Basement structure support changing construction method

Abstract

The invention relates to the technical field of ultrahigh basement support replacement construction, and provides a basement structure support replacement construction method which comprises the steps that concrete is poured into a basement outer wall and a basement bottom floor in sequence, a plurality of support throwing bases are formed on the bottom floor at intervals, and one end of a steel support throwing is connected based on the support throwing bases; the basement outer wall is divided into multiple layers from bottom to top; mounting the other end of the steel throwing support; the bottom first-layer basement outer wall is constructed, specifically, formwork supporting and reinforcing construction is conducted on the bottom first-layer basement outer wall, and then a first-layer basement inner support corresponding to the bottom first-layer basement outer wall is dismantled; according to the construction mode of the bottom first-layer basement, all layers of basement outer walls located above the bottom first-layer basement are constructed in sequence till construction of the basement outer walls is completed; and main body construction and top plate top sealing are conducted on the basement, and basement structure support changing construction is completed. The support replacement construction is simple and efficient, the construction safety can be guaranteed, and deformation in the support replacement process is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of super-high basement support replacement construction, and in particular to a basement structure support replacement construction method. Background Art

[0002] With the rapid development of infrastructure, the building construction industry has developed new types of buildings such as super-high, special-shaped, and large-span buildings. Underground projects have also developed from the simple structure of single-layer basements to deep foundation pit basements. The construction depth is constantly increasing, and the dismantling and replacement of supports is a very important part of the main construction of the basement.

[0003] The essence of deep foundation pit support replacement technology is to transfer, adjust and redistribute stress. After the completion of structural construction, in order to avoid the internal support affecting the subsequent structural construction, the stress generated by the removal of the internal support is transmitted to a third party through a force-transmitting component, thereby maintaining force balance.

[0004] Common traditional support replacement technologies include: 1. Backfill and support replacement. This method is only used as an auxiliary measure due to uneven force; 2. Directly use horizontal structural components as support components, but it has high requirements for the safety of the structure itself; 3. Set diagonal braces between the support piles and the outer wall, which has poor overall effect and low safety; 4. Replace support beams (plates), which has relatively complex construction technology.

[0005] At present, during the main construction of the basement, because the basement is partially too high and there are no horizontal force-transmitting components such as beams and slabs in the middle, the traditional support replacement technology here only relies on backfill replacement and adding diagonal braces between the support piles and the outer wall. It is not enough to provide sufficient temporary support force, and it will produce adverse deformation that threatens the safety of the foundation pit, which is easy to form a major safety hazard of foundation pit collapse. Cracks are likely to appear after the structural construction is completed, affecting the construction quality of the main structure and being detrimental to the normal progress of the project. Summary of the Invention

[0006] The purpose of the present invention is to solve at least one technical problem in the background technology and provide a basement structure replacement support construction method.

[0007] To achieve the above-mentioned purpose, the present invention provides a basement structure support replacement construction method, comprising:

[0008] Concrete the basement exterior wall and the basement ground floor slab in sequence, and form multiple guy bracing bases at intervals on the ground floor slab, and connect one end of the steel guy brace based on the guy bracing bases;

[0009] Based on the height of the basement outer wall, the basement outer wall is divided into multiple layers from bottom to top;

[0010] Install the other end of the steel bracing on the outer wall of the first basement floor at the bottom;

[0011] Construction on the outer wall of the first basement at the bottom: formwork reinforcement construction is carried out on the outer wall of the first basement at the bottom. After reinforcement, the internal support of the first basement corresponding to the outer wall of the first basement at the bottom is removed;

[0012] According to the construction method of the first basement at the bottom, the exterior walls of each basement located above the first basement at the bottom are constructed in sequence until the exterior walls of the basement are completed;

[0013] Carry out main construction and roof sealing of the basement, and complete the basement structure support replacement construction.

[0014] According to one aspect of the present invention, the basement exterior wall and the basement bottom floor are poured with concrete in sequence, and a plurality of guy braces are formed on the bottom floor at intervals, and one end of the steel guy brace is connected to the guy brace based on the guy brace base:

[0015] After the anti-seepage concrete of the basement exterior wall is poured, the concrete of the basement bottom floor is poured. When pouring the concrete of the basement exterior wall, an exterior wall guide wall is set at a preset distance on the bottom floor, and a water-stop steel plate is embedded. Before pouring the bottom floor, the steel bars of the guy support base are tied synchronously with the beam and slab steel bars of the bottom floor. The guy support base is poured together with the bottom floor. After the pouring is completed, one end of the steel guy support is installed on the guy support base.

