Construction method of underground block-by-block removal of deep foundation pit near subway

Abstract

The present application relates to a construction method for underground block-by-block demolition in a deep foundation pit near a subway station, which includes comparing construction drawings, marking the reserved area, the area to be demolished and the area to be newly built in the construction drawings; demolishing the shear walls in the area to be demolished, and building new shear walls in the area to be newly built; cutting and demolishing the shear walls in the reserved area and the structural exterior walls in the area to be demolished; building new columns in the area to be newly built, the new columns are located next to the side walls in the reserved area and next to the modified columns that need to share the load, and the new columns are structurally embedded on the foundation slab of the area to be newly built; dividing the underground building area into compartments according to the set area intervals, and performing skipping demolition, and dismantling and restoring while dismantling the floor slab; after the floor slab is demolished, the beams supporting the floor slab are pulled up and supported down, and then the beams are cut, and the bottom of the beams are supported and reinforced, and finally the cut beams are fixed with hangers. The present application has the effect of reducing the impact of underground building renovation on the super-high-rise buildings nearby.

Description

Technical Field

[0001] The present application relates to the field of underground building construction, and in particular to a method for dismantling underground block-by-block jump compartments in a deep foundation pit near a subway. Background Art

[0002] At present, with the continuous development and progress of cities, central cities have increasingly taller buildings, and these buildings are equipped with functional urban supporting facilities, one of which is the subway. The subway platforms near the central urban area in central cities are designed underground. Therefore, there will be super-high-rise buildings adjacent to the underground subway platforms. When renovating the structure of the subway underground platform adjacent to the super-high-rise building, it is necessary to reinforce the underground building part to reduce the impact on the adjacent super-high-rise building. The underground building part includes shear walls, load-bearing columns, beams and floor slabs.

[0003] With respect to the above-mentioned related technologies, the inventors believe that there is a defect that the existing method of reinforcing the underground building part still has a significant impact on the super high-rise buildings next to the underground buildings. Summary of the invention

[0004] In order to reduce the impact of underground building renovation on super-high-rise buildings next to the underground buildings, the present application provides an underground block-by-block jump-storage demolition construction method for a deep foundation pit near a subway.

[0005] The present application provides a method for underground block-by-block demolition construction of a deep foundation pit near a subway station, which adopts the following technical solution:

[0006] A construction method for underground block-by-block jump-out demolition of a deep foundation pit near a subway station comprises the following steps:

[0007] S1: Compare the construction drawing with the structural drawing of the underground building to be renovated, and mark the reserved area, the area to be demolished, and the area to be newly built in the construction drawing;

[0008] S2: demolish the shear walls in the area to be demolished, and build new shear walls in the area to be newly built according to the steps of planting reinforcement, roughening the concrete surface, tying reinforcement, formwork support and pouring concrete; cut and demolish the shear walls in the reserved area and the structural outer wall located in the area to be demolished;

[0009] S3: construct additional columns in the area to be newly built, the additional columns are located next to the side walls in the reserved area and next to the modified columns that need to share the load, and the additional columns are structurally embedded in the foundation slab of the area to be newly built; and,

[0010] S4: Divide the underground building area into compartments according to the set area intervals, and carry out skip-compartment demolition. When dismantling the floor slab, it is restored while being dismantled. After the floor slab is dismantled, the beams supporting the floor slab are pulled up and supported down, and then the beams are cut, and then the bottom of the beams are supported and reinforced, and finally the cut beams are fixed with hangers.

[0011] By adopting the above technical solution, the drawings are checked first, and the columns with larger loads are renovated or newly added. Then the shear walls with smaller loads are renovated. Finally, the floor area is divided into blocks or compartments, and then the compartments are demolished in a skipping manner, and the beams of the load-bearing floor are pulled up and supported down and then cut. This can minimize the adverse effects of the renovation and demolition on the load-bearing of the underground structure, thereby reducing the impact of the underground building renovation on the super-high-rise buildings next to the underground building.

[0012] Preferably, in S2, before demolishing the shear wall in the area to be demolished, the process further includes:

[0013] For shear walls located in the subway connection area and without structural columns on the sides, a water drill is used to dig grooves at the location of the shear wall outside the edge of the subway connection area, and then temporary support rods are set in the grooves to share the load of the shear wall, and then the subway connection area is demolished.

