Adjustable prefabricated reinforced concrete support changing system for super-large center island foundation pit and construction method

Abstract

The invention provides an adjustable prefabricated reinforced concrete support changing system for a super-large center island foundation pit and a construction method. The adjustable prefabricated reinforced concrete support changing system comprises a positioning reinforced concrete supporting section, a main body reinforced concrete supporting section, a positioning concrete bracket, a post-pouring concrete bracket and a jacking and lifting in-place system. The positioning concrete bracket is located on the lower side of the oblique support changing system and is poured on the fixed vertical component, and the post-pouring concrete bracket is poured on the upper structure; the lower side end of the main body steel-concrete supporting section is coaxially and fixedly connected with the upper side end of the positioning steel-concrete supporting section to form an adjustable prefabricated steel-concrete replacement support; the lower side end of the positioning steel-concrete supporting section is adjustably connected with the positioning concrete bracket through the jacking and lifting in-place system, and the upper side end of the main body steel-concrete supporting section is adjustably connected with the post-pouring concrete bracket through the jacking and lifting in-place system, so that an inclined support changing system is formed. The invention relates to the technical field of deep foundation pit construction, and can solve the technical problems of concrete support replacement and steel support replacement in the prior art.

Description

Technical Field

[0001] The present invention relates to the technical field of deep foundation pit construction, and particularly relates to an adjustable precast steel-concrete replacement bracing system and construction method for an extra-large central island foundation pit. Background Art

[0002] During the construction of an extra-large central island foundation pit, when the construction of the central island soil-retaining area starts after the central island structure is constructed upward to a designated position, it is necessary to set up braces 200 between the retaining structure and the central island structure 100 to transfer the horizontal force. Since the soil-retaining area for extra-large area construction usually has a slope of two to three levels, the horizontal force is extremely large, and the stiffness of the part of the central island structure 100 connected to the brace 200 is insufficient. It is necessary to add diagonal replacement braces 300 to transfer the horizontal force transmitted by the brace to the central island floor slab 400, as shown in the appendix. Figure 1 as shown

[0003] In the field of deep foundation pit construction, the traditional diagonal replacement bracing systems mainly include two forms: concrete replacement bracing and steel bracing replacement bracing. Among them, the concrete replacement bracing system can be integrally cast with the central island structure, having good integrity and stability, and a large bearing capacity; however, for the construction conditions of an extra-large central island foundation pit, it has a series of use defects such as a long construction period, non-reusability, difficult large-scale demolition construction, and affecting the overall structure. The steel bracing replacement bracing system, although having the advantages of a short construction period and material reusability, requires the steel bracing to be anchored into the structure body, which will not only have a certain impact on the strength and stability of the structure body, but also often cannot provide anchoring conditions for the steel bracing when there are complex beam-column joints in the structure body, resulting in the inability to install the steel bracing; moreover, the bearing capacity of the steel bracing is small and cannot meet the force requirements of the replacement bracing. At the same time, for the construction of an extra-large central island foundation pit, its column grid system is complexly arranged, and different column grid spaces have different requirements for the setting angles and size structures of the steel bracing. The shaping and on-site correspondence of each component will greatly affect the overall construction efficiency, and the angle adjustment of the traditional diagonal replacement bracing system is inconvenient.

[0004] Therefore, it is necessary to provide an adjustable precast steel-concrete replacement bracing system and construction method for an extra-large central island foundation pit, which can solve the problems of long construction period, non-reusability, difficult demolition, damage to the structure body by the anchoring of the steel bracing replacement bracing and insufficient bearing capacity, and inconvenient angle adjustment of the traditional diagonal replacement bracing system in the prior art. Summary of the Invention

[0005] The purpose of the present invention is to provide an adjustable precast steel-concrete replacement bracing system and construction method for an extra-large central island foundation pit, which can solve the problems of long construction period, non-reusability, difficult demolition, damage to the structure body by the anchoring of the steel bracing replacement bracing and insufficient bearing capacity, and inconvenient angle adjustment of the traditional diagonal replacement bracing system in the prior art.

[0006] To achieve the above object, the technical solution of the present invention is as follows:

[0007] An adjustable precast steel-concrete replacement bracing system for an extra-large central island foundation pit, comprising: a positioning steel-concrete bracing section, a main body steel-concrete bracing section, a positioning concrete corbel, a post-cast concrete corbel, and a jacking and lifting and positioning system; the positioning concrete corbel is located on the lower side of the inclined replacement bracing system and is cast on a fixed vertical member, and the post-cast concrete corbel is cast on the upper structure; the lower side end of the main body steel-concrete bracing section is coaxially fixedly connected to the upper side end of the positioning steel-concrete bracing section to form an adjustable precast steel-concrete replacement bracing; the lower side end of the positioning steel-concrete bracing section is adjustably connected to the positioning concrete corbel through the jacking and lifting and positioning system, and the upper side end of the main body steel-concrete bracing section is adjustably connected to the post-cast concrete corbel through the jacking and lifting and positioning system to form an inclined replacement bracing system.

[0008] The positioning concrete corbel includes a positioning corbel main body, a rotating end head, and a rotating flange; the positioning corbel main body is cast on a fixed vertical member, the fixed end of the rotating end head is fixedly installed on the positioning corbel main body, and the rotating flange is installed at the rotating end of the rotating end head; connecting flanges are installed at both ends of the positioning steel-concrete bracing section, and the lower side end of the positioning steel-concrete bracing section is coaxially fixedly connected to the rotating flange through the connecting flange, so that the positioning steel-concrete bracing section is rotatably installed in the installation area of the inclined replacement bracing system through the rotating end head by means of the jacking and lifting and positioning system.

[0009] A connecting flange is installed at the lower side end of the main body steel-concrete bracing section, and the lower side end of the main body steel-concrete bracing section is coaxially fixedly connected to the upper side end of the positioning steel-concrete bracing section through the jacking and lifting and positioning system by means of the connecting flange to form an adjustable precast steel-concrete replacement bracing.

[0010] The post-cast concrete corbel includes a post-cast corbel main body and post-embedded connecting bars; the post-cast corbel main body is cast on the upper structure, and several post-embedded connecting bars are embedded in the post-cast corbel main body; several support section connecting bars are embedded in the upper side end of the main body steel-concrete bracing section, and the several post-embedded connecting bars correspond to the several support section connecting bars one by one and are connected by sleeve biting.

[0011] The post-cast concrete corbel includes a post-cast corbel main body and a connecting flange, the post-cast corbel main body is cast on the upper structure, and the connecting flange is installed on the post-cast corbel main body; a connecting flange is provided at the upper side end of the main body steel-concrete bracing section, and the upper side end of the main body steel-concrete bracing section is fixedly connected to the post-cast corbel main body through the connecting flange.

[0012] Lifting lugs are provided on both the positioning steel-concrete bracing section and the main body steel-concrete bracing section; the jacking and lifting and positioning system includes a hoisting device and a hoisting mechanism for lifting the positioning steel-concrete bracing section and the main body steel-concrete bracing section, a jacking mechanism for jacking the positioning steel-concrete bracing section and the main body steel-concrete bracing section, a limiting member, a support system, and a measuring member.