[0016] According to one aspect of the present invention, each of the said propeller bases is arranged on the beam intersection node and the main beam of the bottom floor, and the distance between each propeller base is ≤8m;

[0017] The angle between the steel brace and the bottom floor slab is 45°.

[0018] According to one aspect of the present invention, concrete is poured into the exterior wall of the basement in layers by using a string tube or by opening a hole in the side of the formwork to install an inclined chute. The height of each layer is ≤2m. Each layer of concrete is vibrated and compacted after pouring, and the time interval between pouring the upper and lower layers of concrete is ≤the initial setting time of the concrete.

[0019] According to one aspect of the present invention, the installation of the other end of the steel bracing for the outer wall of the first basement floor at the bottom is as follows:

[0020] During the reinforcement binding process of the outer wall of the first basement floor at the bottom, the steel plate at the upper end of the steel brace is welded. After welding is completed, the upper end of the steel brace is installed. The steel plate and the steel brace are welded together and triangular iron stiffening ribs are evenly arranged at the connection for reinforcement.

[0021] According to one aspect of the present invention, the steel castor is a round steel tube with a diameter of 610 mm and a wall thickness of 10 mm;

[0022] The triangular iron is an isosceles right triangle with a waist length of 100 mm and a thickness of 10 mm.

[0023] According to one aspect of the present invention, the formwork reinforcement construction is a single-sided formwork construction using a standardized tripod and anchored reinforcement.

[0024] According to one aspect of the present invention, the internal supports of each basement floor are removed, including:

[0025] For internal angle bracing structures, disconnect the tie beams first, and then disconnect the angle bracing beams at intervals;

[0026] For internal bracing structures, disconnect the connecting beams first, and then disconnect the bracing beams at intervals;

[0027] After the stress of the corner braces or braces is released, they can be cut and removed on a large scale.

[0028] According to one aspect of the present invention, it also includes: during the construction of the basement exterior wall and the basement ground floor slab, monitoring various monitoring data of the construction foundation pit, comparing the monitoring data with a preset warning value range, and when the monitoring data does not exceed the warning value range, capping the basement roof and completing the basement structure support replacement construction.

[0029] According to one aspect of the present invention, the monitoring data includes: surrounding building settlement data, pipeline settlement data, surrounding groundwater level data, support axial force data, support column settlement data, pile top horizontal displacement data, pile top vertical displacement data, pile body deep horizontal displacement data and pile body stress data.

[0030] According to one embodiment of the present invention, a basement structure replacement support construction method includes: sequentially pouring concrete on the basement exterior wall and the basement bottom floor slab, and forming a plurality of support bases at intervals on the bottom floor slab, and connecting one end of a steel support based on the support bases; dividing the basement exterior wall into multiple layers from bottom to top based on the height of the basement exterior wall; installing the other end of the steel support on the bottom first basement exterior wall; constructing the bottom first basement exterior wall: performing formwork reinforcement construction on the bottom first basement exterior wall, and after reinforcement, removing the first basement internal support corresponding to the bottom first basement exterior wall; sequentially constructing the basement exterior walls above the bottom first basement according to the construction method of the bottom first basement until the basement exterior wall construction is completed; performing main construction and roof sealing on the basement to complete the basement structure replacement support construction. Such an arrangement can ensure that the overall force of the basement structure replacement construction process of the present invention is uniform, safe and reliable, and ensure the efficiency and success rate of the replacement support construction. Moreover, based on the above scheme, during the support replacement construction process, the support is replaced layer by layer from bottom to top, and the support is supported and removed from the outside to the inside. The process has low requirements on the safety of the structure itself, and the support replacement process is reliable, the support replacement effect is good, the construction process is simple, and no complicated operations are required.

