Jacking and pulling combined building lifting construction method

Abstract

The jacking and pulling combined building lifting construction method comprises the following steps that firstly, a to-be-lifted building is disconnected at a preset position; 2, bracket holes are formed respectively, and lifting devices are mounted on lifting parts between the basement and the upper accessory structure respectively; 3, a jack is arranged on a steel corbel at the top of the lifting device supporting steel column; 4, jacks of all the lifting devices are connected to an oil pump pressure system; 5, an instruction is sent to an oil pump pressure system through the computer control system, so that the steel corbels located in the corbel holes are tightly attached to the upper ring beam and the beam bottom structural face; 6, the jacks of all the lifting parts are controlled to conduct lifting work, and lifting is stopped after preset displacement is achieved; and 7, construction of the wall column of the lifting section is conducted, and after construction is completed, all the lifting devices are removed. The technical problems that an existing lifting construction method is complex in procedure and long in construction period are solved, precision is high, accurate positioning can be achieved, and the number of needed lifting devices is small.

Description

Technical Field

[0001] This invention relates to a building lifting method, specifically a top-pull combined lifting method for multi-story buildings. Background Technology

[0002] Substations are typically two-story structures used to house heavy electrical equipment weighing up to 2000 tons (such as high-voltage transformers). Some substations are two-story buildings with a semi-basement. If the substation is located in a low-lying area, it is prone to flooding during rainy weather, which can damage electrical equipment and cause large-scale power outages. Another reason is that the basement may be damp due to a high water table. Therefore, it is necessary to raise the entire substation in these cases.

[0003] Building lifting technology refers to a construction engineering technique that, while preserving the original building structure, uses engineering techniques to increase the overall height of a building to meet the needs of urban planning, infrastructure construction, and geological disaster prevention. Building lifting technology has long been used in the field of specialized construction engineering, with many successful cases. The lifting techniques are mainly divided into two types: the first uses jacks and blocks, with 24 lifting points; the second uses expansion joints and brackets, with 90 lifting points. The disadvantages of these methods are long construction periods, numerous pieces of equipment, and a large number of construction workers. Summary of the Invention

[0004] The purpose of this invention is to solve the technical problems of cumbersome procedures and long construction period in existing lifting methods, and to provide a top-pull combined building lifting method that is highly accurate, can be precisely positioned, and requires fewer lifting devices.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The top-pull combined building lifting method, used for the second-floor electrical distribution room in a semi-basement, is unique in that it includes the following steps: Step 1: Divide the building to be lifted at the bottom of the ring beam into a lower basement and an upper lifting floor; Step 2: Make bracket holes at the bottom of the ring beam, the beam end, and the column top at the intersection of the longitudinal and transverse walls. Install the lifting device at the lifting part between the basement and the lifting floor, and set the steel brackets of the lifting device in the bracket holes according to the design requirements. Step 3: Set the jack on the steel bracket at the top of the lifting device support steel column and lock the steel strand of the steel bracket with anchors; Step 4: Connect the jacks of each lifting device to the oil pump pressure system, and install electronic displacement sensors at each lifting point. Connect the oil pump pressure system and electronic displacement sensors to the computer control system. Step 5: The computer control system sends instructions to the oil pump pressure system, which in turn controls each jack to pre-tension the steel strands, so that the steel brackets located in the bracket holes are tightly fitted with the upper ring beam and the bottom structural surface of the beam. Step 6: Based on the load values ​​of the basement roof slab to be lifted and the heavy equipment, the computer control system controls the jacks of each lifting part to carry out the lifting work, and stops lifting after reaching the preset displacement. Step 7: Construct the raised section wall columns between the basement and the upper raised floor. After the construction is completed, remove all the raising devices and seal the bracket holes opened before the raising.

