A construction method for adding an elevator shaft to a brick-concrete cast-in-place building

Abstract

This invention provides a construction method for reinforcing existing brick-concrete cast-in-place buildings by adding elevator shafts. The method includes: carrying out construction; pre-embedding components in the side walls; installing the columns of this floor and connecting them to the columns of the upper and lower floors; installing beams and fixing subsequent steel plates to the original structural beams; fixing the beams to the subsequent steel plates and injecting structural adhesive into the gaps between the beams and the original floor slab; and cutting the floor slab into sections. The pre-embedded components provide a reliable lower anchoring foundation for the steel structural columns; the columns are connected through the floor slabs using through bolts, forming a vertically continuous load-bearing system between the upper-level columns, the floor slab, and the lower-level columns. Layered installation can be performed without waiting for foundation curing, avoiding safety hazards such as instantaneous structural imbalance, wall cracking, and floor slab deformation caused by cutting the floor slabs before installation; and cutting and hoisting the floor slabs into sections reduces impact disturbance to the original structure and eliminates the risk of falling objects from heights.

Description

Technical Field

[0001] This invention relates to the field of building construction technology, and more specifically, to a method for reinforcing and upgrading existing brick-concrete cast-in-place buildings by adding elevator shafts. Background Technology

[0002] With the advancement of policies on the renovation and upgrading of existing buildings and the installation of elevators in old residential communities in my country, a large number of multi-story residential buildings with brick-concrete structures and cast-in-place slabs urgently need to add elevators to improve the quality of life. These buildings were built relatively early, and their structural form is mainly based on sintered brick load-bearing and cast-in-place concrete slabs. The slabs are relatively thin, and the overall rigidity and load-bearing capacity are limited, which presents many technical challenges when adding elevator shafts.

[0003] Traditional elevator installation methods often involve cutting the floor slabs first and then installing the structure, which can easily cause instantaneous stress imbalance in the original structure, leading to safety hazards such as wall cracks and floor slab deformation. The connection between the steel structure columns and the original structure often uses post-installed anchor plates or simple welding, resulting in insufficient reliability at the joints and poor overall structural coordination, making it difficult to ensure that the steel structure shaft and the original building form a unified structural system. In terms of construction procedures, traditional methods require waiting for the foundation to cure before installing the steel structure layer by layer, leading to long construction periods and significant disruption to residents. Furthermore, the lack of integrated processes for foundation pit waterproofing, shaft sidewall reinforcement, static cutting, and hoisting increases the risk of leaks, loose connections, and high construction safety risks. Floor slab cutting often involves impact crushing or large-scale demolition, causing significant disturbance to the original structure, and the rudimentary hoisting methods pose a risk of falling objects from heights.

[0004] Currently, there is a lack of a complete set of construction technologies for the retrofitting of elevators into brick-concrete cast-in-place buildings that minimizes damage to the original structure, ensures reliable connections, is highly efficient, and is safe and controllable. Summary of the Invention

[0005] In view of this, the present invention proposes a construction method for the renovation and reinforcement of existing brick-concrete cast-in-place buildings by adding elevator shafts, aiming to solve the problems in the prior art, such as structural imbalance, poor reliability of steel structure connection nodes, long construction period, large disturbance to the original structure, and safety hazards caused by cutting before installation.

[0006] This invention proposes a construction method for the renovation and reinforcement of existing brick-concrete cast-in-place buildings by adding elevator shafts. The method includes the following steps: Construction and pre-embedding steps: constructing the foundation and side walls, and pre-embedding components for column anchoring in the side walls; Column installation steps: installing the columns of this floor at the original structural floor slab positioning points, and connecting the columns of this floor to the lower or upper floor columns using through bolts to form a vertically continuous load-bearing system; Beam installation steps: installing beams on the columns to connect the four corner columns into an integral frame load-bearing system, fixing the rear steel plate to the original structural beams using chemical anchors, and fixing the beams to the rear steel plates to form an integral load-bearing structure between the columns of this floor and the original structural beams, and injecting structural adhesive into the gap between the beams and the original floor slab; Cutting and hoisting steps: using static cutting equipment to cut the floor slab into sections and hoisting the sections.