[0013] A construction method for an adjustable precast steel-concrete replacement bracing system for an extra-large central island foundation pit, which is used in the working condition where the upper structure has not been poured. The construction method includes the following steps:

[0014] Step 1: Determine the fixed vertical members according to the design requirements, and construct positioning concrete corbels on the fixed vertical members;

[0015] Step 2: Erect a temporary support bracket at the installation position on the lower side of the inclined replacement bracing system, and hoist the positioning steel-concrete support section to the temporary support bracket through a hoisting device via a lifting ear plate;

[0016] Step 3: Install a jacking mechanism below the lower end of the positioning steel-concrete support section, and jack up the positioning steel-concrete support section to the designed angle of the inclined replacement bracing system through the jacking mechanism, and connect the connecting flange at the lower end of the positioning steel-concrete support section to the rotating flange of the positioning concrete corbel;

[0017] An additional support bracket is installed at the top of the temporary support bracket, so that the additional support bracket supports against the bottom of the positioning steel-concrete support section installed obliquely;

[0018] Step 4: Erect a temporary support bracket at the installation position on the upper side of the inclined replacement bracing system, and hoist the main body steel-concrete support section to the temporary support bracket through a hoisting device via a lifting ear plate;

[0019] Step 5: Lift the upper end of the main body steel-concrete support section through a hoisting device, so that the main body steel-concrete support section rotates to the designed angle of the inclined replacement bracing system;

[0020] Step 6: Install an additional support bracket on the temporary support bracket below the main body steel-concrete support section, so that the additional support bracket supports against the bottom of the main body steel-concrete support section installed obliquely, and connect the lower end of the main body steel-concrete support section to the upper end of the positioning steel-concrete support section through a connecting flange;

[0021] Step 7: Judge whether it is necessary to finely adjust the angle of the adjustable precast steel-concrete replacement bracing; if so, install a jacking mechanism below the lower end of the main body steel-concrete support section, and jack up and rotate the adjustable precast steel-concrete replacement bracing through the jacking mechanism to make the adjustable precast steel-concrete replacement bracing rotate to the designed angle of the inclined replacement bracing system; if not, execute Step 8;

[0022] Step 8: Pour the upper structure integrally, and synchronously construct post-cast concrete corbels and main body concrete corbels on the upper structure, and connect the upper end of the main body steel-concrete support section to the post-cast concrete corbel; after the upper structure is poured and reaches the required strength grade, remove the temporary support bracket and the additional support bracket to complete the installation of the inclined replacement bracing system;

[0023] Step 9: After the construction of the floor slab corresponding to the soil-retaining area of the slope is completed and the overall structure forms an effective force transfer system, the inclined bracing system is demolished.

[0024] The demolition steps of the said inclined bracing system include:

[0025] Step 9.1: During the casting of the upper structure, lifting hooks are embedded synchronously; a temporary support bracket and a supplementary support bracket are erected below the inclined bracing system to make the temporary support bracket and the supplementary support bracket support and position the reinforced concrete support section and the main reinforced concrete support section, disconnect the connection between the upper end of the main reinforced concrete support section and the post-cast concrete corbel, and chisel off the post-cast corbel body of the post-cast concrete corbel.

[0026] Step 9.2: Disconnect the connection between the connecting flange at the upper end of the positioning reinforced concrete support section and the connecting flange at the lower end of the main reinforced concrete support section, and disconnect the connection between the connecting flange at the lower end of the positioning reinforced concrete support section and the rotating flange of the positioning concrete corbel.

[0027] Step 9.3: Install a lifting mechanism on the lifting hook, and sequentially lift the positioning reinforced concrete support section and the main reinforced concrete support section to other areas through the lifting mechanism.

[0028] Step 9.4: Demolish the temporary support bracket and the supplementary support bracket installed in Step 9.1, and remove the lifting mechanism and the lifting hook, and chisel off the positioning concrete corbel; if the fixed vertical member is a vertical temporary support short column, chisel off the vertical temporary support short column synchronously.

[0029] A construction method for an adjustable precast reinforced concrete bracing system for an extra-large central island foundation pit, which is used in the working condition where the upper structure has been cast. This construction method includes the following steps:

[0030] Step 1: Before the casting of the upper structure, the positioning reinforced concrete support section and the main reinforced concrete support section are lifted into the central island structure by a lifting device.

[0031] Step 2: During the casting of the upper structure, the main concrete corbel is cast synchronously, and lifting hooks are embedded.

[0032] Step 3: Determine the fixed vertical member according to the design requirements, and construct the positioning concrete corbel on the fixed vertical member.

[0033] Step 4: Install a lifting mechanism on the lifting hook; erect a temporary support bracket at the installation position below the inclined bracing system, and lift the positioning reinforced concrete support section to the temporary support bracket through the lifting mechanism via the lifting lug plate.

[0034] Step 5: Install a jacking mechanism below the lower end of the positioned reinforced concrete support section. Use the jacking mechanism to jack up the positioned reinforced concrete support section to the designed angle of the inclined replacement support system, and connect the connecting flange at the lower end of the positioned reinforced concrete support section to the rotating flange of the positioned concrete corbel.

[0035] An additional support bracket is installed at the top of the temporary support bracket, so that the additional support bracket supports against the bottom of the positioned reinforced concrete support section installed obliquely.

[0036] Step 6: Set up a temporary support bracket at the upper installation position of the inclined replacement support system. Use the hoisting mechanism to hoist the main reinforced concrete support section to this temporary support bracket through the lifting lugs.

[0037] Step 7: Lift the upper end of the main reinforced concrete support section through the hoisting mechanism, so that the main reinforced concrete support section rotates to the designed angle of the inclined replacement support system.

[0038] Step 8: Install an additional support bracket on the temporary support bracket below the main reinforced concrete support section, so that the additional support bracket supports against the bottom of the main reinforced concrete support section installed obliquely, and connect the lower end of the main reinforced concrete support section to the upper end of the positioned reinforced concrete support section through the connecting flange via a connecting piece.

[0039] Step 9: Determine whether it is necessary to finely adjust the angle of the adjustable precast reinforced concrete replacement support. If so, install a jacking mechanism below the lower end of the main reinforced concrete support section. Use the jacking mechanism to jack up and rotate the adjustable precast reinforced concrete replacement support so that it rotates to the designed angle of the inclined replacement support system. If not, proceed to Step 10.

[0040] Step 10: Pour the post-cast concrete corbel on the superstructure, and connect the upper end of the main reinforced concrete support section to the post-cast concrete corbel. After the superstructure is poured and reaches the required strength grade, remove the temporary support bracket and the additional support bracket to complete the installation of the inclined replacement support system.

[0041] Step 11: After the construction of the floor slab corresponding to the soil-retaining area of the slope is completed and the overall structure forms an effective force transmission system, remove the inclined replacement support system.

[0042] The removal steps of the said inclined replacement support system include:

[0043] Step 11.1: Set up a temporary support bracket below the inclined replacement support system, so that the temporary support bracket supports the positioned reinforced concrete support section and the main reinforced concrete support section. Disconnect the connection between the upper end of the main reinforced concrete support section and the post-cast concrete corbel, and chisel off the post-cast corbel body of the post-cast concrete corbel.

[0044] Step 11.2: Disconnect the connection flange at the upper end of the positioning steel-concrete support section from the connection flange at the lower end of the main steel-concrete support section, and disconnect the connection flange at the lower end of the positioning steel-concrete support section from the rotating flange of the positioning concrete corbel.

[0045] Step 11.3: Use the lifting mechanism to hoist the positioning steel-concrete support section and the main steel-concrete support section to other areas in sequence.

[0046] Step 11.4: Demolish the temporary support bracket installed in Step 11.1, and remove the lifting mechanism and the hook. Chisel the positioning concrete corbel; if the fixed vertical member is a vertical temporary support short column, chisel this vertical temporary support short column synchronously.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] 1. The adjustable precast steel-concrete replacement support system of the present invention effectively solves the problems of the traditional inclined replacement support system, such as the long construction period of the concrete replacement support in the inclined replacement support system required for the construction of an extra-large central island foundation pit due to the need to transfer horizontal forces, non-reusability, difficult demolition, damage to the structure body and insufficient bearing capacity caused by the steel support replacement support being anchored, and inconvenient angle adjustment of the traditional inclined replacement support system. The present invention has technical advantages such as simple construction, reusable materials, small impact on the overall structure during later demolition construction, and good bearing capacity.

[0049] 2. The adjustable precast steel-concrete replacement support system of the present invention effectively solves the problems of size differences and setting angles of the inclined replacement support system caused by the complex layout of the column grid system, without the need for shaping and on-site correspondence of each component of the traditional steel support system, greatly saving working hours, accelerating the construction speed, and improving the overall construction efficiency.