[0014] By adopting the above technical solution, some shear walls in the original structure have no structural beams on the upper part of the new subway connection part and no structural columns on the side. Therefore, the above method can help ensure structural safety during construction.

[0015] Preferably, the step of removing the shear wall in the area to be removed comprises:

[0016] S21: Draw a cutting line on the shear wall to be demolished, and determine the center point of the opening, where the center point of the opening is the corner of the area enclosed by the cutting line;

[0017] S22: Drill a hole at the center point of the hole, insert a fixing screw to fix the water drill device, adjust the water drill bit to be located within the area surrounded by the cutting line, make the bit tangent line coincide with the cutting line, and then perform cutting;

[0018] S23: inserting a support rod into the hole at the center point of the opening, with one end of the support rod extending outside the wall, and cutting a gap between adjacent concrete blocks after cutting, wherein the support rod is used to keep the gap from deforming; and,

[0019] S24: The cut concrete blocks are taken out in sequence according to the demolition order, wherein the support rod is pulled when the concrete block is moved until one end of the support rod outside the wall contacts the ground, and the concrete block slides along the support rod to the ground.

[0020] By adopting the above technical solution and using a water drill for cutting, the impact of the cutting operation on the strength of the surrounding structure can be minimized. At the same time, the cut concrete block can be taken out when the support rod is pulled out. If the concrete block needs to be moved horizontally, the support rod can be rotated to reduce the difficulty of moving the concrete block horizontally. At the same time, the support rod can also allow the concrete block to slide smoothly to the ground, reducing the impact on the structure and improving construction safety.

[0021] Preferably, after constructing the new column in S3, the method further includes:

[0022] S31: Test the bearing capacity of the newly added column and the modified column. If the bearing capacity does not reach the preset bearing value, cut off the part with insufficient bearing capacity and re-reinforce and cast. Otherwise, jump to S4.

[0023] S32: Before cutting, use a water drill to cut horizontally on the top of the modified column to separate the modified column from the upper structure and form a gap; and

[0024] S33: Secure the part to be removed from the modified column and the upper structure of the modified column, use a rope saw to cut the column body, and restore the column body while dismantling it. The restoration includes expanding the column and building a steel pipe frame to support and reinforce the beams and slabs around the modified column.

[0025] By adopting the above technical solution, the columns can be dismantled and restored at the same time, minimizing the impact on the strength of the surrounding structures.

[0026] Preferably, before the column is cut off in S32, the step further includes:

[0027] S321: A support column surrounding the modified column is arranged at the bottom of the force transmission member around the modified column, the support column supports the floor supported by the modified column, a clamping groove is arranged on the support column, and a connection groove with an opening direction away from the side is also arranged on the side of the support column away from the modified column;

[0028] S322: connecting rods are detachably connected between adjacent support columns, and ends of the connecting rods are engaged with the connecting grooves and detachably connected to the inner walls of the connecting grooves; and,

[0029] S323: inserting a support member into the connection groove, the support member supports the floor supported by the modified column, and the support member is detachably connected to the end of the connection rod.

[0030] By adopting the above technical solution, some of the original design columns cannot meet the bearing capacity requirements after the transformation, and some of the original design columns need to be cut and re-cast. Because the original design columns are direct load-bearing components of the structure, the force needs to be dispersed before cutting. Four supporting columns can be set up with H-shaped steel at the bottom of the original design column force transmission component or beam, and they are reinforced to meet the bearing requirements of the original column for the component. The connecting rod improves the structural stability after the support column is connected.

[0031] Preferably, the side surfaces of the pillar are surrounded by a plurality of surrounding plates, the support pillar is crimped to the connection between adjacent surrounding plates, and the side edges of the surrounding plates are pressed tightly into the clamping grooves.

[0032] By adopting the above technical solution, the surrounding plate can further improve the structural stability after the support columns are connected.

[0033] Preferably, the column expansion modification in S33 includes:

[0034] S331: roughening the surface of the column;

[0035] S332: Installing a column steel cladding surrounding the column on the side of the column; and,

[0036] S333: For the modified columns with roughened surfaces or the modified columns with steel cladding, the rebar embedding, concrete surface roughening, steel bar binding, formwork support and concrete pouring are carried out in sequence.

[0037] By adopting the above technical solution, in order to make the new and old concrete bond better, before expanding the column, the original column needs to be roughened and the surrounding beams and slabs need to be supported and reinforced to improve the renovation effect.