[0007] Furthermore, the above-mentioned construction method for the renovation and reinforcement of elevator shafts in existing brick-concrete cast-in-place buildings includes the following sub-steps in the construction and pre-embedding steps: excavation of the foundation pit, excavation of the foundation pit, construction of a brick formwork around the perimeter, and laying of waterproof membrane on the inner side; concrete pouring, binding of reinforcing bars and pouring of concrete; and pre-embedded component construction, construction of the zero-level side wall, binding of reinforcing bars and setting of hooks at the construction location of the side wall, construction to the preset underground height, and pre-embedding of steel plates at the four corners.

[0008] Furthermore, in the above-mentioned construction method for modifying and reinforcing existing brick-concrete cast-in-place buildings by adding elevator shafts, the preset height is 0.5m.

[0009] Furthermore, the above-mentioned construction method for the renovation and reinforcement of existing brick-concrete cast-in-place buildings by adding elevator shafts includes the following specific steps for cutting and hoisting: pre-dividing the blocks into sizes, drilling holes on the floor of each block, using gantry cranes, hand-operated hoists, and wire ropes to unload the blocks to the lower floor, and then clearing them away.

[0010] Furthermore, the above-mentioned construction method for the renovation and reinforcement of elevator shafts in existing brick-concrete cast-in-place buildings includes the following steps before the construction and pre-embedding steps: pre-preparation steps, measuring and setting out lines, determining the column positioning points and floor slab cutting boundaries, and removing the decorative layer of the columns, beams, and post-installed steel plate installation areas down to the original structural base layer.

[0011] Furthermore, the above-mentioned construction method for the renovation and reinforcement of existing brick-concrete cast-in-place buildings by adding elevator shafts includes the following steps after the beam installation step and before the cutting and hoisting step: a static wall removal step, in which the wall in the renovation area is removed in sections.

[0012] Furthermore, the above-mentioned construction method for the renovation and reinforcement of existing brick-concrete cast-in-place buildings by adding elevator shafts also includes the following steps after the cutting and hoisting steps: hook construction steps, construction of column and beam joints, and addition of several hooks at designated locations.

[0013] Furthermore, in the above-mentioned construction method for the renovation and reinforcement of elevator shafts in existing brick-concrete cast-in-place buildings, in the column installation step, through bolts are used to connect the upper and lower columns; in the beam installation step, bolts are used to connect the columns and the beams.

[0014] Furthermore, in the above-mentioned construction method for the renovation and reinforcement of elevator shafts in existing brick-concrete cast-in-place buildings, the chemical anchor is an inverted conical chemical anchor, and the rear steel plate is a pre-made steel plate component; the fixing of the crossbeam and the rear steel plate specifically involves welding the crossbeam and the rear steel plate together, especially using fillet welds for circumferential welding.

[0015] Furthermore, in the above-mentioned construction method for renovating and reinforcing existing brick-concrete cast-in-place buildings by adding elevator shafts, both the columns and the beams are H-beams.

[0016] This invention provides a method for reinforcing existing brick-concrete cast-in-place buildings by adding elevator shafts. This method involves pre-embedding column anchoring components during foundation and sidewall construction to provide a reliable lower anchoring foundation for the steel structure columns. Through-bolts are used to connect the columns through the floor slab, creating a vertically continuous load-bearing system between the upper and lower columns. This allows for layered installation without waiting for foundation curing, avoiding the safety hazards of instantaneous structural imbalance, wall cracking, and floor deformation caused by cutting the floor slab before installation. The method uses chemical anchors to fix the steel plates in the post-installed beam connection step, combined with circumferential welding and pressure injection of structural adhesive, forming a reliable steel-concrete synergistic load-bearing node, significantly improving connection strength and overall stability. Static cutting equipment is used to cut the floor slabs into sections, and a portal hoist is used for stable lifting, greatly reducing impact and disturbance to the original structure and eliminating the risk of falling objects from heights. Therefore, this method effectively solves the technical problems in the prior art, such as the imbalance of the original structure due to cutting before installation, poor reliability of steel structure connection nodes, long construction period, large disturbance to the original structure, and potential safety hazards. Attached Figure Description

[0017] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A flowchart illustrating the construction method for retrofitting and reinforcing existing brick-concrete cast-in-place buildings by adding elevator shafts, as provided in an embodiment of the present invention. Figure 2 Another flowchart of the construction method for adding elevator shafts to existing brick-concrete cast-in-place buildings, provided in the embodiments of the present invention; Figure 3Another flowchart of the construction method for adding elevator shafts to existing brick-concrete cast-in-place buildings, provided in the embodiments of the present invention; Figure 4 Another flowchart of the construction method for adding elevator shafts to existing brick-concrete cast-in-place buildings, provided in the embodiments of the present invention; Figure 5 A flowchart illustrating the construction and pre-embedding steps provided in an embodiment of the present invention. Detailed Implementation