[0050] 3. The construction method of the present invention can monitor and adjust the inclined installation angle of the adjustable precast steel-concrete replacement support system in real time to make it meet the design angle requirements, reduce construction errors, and improve construction quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] By describing the exemplary embodiments of the present disclosure in more detail in conjunction with the drawings, the above and other objects, features, and advantages of the present disclosure will become more obvious. Among them, in the exemplary embodiments of the present disclosure, the same reference numerals generally represent the same components.

[0052] Figure 1 is a structural schematic diagram of the inclined replacement support system of an extra-large central island foundation pit in the prior art;

[0053] Figure 2 is a structural schematic diagram of the adjustable precast steel-concrete replacement support system for an extra-large central island foundation pit of the present invention;

[0054] Figure 3It is the front view of the jacking mechanism in the adjustable precast steel-concrete replacement bracing system for an extra-large central island foundation pit of the present invention;

[0055] Figure 4 It is the side view of the positioning steel-concrete support section in the adjustable precast steel-concrete replacement bracing system for an extra-large central island foundation pit of the present invention;

[0056] Figure 5 It is the construction schematic diagram of step 1 in the construction method of the adjustable precast steel-concrete replacement bracing system for an extra-large central island foundation pit of the present invention;

[0057] Figure 6 It is the construction schematic diagram of step 2 in the construction method of the adjustable precast steel-concrete replacement bracing system for an extra-large central island foundation pit of the present invention;

[0058] Figure 7 It is the construction schematic diagram of step 3 in the construction method of the adjustable precast steel-concrete replacement bracing system for an extra-large central island foundation pit of the present invention;

[0059] Figure 8 It is the construction schematic diagram of step 4 in the construction method of the adjustable precast steel-concrete replacement bracing system for an extra-large central island foundation pit of the present invention;

[0060] Figure 9 It is the construction schematic diagram of step 5 in the construction method of the adjustable precast steel-concrete replacement bracing system for an extra-large central island foundation pit of the present invention;

[0061] Figure 10 It is the construction schematic diagram of step 6 in the construction method of the adjustable precast steel-concrete replacement bracing system for an extra-large central island foundation pit of the present invention;

[0062] Figure 11 It is the construction schematic diagram of step 7 in the construction method of the adjustable precast steel-concrete replacement bracing system for an extra-large central island foundation pit of the present invention;

[0063] Figure 12 It is the construction schematic diagram of step 8 in the construction method of the adjustable precast steel-concrete replacement bracing system for an extra-large central island foundation pit of the present invention;

[0064] Figure 13 It is the construction schematic diagram of step 9 in the construction method of the adjustable precast steel-concrete replacement bracing system for an extra-large central island foundation pit of the present invention;

[0065] Figure 14 It is the construction schematic diagram of step 9.1 in the construction method of the adjustable precast steel-concrete replacement bracing system for an extra-large central island foundation pit of the present invention;

[0066] Figure 15 It is the construction schematic diagram of step 9.2 in the construction method of the adjustable precast steel-concrete replacement bracing system for an extra-large central island foundation pit of the present invention;

[0067] Figure 16 It is a construction schematic diagram of step 9.3 in the construction method of the adjustable precast steel-concrete replacement bracing system for the super-large central island foundation pit of the present invention.

[0068] In the figure, 100 is the central island structure, 200 is the bracing, 300 is the inclined replacement bracing, 400 is the central island floor slab, 1 is the positioning steel-concrete bracing section, 101 is the steel pipe, 102 is the concrete, 2 is the main body steel-concrete bracing section, 21 is the bracing section connecting reinforcement, 3 is the positioning concrete corbel, 31 is the positioning corbel main body, 32 is the rotating end, 33 is the rotating flange, 34 is the embedded part, 4 is the post-cast concrete corbel, 41 is the post-cast corbel main body, 42 is the post-cast connecting reinforcement, 5 is the superstructure, 51 is the main body concrete corbel, 52 is the lifting hook, 6 is the fixed vertical member, 7 is the connecting flange, 8 is the sleeve, 9 is the lifting lug plate, 10 is the lifting equipment, 11 is the temporary bracing bracket, 12 is the limiting member, 13 is the jacking mechanism, 131 is the jack, 132 is the flexible head, 133 is the steel bracing jacking head, 134 is the supporting concave part, 14 is the supplementary bracing bracket, and 15 is the lifting mechanism. Detailed implementation manners

[0069] The adjustable precast steel-concrete replacement bracing system and construction method for the super-large central island foundation pit proposed by the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. According to the following description and the claims, the advantages and features of the present invention will be clearer. It should be noted that the accompanying drawings are all in a very simplified form and use non-precise scales, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0070] Please refer to the attached Figure 2 , An adjustable precast steel-concrete replacement bracing system for a super-large central island foundation pit includes a positioning steel-concrete bracing section 1, a main body steel-concrete bracing section 2, a positioning concrete corbel 3, a post-cast concrete corbel 4, and a jacking and lifting and positioning system; the positioning concrete corbel 3 is located on the lower side of the inclined replacement bracing system and is cast on a fixed vertical member 6 (which can be a temporary bracing short column or an existing structural column), and the post-cast concrete corbel 4 is cast on the superstructure 5 (such as the connection node between the upper floor slab system and the structural column); the lower side end of the main body steel-concrete bracing section 2 is coaxially and fixedly connected to the upper side end of the positioning steel-concrete bracing section 1 to form an adjustable precast steel-concrete replacement bracing; the lower side end of the positioning steel-concrete bracing section 1 is adjustably connected to the positioning concrete corbel 3 through the jacking and lifting and positioning system, and the upper side end of the main body steel-concrete bracing section 2 is adjustably connected to the post-cast concrete corbel 4 through the jacking and lifting and positioning system to form an inclined replacement bracing system.

[0071] Please refer to the attached Figure 4 , Preferably, both the positioning steel-concrete bracing section 1 and the main body steel-concrete bracing section 2 adopt a steel-concrete structure, that is, the outside is made of a steel pipe 101, and concrete 102 is poured inside the steel pipe 101, with high structural strength, which can meet the stress requirements of the inclined replacement bracing and solve the problem of insufficient bearing capacity of the steel bracing in the prior art.

[0072] The positioning steel-concrete support section 1 and the main body steel-concrete support section 2 can be prefabricated and formed in the factory according to the design requirements of the inclined replacement support system, transported to the site for installation, with simple construction, convenient disassembly and assembly, and easy to turnover, avoiding the problems of long construction period, non-turnover and difficult demolition of concrete replacement support in the prior art.

[0073] By pouring the positioning concrete corbel 3 and the post-cast concrete corbel 4, fixed installation fulcrums are provided for the lower end of the positioning steel-concrete support section 1 and the upper end of the main body steel-concrete support section 2, ensuring the integrity and bearing capacity of the inclined replacement support system, and avoiding the problem that the anchoring installation of steel support replacement in the prior art affects the main structure.

[0074] The described positioning concrete corbel 3 includes a positioning corbel main body 31, a rotating end 32 and a rotating flange 33; the positioning corbel main body 31 is poured on the fixed vertical member 6, the fixed end of the rotating end 32 is fixedly installed on the positioning corbel main body 31 through the embedded part 34, and the rotating flange 33 is installed at the rotating end of the rotating end 32; connecting flanges 7 are installed at both ends of the positioning steel-concrete support section 1, and the lower end of the positioning steel-concrete support section 1 is coaxially fixedly connected to the rotating flange 33 through the connecting flange 7 and the connecting member, so that the positioning steel-concrete support section 1 can be rotatably installed in the installation area of the inclined replacement support system through the rotating end 32 by the jacking and lifting in-place system.

[0075] Preferably, the rotating end 32 includes a rotating end and a fixed end, and the rotating end is installed on the fixed end through a rotating shaft, so that the rotating end can rotate relative to the fixed end.

[0076] Preferably, the embedded part 34 can be composed of an embedded plate and anchor bolts, and several anchor bolts are anchored in the positioning corbel main body 31, so that the embedded plate is embedded in the positioning corbel main body 31, facilitating the fixed connection between the fixed end of the rotating end 32 and the embedded plate.

