Expressway intercommunication and communication-keeping reconstruction embracing column dragging and replacing construction process

Abstract

The invention provides an expressway intercommunication and communication-keeping reconstruction embracing column dragging and replacing construction technology. The technology comprises the following steps that S10, a newly-built pile foundation, a newly-built bearing platform and a newly-built pier column are sequentially constructed; s20, construction of a newly-built bent cap is conducted, and after the strength of concrete of the newly-built bent cap is achieved, prestressed steel beams of the newly-built pier and the newly-built bent cap are tensioned; s30, an old pier column on one side is cut off firstly, and vertical deformation and transverse deformation of the newly-built bent cap and the original steel box girder above the newly-built bent cap are synchronously monitored; s40, the old pier column on the other side is cut off, 1 cm of the old pier column is cut firstly, vertical and transverse deformation of the newly-built bent cap and the original steel box beam above the newly-built bent cap is monitored synchronously, and then the pier column is cut again; s50, the basin-type support at the position of the original steel box girder transition pier is replaced through jacking; and S60, stress of the newly-built pier body and deformation of the newly-built bent cap are checked and calculated again, and whether vertical prestress needs to be arranged on the newly-built pier body or not is checked. The construction risk is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of bridge pier replacement, and in particular relates to a pier replacement construction process for highway interchange maintenance and reconstruction. Background Art

[0002] Pier No. 3 of the A ramp bridge of Jinpen Hub is the transition pier between the first and second steel box girders. The existing piers invade the limit after the main line is widened. The construction drawing design adopts a replacement plan of temporarily lifting the steel box girder, then dismantling the old piers and building new piers.

[0003] The implementation of this replacement plan will involve adding temporary support piers to support the lifted steel box girder. After the old piers are removed and the new piers are built, these temporary facilities will be gradually removed, realizing two major transformations of the entire bridge support system.

[0004] This process not only has a long construction period and causes great interference to surrounding traffic, but also has extremely high construction safety risks because it involves high-altitude operations and the movement and support of large structures. It also poses a considerable challenge to the normal operation of existing bridges. Summary of the invention

[0005] The embodiment of the present invention provides a highway interchange maintenance reconstruction column dragging and replacing construction process, aiming to solve the technical problem of high construction risk.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is: to provide a construction process for replacing columns for highway interchange maintenance reconstruction, the steps are as follows:

[0007] S10: construct new pile foundation, new cap and new pier in sequence;

[0008] S20: Construction of new cap beam: Firstly, the concrete at the interface between the original pier column and the new cap beam, and between the new pier column and the new cap beam shall be roughened and reinforced, then the reinforcement skeleton of the new cap beam shall be laid, and then the concrete of the new cap beam shall be poured. After the concrete strength of the new cap beam reaches a certain level, the prestressed steel strands of the new bridge pier and the new cap beam shall be tensioned;

[0009] S30: First, remove the old pier on one side, and simultaneously monitor the vertical and lateral deformation of the newly built cap beam and the original steel box beam above the newly built cap beam;

[0010] S40: Cut off the old pier on the other side, first cut 1 cm, and simultaneously monitor the vertical and lateral deformation of the new cap beam and the original steel box beam above the new cap beam, and then cut the pier again;

[0011] S50: Replace the pot-type support at the original steel box girder transition pier position by jacking, install a jack near the cap beam top surface support, replace the pot-type support at the original steel box girder transition pier position with a force measuring and height adjustment support after the jack is lifted, control the force measuring and height adjustment support step by step, and transfer the jack load to the force measuring and height adjustment support;

[0012] S60: Review and verify the stress on the newly built pier body and the deformation of the newly built cap beam, and check whether vertical prestressing is required on the newly built pier body.

[0013] In a possible implementation, during the construction of the new foundation in S10, in order to reduce the hydration heat, in addition to using low-heat or medium-heat cement, a mix ratio test is conducted without reducing the concrete grade, and a mix ratio with less cement and larger crushed stone particle size is selected, and the aggregate should be sprinkled with water to cool down before mixing;

[0014] The newly built foundation is poured in layers. The thickness of each pouring layer is half the thickness of the foundation. The second layer is poured after 5 to 7 days. Each layer is poured in 3 times and is poured in layers within the initial setting time.