[0031] According to one solution of the present invention, concrete is poured into the basement exterior wall and the basement ground floor slab in sequence, and multiple guy braces are formed at intervals on the ground floor slab. One end of the steel guy brace is connected based on the guy brace base: after the anti-seepage concrete pouring of the basement exterior wall is completed, the basement ground floor slab is poured with concrete, and when the concrete of the basement exterior wall is poured, an exterior wall guide wall is set at a preset distance on the ground floor slab, and a water-stop steel plate is pre-embedded. Before the ground floor slab is poured, the guy brace base reinforcement is tied synchronously with the beam and slab reinforcement of the ground floor slab. The guy brace base is poured together with the ground floor slab, and after the pouring is completed, one end of the steel guy brace is installed on the guy brace base. This arrangement can make the arrangement of each guy brace base stable and reliable. The installation of the steel guy brace based on the guy brace base can ensure that the steel guy brace provides safe and reliable support to the bottom of the basement exterior wall, ensure that the replacement process has a strong and reliable foundation support, and ensure the safety of the overall structure.

[0032] According to one solution of the present invention, each guy brace base is installed at the beam intersection nodes and main beams of the ground floor slab, with the spacing between each guy brace base ≤ 8m. The angle between the steel guy brace and the ground floor slab is 45°. This arrangement creates an orderly array of bottom supports between each combination of guy brace base and steel guy brace, ensuring effective support for the basement exterior wall, ensuring uniform stress distribution, and ensuring safe and efficient brace replacement.

[0033] According to one solution of the present invention, the other end of the steel brace for the exterior wall of the first basement floor is installed by welding a steel plate to the upper end of the brace during the reinforcement binding process of the first basement floor. After welding, the upper end of the brace is installed. The steel plate is welded to the brace, and triangular iron stiffeners are evenly arranged at the connection for reinforcement. This arrangement effectively improves the support strength and stability of the upper end of the brace, providing a safe and reliable support foundation for the entire brace replacement process.

[0034] According to one solution of the present invention, the internal supports of each basement floor are removed by first disconnecting the connecting beams for internal angle bracing structures, then disconnecting the angle bracing beams at intervals; for internal bracing structures, first disconnecting the connecting beams, then disconnecting the bracing beams at intervals; and after the angle bracing or bracing has released its stress, large-scale cutting and removal are performed. This arrangement effectively prevents uneven unloading on one side of the foundation pit due to excessive unloading. Each section of each support beam is unloaded simultaneously in stages, ensuring uniform unloading of the foundation pit during the removal of the basement internal supports, ensuring the safety of the internal support removal process, and ensuring the safety and efficiency of the entire support replacement construction process.

[0035] According to one solution of the present invention, the basement structure replacement support construction method of the present invention further includes: during the construction of the basement exterior wall and the basement bottom floor slab, monitoring various monitoring data of the construction foundation pit, comparing the monitoring data with the preset warning value range, and when the monitoring data does not exceed the warning value range, capping the basement roof to complete the basement structure replacement support construction. Among them, the monitoring data include: surrounding building settlement data, pipeline settlement data, surrounding groundwater level data, support axial force data, support column settlement data, pile top horizontal displacement data, pile top vertical displacement data, pile body deep horizontal displacement data and pile body stress data. Such an arrangement can make the monitoring data comprehensive, and based on the monitoring data, it can be comprehensively and accurately analyzed whether the foundation pit has undergone abnormal deformation during the basement structure replacement support construction process, thereby ensuring the comprehensiveness and accuracy of the monitoring.

[0036] According to the above scheme of the present invention, the support replacement construction of the present invention is based on the bottom floor and the support structure to carry out layered support replacement construction of the super-high basement, that is, the outer wall formwork of each basement layer and the internal formwork of each basement layer are supported and dismantled from bottom to top. The logic of this support replacement construction process is simple and the construction is safe and efficient. The construction process ensures that the basement structure is uniformly stressed, avoids deformation during the support replacement process, effectively improves the efficiency of the support replacement construction, and ensures the overall safety of the foundation pit. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A flowchart schematically showing a basement structure support replacement construction method according to one embodiment of the present invention;

[0038] Figure 2 A schematic diagram showing the structural arrangement of a towing support base and a steel towing support according to an embodiment of the present invention;

[0039] Figure 3 Schematically showing a top view of an internal support structure of a basement according to one embodiment of the present invention. DETAILED DESCRIPTION

[0040] The present invention will now be discussed with reference to exemplary embodiments. It should be understood that the embodiments discussed are only for enabling those skilled in the art to better understand and implement the present invention, rather than implying any limitation on the scope of the present invention.

[0041] As used herein, the term "including" and variations thereof are to be interpreted as open-ended terms meaning "including, but not limited to." The term "based on" is to be interpreted as "based, at least in part, on." The terms "one embodiment" and "an embodiment" are to be interpreted as "at least one embodiment."