[0006] Furthermore, the specific steps of step 6 are as follows: Step 6.1: Based on the load values ​​of the basement roof slab and the upper auxiliary structure to be lifted, set multiple lifting points and multiple lifting levels through the computer control system, and ensure that the vertical displacement of each lifting point does not exceed 3mm. Step 6.2: The computer control system sends a command to the oil pump pressure system, and the oil pump pressure system controls the jacks to lift the tensioned steel strand, so that the jacks are lifted upward. Step 6.3: Electronic displacement sensors at each lifting point collect real-time data on the lifting height, analyze the numerical deviation between the actual lifting height and the preset lifting height, and transmit the data to the computer control system. Step 6.4: The computer control system adjusts the pressure value of the oil pump pressure system according to the numerical deviation to ensure that the vertical displacement of each lifting point is consistent. Step 6.5: After reaching the preset displacement, lock the force value of each jack and stop lifting.

[0007] Furthermore, in step 6, there are no fewer than 80 lifting points, and the computer control system controls the jacks at each lifting point to operate synchronously, with each level of lifting having a vertical displacement of 1 mm.

[0008] Furthermore, in step 2, the lifting device has three steel brackets, two of which are used to fix to the jack, and the other passes through the bracket hole at the bottom of the ring beam for lifting the ring beam.

[0009] Furthermore, in step 3, vertical supports are installed between the supporting steel columns, and horizontal supports are installed at the top in both longitudinal and transverse directions.

[0010] Furthermore, in step 6.2, the jack lifting adopts a front-clamping tension jack; during lifting, the jack piston and tension bushing are stationary, the outer cylinder sleeve, the through sleeve, and the tool anchor move backward relative to the jack piston, and the tool anchor and tool clamp clamp the steel strand for tensioning. After reaching the required prestress value, the oil is returned, the outer cylinder sleeve and the through sleeve are reset, and the working clamp and working anchor are automatically anchored.

[0011] Furthermore, in step 4, string strain gauges are attached to each lifting point and connected to a strain gauge and a computer control system; the strain gauge is used to monitor whether there are any abnormalities in the data, and the computer control system is used to analyze the abnormal data and adjust the lifting plan.

[0012] Furthermore, the multi-story building is equipped with heavy electrical equipment.

[0013] Furthermore, step 7 also includes the step of constructing a mezzanine between the basement and the upper raised floor. Compared with the prior art, the present invention has the following beneficial technical effects: The jacking-and-lifting method for building construction of this invention utilizes the original structural ring beams and concrete beams as the lifting force transmission system. Loads are applied by jacks installed on the lifting device, which drive steel brackets to lift the upper structure upwards. This method is suitable for harsh environments such as power distribution rooms with high groundwater levels, and is safe, reliable, and cost-effective. During the lifting process, a computer control system allows for precise positioning and continuous monitoring and control of the lifting amount and accuracy, adjusting the stress on the lifting structure to avoid uneven stress distribution. Attached Figure Description

[0014] Figure 1 This is a schematic flowchart illustrating an embodiment of the top-pull combined building lifting method of the present invention; Figure 2 This is a schematic diagram of the lifting device structure in an embodiment of the top-pull combined building lifting method of the present invention; Figure 3 This is a schematic diagram of the lifting process in an embodiment of the top-pull combined building lifting method of the present invention; Figure 4 This is a schematic cross-sectional view of the jacking-pull combined building lifting method embodiment of the present invention before and after lifting; The annotations in the attached figures are explained as follows: 1-Ring beam, 2-Raft foundation, 3-Jack, 4-Steel bracket. Detailed Implementation

[0015] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0016] The top-pull composite building lifting method of this invention is used for a power distribution room. The room has a masonry structure with one basement level and one above-ground level, with an indoor-outdoor height difference of 0.45m. The building structure is a longitudinal and transverse wall load-bearing system. The exterior walls are 360mm thick, and the interior walls are 240mm thick. Below ±0.000, MU10 shale sintered bricks are laid using M7.5 cement mortar; above ±0.000, MU10 shale sintered bricks are laid using M7.5 mixed mortar. Structural columns are provided at the four corners of the exterior walls and at the junctions of the interior and exterior walls of large rooms. A total of three ring beams are installed within the walls of the entire building. The floor (roof) slabs are cast-in-place reinforced concrete slabs with a concrete strength grade of C25. The foundation type is a raft foundation 2, with a raft slab thickness of 350mm and a bottom elevation of -2.450.