[0077] Preferably, the rotating flange 33 and the connecting flange 7 can adopt the same flange, which is convenient for the rotating flange 33 and the connecting flange 7 to be butt-jointed through bolts and nuts, thereby installing the positioning steel-concrete support section 1 on the positioning corbel main body 31, and the installation angle can be adjusted by rotating the rotating end of the rotating end 32 to make the installation angle consistent with the design angle.

[0078] A connecting flange 7 is installed at the lower end of the main body steel-concrete support section 2, and the lower end of the main body steel-concrete support section 2 is coaxially fixedly connected to the upper end of the positioning steel-concrete support section 1 through the jacking and lifting in-place system via the connecting flange 7 and its connecting member, forming an adjustable precast steel-concrete replacement support.

[0079] Connecting the positioning steel-concrete support section 1 and the main body steel-concrete support section 2 through the connecting flange 7 and its bolts and nuts, i.e., the connecting member, is a conventional construction method in the art and will not be elaborated here.

[0080] As a preferred embodiment, the post-cast concrete corbel 4 includes a post-cast corbel main body 41 and post-embedded connecting bars 42; the post-cast corbel main body 41 is cast on the upper structure 5, and a plurality of post-embedded connecting bars 42 are embedded in the post-cast corbel main body 41; a plurality of support-section connecting bars 21 are embedded and installed at the upper side end of the main reinforced concrete support section 2, and the plurality of post-embedded connecting bars 42 and the plurality of support-section connecting bars 21 correspond one by one and are connected by a sleeve 8 in a bite connection.

[0081] If the upper structure 5 has not been cast and constructed, the main reinforced concrete support section 2 and the post-cast concrete corbel 4 can be connected by the bite connection of the sleeve 8, with reliable connection and convenient disassembly and assembly.

[0082] As another preferred embodiment, the post-cast concrete corbel 4 includes a post-cast corbel main body 41 and a connecting flange 7. The post-cast corbel main body 41 is cast on the upper structure 5, and the connecting flange 7 is installed on the post-cast corbel main body 41 through a pre-embedded part 34; a connecting flange 7 is provided at the upper side end of the main reinforced concrete support section 2, and the upper side end of the main reinforced concrete support section 2 is fixedly connected to the post-cast corbel main body 41 through the connecting flange 7 via a connecting member.

[0083] If the upper structure 5 has been cast and constructed, the main reinforced concrete support section 2 and the post-cast concrete corbel 4 can be connected by setting a pre-embedded part 34 on the post-cast corbel main body 41.

[0084] The setting of the pre-embedded part 34 on the post-cast corbel main body 41 is the same as the setting of the pre-embedded part 34 on the positioning corbel main body 31, which will not be elaborated here. The connecting flange 7 can be installed and connected to the pre-embedded part 34 of the post-cast corbel main body 41 through bolts and nuts, i.e., connecting members.

[0085] Lifting lugs 9 are provided on both the positioning reinforced concrete support section 1 and the main reinforced concrete support section 2, which is convenient for the lifting and hoisting of the positioning reinforced concrete support section 1 and the main reinforced concrete support section 2 by the jacking and lifting positioning system.

[0086] The jacking and lifting positioning system includes a hoisting device 10 and a hoisting mechanism 15 for lifting the positioning reinforced concrete support section 1 and the main reinforced concrete support section 2, a jacking mechanism 13 for jacking the positioning reinforced concrete support section 1 and the main reinforced concrete support section 2, a limiting member 12, a support system, and a measuring member.

[0087] Preferably, the jacking mechanism 13 can be composed of a hydraulic jack, an oil pump power system, and a reinforced concrete support jacking head, and is used to jack the shorter positioning reinforced concrete support section 1 to a specified angle in the initial stage of construction, and for the angle fine-tuning construction that may occur after the completion of the adjustable precast reinforced concrete replacement support connection in the later stage. The jacking mechanism 13 is a conventional device in the field, and its working process will not be elaborated here.

[0088] Preferably, the hoisting equipment 10 can adopt large hoisting machinery commonly used in construction, such as truck-mounted cranes, for horizontally hoisting and positioning the reinforced concrete support section 1 and the main body reinforced concrete support section 2 to the designated positions in sequence, as well as related operations of laterally lifting one side of the main body reinforced concrete support section 2 to the designated angle and connecting it with the positioning reinforced concrete support section 1. The hoisting machinery is a conventional equipment in this field, and its working process will not be elaborated here.

[0089] Preferably, the hoisting mechanism 15 can adopt small manual hoisting machinery commonly used in construction, such as chain hoists, for lifting and connecting the positioning reinforced concrete support section 1 and the main body reinforced concrete support section 2. The hoisting machinery is a conventional equipment in this field, and its working process will not be elaborated here.

[0090] Preferably, the limiting member 12 can be made of section steel, and is used to limit the lower ends of the positioning reinforced concrete support section 1 and the main body reinforced concrete support section 2 when they are lifted and rotated, so as to prevent the positioning reinforced concrete support section 1 and the main body reinforced concrete support section 2 from slipping and deviating.

[0091] Preferably, the support system can include a temporary support bracket 11 for positioning and supporting the horizontally placed positioning reinforced concrete support section 1 and the main body reinforced concrete support section 2, and a supplementary support bracket 14 for positioning and supporting the positioning reinforced concrete support section 1 and the main body reinforced concrete support section 2 after they are obliquely installed. The temporary support bracket 11 and the supplementary support bracket 14 can be made by erecting steel pipe members, similar to scaffolding, and can be erected adaptively according to the sizes and weights of the positioning reinforced concrete support section 1 and the main body reinforced concrete support section 2. The construction process and specific structure will not be elaborated here.

[0092] Preferably, the measuring member can be composed of a laser theodolite and receiving targets preset on the positioning reinforced concrete support section 1 and the main body reinforced concrete support section 2, and is used to accurately position the actual angles of the positioning reinforced concrete support section 1 and the main body reinforced concrete support section 2 to ensure that their installation angles are consistent with the design angles. The laser theodolite and the receiving targets are conventional measuring tools in this field, and their working processes and principles will not be elaborated here.

[0093] Embodiment 1: A construction method for an adjustable precast reinforced concrete replacement support system for an extra-large central island foundation pit. This construction method is used in the condition where the upper structure 5 has not been poured. This construction method includes the following steps:

[0094] Please refer to the appendix Figure 5 , Step 1: Determine the fixed vertical member 6 according to the design requirements, and construct the positioning concrete corbel 3 on the fixed vertical member 6.

[0095] Specifically, the fixed vertical member 6 can be a vertically temporary support short column constructed by casting, or directly utilize the original structural column in the central island structure. After the fixed vertical member 6 is determined, a positioning corbel body 31 of the positioning corbel 3 is cast at the connection node between the fixed vertical member 6 and the floor slab, and a buried part 34 is set when casting the positioning corbel body 31. The fixed end of the rotating end 32 is fixed on the buried part 34, and a rotating flange 33 is installed at the rotating end of the rotating end 32.

[0096] When the rotating end of the rotating end 32 rotates relative to the fixed end, it can drive the rotating flange 33 to rotate synchronously, thus facilitating the installation and adjustment of the positioning steel-concrete support section 1.

[0097] Please refer to the appendix Figure 6 , Step 2: Erect a temporary support bracket 11 at the installation position on the lower side of the inclined replacement support system. The positioning steel-concrete support section 1 is hoisted onto the temporary support bracket 11 through a hoisting device 10 via a lifting lug plate 9.

[0098] Specifically, after the positioning steel-concrete support section 1 is hoisted onto the temporary support bracket 11, the horizontal height position of the lower end of the positioning steel-concrete support section 1 is kept consistent with the horizontal height position of the rotating end 32 of the positioning corbel 3, facilitating the butt joint between the positioning steel-concrete support section 1 and the positioning corbel 3.