[0015] In one possible implementation, cooling pipes are set up from the time of pouring, and cooling water must be immediately filled into the cooling pipes for 12 consecutive days. The flow rate of each water outlet is 30 to 45 liters / minute, and the inlet and outlet water flow directions are changed twice a day;

[0016] In the first 7 days, the cooling water temperature is controlled within 5℃ to 10℃. During the water flow, the water flow, inlet and outlet water temperature, and temperature of the temperature measuring hole should be measured and recorded every 1 to 2 hours;

[0017] After the water flow in the cooling pipe stops, measure the temperature of the concrete in the temperature measuring hole every 12 hours until the temperature measuring hole is filled and sealed with pebble concrete during the construction of the new pouring layer of concrete. The cooling pipe should be grouted and sealed, and the cooling pipe extending out of the newly built foundation should be cut off. If the steel bars of the newly built foundation collide with the cooling pipe, move the steel bars of the newly built foundation.

[0018] In a possible implementation, in S20, the prestressed steel strands of the newly built cap beam are tensioned first, and then the prestressed steel strands of the newly built pier are tensioned.

[0019] In a possible implementation, the prestressed steel strands of the newly built cap beam and the newly built bridge piers are both made of high-strength, low-relaxation steel strands;

[0020] Prestressing can only be done when the concrete strength and corresponding stiffness of the newly built cap beam and newly built bridge piers reach more than 90% of the design value and the concrete age reaches more than 10 days. Grouting must be carried out in time after the prestressing steel strands of the newly built cap beam and newly built bridge piers are tensioned.

[0021] During prestressing, both elongation and tensioning force are controlled, with tensioning force being the main factor. The allowable error between the measured elongation and the calculated elongation should be controlled within ±6%.

[0022] In one possible implementation, the newly built cap beam prestressed steel bundle is tensioned symmetrically at both ends, the corrugated pipe positioning steel bars are in a criss-cross shape with a spacing of no more than 50 cm, the anchor plate must be perpendicular to the center line of the newly built cap beam prestressed steel bundle, and when the position of the ordinary steel bars in the newly built cap beam is inconsistent with the position of the newly built cap beam prestressed steel bundle, the ordinary steel bars can be appropriately adjusted to ensure accurate positioning of the pipeline.

[0023] In a possible implementation, the prestressed steel bundles of the newly built bridge piers are tensioned at a single end, the inside of the newly built abutment is the fixed end, and the top of the pier is the tensioning end. The tensioning sequence of the prestressed steel bundles of the newly built bridge piers is symmetrical tensioning from the outside to the inside in the direction of the short side of the cap beam. The corrugated tube positioning steel bars are in a tic-tac-toe shape with a spacing of no more than 50 cm. The anchor pad must be perpendicular to the center line of the prestressed steel bundles of the newly built bridge piers.

[0024] When the positions of ordinary steel bars in the newly built cap beam, newly built pier body and newly built abutment are inconsistent with the prestressed steel strands in the newly built pier, the ordinary steel bars can be adjusted to ensure accurate positioning of the pipeline. The vertical prestressed length needs to be adjusted based on the cap beam cross slope determined by the actual measured tie beam cross slope on site.

[0025] In a possible implementation, in S10, the distance between the existing pier pile foundation and the newly built pile foundation is increased to ensure a minimum clear distance of 1.3 meters, and a permanent steel casing is installed. The new pile foundation construction needs to be carried out using a rotary drilling rig, the size of the new pier cap is increased, and the distance between the new and old pile foundations is increased.

[0026] In a possible implementation, in S20, when roughening, the surface of the original pier column should be chiseled into a rough surface with a convex-concave difference of not less than 6 mm, and then grooves are engraved circumferentially along the surface of the original pier column, with a spacing between two adjacent grooves, and the surface of the leaked steel bars is derusted, and before pouring concrete, the contact surface between the original pier column surface and the newly built cap beam is coated with structural interface glue.

[0027] In a possible implementation, in S20, the rebar planting should be performed in batches and crosswise;

[0028] Before planting reinforcement, the position of reinforcement should be found and marked by using reinforcement detector in combination with the completion drawing. When planting reinforcement, the position can be appropriately shifted according to the on-site conditions to prevent the planting reinforcement and the cross-bar from hitting the original reinforcement.