[0042] Figure 1The following is a flow chart schematically showing a basement structure replacement construction method according to one embodiment of the present invention. Figure 1 As shown, in this embodiment, the basement structure support replacement construction method includes:

[0043] Concrete the basement exterior walls and the basement ground floor slab in sequence, and form multiple guy bracing bases at intervals on the ground floor slab, and connect one end of the steel guy brace to the guy bracing bases;

[0044] Based on the height of the basement outer wall, the basement outer wall is divided into multiple layers from bottom to top;

[0045] Install the other end of the steel bracing on the outer wall of the first basement floor at the bottom;

[0046] Construction on the outer wall of the first basement at the bottom: formwork reinforcement construction is carried out on the outer wall of the first basement at the bottom. After reinforcement, the internal support of the first basement corresponding to the outer wall of the first basement at the bottom is removed;

[0047] According to the construction method of the first basement at the bottom, the exterior walls of each basement located above the first basement at the bottom are constructed in sequence until the exterior walls of the basement are completed;

[0048] The main body construction and top plate sealing of the basement are carried out to complete the basement structure replacement construction. Such an arrangement can make the overall force uniform, safe and reliable during the basement structure replacement construction process of the present invention, and ensure the efficiency and success rate of the replacement construction. Moreover, based on the above scheme, during the replacement construction process, the support is replaced layer by layer from bottom to top, and during the replacement process of each layer, the support is supported and dismantled from the outside to the inside. The safety requirements of the structure itself are low during the process, and the replacement process is reliable, the replacement effect is good, the construction process is simple, and no complicated operation is required. The replacement construction method of the present invention is suitable for the construction of ultra-high basements (such as four-story basement structures) in deep foundation pits.

[0049] Furthermore, according to one embodiment of the present invention, concrete is poured sequentially on the basement exterior wall and the basement bottom floor slab, and a plurality of guy braces are formed on the bottom floor slab at intervals, and one end of the steel guy brace is connected to the guy brace base as follows:

[0050] After the anti-seepage concrete pouring of the basement exterior wall is completed, the concrete pouring of the basement bottom floor is carried out, and when the concrete pouring of the basement exterior wall is carried out, an exterior wall guide wall is set at a preset distance (for example, 300mm) on the bottom floor, and a water-stop steel plate is pre-buried. Before the bottom floor is poured, the steel bars of the guy support base are tied synchronously with the beam and slab steel bars of the bottom floor, and the guy support base is poured together with the bottom floor. After the pouring is completed, one end of the steel guy support is installed on the guy support base. With such a setting, the setting of each guy support base can be firm and reliable. The installation of the steel guy support based on the guy support base can make the steel guy support safely and reliably support the bottom of the basement exterior wall, ensure that the replacement process has a strong and reliable foundation support, and ensure the safety of the overall structure.

[0051] In this embodiment, concrete pouring is vibrated using an inserted vibrator. Basement exterior wall concrete should be poured and vibrated in layers, with a layer thickness no greater than 500mm. When vibrating with an inserted vibrator, the overlap between the upper and lower layers should be at least 50mm. Exterior wall and floor concrete is vibrated using an inserted vibrator, with a travel distance no greater than 400mm. The vibrator should minimize collisions with rebar and formwork. Each vibration point should be vibrated for 15-30 seconds. After initial vibration, the concrete should settle for 20-30 minutes before re-vibration.

[0052] Furthermore, according to one embodiment of the present invention, each of the support bases is arranged on the beam intersection node and the main beam of the bottom floor, and the spacing between each of the support bases is ≤8m;

[0053] The angle between the steel guy brace and the ground floor slab is 45 degrees. This arrangement allows each combination of the guy brace base and the steel guy brace to form an orderly array of bottom supports, ensuring the support effect of the basement exterior wall, ensuring that the basement exterior wall is evenly stressed, and ensuring that the brace replacement construction is carried out safely and effectively.