[0038] Preferably, the jump warehouse removal in S4 further includes:

[0039] S41: mark the floor to be demolished in the compartment, and demolish the middle part of the floor to be demolished;

[0040] S42: Reserve steel bars at the edge of the floor to be demolished as temporary horizontal support; and,

[0041] S43: Build a new floor slab on the reserved steel bars, and then demolish the remaining part of the floor slab to be demolished after the concrete of the new floor slab reaches sufficient strength.

[0042] By adopting the above technical solution, the uneven lateral force on the structure caused by the removal of beams and slabs can be reduced, thereby reducing structural damage.

[0043] Preferably, a force transmission block is fixedly connected between the structural outer wall and the ground wall of each floor of the underground building, a temporary support frame is fixedly connected to the side of the structural outer wall away from the force transmission block, and one end of the temporary support frame away from the structural outer wall is fixedly connected to the floor slab of the current floor.

[0044] By adopting the above technical solution, it is possible to prevent the concrete components from being locally subjected to large forces, causing uneven forces on the concrete components, and to transfer stress so that adjacent concrete blocks are subjected to forces together, thereby achieving the purpose of protecting the structure.

[0045] Preferably, the reinforcing bar implantation comprises:

[0046] Drill holes and remove dust and debris from the holes;

[0047] First, clean the hole with a brush and then blow air, and repeat this process for more than 3 times. During the cleaning process, an expanded inner groove is formed on the inner wall of the hole, and the expanded inner groove is away from the axis of the hole.

[0048] Then wipe the hole wall with clean cotton yarn and blow hot air to dry;

[0049] Pour the rebar glue into the hole, insert the injection nozzle deep into the bottom of the rebar hole, and slowly withdraw it outward while injecting to remove the air in the hole; and,

[0050] Insert the steel bar dipped in adhesive, insert it while turning it in a clockwise direction, push it inward and rotate the anchor bar, and wait for the anchor glue and adhesive to cure.

[0051] By adopting the above technical scheme, the inner groove is conducive to more anchoring glue, and is conducive to reducing heat loss, extending the solidification time of the anchoring glue before inserting the steel bars, thereby providing more time for adjusting the posture of the inserted steel bars, and when the steel bars are rotated, the anchoring glue in the inner groove can fill the local cavity caused by the rotation of the steel bars driving the anchor bars on its surface, thereby improving the effect of anchoring.

[0052] In summary, the present application includes at least one of the following beneficial technical effects:

[0053] 1. The floor area is demolished in a skipped manner, and the demolition and restoration are carried out at the same time, so as to minimize the adverse effects of the renovation and demolition on the load-bearing of the underground structure, thereby reducing the impact of the underground building renovation on the super high-rise buildings next to the underground building;

[0054] 2. During the demolition of the skip warehouse, the steel bars to be removed are used as relays for the new floor slabs to reduce the uneven lateral force on the structure caused by the removal of beams and slabs, which may cause structural damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 It is a method flow chart of steps S1-S4 of an underground block-by-block jump-bin demolition construction method for a deep foundation pit near a subway.

[0056] Figure 2 It is a top view schematic diagram of the structure supporting the modified column before it is cut out.

[0057] Figure 3 It is a structural diagram of adding a new floor slab using the original floor slab.

[0058] Figure 4 It is a structural diagram of the demolition of the skip warehouse and the new construction of the floor.

[0059] Figure 5 It is a schematic diagram of the structure using a temporary support frame.

[0060] Figure 6 It is a structural schematic diagram of using support rods to assist in dismantling concrete blocks.

[0061] Figure numerals: 1. support column; 2. snap-in groove; 3. connecting groove; 4. connecting rod; 5. support member; 6. surrounding plate; 7. force transmission block; 8. temporary support frame; 9. support rod. DETAILED DESCRIPTION

[0062] The following is combined with Figure 1-6 This application is described in further detail.

[0063] The embodiment of the present application discloses an underground block-by-block jump-bin demolition construction method for a deep foundation pit near a subway.

[0064] The underground building is a basement structure, which is divided into 5 areas, all of which are 5-story basements. It is adjacent to two subway lines and has a 220KV regional substation on one side. There are also super high-rise buildings next to the underground building, such as super high-rise commercial buildings or residential buildings.

[0065] Reference Figure 1 , the method comprises the following steps:

[0066] S1: Compare the construction drawings with the structural drawings of the underground buildings to be renovated, and mark the areas to be retained, demolished, and newly built in the construction drawings. Because the form of the underground building needs to be changed, some areas of the underground building need to be demolished. The demolition process is different from that of the above-ground building. It needs to be demolished and rebuilt at the same time, otherwise it will affect the surrounding buildings.