[0017] The lifting principle involves installing lifting devices at the bottom of the ring beam 1 at the intersection of longitudinal and transverse walls, at the connection between columns and beams, and at both ends of the beams, totaling 90 lifting devices. For example... Figures 1 to 4 As shown, the specific lifting steps are as follows: (1) Make bracket holes at the bottom of the ring beam 1, the beam end and the column top, and install the lifting device in place, ensuring that the upper steel bracket 4 of the lifting device is set in the bracket hole as required by the design. (2) Set the jack 3 on the steel bracket 4 at the top of the supporting steel column, lock the steel strand with anchors, set vertical supports between the supporting steel columns, and set horizontal supports at the top in both directions; (3) Connect the jacks 3 of each lifting device to the oil pump pressure system, and connect the oil pump pressure system to the computer control system; (4) Install electronic displacement sensors at each lifting point and connect each electronic displacement sensor to the computer control system; (5) Send instructions to the oil pump pressure system through the computer control system, and the oil pump pressure system controls each jack 3 to pre-tension each steel strand so that the upper steel bracket 4 located in the bracket hole is tightly attached to the upper ring beam and the bottom structural surface of the beam. (6) Adjust the initial value of the electronic displacement sensor to make the initial value of the electronic displacement sensor zero; (7) Based on the load values ​​of the basement roof slab and the superstructure to be lifted, the computer control system set 90 lifting points, with a vertical displacement of 1 mm per level, for a total of 2000 levels. During the lifting process, the computer control system sends instructions to the oil pump pressure system, which controls the jacks to lift and tension the steel strands. When the jacks lift upwards, the steel strands drive the lifting steel columns to rise, thereby achieving the overall lifting of the basement roof slab and the superstructure. The computer control system collects real-time data from each electronic displacement sensor, stops operating after each level of displacement is reached, automatically analyzes the numerical deviation of the lifting height of each lifting device, and adjusts the pressure values ​​of each oil pump pressure system in a timely manner to ensure that the vertical displacement of each lifting point remains consistent until the basement roof slab and the superstructure are lifted 2.0 meters, at which point the force value of each jack is locked. The lifting mechanism uses a front-clamping tensioning jack with a "static piston, moving cylinder" structure. During lifting, the jack piston and tensioning sleeve remain stationary, while the outer cylinder sleeve, through sleeve, and tool anchor move backward relative to the jack piston. The tool anchor and tool clamps hold the steel strand for tensioning. After reaching the required prestress value, the oil is returned to its original position, the outer cylinder sleeve and through sleeve reset, and the working clamps and working anchors automatically anchor, completing the lifting process.

[0018] During the lifting process, the vertical displacement is 1mm for each lifting level, and there are a total of 2000 levels. After each lifting level is completed, the overall displacement is checked promptly using a fixed scale to prevent cumulative errors.

[0019] (8) Complete the construction of walls and columns within the lifting height range; (9) After the mortar and concrete columns of the newly added walls within the lifting height range have been cured to the design strength, the oil pump pressure system is controlled again by the computer control system to release the force on the steel strands by using jacks, so that the load of the basement roof and the upper auxiliary structure is applied to the newly added walls or structural columns. (10) Remove the lifting device and seal the bracket holes opened before lifting.

[0020] The main function of electronic displacement sensors is to monitor the relative displacement of the lifting system. The measured displacement data is then processed by a signal amplifier, and the amplified signal is transmitted to a computer via sensing circuitry for further processing. The placement of electronic displacement sensors directly affects the accuracy of the monitoring; a properly placed sensor array can objectively reflect the overall displacement posture. Therefore, when dividing the control area, it is necessary to consider whether the placement of the displacement sensors can objectively reflect the overall displacement of that control area. Of course, the verticality of the electronic displacement sensors should be ensured during installation to minimize human error and guarantee the sensor's accuracy.

[0021] The lifting principle of the top-pull combined building lifting method of the present invention is as follows: Precise synchronous control is crucial during lifting operations, and the control system should be a PLC-based synchronous displacement control system. The lifting power system of this invention consists of 90 jacks, including 75 27t jacks and 15 50t jacks. Vertical displacement control is the primary function, supplemented by structural stress and strain monitoring. To ensure synchronous movement of all jacks, this invention employs a PLC computer control system to achieve synchronous control during the lifting process.

