing to the design elevation of the pile foundation and excavating the soil within the casing at the preset position of the structural column specifically includes: Sink the casing in sections at the marked position. After sinking each section of the casing, excavate the soil within that section of the casing, and then detect the verticality of that section of the casing; After the verticality of that section of the casing meets the requirements, introduce the mark onto the inner wall of that section of the casing; Continue to sink the next section of the casing until the design elevation of the pile foundation is reached.

3. The structural column construction method according to claim 1, characterized in that, After inserting the end of the steel bar cage that protrudes from the column formwork into the groove, it further includes: According to the marked position, install cross fixing steel bars on the end face of the casing, and connect and fix the steel bar cage with the cross fixing steel bars. The cross position of the cross fixing steel bars corresponds to the corners of the steel bar cage.

4. The structural column construction method according to claim 1, characterized in that, After inserting the end of the steel bar cage that protrudes from the column formwork into the second section of the groove, it further includes: Carry out waterproof reinforcement at the connection position between the outer periphery of the column formwork and the first section of the groove.

5. The construction method of the structural column according to claim 1, characterized in that, sinking the casing to the designed elevation of the pile foundation at a preset position of the structural column, and excavating the soil inside the casing, and then further comprising: installing a rotating ladder on the inner wall of the casing, wherein the rotating ladder is spirally distributed on the inner wall of the casing.

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