[0067] S2: demolish the shear wall in the area to be demolished, and build a new shear wall in the area to be newly built according to the steps of planting reinforcement, roughening the concrete surface, tying reinforcement, formwork support and pouring concrete; cut and demolish the shear wall in the reserved area, and the structural outer wall in the area to be demolished. Among them, before demolishing the shear wall in the area to be demolished, it also includes: for the shear wall located in the subway connection area and without structural columns on the side, use a water drill to dig a groove at the part of the shear wall outside the edge of the subway connection area, and then set a temporary support rod in the groove to share the load of the shear wall, and then demolish the subway connection area, and re-set the subway connection port. Since the original structural outer wall and the ground connection wall, and the ground connection wall and the subway structural outer wall have been backfilled, it is designed to be backfilled with sand, and construction waste may be backfilled on site. In order to prevent the collapse of the backfill during the demolition process, the backfill needs to be consolidated before cutting and demolition, and the backfill is consolidated by consolidation grouting. Some shear walls in the original structure have no structural beams on the upper part of the new subway connection part and no structural columns on the side, so the above method can help ensure structural safety during construction. The new shear wall is built to meet the requirements of the new design on the drawings and to replace the original shear wall to provide support.

[0068] The steps for removing the shear wall in the area to be removed include:

[0069] S21: Draw a cutting line on the shear wall to be demolished and determine the center point of the hole, where the center point of the hole is the corner of the area surrounded by the cutting line. S22: Drill a hole at the center point of the hole, insert a fixing screw to fix the water drill device, adjust the water drill bit to be located within the area surrounded by the cutting line, make the bit tangent line coincide with the cutting line, and then cut. Figure 6 As shown, S23: insert a support rod 9 into the hole at the center point of the opening, one end of the support rod 9 extends outside the wall, and a gap is cut between adjacent concrete blocks after cutting, and the support rod 9 is used to keep the gap from deforming. S24: Take out the cut concrete blocks in sequence according to the order of demolition, wherein the support rod 9 is pulled out when moving the concrete block until the end of the support rod 9 outside the wall touches the ground, and the concrete block slides to the ground along the support rod 9. More specifically, use a water drill for cutting, use an M12 drill rod to drill a 5 cm deep hole 42 cm outside the proposed center point of the opening, insert a fixing screw to fix the water drill machine, adjust the water drill bit and fix the water drill machine. Adjust the water drill bit so that it is in the cutting position, and make the bit tangent coincide with the marking line, and then tighten the nut on the fixing screw to prevent the machine from shaking during water drill construction. Connect the water supply pipeline and start the water drill construction. The cut concrete blocks are taken out one by one in the order of demolition. Because cranes and forklifts are difficult to put in place at certain locations during the demolition construction, electric hoists are used for partial demolition to place the cut concrete on the floor slab, and then forklifts are used to transport it to the lifting port.

[0070] In order to minimize the impact of the cutting operation on the strength of the surrounding structure, the support rod 9 can be used to bring out the cut concrete block when the support rod 9 is pulled out. If the concrete block needs to be moved horizontally, the support rod 9 can be rotated to reduce the difficulty of horizontally moving the concrete block. At the same time, the support rod 9 can also allow the concrete block to slide smoothly to the ground, reducing the impact on the structure and improving construction safety.