[0022] 1) Working principle of PLC computer control system The PLC computer control system consists of several parts, including the hydraulic system (oil pump, oil cylinder, etc.), monitoring sensors, and computer control system.

[0023] 2) Hydraulic system The hydraulic system is computer-controlled and can automatically complete synchronous displacement, achieving control of force and displacement, displacement error, stroke, and load pressure. It features automatic protection against misoperation, process display, fault alarm, and emergency stop functions. The hydraulically controlled check valves in the cylinders prevent any form of system or pipeline pressure loss, ensuring effective load support. The A2F high-pressure plunger pump, check valve, accumulator, pressure sensor, and electromagnetic relief valve form an electronic unloading energy-saving oil supply circuit, stably providing the system with an oil pressure of 30.00-31.5 MPa (peak pressure value 35 MPa). A pressure-reducing valve is connected to the lower chamber of each lifting cylinder. Based on the measured pressure of each top load, the zero back pressure outlet pressure of the pressure-reducing valve is adjusted to be 2.0 MPa lower than the actual load pressure; that is, the zero back pressure outlet pressure of the pressure-reducing valve = measured top load pressure - 2.0 MPa. The pressure reducing valve has three ports: inlet, outlet, and return. If the set pressure of the pressure reducing valve is Po, and the pressure at the return port is Pc, then the pressure at the outlet is Po + Pc. It can be seen that the return port pressure is controlled by a proportional servo valve. When the outlet pressure Pc of the proportional servo valve is 2.0 MPa, the total thrust of the lifting cylinder balances the weight of the object being lifted. When Pc > 2.0 MPa, the object will rise, and when Pc < 2.0 MPa, the object will fall back. Therefore, a force closed-loop circuit consisting of several pressure reducing valves, one proportional servo valve, and one pressure sensor, together with several lifting cylinders, forms a proportionally controlled component. This component, together with an external displacement sensor, constitutes a position closed-loop system, which enables precise position control.

[0024] To avoid excessively large variations in Pc, which could lead to excessively rapid lifting, the inlet oil pressure of the proportional servo valve is reduced to 8.0-10.0 MPa. This pressure is supplied by a pressure reducing valve that lowers the oil pressure in the main circuit. To improve the closed-loop stability of the proportional servo valve, an accumulator is connected to its oil supply circuit.

[0025] In the lower chamber of each lifting cylinder, a hydraulically controlled check valve and a pressure testing connector are connected. As soon as the solenoid valve is de-energized, the hydraulically controlled check valve immediately closes, ensuring that the lifting cylinder does not slide down under load. A small amount of oil can be added to the lifting cylinder through the pressure testing connector.

[0026] During normal operation, solenoid A of the solenoid valve is always energized. In the neutral position, the solenoid valve provides support when the lifting cylinder completes a single lifting step. When the solenoid valve is in the neutral position, the oil pressure in both the upper and lower chambers of the lifting cylinder is zero. After closing the hydraulic check valve, the oil pipe can be disconnected. When solenoid B is energized, the lifting cylinder is in a no-load rapid retraction state. To prevent excessive speed during lifting or retraction, a speed control valve is connected to the oil inlet of the solenoid valve, which controls the maximum movement speed of the lifting cylinder.

[0027] Except for the check valve, pressure sensor, pressure gauge, and pressure test connector which are installed in the jack, the other components, including the control electrical components, are assembled in a hydraulic pump station. The hydraulic station and the jack are connected by two hoses, namely the oil inlet pipe and the oil return pipe, thus forming a complete hydraulic system.

[0028] A proportional valve, pressure sensor, and electronic amplifier form a pressure closed loop. The pressure of the pressure reducing valve is adjusted according to the load on each lifting cylinder. Several jacks form a lifting group to support the superstructure. However, if only force balance is achieved, the lifting position of the building is unstable. To stabilize the position, a monitoring sensor system is installed in the middle of each group for position feedback, forming a position closed loop. Once there is a deviation between the measured position and the commanded position, an error signal is generated. This signal is amplified and superimposed on the command signal, causing the total lifting force of the lifting group to increase or decrease. This results in a change in the position of each cylinder until the position error is eliminated. Since the position signals of each lifting system are provided by the same digital integrator, synchronous lifting of each lifting group can be maintained. By simply changing the time constant of the digital integrator, the lifting or lowering speed can be easily changed.