[0018] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0019] See Figure 1 This is a flowchart illustrating the construction method for retrofitting and reinforcing elevator shafts in existing brick-concrete cast-in-place buildings, as provided in this embodiment of the invention. As shown, the method includes the following steps: Construction and pre-embedding steps S1: Carry out foundation and side wall construction, and pre-embed pre-embedded parts for column anchoring in the side walls.

[0020] Specifically, the foundation construction includes: excavating the foundation pit, building a brick formwork, laying waterproof membrane, tying double-layer bidirectional steel bars, and pouring impermeable concrete; the side wall construction includes: tying double-layer bidirectional steel bars and setting quincunx-shaped hooks, and constructing to the preset elevation; and pre-embedding steel plates at the four corners of the side wall as anchoring connectors for the columns.

[0021] Step S2 for column installation: Install the four corner columns of this floor at the original structural floor slab positioning location, and connect the columns of this floor to the columns of the lower or upper floors through the floor slab using through bolts to form a vertical continuous force-bearing system.

[0022] Specifically, without waiting for the foundation to be fully completed, the columns for this floor can be installed directly at the original structural floor slab location. These columns can be steel profiles, model HW200×200×8×12 (wide-flange H-beams), with a section height of 200mm, flange width of 200mm, web thickness of 8mm, and flange thickness of 12mm. High-strength through bolts are used to connect the upper and lower floor columns, penetrating the floor slab. Specifically, 4M20 (10.9S) high-strength through bolts are used between the upper and lower floor columns, penetrating the floor slab. This means four high-strength bolts with a nominal diameter of 20mm and a performance grade of 10.9 (tensile strength ≥1000MPa, yield strength ≥900MPa) are used. Through bolts create a continuous vertical load-bearing system connecting the upper columns, the cast-in-place floor slab, and the lower columns, ensuring a clear load transfer path and avoiding the instantaneous instability caused by traditional dismantling-then-reassembly methods.

[0023] Step S3: Install the crossbeam on the column to connect the four corner columns into an overall frame load-bearing system. Use chemical anchors to fix the rear steel plate on the original structural beam. Fix the crossbeam to the rear steel plate so that the column of this floor and the original structural beam form an overall load-bearing structure. Fill the gap between the crossbeam and the original floor with structural adhesive.

[0024] Specifically, after the columns are installed, crossbeams are installed, especially between the columns, to form a load-bearing frame structure. This means the four corner columns are connected by crossbeams to form an overall load-bearing frame system, and smaller crossbeams are added according to elevator requirements to form the elevator shaft. The crossbeams can be steel beams, specifically H-beams, model H194×150×6×9, with a section height of 194mm, flange width of 150mm, web thickness of 6mm, and flange thickness of 9mm. The columns and crossbeams are connected by bolts. In particular, 2M20 (10.9S) high-strength bolts can be used for web connection between the columns and crossbeams. This means the bolts pass through the vertically arranged flange plates and connecting plates of the crossbeams and are fixed to the web or flange plates of the columns. Specifically, two high-strength bolts with a nominal diameter of 20mm and a performance grade of 10.9 (tensile strength ≥1000MPa, yield strength ≥900MPa) are used. To ensure the newly added steel structure elevator shaft forms an integrated load-bearing structure with the original building structure, a crossbeam can be used to connect the elevator shaft frame (i.e., the column on this floor) to the original structural beams, creating a unified load-bearing structure. This connection can be made from the elevator shaft steel structure. Specifically, a rear-mounted steel plate is fixed to the original structural beam using chemical anchors. The rear-mounted steel plate has dimensions of 250mm in length, 300mm in width, and 16mm in thickness. The insertion depth of the chemical anchors must meet product requirements, and a special rebar adhesive is used for anchoring. The fixing of the crossbeam to the rear-mounted steel plate involves welding, particularly using circumferential fillet welds. The fillet weld height is 6mm, ensuring a full and defect-free weld. The chemical anchors are inverted conical chemical anchors, and the rear-mounted steel plate is a pre-fabricated steel plate. After the crossbeam is installed, gaps may remain between the upper surface of the crossbeam and the original floor surface. The gap was filled tightly by pressure injection of structural adhesive. After the structural adhesive cured, it formed a reliable force transmission medium, avoiding loose connections and uneven stress.