[0099] Preferably, a limiting member 12 is installed on the temporary support bracket 11, and the lower end of the positioning steel-concrete support section 1 abuts against the L-shaped limiting member 12 and can rotate relative to the limiting member 12.

[0100] Please refer to the appendix Figure 7 , Step 3: Set up a jacking mechanism 13 below the lower end of the positioning steel-concrete support section 1. The positioning steel-concrete support section 1 is jacked up to the designed angle of the inclined replacement support system through the jacking mechanism 13, and the connecting flange 7 at the lower end of the positioning steel-concrete support section 1 is connected to the rotating flange 33 of the positioning corbel 3 through a connecting member.

[0101] Please refer to the appendix Figure 3 , The jacking mechanism 13 includes a jack 131, a flexible head 132, and a steel support jacking head 133. The lower end of the steel support jacking head 133 is rotatably installed on the jacking end of the jack 131 through the flexible head 132. A supporting concave part 134 coated with a polytetrafluoroethylene layer is formed at the upper end of the steel support jacking head 133. The supporting concave part 134 matches and supports the lower part of the lower end of the positioning steel-concrete support section 1, enabling the positioning steel-concrete support section 1 to be jacked up and rotationally adjusted to the designed angle of the inclined replacement support system through the jack 131 and the flexible head 132.

[0102] Preferably, the jack 131 can adopt a hydraulic jack in the prior art to provide a jacking driving force by hydraulic pressure, jack up the positioning steel-concrete support section 1, and adjust it to the designed angle. The flexible head 132 can adopt a ball shaft in the prior art. Its fixed end is installed on the jacking end of the jack 131, and its rotating end can rotate relative to the jacking end of the jack 131, so as to adapt to the angle change of the positioning steel-concrete support section 1.

[0103] The steel support jacking head 133 is supported by the supporting concave part 134. The arc-shaped concave supporting concave part 134 can better fit the surface of the positioning steel-concrete support section 1 to ensure the supporting stability.

[0104] Preferably, when jacking up and rotating to adjust the positioning steel-concrete support section 1, a laser theodolite can be used in cooperation with a receiving target to assist in the measurement construction to ensure the consistency between the installation angle and the designed angle of the positioning steel-concrete support section 1.

[0105] During the process of jacking up and rotating to adjust the positioning steel-concrete support section 1, the bottom of the lower side end of the positioning steel-concrete support section 1 abuts against the limiting member 12 of the L-shaped structure, which can prevent the positioning steel-concrete support section 1 from sliding and deviating or falling, and enable the positioning steel-concrete support section 1 to rotate and adjust in the vertical plane with the limiting member 12 as the center.

[0106] The supplementary support bracket 14 is installed on the top of the temporary support bracket 11, so that the supplementary support bracket 14 supports the bottom of the obliquely installed positioning steel-concrete support section 1.

[0107] The positioning steel-concrete support section 1 is positioned and supported by the supplementary support bracket 14, so that the positioning steel-concrete support section 1 remains stable at the designed angle, which is convenient for subsequent construction.

[0108] Please refer to the appendix Figure 8 , Step 4: Set up the temporary support bracket 11 at the upper side installation position of the inclined replacement support system, and hoist the main body steel-concrete support section 2 to this temporary support bracket 11 through the hoisting equipment 10 via the lifting ear plate 9.

[0109] After the main body steel-concrete support section 2 is hoisted onto the temporary support bracket 11, the horizontal height position of the main body steel-concrete support section 2 is consistent with the horizontal height position of the upper side end of the obliquely installed positioning steel-concrete support section 1, which is convenient for docking the main body steel-concrete support section 2 with the positioning steel-concrete support section 1.

[0110] Preferably, the limiting member 12 is installed on the temporary support bracket 11, and the lower side end of the main body steel-concrete support section 2 abuts against the limiting member 12 of the L-shaped structure and can rotate relative to the limiting member 12.

[0111] Please refer to the appendix Figure 9, Step 5: Lift the upper side end of the main reinforced concrete support section 2 by the hoisting device 10 to rotate the main reinforced concrete support section 2 to the designed angle of the inclined replacement support system.

[0112] During the rotation of the main reinforced concrete support section 2, the construction can be assisted by measuring with a laser theodolite and a receiving target to ensure the consistency between the installation angle and the designed angle of the main reinforced concrete support section 2.

[0113] During the jacking and rotation adjustment process of the main reinforced concrete support section 2, the bottom of the lower side end of the main reinforced concrete support section 2 abuts against the limiting member 12 of the L-shaped structure, preventing the main reinforced concrete support section 2 from sliding and deviating or falling, so that the main reinforced concrete support section 2 rotates and adjusts in the vertical plane with the limiting member 12 as the center.

[0114] Please refer to the appendix Figure 10 , Step 6: Install the supplementary support bracket 14 on the temporary support bracket 11 below the main reinforced concrete support section 2, so that the supplementary support bracket 14 supports the bottom of the main reinforced concrete support section 2 installed obliquely, and connect the lower side end of the main reinforced concrete support section 2 to the upper side end of the positioning reinforced concrete support section 1 through the connecting flange 7 and the connecting piece.

[0115] Please refer to the appendix Figure 11 , Step 7: Determine whether it is necessary to finely adjust the angle of the adjustable precast reinforced concrete replacement support; if so, install the jacking mechanism 13 below the lower side end of the main reinforced concrete support section 2, and jack and rotate the adjustable precast reinforced concrete replacement support through the jacking mechanism 13 to rotate the adjustable precast reinforced concrete replacement support to the designed angle of the inclined replacement support system; if not, go to Step 8.

[0116] The adjustable precast reinforced concrete replacement support is propped up by the jacking mechanism 13, so that the adjustable precast reinforced concrete replacement support rotates around the rotating end 32, realizing the fine adjustment of the angle of the adjustable precast reinforced concrete replacement support, ensuring that the installation angle of the adjustable precast reinforced concrete replacement support meets the design requirements, and solving the problem of inconvenient angle adjustment of the inclined replacement support system in the prior art.

[0117] Please refer to the appendix Figure 12 , Step 8: Pour the upper structure 5 integrally, and synchronously construct the post-cast concrete corbel 4 and the main concrete corbel 51 on the upper structure 5, and connect the upper side end of the main reinforced concrete support section 2 to the post-cast concrete corbel 4; after the upper structure 5 is poured and reaches the required strength grade, remove the temporary support bracket 11 and the supplementary support bracket 14 to complete the installation of the inclined replacement support system.

[0118] Specifically, the post-cast corbel body 41 of the post-cast concrete corbel 4 is poured synchronously with the upper structure 5, and a number of post-embedded connecting bars 42 are embedded during the pouring of the post-cast corbel body 41, and the post-embedded connecting bars 42 in the post-cast corbel body 41 are connected to the support section connecting bars 21 in the upper side end of the main reinforced concrete support section 2 through the sleeve 8.

[0119] The main concrete corbel 51 is located at the top of the upper floor system and is used to connect with the horizontal force support transferred from the outside of the central island structure to form an effective force transmission system.

[0120] Please refer to the appendix Figure 13 , Step 9: After the construction of the bottom slab corresponding to the soil-retaining area of the slope is completed and the overall structure forms an effective force transmission system, remove the inclined replacement support system.

[0121] The removal steps of the said inclined replacement support system include:

[0122] Please refer to the appendix Figure 14 , Step 9.1: Synchronously embed lifting hooks 52 during the casting of the upper structure 5; erect a temporary support bracket 11 and a supplementary support bracket 14 under the inclined replacement support system so that the temporary support bracket 11 and the supplementary support bracket 14 support and position the steel-concrete support section 1 and the main body steel-concrete support section 2, release the connection between the upper side end of the main body steel-concrete support section 2 and the post-cast concrete corbel 4, and chisel off the post-cast corbel body 41 of the post-cast concrete corbel 4.