[0054] In this embodiment, each guy support base is set on the beam intersection node and the main beam to ensure the safe transmission of stress, and the arrangement spacing is ≤8m, and the angle between the guy support and the floor is controlled at 45°. Figure 2 As shown, the longitudinal width (front-to-back direction in the figure) of the guy support base 1 is 1m, and the transverse length (left-to-right direction in the figure) is 1.188m. The main reinforcement is triangular in shape and is made of 16C20 steel bars. Both ends are extended and anchored toward the bottom floor slab, with a length of not less than 700mm. Every two bars are tied together, and the stirrups are made of 7C12 steel bars and evenly arranged. After the steel bars of the guy support base are tied, the steel plate 2 is welded to the steel guy support 3. The size of the steel plate is 810mm×810mm×20mm. A C20 steel bar is welded at each corner of the steel plate, and the steel bar extends into the guy support seat by not less than 500mm. This arrangement can make the structure of the guy support base and the steel guy support stable and reliable, and it is not easy to deform during the force-bearing process, thereby ensuring the support effect.

[0055] Furthermore, according to one embodiment of the present invention, concrete is poured for the exterior wall of the basement by using a string tube or by opening a hole in the side of the formwork to install an inclined chute for layered pouring, with the height of each layer ≤ 2m. Each layer of concrete is vibrated and compacted after pouring, and the time interval between pouring the upper and lower layers of concrete is ≤ the initial setting time of the concrete.

[0056] Furthermore, according to one embodiment of the present invention, the installation of the other end of the steel bracing on the outer wall of the first basement floor at the bottom is as follows:

[0057] During the reinforcement tying process for the first basement exterior wall, the steel plate at the top of the steel brace was welded. Once welded, the top of the brace was installed, the steel plate welded to the brace, and triangular iron stiffeners were evenly arranged at the joint for reinforcement. This arrangement effectively improved the support strength and stability of the top of the brace, providing a safe and reliable foundation for the entire brace replacement process.

[0058] In this embodiment, the steel castor is a round steel tube with a diameter of 610 mm and a wall thickness of 10 mm;

[0059] The triangle iron is an isosceles right triangle with a waist length of 100 mm and a thickness of 10 mm.

[0060] Furthermore, according to one embodiment of the present invention, the formwork reinforcement construction is a single-sided formwork construction using a standardized tripod and anchored reinforcement.

[0061] In this implementation, due to the high exterior walls of the super-high basement, a layered construction method was adopted. The first-floor exterior wall was constructed to a height of 5.2m. The exterior walls of the second-floor basement above 5.2m were reinforced with planted rebar. During construction, a full-floor bracing (formwork) frame was erected, with frame parameters controlled to a length and width of 0.9m × 0.9m, with a step distance of 1.5m.

[0062] Furthermore, according to one embodiment of the present invention, the internal supports of each basement floor are removed, including:

[0063] For internal angle bracing structures, disconnect the tie beams first, and then disconnect the angle bracing beams at intervals;

[0064] For internal bracing structures, disconnect the connecting beams first, and then disconnect the bracing beams at intervals;

[0065] After the stress of the corner braces or braces is released, they can be cut and removed on a large scale.

[0066] In this embodiment, if Figure 3As shown, the stress release sequence for the angle brace structure 4 is as follows: Before demolition, the first monitoring of the foundation pit displacement and settlement data is performed. Using this data as a reference, the connecting beam 5 is cut first during demolition. After cutting, the data is monitored for abnormalities for a second time. If no changes are found, the angle brace beams 6 are cut at intervals. After cutting, the data is monitored for abnormalities for a third time. If the foundation pit monitoring data is safe, large-scale demolition of the angle brace area can begin.

[0067] The stress release order of the supporting structure 7 is as follows: taking the middle supporting beam 8 as an example, the displacement and settlement data of the foundation pit are monitored for the first time before demolition. Based on this, the five connecting beams 9 are cut first during demolition. After the cutting is completed, the second monitoring data is started to see if there is any abnormality. If there is no change, the two supporting beams 8 are cut. After the cutting is completed, the third monitoring data is started to see if there is any abnormality. When the monitoring data of the foundation pit is safe, the large-scale demolition of the supporting area can be started. Such a setting can effectively avoid uneven unloading due to excessive unloading on one side of the foundation pit. Each section of each supporting beam is unloaded synchronously in batches, ensuring that the foundation pit is evenly unloaded during the process of removing the internal support of the basement, ensuring the safety of the internal support removal process, and ensuring the safety and efficiency of the entire replacement support construction process. Furthermore, the use of the intermittent disconnection of the angle support beams and the supporting beams combined with the foundation pit deformation monitoring can effectively ensure that the deformation of the foundation pit is fully controllable during the construction process, so that the deformation can always be within the allowable range until the internal support is finally removed and the structural construction is completed.