[0071] Rebar planting includes: drilling holes to form holes and removing dust and debris from the holes. The holes should be completely cleaned of dust and debris after forming to avoid dust and debris from isolating and affecting the bonding effect of the adhesive. First use a brush to clean the hole and then blow air and repeat more than 3 times until there is no dust and debris. When cleaning, form an expanded inner groove on the inner wall of the hole, and the expansion of the inner groove is away from the axis of the hole. Then use clean cotton yarn to wipe the hole wall and blow hot air to dry. The rebar planting hole should be complete, without cracks and other local damage. Use clean cotton yarn and a brush to wipe the hole wall to ensure that the hole wall and the adhesive can have a good bonding effect. After the wall of the rebar planting hole is cleaned, if the glue is not injected and the rebar is planted immediately, the hole should be tightly sealed with clean cotton yarn to prevent dust and foreign matter from falling into pollution and protect it for standby use. Pour the rebar glue into the hole, use Hilti structural rebar glue to plant the rebar, and insert the injection nozzle deep into the bottom of the rebar hole, slowly withdraw it while injecting, remove the air in the hole, and prevent the formation of air pockets. The amount of injection should be determined according to the product instructions. Generally, about 2 / 3 of the hole is injected, and a small amount of glue overflows the hole after the rebar is implanted. Insert the rebar dipped in adhesive, turn it clockwise while inserting, push it inward and rotate the anchor bar, and wait for the rebar glue and adhesive to solidify. The inner groove is conducive to more rebar glue, and it is conducive to reducing heat loss, extending the solidification time of the rebar glue before inserting the rebar, thereby providing more time to adjust the posture of the inserted rebar, and when the rebar is rotated, the rebar glue in the inner groove can fill the local cavity caused by the rebar rotating and driving the anchor bar on its surface, thereby improving the effect of rebar planting. The implanted rebar must not be disturbed before the adhesive solidifies. Independent or row rebars should be supported to ensure that the position is centered and correctly positioned to prevent displacement due to human influence. The implanted steel bars should be statically cured to protect the finished product. According to the product manual, the curing time generally takes several hours depending on the temperature conditions of the construction environment.

[0072] S3: Construct new columns in the area to be newly built. The new columns are located next to the side walls in the reserved area and next to the modified columns that need to share the load. The new columns are structurally embedded with reinforcement on the foundation slab of the area to be newly built. After the new columns are constructed in S3, it also includes: S31: Test the bearing capacity of the new columns and the modified columns. If the bearing capacity does not reach the preset bearing capacity, cut off the part with insufficient bearing capacity and re-reinforce and cast, otherwise jump to S4. S32: Before cutting, use a water drill to cut horizontally on the top of the modified column to separate the modified column from the upper structure and form a gap. Before demolition, the demolished column is supported and reinforced with a steel pipe rack. The specific method is: set up a steel pipe scaffolding to support the surrounding beams and slabs, and then cut after support. Combined with Figure 2As shown, before the modified column is cut off in S32, the following is also included: S321: A support column 1 surrounding the modified column is arranged at the bottom of the force transmission component around the modified column, the support column 1 is used to support the floor supported by the modified column, a clamping groove 2 is provided on the support column 1, and the side of the modified column can also be clamped in the clamping groove 2, and a connecting groove 3 with an opening direction away from the side is also provided on the side of the support column 1 away from the modified column. S322: A connecting rod 4 is detachably connected between adjacent support columns 1, and the end of the connecting rod 4 is clamped in the connecting groove 3 and detachably connected to the inner wall of the connecting groove 3. S323: A support member 5 is inserted into the connecting groove 3, the support member 5 supports the floor supported by the modified column, and the support member 5 is detachably connected to the end of the connecting rod 4. Some of the original design columns cannot meet the bearing capacity requirements after the transformation, and some of the original design columns need to be cut and re-cast. Because the original design columns are direct load-bearing components of the structure, the force needs to be dispersed before cutting. Four support columns 1 can be set with H-shaped steel at the original design column force transmission components or beam bottoms, and they are reinforced to meet the bearing requirements of the original columns for components. The connecting rod 4 improves the structural stability of the support columns 1 after connection. The side of the modified column is surrounded by multiple surrounding plates 6. The support column 1 is pressed at the connection of adjacent surrounding plates 6, and the side of the surrounding plate 6 is pressed tightly in the clamping groove 2. The surrounding plate 6 can further improve the structural stability of the support column 1 after connection.

[0073] S33: Fasten the part to be cut off on the modified column and the upper structure of the modified column, use a rope saw to cut the column body of the modified column, and restore the column body while dismantling it. The restoration includes expanding the modified column and supporting and reinforcing the beams and slabs around the modified column with steel pipe frames. The modified column is restored while being dismantled to minimize the impact on the strength of the surrounding structure. The column expansion and reconstruction in S33 include: S331: Roughening the surface of the modified column. S332: Installing the column steel cladding surrounding the column body on the side of the modified column body. S333: For the modified column with roughened surface or the modified column with column steel cladding installed, planting reinforcement, roughening the concrete surface, steel bar binding, formwork support and concrete pouring are carried out in sequence. In order to make the new and old concrete bond better, the original column needs to be roughened before the column expansion and reconstruction, and the surrounding beams and slabs need to be supported and reinforced to improve the reconstruction effect.