[0025] In step S4, the floor slab is cut into sections using static cutting equipment, and the sections are then hoisted and transported.

[0026] Specifically, this includes: pre-dividing the floor into sections, drilling holes in each section, using gantry cranes, hand-operated hoists, and wire ropes to unload the sections to the lower level and remove them from the site. In particular, after the walls have been removed and beams installed, the floor slabs in the renovation area can be demolished. Floor slab demolition uses static cutting equipment such as wire saws and disc saws to cut the slabs into sections. The section dimensions are pre-determined based on hoisting capacity. Holes are drilled in each section of the floor slab as lifting points. A hoisting system composed of gantry cranes, hand-operated hoists, wire ropes, and shackles is used to smoothly lift the cut floor slabs to the lower ground level and remove them from the site promptly to avoid concentrated loads on the floor slabs and prevent overloading of the original floor slabs.

[0027] This construction method adheres to the core principle of "reinforcement before cutting": first, the steel structure columns and beams are installed to form a complete steel frame reinforcement system, and then the floor slabs are statically cut and hoisted. This sequence effectively avoids the safety hazards caused by the traditional method of cutting before installation, such as instantaneous stress imbalance in the original structure, wall cracking, and floor slab deformation. Simultaneously, the columns are connected by through bolts penetrating the floor slab, allowing for layered, continuous operation without waiting for foundation curing, significantly shortening the construction period. The combined connection nodes of chemical anchors, post-installed steel plates, circumferential welding, and pressure grouting ensure coordinated steel-concrete stress, reliable nodes, waterproof durability, and controllable construction safety.

[0028] Therefore, the existing brick-concrete cast-in-place building elevator shaft renovation and reinforcement construction method provided in this embodiment provides a reliable lower anchoring foundation for the steel structure columns by pre-embedding column anchoring components during foundation and side wall construction; the column through bolts are used to connect the upper column, floor, and lower column to form a vertical continuous force system, allowing for layered installation without waiting for foundation curing, and avoiding safety hazards such as instantaneous stress imbalance, wall cracking, and floor deformation caused by cutting the floor slab before installing the structure; the use of chemical anchors to fix the post-installed steel plate in the beam connection step, combined with circumferential welding and pressure injection of structural adhesive, forms a reliable steel-concrete synergistic force-bearing node, significantly improving connection strength and overall stability; the use of static cutting equipment to cut the floor slab into sections and using a portal hoist for stable lifting greatly reduces the impact and disturbance to the original structure and eliminates the risk of falling objects from heights. Therefore, this method effectively solves the technical problems in the prior art, such as the imbalance of the original structure due to cutting before installation, poor reliability of steel structure connection nodes, long construction period, large disturbance to the original structure, and potential safety hazards.

[0029] See Figure 2 This is another flowchart illustrating the construction method for retrofitting and reinforcing elevator shafts in existing brick-concrete cast-in-place buildings, as provided in this invention. As shown in the figure, the method includes the following steps: Preparatory step S5: Measure and lay out the lines to determine the column positioning points and floor slab cutting boundaries, and remove the decorative layer of the columns, beams, and the area where the rear steel plate is installed down to the original structural base.

[0030] Specifically, before construction, based on the required clearance of the elevator shaft, the walls and floors to be demolished on each floor should be positioned and marked. The column positioning points should fall on the original floor slab structure, without occupying the effective dimensions of the elevator shaft. At the same time, the cutting boundaries of the walls and floors should be marked. The decorative layers of the walls and floors in the areas where the columns, beams, and rear-mounted steel plates are installed should be removed until the original structural base layer is exposed, ensuring that the connection surfaces are clean, firm, and free of dust and oil stains.

[0031] Construction and pre-embedding steps S1: Carry out foundation and side wall construction, and pre-embed pre-embedded parts for column anchoring in the side walls.

[0032] Step S2 for column installation: Install the column of this floor at the original structural floor slab positioning location, and connect the column of this floor to the column of the lower or upper floor through the floor slab with through bolts to form a vertical continuous force-bearing system.