[0123] Please refer to the appendix Figure 15 , Step 9.2: Release the connection between the connection flange 7 at the upper side end of the positioning steel-concrete support section 1 and the connection flange 7 at the lower side end of the main body steel-concrete support section 2, and release the connection between the connection flange 7 at the lower side end of the positioning steel-concrete support section 1 and the rotating flange 33 of the positioning concrete corbel 3.

[0124] At this time, the weights of the positioning steel-concrete support section 1 and the main body steel-concrete support section 2 are borne by the temporary support bracket 11 and the supplementary support bracket 14.

[0125] Please refer to the appendix Figure 15 , Step 9.3: Install a lifting mechanism 15 on the lifting hook 52, and sequentially lift the positioning steel-concrete support section 1 and the main body steel-concrete support section 2 to other areas (such as the placement area, etc.) through the lifting mechanism 15, which is convenient for the turnover use or storage of the positioning steel-concrete support section 1 and the main body steel-concrete support section 2.

[0126] Please refer to the appendix Figure 16 , Step 9.4: Remove the temporary support bracket 11 and the supplementary support bracket 14 installed in Step 9.1, and remove the lifting mechanism 15 and the lifting hook 52, and chisel off the positioning concrete corbel 3; if the fixed vertical member 6 is a vertical temporary support short column, synchronously chisel off the vertical temporary support short column.

[0127] Embodiment 2: A construction method of an adjustable precast steel-concrete replacement support system for an extra-large central island foundation pit. This construction method is used in the working condition where the upper structure 5 has been cast. This construction method includes the following steps:

[0128] Step 1: Before pouring the upper structure 5, hoist the positioning steel-concrete support section 1 and the main body steel-concrete support section 2 into the central island structure by the hoisting equipment 10.

[0129] Preferably, a placement area can be reserved on the floor slab within the central island structure and a temporary support bracket 11 can be erected for placing the positioning steel-concrete support section 1 and the main body steel-concrete support section 2. During installation, the positioning steel-concrete support section 1 and the main body steel-concrete support section 2 are then transported to the installation area of the inclined replacement support system by a forklift.

[0130] Step 2: When pouring the upper structure 5, simultaneously pour the main body concrete corbel 51 and embed a lifting hook 52.

[0131] The main body concrete corbel 51 is located at the top of the upper floor slab system and is used to connect with the horizontal force transfer support on the outside of the central island structure to form an effective force transfer system.

[0132] Step 3: Determine the fixed vertical member 6 according to the design requirements and construct the positioning concrete corbel 3 on the fixed vertical member 6.

[0133] Specifically, the fixed vertical member 6 can adopt a vertically temporary support short column constructed by pouring, or directly use the original structural column in the central island structure. After determining the fixed vertical member 6, pour the positioning corbel body 31 of the positioning concrete corbel 3 at the connection node between the fixed vertical member 6 and the floor slab, and set an embedded part 34 when pouring the positioning corbel body 31. Fix the fixed end of the rotating end 32 to the embedded part 34, and install a rotating flange 33 at the rotating end of the rotating end 32.

[0134] When the rotating end of the rotating end 32 rotates relative to the fixed end, it can drive the rotating flange 33 to rotate synchronously, thus facilitating the installation adjustment of the positioning steel-concrete support section 1.

[0135] Step 4: Install a hoisting mechanism 15 on the lifting hook 52; erect a temporary support bracket 11 at the installation position on the lower side of the inclined replacement support system, and hoist the positioning steel-concrete support section 1 onto the temporary support bracket 11 through the hoisting mechanism 15 via the lifting lug plate 9.

[0136] Specifically, after the positioning steel-concrete support section 1 is hoisted onto the temporary support bracket 11, the horizontal height position of the lower end of the positioning steel-concrete support section 1 is kept consistent with the horizontal height position of the rotating end 32 of the positioning concrete corbel 3, which is convenient for the docking of the positioning steel-concrete support section 1 and the positioning concrete corbel 3.

[0137] Preferably, a limiting member 12 is installed on the temporary support bracket 11, and the lower end of the positioning steel-concrete support section 1 abuts against the limiting member 12 of the L-shaped structure and can rotate relative to the limiting member 12.

[0138] Step 5: Install a jacking mechanism 13 below the lower end of the positioned reinforced concrete support section 1. Use the jacking mechanism 13 to jack up the positioned reinforced concrete support section 1 to the designed angle of the inclined replacement support system, and connect the connecting flange 7 at the lower end of the positioned reinforced concrete support section 1 to the rotating flange 33 of the positioned concrete corbel 3 through a connecting member.

[0139] The jacking mechanism 13 includes a jack 131, a swivel head 132, and a steel support jacking head 133. The lower end of the steel support jacking head 133 is rotatably installed on the jacking end of the jack 131 through the swivel head 132. The upper end of the steel support jacking head 133 is formed with a supporting recess 134 coated with a polytetrafluoroethylene layer. The supporting recess 134 matches and supports the lower part of the lower end of the positioned reinforced concrete support section 1, so that the positioned reinforced concrete support section 1 is jacked up and rotationally adjusted to the designed angle of the inclined replacement support system through the jack 131 and the swivel head 132.

[0140] Preferably, when jacking up and rotationally adjusting the positioned reinforced concrete support section 1, a laser theodolite can be used to assist in the measurement during construction to ensure the angle accuracy of the positioned reinforced concrete support section 1.

[0141] During the jacking up and rotationally adjusting process of the positioned reinforced concrete support section 1, the bottom of the lower end of the positioned reinforced concrete support section 1 abuts against the limiting member 12 of the L-shaped structure, which can prevent the positioned reinforced concrete support section 1 from sliding and deviating or falling, and enables the positioned reinforced concrete support section 1 to rotate and adjust in the vertical plane with the limiting member 12 as the center.

[0142] An additional support bracket 14 is installed on the top of the temporary support bracket 11, so that the additional support bracket 14 supports the bottom of the positioned reinforced concrete support section 1 after the inclined installation is completed.

[0143] Step 6: Erect a temporary support bracket 11 at the upper side installation position of the inclined replacement support system. Use the hoisting mechanism 15 to hoist the main reinforced concrete support section 2 to the temporary support bracket 11 through the lifting lugs 9.

[0144] After the main reinforced concrete support section 2 is hoisted to the temporary support bracket 11, the horizontal height position of the main reinforced concrete support section 2 is the same as the horizontal height position of the upper end of the positioned reinforced concrete support section 1 after the inclined installation, which is convenient for the docking of the main reinforced concrete support section 2 and the positioned reinforced concrete support section 1.

[0145] Preferably, a limiting member 12 is installed on the temporary support bracket 11, and the lower end of the main reinforced concrete support section 2 abuts against the limiting member 12 of the L-shaped structure and can rotate relative to the limiting member 12.

[0146] Step 7: Lift the upper end of the main reinforced concrete support section 2 through the hoisting mechanism 15 to rotate the main reinforced concrete support section 2 to the designed angle of the inclined replacement support system.

[0147] During the rotation of the main steel-concrete support section 2, a laser theodolite can be used to assist in the measurement during construction to ensure the consistency between the installation angle and the designed angle of the main steel-concrete support section 2.

[0148] During the jacking and rotation adjustment process of the main steel-concrete support section 2, the bottom of the lower side end of the main steel-concrete support section 2 abuts against the limiting member 12 of the L-shaped structure, preventing the main steel-concrete support section 2 from sliding and deviating or falling, enabling the main steel-concrete support section 2 to rotate and adjust in the vertical plane with the limiting member 12 as the center.

[0149] Step 8: Install the supplementary support bracket 14 on the temporary support bracket 11 below the main steel-concrete support section 2, making the supplementary support bracket 14 support the bottom of the obliquely installed main steel-concrete support section 2, and connecting the lower side end of the main steel-concrete support section 2 to the upper side end of the positioning steel-concrete support section 1 through the connecting flange 7 via a connecting member.

[0150] Step 9: Determine whether it is necessary to finely adjust the angle of the adjustable precast steel-concrete replacement support; if so, install the jacking mechanism 13 below the lower side end of the main steel-concrete support section 2, and jack and rotate the adjustable precast steel-concrete replacement support through the jacking mechanism 13 to rotate the adjustable precast steel-concrete replacement support to the designed angle of the inclined replacement support system; if not, execute Step 10.