[0029] When planting rebars, the planting glue must meet the requirements of high temperature resistance and aging resistance for welding, and cooling measures such as wrapping the roots of the exposed parts of the planted rebars with wet towels soaked in ice water should be used.

[0030] Compared with the prior art, the present invention:

[0031] By clarifying the step-by-step construction process, the systematic and consistent nature of the reconstruction project was ensured, which helped reduce uncertainty and risks in construction; by real-time monitoring of the deformation of the newly built cap beam and the original steel box beam, the safety of the construction process and the stability of the structure were ensured, and the construction plan was adjusted in time according to the monitoring results; by rechecking and verifying the stress on the newly built pier body and the deformation of the newly built cap beam, the reliability and safety of the structure were ensured, and the vertical prestress was adjusted according to the verification results. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is the construction flow chart for pier replacement. DETAILED DESCRIPTION

[0033] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0034] Please also read Figure 1 The present invention describes the construction process of replacing the pillars for the reconstruction of the interchange of the expressway. The construction process of replacing the pillars for the reconstruction of the interchange of the expressway comprises the following steps:

[0035] S10: construct new pile foundation, new cap and new pier in sequence;

[0036] S20: Construction of new cap beam: Firstly, the concrete at the interface between the original pier column and the new cap beam, and between the new pier column and the new cap beam shall be roughened and reinforced, then the reinforcement skeleton of the new cap beam shall be laid, and then the concrete of the new cap beam shall be poured. After the concrete strength of the new cap beam reaches a certain level, the prestressed steel strands of the new bridge pier and the new cap beam shall be tensioned;

[0037] S30: First, remove the old pier on one side, and simultaneously monitor the vertical and lateral deformation of the newly built cap beam and the original steel box beam above the newly built cap beam;

[0038] S40: Cut off the old pier on the other side, first cut 1 cm, and simultaneously monitor the vertical and lateral deformation of the new cap beam and the original steel box beam above the new cap beam, and then cut the pier again;

[0039] S50: Replace the pot-type support at the original steel box girder transition pier position by jacking, install a jack near the cap beam top surface support, replace the pot-type support at the original steel box girder transition pier position with a force measuring and height adjustment support after the jack is lifted, control the force measuring and height adjustment support step by step, and transfer the jack load to the force measuring and height adjustment support;

[0040] S60: Review and verify the stress on the newly built pier body and the deformation of the newly built cap beam, and check whether vertical prestressing is required on the newly built pier body.

[0041] Compared with the prior art, this embodiment provides:

[0042] By clarifying the step-by-step construction process, the systematic and consistent nature of the reconstruction project was ensured, which helped reduce uncertainty and risks in construction; by real-time monitoring of the deformation of the newly built cap beam and the original steel box beam, the safety of the construction process and the stability of the structure were ensured, and the construction plan was adjusted in time according to the monitoring results; by rechecking and verifying the stress on the newly built pier body and the deformation of the newly built cap beam, the reliability and safety of the structure were ensured, and the vertical prestress was adjusted according to the verification results.

[0043] In some embodiments, during the construction of the new foundation in S10, in order to reduce the hydration heat, in addition to using low-heat or medium-heat cement, a mix ratio test is carried out without lowering the concrete grade, and a mix ratio with less cement and larger crushed stone particle size is selected. Aggregates should be sprinkled with water to cool down before mixing.

[0044] The newly built foundation is poured in layers. The thickness of each pouring layer is half the thickness of the foundation. The second layer is poured after 5 to 7 days. Each layer is poured in 3 times and is poured in layers within the initial setting time.

[0045] Specifically, cooling pipes are installed from the time of pouring, and cooling water must be immediately poured into the cooling pipes for continuous water flow for 12 days. The flow rate of each water outlet is 30 to 45 liters / minute, and the inlet and outlet water flow directions are changed twice a day. Within the first 7 days, the cooling water temperature is controlled within 5°C to 10°C. During the water flow process, the water pipe flow, inlet and outlet water temperatures, and temperature of the temperature measuring holes must be measured and recorded every 1 to 2 hours; after the water flow of the cooling pipes stops, the temperature of the concrete is measured in the temperature measuring holes every 12 hours until the temperature measuring holes are filled and sealed with pebble concrete during the construction of the new pouring layer of concrete. The cooling pipes should be grouted and sealed, and the cooling pipes extending out of the newly built cap should be cut off. If the steel bars of the newly built cap collide with the cooling pipes, move the steel bars of the newly built cap.