[0033] Step S3: Install the crossbeam on the column to connect the four corner columns into an overall frame load-bearing system. Use chemical anchors to fix the rear steel plate on the original structural beam. Fix the crossbeam to the rear steel plate so that the column of this floor and the original structural beam form an overall load-bearing structure. Fill the gap between the crossbeam and the original floor with structural adhesive.

[0034] In step S4, the floor slab is cut into sections using static cutting equipment, and the sections are then hoisted and transported.

[0035] See Figure 3 This is another flowchart illustrating the construction method for retrofitting and reinforcing elevator shafts in existing brick-concrete cast-in-place buildings, as provided in this invention. As shown in the figure, the method includes the following steps: Preparatory step S5: Measure and lay out the lines to determine the column positioning points and floor slab cutting boundaries, and remove the decorative layer of the columns, beams, and the area where the rear steel plate is installed down to the original structural base.

[0036] Construction and pre-embedding steps S1: Carry out foundation and side wall construction, and pre-embed pre-embedded parts for column anchoring in the side walls.

[0037] Step S2 for column installation: Install the column of this floor at the original structural floor slab positioning location, and connect the column of this floor to the column of the lower or upper floor through the floor slab with through bolts to form a vertical continuous force-bearing system.

[0038] Step S3: Install the crossbeam on the column to connect the four corner columns into an overall frame load-bearing system. Use chemical anchors to fix the rear steel plate on the original structural beam. Fix the crossbeam to the rear steel plate so that the column of this floor and the original structural beam form an overall load-bearing structure. Fill the gap between the crossbeam and the original floor with structural adhesive.

[0039] Step S6, static wall removal, involves removing sections of the wall in the renovation area.

[0040] Specifically, when the planar dimensions of the newly added steel structure shaft are insufficient, i.e., the space is insufficient, and it is necessary to occupy the area of ​​the original building's public area, the walls in the area to be modified shall be removed. Static removal tools such as electric picks and cutting saws can be used for segmented construction to avoid causing cracks or loosening of the original load-bearing walls. During the removal process, the main load-bearing components of the original structure, such as beams and columns, must not be damaged.

[0041] In step S4, the floor slab is cut into sections using static cutting equipment, and the sections are then hoisted and transported.

[0042] See Figure 4 This is another flowchart illustrating the construction method for retrofitting and reinforcing elevator shafts in existing brick-concrete cast-in-place buildings, as provided in this invention. As shown in the figure, the method includes the following steps: Preparatory step S5: Measure and lay out the lines to determine the column positioning points and floor slab cutting boundaries, and remove the decorative layer of the columns, beams, and the area where the rear steel plate is installed down to the original structural base.

[0043] Construction and pre-embedding steps S1: Carry out foundation and side wall construction, and pre-embed pre-embedded parts for column anchoring in the side walls.

[0044] Step S2 for column installation: Install the column of this floor at the original structural floor slab positioning location, and connect the column of this floor to the column of the lower or upper floor through the floor slab with through bolts to form a vertical continuous force-bearing system.

[0045] Step S3: Install the crossbeam on the column to connect the four corner columns into an overall frame load-bearing system. Use chemical anchors to fix the rear steel plate on the original structural beam. Fix the crossbeam to the rear steel plate so that the column of this floor and the original structural beam form an overall load-bearing structure. Fill the gap between the crossbeam and the original floor with structural adhesive.

[0046] Step S6, static wall removal, involves removing sections of the wall in the renovation area.

[0047] In step S4, the floor slab is cut into sections using static cutting equipment, and the sections are then hoisted and transported.

[0048] In the hook construction step S7, construct the joint between the column and the beam, and add several hooks at the designated locations.

[0049] Specifically, for the portion of the elevator shaft that needs to extend above the roof, the roof columns and beams are installed using the standard floor steel structure construction method. Two additional beam hooks are added at pre-designed locations. These hooks are made of round steel and welded to the beams to meet the lifting requirements for elevator installation and subsequent maintenance. The pre-designated locations can correspond to the elevator main unit's lifting points. After construction, the bolt torque, weld quality, concrete strength, steel structure verticality, and waterproofing effect are checked. Elevator installation proceeds only after all specifications are met. In particular, the final tightening torque of all high-strength bolts is randomly checked; welds undergo visual inspection and non-destructive testing; the foundation and sidewall concrete undergo strength rebound or test block testing; the verticality deviation of the columns is measured using a theodolite; and a water tightness test is conducted on the foundation pit's waterproofing layer. Elevator installation can only proceed after all tests are passed.