[0151] The adjustable precast steel-concrete replacement support is jacked by the jacking mechanism 13, enabling the adjustable precast steel-concrete replacement support to rotate around the rotating end 32, realizing the fine adjustment of the angle of the adjustable precast steel-concrete replacement support to ensure that the installation angle of the adjustable precast steel-concrete replacement support meets the design requirements, solving the problem of inconvenient angle adjustment in the existing inclined replacement support system.

[0152] Step 10: Pour the post-cast concrete corbel 4 on the upper structure 5, and connect the upper side end of the main steel-concrete support section 2 to the post-cast concrete corbel 4; after the upper structure 5 is poured and reaches the strength grade requirement, remove the temporary support bracket 11 and the supplementary support bracket 14 to complete the installation of the inclined replacement support system.

[0153] Specifically, the post-cast corbel body 41 of the post-cast concrete corbel 4 is poured on the upper structure 5, and embedded parts 34 are set during the pouring of the post-cast corbel body 41. The upper side end of the main steel-concrete support section 2 is connected to the embedded parts 34 through the connecting flange 7 via a connecting member.

[0154] Step 11: After the construction of the floor corresponding to the slope soil-retaining area is completed and the overall structure forms an effective force transfer system, remove the inclined replacement support system.

[0155] The removal steps of the described inclined replacement support system include:

[0156] Step 11.1: Erect a temporary support bracket 11 below the diagonal bracing system, so that the temporary support bracket 11 supports and locates the steel-concrete support section 1 and the main steel-concrete support section 2, release the connection between the upper end of the main steel-concrete support section 2 and the post-cast concrete corbel 4, and chisel off the post-cast corbel body 41 of the post-cast concrete corbel 4.

[0157] Step 11.2: Release the connection between the connecting flange 7 at the upper end of the positioning steel-concrete support section 1 and the connecting flange 7 at the lower end of the main steel-concrete support section 2, and release the connection between the connecting flange 7 at the lower end of the positioning steel-concrete support section 1 and the rotating flange 33 of the positioning concrete corbel 3.

[0158] At this time, the weights of the positioning steel-concrete support section 1 and the main steel-concrete support section 2 are borne by the temporary support bracket 11 and the supplementary support bracket 14.

[0159] Step 11.3: Use the hoisting mechanism 15 to hoist the positioning steel-concrete support section 1 and the main steel-concrete support section 2 to other areas (such as the placement area, etc.) in sequence, so as to facilitate the turnover use or storage of the positioning steel-concrete support section 1 and the main steel-concrete support section 2.

[0160] Step 11.4: Demolish the temporary support bracket 11 installed in Step 11.1, and demolish the hoisting mechanism 15 and the hook 52, and chisel off the positioning concrete corbel 3; if the fixed vertical member 6 is a vertical temporary support short column, synchronously chisel off the vertical temporary support short column.

[0161] The above description is only a description of the preferred embodiments of the present invention, and does not limit the scope of the present invention in any way. Any changes and modifications made by those of ordinary skill in the art of the present invention according to the above disclosure shall fall within the scope of protection of the claims.

Claims

1. An adjustable prefabricated steel-concrete replacement support system for a super-large central island foundation pit, characterized in that: include: A positioning steel-concrete support section (1), a main steel-concrete support section (2), a positioning concrete corbel (3), a post-cast concrete corbel (4) and a jacking and lifting system; the positioning concrete corbel (3) is located at the lower side of the oblique replacement support system and cast on a fixed vertical member (6), and the post-cast concrete corbel (4) is cast on an upper structure (5); the lower side end of the main steel-concrete support section (2) is coaxially fixedly connected with the upper side end of the positioning steel-concrete support section (1) to form an adjustable prefabricated steel-concrete replacement support; the lower side end of the positioning steel-concrete support section (1) is adjustably connected to the positioning concrete corbel (3) through the jacking and lifting system, and the upper side end of the main steel-concrete support section (2) is adjustably connected to the post-cast concrete corbel (4) through the jacking and lifting system to form an oblique replacement support system.

2. The adjustable prefabricated steel-concrete exchange support system for a super-large central island foundation pit according to claim 1, characterized in that: The positioning concrete corbel (3) comprises a positioning corbel body (31), a rotating end head (32) and a rotating flange (33); the positioning corbel body (31) is cast on a fixed vertical member (6), the fixed end of the rotating end head (32) is fixedly mounted on the positioning corbel body (31), and the rotating end of the rotating end head (32) is mounted with a rotating flange (33); both ends of the positioning steel-concrete support section (1) are mounted with connecting flanges (7), the lower side end of the positioning steel-concrete support section (1) is coaxially fixedly connected with the rotating flange (33) through the connecting flange (7), so that the positioning steel-concrete support section (1) can be rotatably mounted in the installation area of ​​the oblique support replacement system through the rotating end head (32) through the jacking lifting system.

3. The adjustable prefabricated steel-concrete exchange support system for a super-large central island foundation pit according to claim 1, characterized in that: The lower side end of the main steel-concrete support section (2) is installed with a connecting flange (7), and the lower side end of the main steel-concrete support section (2) is coaxially fixedly connected with the upper side end of the positioning steel-concrete support section (1) through the connecting flange (7) through the jacking and lifting system to form an adjustable prefabricated steel-concrete replacement support.

4. The adjustable prefabricated steel-concrete exchange support system for a super-large central island foundation pit according to claim 1, characterized in that: The post-cast concrete corbel (4) comprises a post-cast corbel body (41) and post-placed connecting bars (42); the post-cast corbel body (41) is cast on the upper structure (5), and a plurality of post-placed connecting bars (42) are pre-buried in the post-cast corbel body (41); a plurality of support segment connecting bars (21) are embedded in the upper side end of the main steel-concrete support segment (2), and the plurality of post-placed connecting bars (42) correspond to the plurality of support segment connecting bars (21) one by one and are engaged and connected through a sleeve (8).

5. The adjustable prefabricated steel-concrete exchange support system for a super-large central island foundation pit according to claim 1, characterized in that: The post-cast concrete corbel (4) comprises a post-cast concrete corbel body (41) and a connecting flange (7); the post-cast concrete corbel body (41) is cast on the upper structure (5), and the connecting flange (7) is installed on the post-cast concrete corbel body (41); the upper side end of the main steel-concrete supporting section (2) is provided with a connecting flange (7), and the upper side end of the main steel-concrete supporting section (2) is fixedly connected to the post-cast concrete corbel body (41) through the connecting flange (7).

6. The adjustable prefabricated steel-concrete exchange support system for super-large central island foundation pit according to claim 1, characterized in that: The positioning steel-concrete support section (1) and the main steel-concrete support section (2) are both provided with lifting lugs (9); the jacking and lifting system comprises a lifting device (10) and a lifting mechanism (15) for lifting the positioning steel-concrete support section (1) and the main steel-concrete support section (2), a lifting mechanism (13) for lifting the positioning steel-concrete support section (1) and the main steel-concrete support section (2), a limiting component (12), a support system and a measuring component.