[0068] Furthermore, according to one embodiment of the present invention, the basement structure support replacement construction method of the present invention also includes: during the construction of the basement exterior wall and the basement bottom floor slab, monitoring various monitoring data of the construction foundation pit, comparing the monitoring data with a preset warning value range, and when the monitoring data does not exceed the warning value range, capping the basement top slab to complete the basement structure support replacement construction.

[0069] Due to the complex foundation pit conditions during the actual construction of super-high basements, the actual construction depth has exceeded 20m. Accordingly, the foundation pit safety level is set to level one. In conventional monitoring construction, for foundation pits with an excavation depth of less than 5m, only the support structure, groundwater level and surrounding environment are monitored. For foundation pits with an excavation depth of 5-10m, the support structure, internal force of the support structure, soil and groundwater, and surrounding environment are mainly monitored. The present invention deals with deep foundation pits exceeding 10m. In addition to the above monitoring items, the internal force monitoring of support columns, internal force monitoring of pile supports, deformation and inclination monitoring of surrounding pipelines, etc. are added to the entire foundation pit, in order to fully demonstrate the impact of the support replacement construction on the foundation pit itself and the surrounding ancillary structures, so as to make timely response measures when over-control is required. Specifically, in this embodiment, the monitoring data include: settlement data of surrounding buildings, pipeline settlement data, surrounding groundwater level data, support axial force data, support column settlement data, pile top horizontal displacement data, pile top vertical displacement data, pile deep horizontal displacement data and pile body stress data. Such a setting can make the monitoring data comprehensive. Based on the monitoring data, it is possible to fully and accurately analyze whether the foundation pit has undergone abnormal deformation during the basement structure replacement construction process, thus ensuring the comprehensiveness and accuracy of the monitoring. During the basement replacement construction process, if there is bad weather, typhoons, rainstorms, etc., or when removing key internal supports or temporarily replacing supports, the monitoring frequency will be increased from 1 time / 3 days to 1 time / 1 day. When the values are stable, continuous monitoring will be carried out for 3 days or more to ensure the timeliness and accuracy of the data. According to relevant monitoring statistics, during the replacement construction of the super-high basement structure, the cumulative value of the change in various data of the foundation pit did not exceed the standard warning value, and the change in the corresponding time period was far lower than the warning value, and the foundation pit was safe and controllable.

[0070] Furthermore, according to one embodiment of the present invention, various monitoring data of the construction pit are obtained by:

[0071] Arrange settlement monitoring points. Settle settlement monitoring points on the ground near the top of the foundation pit, on the tops of the supporting piles around the basement structure, and on the tops of the columns used to support the internal support in the basement structure. This arrangement allows the settlement of various parts of the basement structure and the foundation pit to be monitored through the settlement monitoring points.

[0072] Arrange horizontal displacement monitoring points on the top of the crown beam and near the top of the foundation pit. This arrangement allows the horizontal deformation of various parts of the basement structure and the foundation pit to be monitored through the horizontal displacement monitoring points.

[0073] Arrange groundwater level monitoring points at the top of the foundation pit and within 1m of the surrounding super-high basement structure. This arrangement allows the groundwater level monitoring points to monitor the water level changes in the foundation pit that affect the basement structure.

[0074] Arrange support pile inclination monitoring points on the support pile columns around the basement structure; such an arrangement enables the support pile inclination monitoring points to monitor the inclination deformation of the support piles outside the basement structure;

[0075] Arrange the support pile internal force monitoring points on the longitudinal tensile reinforcement at the point where the bending moment of the support pile is the largest; such arrangement enables the force changes of the support pile to be monitored through the support pile internal force monitoring points;

[0076] Arrange axial force monitoring points on the internal angle bracing beams and bracing beams of each floor of the super-high basement structure; this arrangement allows the axial force support conditions of the internal supports of each floor of the basement to be monitored through the axial force monitoring points;

[0077] As set up above, the overall stress changes of the super-high basement structure during the support replacement construction in the deep foundation pit can be comprehensively monitored through various monitoring points, especially based on the above-mentioned bottom-up combined with outside-to-inside layer-by-layer support replacement construction method, by overall monitoring of the super-high basement structure and the corresponding deep foundation pit settlement deformation combined with layer-by-layer monitoring of the axial force support changes of the internal supporting structure of the super-high basement, the overall monitoring and analysis of the overall structure during the layer-by-layer support replacement construction process and the local monitoring and analysis of the internal supporting structure of each layer during the support replacement process and at the end of the support replacement are realized. In this way, a monitoring plan from the whole to the part is formed, which effectively ensures the accuracy of monitoring and early warning, ensures its applicability to the support replacement construction plan of the super-high basement, and ensures the safety of the support replacement construction of the super-high basement structure and the efficient progress of the construction process.