[0050] See Figure 5 This is a flowchart of the construction and pre-embedding steps provided in an embodiment of the present invention. As shown in the figure, the construction and pre-embedding step S1 specifically includes the following sub-steps: Step S11 of the foundation pit excavation: excavate the foundation pit, build a brick formwork around the perimeter, and lay waterproof membrane on the inner side.

[0051] Specifically, the elevator shaft foundation is first excavated to a predetermined depth, such as 450mm, or any other depth. A brick formwork is then constructed around the pit, and a waterproof membrane, which can be SBS modified bitumen waterproof membrane, is laid inside the brick formwork to form a waterproof layer. The overlap width of the waterproof membrane should be no less than 100mm, with an additional layer at corners.

[0052] In concrete pouring sub-step S12, the reinforcing bars are tied and the concrete is poured.

[0053] Specifically, the foundation slab reinforcement is tied using double-layer, bidirectional reinforcement with a spacing of 200mm and a diameter of 12mm. The foundation depth is 450mm. C35P6 impermeable concrete is poured, vibrated to ensure compaction, and cured according to regulations. Vibration rods can be used for compaction, the surface is smoothed and polished, and then covered for moisture retention curing.

[0054] In the pre-embedded part construction sub-step S13, construct the zero-level side wall, tie steel bars and set hooks at the side wall construction location, construct to the preset underground height position, and pre-embed steel plates at the four corners.

[0055] Specifically, after the foundation construction is completed, the zero-level sidewall construction will proceed. The sidewall will utilize double-layer, bidirectional steel reinforcement and will be equipped with staggered hooks (Φ8@600×600, 8mm in diameter, spaced 600×600mm in a staggered pattern). Formwork will be erected and concrete of the same grade will be poured. The sidewall will be constructed to a predetermined underground height of 0.5m, meaning the sidewall will be constructed to -0.5m, or 0.5 meters below ground level. Steel plates will be embedded at the four corners of the sidewall for subsequent column anchoring. The position and elevation of the embedded steel plates must be precisely controlled to ensure they correspond to the column bases. Anchor bars will be welded to the back of the embedded steel plates and anchored into the concrete, ensuring a positioning deviation of ≤5mm.

[0056] In summary, the construction method for retrofitting and reinforcing existing brick-concrete cast-in-place buildings by adding elevator shafts, provided in this embodiment, provides a reliable lower anchoring foundation for the steel structure columns by pre-embedding column anchoring components during foundation and side wall construction. Through-bolts are used to connect the columns through the floor slab, creating a vertically continuous load-bearing system between the upper and lower columns. This allows for layered installation without waiting for foundation curing, avoiding the safety hazards of instantaneous stress imbalance, wall cracking, and floor deformation that can occur when the original structure is cut before installation. The use of chemical anchors to fix the steel plates in the post-installation beam connection step, combined with circumferential welding and pressure injection of structural adhesive, forms a reliable steel-concrete synergistic load-bearing node, significantly improving connection strength and overall stability. Static cutting equipment is used to cut the floor slabs into sections, and a portal hoist is used for stable lifting, greatly reducing impact and disturbance to the original structure and eliminating the risk of falling objects from heights. Therefore, this method effectively solves the technical problems in the prior art, such as the imbalance of the original structure due to cutting before installation, poor reliability of steel structure connection nodes, long construction period, large disturbance to the original structure, and potential safety hazards.

[0057] In addition, this method also has the following technical effects: 1. High construction efficiency and significantly shortened construction period: The columns can be installed without starting from the foundation, and construction can proceed layer by layer without waiting for the foundation to be cured. Layered and continuous operation greatly reduces the total construction period.

[0058] 2. Superior waterproofing and durability: The elevator pit and side walls are made of C35P6 impermeable concrete with double-layer bidirectional reinforcement and waterproof membrane, combined with standardized embedded parts and sealant injection, which solves the problems of easy leakage and poor durability of traditional elevator installations.

[0059] 3. Strong applicability and good economy: It is specifically optimized for old brick-concrete buildings with sintered brick load-bearing and thin cast-in-place floor slabs. It does not require large-scale structural reinforcement, the material usage is reasonable, the construction is simple, and the overall cost is lower. It is suitable for the mass promotion and application of elevator installation in old residential communities.