7. A construction method for an adjustable prefabricated steel-concrete exchange support system for a super-large central island foundation pit as described in any one of claims 1 to 6, characterized in that: The construction method is used in a working condition where the upper structure (5) has not been cast, and the construction method comprises the following steps: Step 1: Determine the fixed vertical member (6) according to the design requirements, and construct and position the concrete bracket (3) on the fixed vertical member (6); Step 2: a temporary support bracket (11) is set up at the lower installation position of the oblique support replacement system, and the positioning steel-concrete support section (1) is hoisted onto the temporary support bracket (11) via the hoisting lug plate (9) using the hoisting equipment (10); Step 3: a lifting mechanism (13) is arranged below the lower side end of the positioning steel-concrete support section (1), the positioning steel-concrete support section (1) is lifted to the design angle of the oblique support replacement system by the lifting mechanism (13), and the connection flange (7) at the lower side end of the positioning steel-concrete support section (1) is connected to the rotating flange (33) of the positioning concrete bracket (3); A supplementary support bracket (14) is installed on the top of the temporary support bracket (11), so that the supplementary support bracket (14) is supported on the bottom of the obliquely installed positioning steel-concrete support section (1); Step 4: erecting a temporary support bracket (11) at the upper installation position of the oblique support replacement system, and hoisting the main steel-concrete support section (2) onto the temporary support bracket (11) via the hoisting lugs (9) using a hoisting device (10); Step 5: lifting the upper side end of the main steel-concrete support section (2) by means of a lifting device (10) so as to rotate the main steel-concrete support section (2) to the design angle of the oblique support replacement system; Step 6: Install the supplementary support bracket (14) on the temporary support bracket (11) below the main steel-concrete support section (2), so that the supplementary support bracket (14) is supported on the bottom of the main steel-concrete support section (2) that has been installed obliquely, and connect the lower side end of the main steel-concrete support section (2) to the upper side end of the positioning steel-concrete support section (1) through the connecting flange (7); Step 7: Determine whether it is necessary to fine-tune the angle of the adjustable prefabricated steel-concrete exchange support; if so, install a jacking mechanism (13) below the lower side end of the main steel-concrete support section (2), and use the jacking mechanism (13) to jack up and rotate the adjustable prefabricated steel-concrete exchange support to rotate the adjustable prefabricated steel-concrete exchange support to the design angle of the oblique exchange support system; if not, execute step 8; Step 8: integrally cast the upper structure (5), and simultaneously construct the post-cast concrete corbel (4) and the main concrete corbel (51) on the upper structure (5), and connect the upper side end of the main steel-concrete support section (2) to the post-cast concrete corbel (4); after the upper structure (5) is cast and reaches the strength grade requirement, remove the temporary support bracket (11) and the additional support bracket (14), and complete the installation of the oblique replacement support system; Step 9: After the base plate construction corresponding to the slope soil retention area is completed and the overall structure forms an effective force transmission system, remove the oblique support replacement system.

8. The construction method according to claim 7, characterized in that: The dismantling steps of the oblique support replacement system include: Step 9.1: When the upper structure (5) is cast, a hook (52) is embedded synchronously; a temporary support bracket (11) and an additional support bracket (14) are set up below the oblique support replacement system, so that the temporary support bracket (11) and the additional support bracket (14) support and position the steel-concrete support section (1) and the main steel-concrete support section (2), release the connection between the upper side end of the main steel-concrete support section (2) and the post-cast concrete corbel (4), and chisel out the post-cast concrete corbel body (41) of the post-cast concrete corbel (4); Step 9.2: Release the connection between the connection flange (7) at the upper end of the positioning steel-concrete support section (1) and the connection flange (7) at the lower end of the main steel-concrete support section (2), and release the connection between the connection flange (7) at the lower end of the positioning steel-concrete support section (1) and the rotation flange (33) of the positioning concrete bracket (3); Step 9.3: Install a lifting mechanism (15) on the lifting hook (52), and use the lifting mechanism (15) to lift the positioning steel-concrete support section (1) and the main steel-concrete support section (2) to other areas in sequence; Step 9.4: Remove the temporary support bracket (11) and the additional support bracket (14) installed in step 9.1, remove the lifting mechanism (15) and the hook (52), and chisel out the positioning concrete corbel (3); if the fixed vertical member (6) is a vertical temporary support short column, chisel out the vertical temporary support short column simultaneously.

9. A construction method for an adjustable prefabricated steel-concrete exchange support system for a super-large central island foundation pit as described in any one of claims 1 to 6, characterized in that: The construction method is used in a working condition where the upper structure (5) has been cast, and the construction method comprises the following steps: Step 1: Before the upper structure (5) is poured, the positioning steel-concrete support section (1) and the main steel-concrete support section (2) are hoisted into the central island structure by a hoisting device (10); Step 2: When pouring the upper structure (5), the main concrete corbel (51) is poured synchronously, and the hook (52) is embedded in advance; Step 3: Determine the fixed vertical member (6) according to the design requirements, and construct the positioning concrete bracket (3) on the fixed vertical member (6); Step 4: Install a lifting mechanism (15) on the lifting hook (52); set up a temporary support bracket (11) at the lower installation position of the oblique support replacement system, and use the lifting mechanism (15) to lift the positioning steel-concrete support section (1) onto the temporary support bracket (11) via the lifting ear plate (9); Step 5: a lifting mechanism (13) is arranged below the lower side end of the positioning steel-concrete support section (1), the positioning steel-concrete support section (1) is lifted to the design angle of the oblique support replacement system by the lifting mechanism (13), and the connection flange (7) at the lower side end of the positioning steel-concrete support section (1) is connected to the rotating flange (33) of the positioning concrete bracket (3); A supplementary support bracket (14) is installed on the top of the temporary support bracket (11), so that the supplementary support bracket (14) is supported on the bottom of the obliquely installed positioning steel-concrete support section (1); Step 6: erecting a temporary support bracket (11) at the upper installation position of the oblique support replacement system, and hoisting the main steel-concrete support section (2) onto the temporary support bracket (11) via the hoisting lug plate (9) using the hoisting mechanism (15); Step 7: lifting the upper side end of the main steel-concrete support section (2) by means of the lifting mechanism (15) so that the main steel-concrete support section (2) is rotated to the design angle of the oblique support replacement system; Step 8: Install the supplementary support bracket (14) on the temporary support bracket (11) below the main steel-concrete support section (2), so that the supplementary support bracket (14) is supported on the bottom of the main steel-concrete support section (2) that has been installed obliquely, and connect the lower side end of the main steel-concrete support section (2) to the upper side end of the positioning steel-concrete support section (1) through the connecting flange (7) via the connecting piece; Step 9: Determine whether it is necessary to fine-tune the angle of the adjustable prefabricated steel-concrete exchange support; if so, install a jacking mechanism (13) below the lower side end of the main steel-concrete support section (2), and use the jacking mechanism (13) to jack up and rotate the adjustable prefabricated steel-concrete exchange support to rotate the adjustable prefabricated steel-concrete exchange support to the design angle of the oblique exchange support system; if not, execute step 10; Step 10: Cast and construct a post-cast concrete corbel (4) on the upper structure (5), and connect the upper side end of the main steel-concrete support section (2) to the post-cast concrete corbel (4); after the upper structure (5) is cast and reaches the strength grade requirement, remove the temporary support bracket (11) and the additional support bracket (14), and complete the installation of the oblique replacement support system; Step 11: After the base plate construction corresponding to the slope soil retention area is completed and the overall structure forms an effective force transmission system, remove the oblique support replacement system.

10. The construction method according to claim 9, characterized in that: The dismantling steps of the oblique support replacement system include: Step 11.1: A temporary support bracket (11) is set up below the oblique support replacement system, so that the temporary support bracket (11) supports and positions the steel-concrete support section (1) and the main steel-concrete support section (2), disconnects the upper side end of the main steel-concrete support section (2) from the post-cast concrete corbel (4), and chisels out the post-cast concrete corbel body (41) of the post-cast concrete corbel (4); Step 11.2: Release the connection between the connection flange (7) at the upper end of the positioning steel-concrete support section (1) and the connection flange (7) at the lower end of the main steel-concrete support section (2), and release the connection between the connection flange (7) at the lower end of the positioning steel-concrete support section (1) and the rotation flange (33) of the positioning concrete bracket (3); Step 11.3: The positioning steel-concrete support section (1) and the main steel-concrete support section (2) are sequentially lifted to other areas by the lifting mechanism (15); Step 11.4: Remove the temporary support bracket (11) installed in step 11.1, remove the lifting mechanism (15) and the hook (52), and chisel out the positioning concrete corbel (3); if the fixed vertical member (6) is a vertical temporary support short column, chisel out the vertical temporary support short column simultaneously.

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