[0078] According to the above scheme of the present invention, the method of the present invention is applicable to the replacement support construction of super-high basement structures. The traditional steel pipe diagonal bracing with a diameter of 48mm and ordinary specifications is not applicable to high heights and has insufficient strength, and cannot be used for replacement support construction of super-high basement structures. The temporary bracing of horizontal I-beams has a complicated construction process, which has a great impact on the construction period. The required materials are huge, and there is a great impact on the structural construction of other areas. It cannot be applied to the replacement support construction of super-high basement structures corresponding to deep foundation pits. The steel bracing of the present invention is simple and convenient to construct. It only requires prefabricated steel pipes and two matching steel plates to construct a replacement support. It can also meet the requirements of the replacement support force transmission during the construction of super-high basement structures. The replacement support construction process does not affect the construction of other main structures. After actual construction inspection, the safety is effectively verified. What is important is that, based on the rigid support of the ground floor slab and the first basement floor at the bottom, the present invention carries out the support replacement construction from bottom to top and from outside to inside for the super-high basement structure (that is, the exterior walls of each basement floor are constructed from bottom to top, and in the process of constructing the exterior walls of each floor, the exterior wall formwork is first reinforced, and then the corresponding internal support structure is dismantled). In this way, it can effectively ensure that the foundation of the super-high basement always remains stable and firm, ensure the safety of the support replacement of the super-high basement structure in the deep foundation pit, avoid safety hazards in the deep foundation pit, and ensure the quality of construction and normal progress.

[0079] It should be emphasized that the deeper the foundation pit, the greater the pressure on the corresponding super-high basement structure and the pressure on the surrounding soil it faces. On the one hand, because the higher the number of floors of the super-high basement, the greater its overall gravity, the greater the overall pressure on the super-high basement structure in the deep foundation pit, so greater support force and more reasonable support replacement methods are required during the support replacement process; on the other hand, because the gravity exerted on the upper soil will be transmitted downward and applied to the lower soil through the foundation pit retaining wall, the soil pressure around the super-high basement increases. Therefore, during the support replacement construction of the super-high basement structure in the deep foundation pit, the surrounding lateral pressure will be greater, and the construction difficulty and danger will increase. Once the support force is insufficient or the support replacement method is unreasonable during the support replacement process, it will greatly increase the deformation of the super-high basement structure and cause the collapse of the deep foundation pit and other major safety hazards. Based on this, the present invention targets super-high basement structures in deep foundation pits, and uses a foundation array steel bracing structure to provide foundation support at the bottom of the super-high basement. On this basis, the super-high basement is subjected to layer-by-layer support replacement. During the support replacement process, the support is replaced layer by layer from the bottom to the top of the super-high basement. In addition, during the support replacement construction process of each layer, the outer wall of each basement must first be reinforced with formwork to ensure that the reinforced support is secure before the internal support of the corresponding basement layer is removed. Moreover, when removing the internal support, it is necessary to strictly follow the above-mentioned removal method to ensure that the stress release process is safe and stable, and to ensure that the foundation pit does not deform or other abnormalities occur. Therefore, the present invention can effectively ensure the safety of replacing the support of the super-high basement structure in a deep foundation pit through the above-mentioned support replacement construction method, effectively enhance the temporary support bearing capacity of the super-high basement structure during the support replacement process, avoid the safety hazards of the deep foundation pit caused by adverse deformation during the support replacement process, ensure construction quality, and ensure the normal progress of the project.

[0080] According to the above scheme of the present invention, the support replacement construction of the present invention is based on the bottom floor and the support structure to carry out layered support replacement construction of the super-high basement, that is, the outer wall formwork of each basement layer and the internal formwork of each basement layer are supported and dismantled from bottom to top. The logic of this support replacement construction process is simple and the construction is safe and efficient. The construction process ensures that the basement structure is uniformly stressed, effectively improves the efficiency of the support replacement construction, and at the same time ensures the overall safety of the foundation pit.