[0074] like Figure 3 and Figure 4As shown, S4: the underground building area is divided into compartments according to the set area intervals, and the compartments are removed in a skipping manner. When the floor slab is removed, the floor slab is removed and restored at the same time. Some beams need to be shifted, and the original beam slab needs to be removed and restored. According to the on-site conditions, a combination of a water drill, a cutting machine, and a rope saw is selected for removal. For example, the frame columns and frame beams are removed by drilling holes with a water drill; the floor slab is removed by cutting and removal with a cutting machine; and the shear wall is removed by cutting and removal with a diamond chain saw. Some beams need to be enlarged in cross section, such as roughening, reinforcing bars, and civil engineering operations. After the floor slab is removed, the beams supporting the floor slab are pulled up and supported down, and then the beams are cut, and then the bottom of the beams are supported and reinforced, and finally the cut beams are fixed with hanging parts. The skipping compartment removal of S4 also includes: S41: the compartment marks the floor slab to be removed, and the middle part of the floor slab to be removed is removed. S42: the steel bars at the edge of the floor slab to be removed are reserved as temporary horizontal supports. S43: a new floor slab is built on the reserved steel bars, and the remaining part of the floor slab to be removed is removed after the concrete of the new floor slab reaches the strength. Reduce the uneven horizontal force on the structure caused by the removal of beams and slabs, which may cause structural damage. More specifically, the new structure and the middle partition wall are separated by about 1.5m and the floor slab is to be removed. Then the floor slab is cast according to the reconstruction drawings, and steel bars are reserved as temporary horizontal supports. Then the remaining parts are removed after the concrete reaches the required strength. Figure 5 As shown, a force transmission block 7 is fixedly connected between the structural outer wall and the ground wall of each floor of the underground building, a temporary support frame 8 is fixedly connected to the side of the structural outer wall away from the force transmission block 7, and the end of the temporary support frame 8 away from the structural outer wall is fixedly connected to the floor slab of the current floor. This prevents the concrete components from being subjected to large local forces, resulting in uneven forces on the concrete components, and transfers stress to make adjacent concrete blocks subjected to forces together, thereby achieving the purpose of protecting the structure.

[0075] The implementation principle of the embodiment is as follows: first check the drawings, remodel or add new columns to columns with larger loads, then remodel the shear walls with smaller loads, at which time force transfer blocks 7 can be arranged to improve the structural strength of the building and reduce the impact of construction on the structural strength. Finally, the floor area is divided into blocks, i.e., compartments, and then the compartments are removed by skipping, and the horizontal steel bars in the floor to be removed are used to achieve simultaneous removal and restoration. During the construction, the beams of the load-bearing floor are pulled up and supported down and then cut, so as to minimize the adverse effects of the renovation and demolition on the load-bearing of the underground structure, thereby reducing the impact of the underground building renovation on the super-high-rise buildings next to the underground building.

[0076] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A construction method for underground block-by-block demolition of a deep foundation pit near a subway, characterized in that: The steps include: S1: Compare the construction drawing with the structural drawing of the underground building to be renovated, and mark the reserved area, the area to be demolished, and the area to be newly built in the construction drawing; S2: demolish the shear walls in the area to be demolished, and build new shear walls in the area to be newly built according to the steps of planting reinforcement, roughening the concrete surface, tying reinforcement, formwork support and pouring concrete; cut and demolish the shear walls in the reserved area and the structural outer wall located in the area to be demolished; S3: constructing new columns in the area to be newly built, the new columns are located beside the side walls in the reserved area and beside the modified columns that need to share the load, and the new columns are structurally embedded on the foundation slab of the area to be newly built; after constructing the new columns in S3, it also includes: S31: Test the bearing capacity of the newly added column and the modified column. If the bearing capacity does not reach the preset bearing value, cut off the part with insufficient bearing capacity and re-reinforce and cast. Otherwise, jump to S4. S32: Before cutting, use a water drill to cut horizontally on the top of the modified column to separate the modified column from the upper structure and form a gap; Before the column is cut off in S32, the following steps are also included: S321: A support column (1) is arranged at the bottom of the force transmission component around the modified column to surround the modified column, the support column (1) supports the floor supported by the modified column, a clamping groove (2) is provided on the support column (1), and a connection groove (3) with an opening direction away from the side is also provided on the side of the support column (1) away from the modified column; S322: A connecting rod (4) is detachably connected between adjacent support columns (1), and an end of the connecting rod (4) is snap-fitted into the connecting groove (3) and detachably connected to the inner wall of the connecting groove (3); S323: inserting a support member (5) into the connection groove (3), the support member (5) supporting the floor slab supported by the modified column, the support member (5) being detachably connected to the end of the connection rod (4); S33: Lock the part to be cut off on the modified column and the upper structure of the modified column, use a rope saw to cut the column body of the modified column, and restore the column body while dismantling it. The restoration includes expanding the column and building a steel pipe frame to support and reinforce the beams and slabs around the modified column; S4: Divide the underground building area into compartments according to the set area intervals, and carry out skip-compartment demolition. When dismantling the floor slab, it is restored while being dismantled. After the floor slab is dismantled, the beams supporting the floor slab are pulled up and supported down, and then the beams are cut, and then the bottom of the beams are supported and reinforced, and finally the cut beams are fixed with hangers.