[0046] Specifically, the cooling pipe uses a water pipe with a certain strength and an outer diameter of 42x2.5mm. During installation, attention must be paid to ensuring that the pipe is unobstructed and the joints are reliable and leak-proof. After the cooling pipe is installed, a water-tightness check should be carried out.

[0047] By setting up cooling pipes and continuously passing water, strictly controlling the cooling water temperature and measuring records, the temperature of the foundation concrete is effectively managed, avoiding cracks and deformation caused by excessive temperature.

[0048] In some embodiments, in S20, the newly built cap beam prestressed steel strands are tensioned first, and then the newly built pier prestressed steel strands are tensioned.

[0049] In some embodiments, the prestressed steel strands of the newly built cap beam and the newly built bridge piers are made of high-strength, low-relaxation steel strands; the prestressing can only be done when the concrete strength and corresponding stiffness of the newly built cap beam and the newly built bridge piers reach more than 90% of the design value and the concrete age reaches more than 10 days. After the prestressing of the prestressed steel strands of the newly built cap beam and the newly built bridge piers is completed, grouting must be carried out in time; when prestressing, the elongation and tensioning force are both controlled, and the tensioning force is mainly used. The allowable error between the measured elongation and the calculated elongation should be controlled within ±6%.

[0050] In some embodiments, the prestressed steel bundles of the newly built cap beam are tensioned symmetrically at both ends, the corrugated pipe positioning steel bars are in a criss-cross shape with a spacing of no more than 50 cm, the anchor plate must be perpendicular to the center line of the prestressed steel bundles of the newly built cap beam, and when the position of the ordinary steel bars in the newly built cap beam is inconsistent with the position of the prestressed steel bundles of the newly built cap beam, the ordinary steel bars can be appropriately adjusted to ensure accurate positioning of the pipeline.

[0051] In some embodiments, the prestressed steel bundles of the newly built piers are tensioned at a single end, with the fixed end inside the newly built abutment and the tensioning end on the pier top. The tensioning order of the prestressed steel bundles of the newly built piers is symmetrical tensioning from the outside to the inside on both sides of the short side of the cap beam. The corrugated pipe positioning steel bars are in a tic-tac-toe shape with a spacing of no more than 50 cm. The anchor plate must be perpendicular to the center line of the prestressed steel bundles of the newly built piers. When the positions of the ordinary steel bars in the newly built cap beam, the pier body of the newly built pier and the newly built abutment are inconsistent with the positions of the prestressed steel bundles of the newly built piers, the ordinary steel bars can be adjusted to ensure accurate positioning of the pipeline, and the vertical prestressed length needs to be adjusted in combination with the cap beam cross slope determined by the actual measured tie beam cross slope on site.

[0052] Specifically, the prestressed steel strands of the newly built piers and the newly built cap beams all use steel strands with fpk=1860MPa, and the tensioning control stress of a single prestressed steel strand of the newly built piers and the newly built cap beams is 0.75fpk.

[0053] High-strength, low-relaxation steel strands, dual-control tensioning methods, and precise tensioning sequences ensured the accuracy and effectiveness of the prestressed steel strands of the newly built cap beams and bridge piers, improving the overall stability and bearing capacity of the structure. Both the newly built cap beams and the prestressed pipes of the bridge piers used well-shaped positioning steel bars to ensure accurate positioning of the pipes and avoid prestress loss and structural deformation.

[0054] In some embodiments, in S10, the distance between the existing pier pile foundation and the newly built pile foundation is increased to ensure a minimum clear distance of 1.3 meters, and a permanent steel casing is set. The new pile foundation construction needs to be constructed using a rotary drilling rig, the size of the new pier cap is increased, and the distance between the new and old pile foundations is increased.

[0055] By increasing the distance between the existing pier pile foundation and the newly built pile foundation, installing permanent steel casing, optimizing the size of the new pier cap, and other measures, safety was ensured during the construction process and the mutual impact between the new and old structures was reduced.