[0081] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. The basement structure replacement support construction method is characterized by: include: Concrete the basement exterior wall and the basement ground floor slab in sequence, and form multiple guy bracing bases at intervals on the ground floor slab, and connect one end of the steel guy brace based on the guy bracing bases; Based on the height of the basement outer wall, the basement outer wall is divided into multiple layers from bottom to top; Install the other end of the steel bracing on the outer wall of the first basement floor at the bottom; Construction on the outer wall of the first basement at the bottom: formwork reinforcement construction is carried out on the outer wall of the first basement at the bottom. After reinforcement, the internal support of the first basement corresponding to the outer wall of the first basement at the bottom is removed; According to the construction method of the first basement at the bottom, the exterior walls of each basement located above the first basement at the bottom are constructed in sequence until the exterior walls of the basement are completed; Carry out main construction and roof sealing of the basement, and complete the basement structure support replacement construction.

2. The basement structure replacement construction method according to claim 1 is characterized in that: The basement exterior wall and the basement bottom floor are poured with concrete in sequence, and a plurality of guy support bases are formed at intervals on the bottom floor. One end of the steel guy support is connected to the guy support base as follows: After the anti-seepage concrete of the basement exterior wall is poured, the concrete of the basement bottom floor is poured. When pouring the concrete of the basement exterior wall, an exterior wall guide wall is set at a preset distance on the bottom floor, and a water-stop steel plate is embedded. Before pouring the bottom floor, the steel bars of the guy support base are tied synchronously with the beam and slab steel bars of the bottom floor. The guy support base is poured together with the bottom floor. After the pouring is completed, one end of the steel guy support is installed on the guy support base.

3. The basement structure replacement construction method according to claim 1 is characterized in that: Each of the above-mentioned support bases is arranged on the beam intersection node and the main beam of the bottom floor, and the spacing between each support base is ≤8m; The angle between the steel brace and the bottom floor is 45 degrees.

4. The basement structure replacement construction method according to claim 1 is characterized in that: When pouring concrete for the basement exterior wall, use a string tube or open a hole on the side of the formwork to install an inclined chute for layered pouring. The height of each layer is ≤2m. After each layer of concrete is poured, it is vibrated to make it dense, and the time interval between the pouring of the upper and lower layers of concrete is ≤the initial setting time of the concrete.

5. The basement structure replacement construction method according to claim 1 is characterized in that: The installation of the other end of the steel bracing for the outer wall of the first basement floor at the bottom is as follows: During the reinforcement binding process of the outer wall of the first basement floor at the bottom, the steel plate at the upper end of the steel brace is welded. After welding is completed, the upper end of the steel brace is installed. The steel plate and the steel brace are welded together and triangular iron stiffening ribs are evenly arranged at the connection for reinforcement.

6. The basement structure replacement construction method according to claim 5 is characterized in that: The steel support is a round steel tube with a diameter of 610 mm and a wall thickness of 10 mm; The triangular iron is an isosceles right triangle with a waist length of 100 mm and a thickness of 10 mm.

7. The basement structure replacement construction method according to claim 1 is characterized in that: The formwork reinforcement construction adopts a single-sided formwork construction with standardized tripod and embedded steel bars.

8. The basement structure replacement construction method according to claim 1 is characterized in that: Remove the internal supports of each basement, including: For internal angle bracing structures, disconnect the tie beams first, and then disconnect the angle bracing beams at intervals; For internal bracing structures, disconnect the connecting beams first, and then disconnect the bracing beams at intervals; After the stress of the corner braces or braces is released, they can be cut and removed on a large scale.

9. The basement structure replacement construction method according to any one of claims 1 to 8, characterized in that: Also includes: During the construction of the basement exterior walls and the basement ground floor slabs, various monitoring data of the construction foundation pit are monitored and compared with the preset warning value range. When the monitoring data does not exceed the warning value range, the basement top slab is capped and the basement structure support replacement construction is completed.

10. The basement structure replacement construction method according to claim 9, characterized in that: The monitoring data includes: settlement data of surrounding buildings, pipeline settlement data, surrounding groundwater level data, support axial force data, support column settlement data, pile top horizontal displacement data, pile top vertical displacement data, pile body deep horizontal displacement data and pile body stress data.

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