[0060] 4. Safe and controllable construction process: The entire process adopts static cutting and dust-free chiseling technology, without impact or explosion; the floor slab is cut into sections and hoisted stably by gantry crane, eliminating the risk of falling objects from heights. The process is clear and the load is controllable, making it suitable for construction in small spaces in old residential areas.

[0061] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0062] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0063] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A construction method for retrofitting and reinforcing existing brick-concrete cast-in-place buildings by adding elevator shafts, characterized in that, Includes the following steps: Construction and pre-embedding steps: carry out foundation and side wall construction, and pre-embed pre-embedded parts for column anchoring in the side walls; The column installation steps are as follows: install the column of this floor at the original structural floor slab positioning location, and connect the column of this floor to the column of the lower or upper floor with through bolts through the floor slab to form a vertical continuous force-bearing system; The installation steps for the crossbeams are as follows: install the crossbeams on the columns to connect the four corner columns into an overall frame load-bearing system, and use chemical anchors to fix the rear steel plate on the original structural beams. Fix the crossbeams to the rear steel plate so that the columns of this floor and the original structural beams form an overall load-bearing structure. Then, inject structural adhesive into the gap between the crossbeams and the original floor. The cutting and hoisting process involves cutting the floor slabs into sections and then hoisting the sections.

2. The construction method for renovating and reinforcing existing brick-concrete cast-in-place buildings by adding elevator shafts according to claim 1, characterized in that, The construction and pre-embedding steps specifically include the following sub-steps: The steps for excavating a foundation pit are as follows: excavate the foundation pit, build a brick formwork around the perimeter, and lay a waterproof membrane on the inside. The concrete pouring sub-step involves tying reinforcing bars and pouring concrete. The construction steps for embedded parts include: constructing the zero-level side wall, tying reinforcing bars and setting hooks at the construction site of the side wall, constructing to the preset underground height, and embedding steel plates at the four corners.

3. The construction method for modifying and reinforcing existing brick-concrete cast-in-place buildings by adding elevator shafts according to claim 2, characterized in that, The preset height is 0.5m.

4. The construction method for renovating and reinforcing existing brick-concrete cast-in-place buildings by adding elevator shafts according to any one of claims 1 to 3, characterized in that, The specific steps of cutting and hoisting include: pre-dividing the blocks into different sizes, drilling holes in the floor of each block, using gantry cranes, hand-operated hoists, and wire ropes to unload the blocks to the lower floor, and then clearing them away.

5. The construction method for renovating and reinforcing existing brick-concrete cast-in-place buildings by adding elevator shafts according to any one of claims 1 to 3, characterized in that, Before the construction and pre-embedding steps, the following steps are also included: The preliminary preparation steps include measuring and setting out lines to determine the column positioning points and floor slab cutting boundaries, and removing the decorative layer of the columns, beams, and the area where the rear steel plates are installed down to the original structural base.

6. The construction method for renovating and reinforcing existing brick-concrete cast-in-place buildings by adding elevator shafts according to any one of claims 1 to 3, characterized in that, After the beam installation step and before the cutting and hoisting step, the following steps are also included: The static wall removal process involves removing sections of the wall in the renovation area.

7. The construction method for renovating and reinforcing existing brick-concrete cast-in-place buildings by adding elevator shafts according to any one of claims 1 to 3, characterized in that, The following steps are included after the cutting and hoisting step: The construction steps for the hooks include: constructing the joint between the column and the beam, and adding several hooks at designated locations.

8. The construction method for renovating and reinforcing existing brick-concrete cast-in-place buildings by adding elevator shafts according to any one of claims 1 to 3, characterized in that, In the column installation step, the upper and lower columns are connected by through bolts; In the beam installation step, the column and the beam are connected by bolts.

9. The construction method for renovating and reinforcing existing brick-concrete cast-in-place buildings by adding elevator shafts according to any one of claims 1 to 3, characterized in that, The chemical anchor is an inverted conical chemical anchor, and the post-installed steel plate is a pre-fabricated steel plate component; The specific method of fixing the crossbeam to the rear steel plate is to weld the crossbeam to the rear steel plate, especially by using fillet welds for circumferential welding.

10. The construction method for renovating and reinforcing existing brick-concrete cast-in-place buildings by adding elevator shafts according to any one of claims 1 to 3, characterized in that, Both the columns and the beams are H-beams.

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