2. The method according to claim 1, characterized in that: In the above S2, before demolishing the shear wall in the area to be demolished, the method further includes: For shear walls located in the subway connection area and without structural columns on the sides, a water drill is used to dig grooves at the location of the shear wall outside the edge of the subway connection area, and then temporary support rods are set in the grooves to share the load of the shear wall, and then the subway connection area is demolished.

3. The method according to claim 1, characterized in that: The step of removing the shear wall in the area to be removed comprises: S21: Draw a cutting line on the shear wall to be demolished and determine the center point of the opening, where the center point of the opening is the corner of the area enclosed by the cutting line; S22: Drill a hole at the center point of the hole, insert a fixing screw to fix the water drill device, adjust the water drill bit to be located within the area surrounded by the cutting line, make the bit tangent line coincide with the cutting line, and then perform cutting; S23: inserting a support rod (9) into the hole at the center point of the opening, one end of the support rod (9) extending outside the wall, cutting a gap between adjacent concrete blocks after cutting, and the support rod (9) is used to keep the gap from deforming; and, S24: The cut concrete blocks are taken out in sequence according to the order of removal, wherein the support rod (9) is pulled when the concrete block is moved until one end of the support rod (9) outside the wall contacts the ground, and the concrete block slides along the support rod (9) to the ground.

4. The method according to claim 1, characterized in that: The side surfaces of the supporting column are surrounded by a plurality of surrounding plates (6); the supporting column (1) is pressed at the connection points of adjacent surrounding plates (6); and the side edges of the surrounding plates (6) are pressed tightly into the clamping grooves (2).

5. The method according to claim 1, characterized in that: The column expansion modification in S33 includes: S331: roughening the surface of the column; S332: Installing a column steel cladding surrounding the column on the side of the column; and, S333: For the modified columns with roughened surfaces or the modified columns with steel cladding, the rebar embedding, concrete surface roughening, steel bar binding, formwork support and concrete pouring are carried out in sequence.

6. The method according to claim 1, characterized in that: The S4 jump warehouse removal also includes: S41: mark the floor to be demolished in the compartment, and demolish the middle part of the floor to be demolished; S42: Reserve steel bars at the edge of the floor to be demolished as temporary horizontal support; and, S43: Build a new floor slab on the reserved steel bars, and then demolish the remaining part of the floor slab to be demolished after the concrete of the new floor slab reaches sufficient strength.

7. The method according to claim 6, characterized in that: A force transmission block (7) is fixedly connected between the structural outer wall and the ground wall of each floor of the underground building, a temporary support frame (8) is fixedly connected to the side of the structural outer wall away from the force transmission block (7), and an end of the temporary support frame (8) away from the structural outer wall is fixedly connected to the floor slab of the current floor.

8. The method according to claim 1, characterized in that: The reinforcing bar implant comprises: Drill holes and remove dust and debris from the holes; First, clean the hole with a brush and then blow air, and repeat this process for more than 3 times. During the cleaning process, an expanded inner groove is formed on the inner wall of the hole, and the expanded inner groove is away from the axis of the hole. Then wipe the hole wall with clean cotton yarn and blow hot air to dry; Pour the rebar glue into the hole, insert the injection nozzle deep into the bottom of the rebar hole, and slowly withdraw it outward while injecting to remove the air in the hole; and, Insert the steel bar dipped in adhesive, insert it while turning it in a clockwise direction, push it inward and rotate the anchor bar, and wait for the anchor glue and adhesive to cure.

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