[0056] In some embodiments, in S20, when roughening, the surface of the original pier column should be chiseled into a rough surface with a convex-concave difference of not less than 6 mm, and then grooves are engraved circumferentially along the surface of the original pier column, leaving a gap between two adjacent grooves, and the surface of the leaked steel bars is derusted, and before pouring concrete, the contact surface between the original pier column surface and the newly built cap beam is coated with structural interface glue.

[0057] Specifically, the size of the groove is 1 cm×1 cm, and the distance between two adjacent grooves is 5 cm.

[0058] In some embodiments, in S20, the rebar planting should be carried out in batches and crosswise; before planting the rebars, the completion drawings should be combined and the positions of the rebars should be detected and marked using a rebar detector. When planting the rebars, they can be appropriately shifted based on the on-site conditions to prevent the planted rebars and cross-rebars from hitting the original rebars; when planting the rebars, the rebar planting glue must meet the requirements of high temperature resistance and aging resistance for welding, and cooling measures such as wrapping the roots of the exposed parts of the planted rebars with wet towels soaked in ice water should be adopted.

[0059] Specifically, when single-sided lap welding is used, the weld length shall not be less than 10d; when embedding reinforcement, the distance between the welding point and the surface of the base concrete shall be greater than 15d.

[0060] Through meticulous roughening and rebar implantation, the bonding between the new and old structures was enhanced, improving the integrity and stability of the rebuilt structure.

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A construction process for replacing pillars for highway interchange maintenance and reconstruction, characterized in that: Here are the steps: S10: construct new pile foundation, new cap and new pier in sequence; S20: Construction of new cap beam: Firstly, the concrete at the interface between the original pier column and the new cap beam, and between the new pier column and the new cap beam shall be roughened and reinforced, then the reinforcement skeleton of the new cap beam shall be laid, and then the concrete of the new cap beam shall be poured. After the concrete strength of the new cap beam reaches a certain level, the prestressed steel strands of the new bridge pier and the new cap beam shall be tensioned; S30: First, remove the old pier on one side, and simultaneously monitor the vertical and lateral deformation of the newly built cap beam and the original steel box beam above the newly built cap beam; S40: Cut off the old pier on the other side, first cut 1 cm, and simultaneously monitor the vertical and lateral deformation of the new cap beam and the original steel box beam above the new cap beam, and then cut the pier again; S50: Replace the pot-type support at the original steel box girder transition pier position by jacking, install a jack near the cap beam top surface support, replace the pot-type support at the original steel box girder transition pier position with a force measuring and height adjustment support after the jack is lifted, control the force measuring and height adjustment support step by step, and transfer the jack load to the force measuring and height adjustment support; S60: Review and verify the stress on the newly built pier body and the deformation of the newly built cap beam, and check whether vertical prestressing is required on the newly built pier body.

2. The highway interchange maintenance reconstruction column dragging and replacement construction process as claimed in claim 1 is characterized in that: When constructing the new foundation in S10, in order to reduce the hydration heat, in addition to using low-heat or medium-heat cement, a mix ratio test is carried out without reducing the concrete grade, and a mix ratio with less cement and larger crushed stone particle size is selected. Aggregates should be sprinkled with water to cool down before mixing; The newly built foundation is poured in layers. The thickness of each pouring layer is half the thickness of the foundation. The second layer is poured after 5 to 7 days. Each layer is poured in 3 times and is poured in layers within the initial setting time.

3. The highway interchange maintenance reconstruction and column replacement construction process as claimed in claim 2 is characterized in that: Cooling pipes shall be installed from the time of pouring, and cooling water shall be immediately poured into the cooling pipes for 12 consecutive days. The flow rate of each water outlet shall be 30 to 45 liters / minute, and the inlet and outlet water flow directions shall be changed twice a day; In the first 7 days, the cooling water temperature is controlled within 5℃ to 10℃. During the water flow, the water flow, inlet and outlet water temperature, and temperature of the temperature measuring hole should be measured and recorded every 1 to 2 hours; After the water flow in the cooling pipe stops, measure the temperature of the concrete in the temperature measuring hole every 12 hours until the temperature measuring hole is filled and sealed with pebble concrete during the construction of the new pouring layer of concrete. The cooling pipe should be grouted and sealed, and the cooling pipe extending out of the newly built foundation should be cut off. If the steel bars of the newly built foundation collide with the cooling pipe, move the steel bars of the newly built foundation.

4. The highway interchange maintenance reconstruction and column replacement construction process according to claim 1 is characterized in that: In S20, the newly built cap beam prestressed steel strands are tensioned first, and then the newly built pier prestressed steel strands are tensioned.

5. The highway interchange maintenance reconstruction and column replacement construction process as claimed in claim 4 is characterized in that: The prestressed steel strands of the newly built cap beam and the newly built bridge piers are all made of high-strength, low-relaxation steel strands; Prestressing can only be done when the concrete strength and corresponding stiffness of the newly built cap beam and newly built bridge piers reach more than 90% of the design value and the concrete age reaches more than 10 days. Grouting must be carried out in time after the prestressing steel strands of the newly built cap beam and newly built bridge piers are tensioned. During prestressing, both elongation and tensioning force are controlled, with tensioning force being the main factor. The allowable error between the measured elongation and the calculated elongation should be controlled within ±6%.

6. The highway interchange maintenance reconstruction column dragging and replacement construction process as claimed in claim 5 is characterized in that: The newly built cap beam prestressed steel bundle is tensioned symmetrically at both ends, the corrugated pipe positioning steel bars are in a criss-cross shape with a spacing of no more than 50 cm, the anchor plate must be perpendicular to the center line of the newly built cap beam prestressed steel bundle, and when the position of the ordinary steel bars in the newly built cap beam is inconsistent with the position of the newly built cap beam prestressed steel bundle, the ordinary steel bars can be appropriately adjusted to ensure accurate positioning of the pipeline.

7. The highway interchange maintenance reconstruction and column replacement construction process as claimed in claim 5 is characterized in that: The prestressed steel strands of the newly built bridge piers are tensioned at one end, with the fixed end inside the newly built abutment and the tensioned end at the top of the pier. The tensioning sequence of the prestressed steel strands of the newly built bridge piers is symmetrical tensioning from the outside to the inside along the short side of the cap beam. The corrugated tube positioning steel bars are in a tic-tac-toe shape with a spacing of no more than 50 cm. The anchor pad must be perpendicular to the center line of the prestressed steel strands of the newly built bridge piers. When the positions of ordinary steel bars in the newly built cap beam, newly built pier body and newly built abutment are inconsistent with the prestressed steel strands in the newly built pier, the ordinary steel bars can be adjusted to ensure accurate positioning of the pipeline. The vertical prestressed length needs to be adjusted based on the cap beam cross slope determined by the actual measured tie beam cross slope on site.

8. The highway interchange maintenance reconstruction and column replacement construction process as claimed in claim 1 is characterized in that: In S10, the distance between the existing pier pile foundation and the newly built pile foundation is increased to ensure a minimum clear distance of 1.3 meters, and a permanent steel casing is set. The new pile foundation construction needs to be constructed using a rotary drilling rig, the size of the new pier cap is increased, and the distance between the new and old pile foundations is increased.

9. The highway interchange maintenance reconstruction and column replacement construction process as claimed in claim 1, characterized in that: In said S20, when roughening, the surface of the original pier column should be chiseled into a rough surface with a concave-convex difference of not less than 6 mm, and then grooves are engraved circumferentially along the surface of the original pier column, leaving a spacing between two adjacent grooves, and the surface of the leaked steel bars is derusted, and before pouring concrete, the contact surface between the original pier column surface and the newly built cap beam is coated with structural interface glue.

10. The highway interchange maintenance reconstruction column dragging and replacement construction process as claimed in claim 1, characterized in that: In S20, the reinforcing bars should be planted in batches and crosswise; Before planting reinforcement, the position of reinforcement should be found and marked by using reinforcement detector in combination with the completion drawing. When planting reinforcement, the position can be appropriately shifted according to the on-site conditions to prevent the planting reinforcement and the cross-bar from hitting the original reinforcement. When planting rebars, the planting glue must meet the requirements of high temperature resistance and aging resistance for welding, and cooling measures such as wrapping the roots of the exposed parts of the planted rebars with wet towels soaked in ice water should be used.

Images