[0029] 3) Monitoring and sensing system The monitoring and sensing system is crucial to the entire lifting system, serving as the primary source of data. Its sensitivity directly impacts the synchronization accuracy of the lifting. The monitoring and sensing system mainly consists of displacement sensors, signal amplifiers, sensing circuitry, and a computer. The most important component is the electronic displacement sensor, which boasts a resolution of 0.01 mm.

[0030] The main function of electronic displacement sensors is to monitor the relative displacement of the lifting system. The measured displacement data is then processed by a signal amplifier, and the amplified signal is transmitted to a computer via sensing circuitry for further processing. The placement of electronic displacement sensors directly affects the accuracy of the monitoring; a well-placed system can objectively reflect the overall displacement attitude. Therefore, when dividing the control area, it is necessary to consider whether the placement of the electronic displacement sensors can objectively reflect the overall displacement of that control area. Of course, the verticality of the electronic displacement sensors should be ensured during installation to minimize human error and guarantee the accuracy of the sensors.

[0031] 4) Computer System The computer system is the core of the entire PLC system. It analyzes and processes the data collected by the monitoring and sensing system, and feeds the processed data back to the hydraulic system. The hydraulic system then adjusts the oil pressure of each jack to ensure the synchronization of the entire lifting system.

[0032] 5) Lifting process of the synchronous lifting system a. Install the jack and displacement detection sensor device. The jack must be installed with a flat contact surface, and the displacement sensor must be installed with the pull line perpendicular.

[0033] b. Install hydraulic hoses. According to the distribution of the jacks, connect the oil inlet and outlet of each jack to the hydraulic lifting pump station using hydraulic hoses.

[0034] c. Connect the power cable. Insert the main power plug into the pump station. Then, according to the distribution of control points, connect the displacement detection device and the displacement detection port on the hydraulic lifting pump station with signal cables.

[0035] d. Before synchronous lifting, check whether the displacement sensor reading is accurate. Arrange for on-site personnel to pull out the displacement sensor rope and confirm whether the reading on the display screen is the same as the displacement reading pulled out by the rope on site.

[0036] e. Before synchronous lifting, press the "fit" button. The jack will then begin lifting, and will automatically stop lifting when the actual pressure reaches the fit pressure value. The optimal fit pressure setting is approximately 50% of the actual load.

[0037] f. After the bonding is completed, first set the target displacement, then press the rise button. The jack will then rise automatically and stop automatically when it reaches the set target displacement.

[0038] g. Single-action operation: Switch the single-action switch to the left position, and then press the up or down button. To stop, press the stop or master stop button.

Claims

1. A top tensioned combined building lifting method for a two-story power distribution room of a semi-basement, characterized in that, The method comprises the following steps: Step 1, disconnect the building to be lifted at the bottom of the ring beam, and divide it into the lower basement and the upper lifting layer; Step 2, open bracket holes at the bottom of the ring beam, the beam end and the column top at the intersection of the longitudinal and transverse walls, respectively, install lifting devices at the lifting positions between the basement and the lifting layer, and make the steel brackets of the lifting devices be arranged in the bracket holes according to design requirements; Step 3, arrange the jacks on the steel brackets at the top of the steel columns supported by the lifting devices, and lock the steel strands of the steel brackets by using an anchor; Step 4, connect the jacks of the lifting devices to an oil pump pressure system, and install electronic displacement sensors at each lifting position to be lifted, wherein the oil pump pressure system and the electronic displacement sensors are connected to a computer control system; Step 5, send instructions to the oil pump pressure system through the computer control system, and control the jacks to pre-tension the steel strands, so that the steel brackets in the bracket holes are tightly combined with the upper ring beam and the structural surface at the bottom of the beam; Step 6, according to the load values of the basement roof to be lifted and heavy equipment, control the jacks at each lifting position to perform lifting work, and stop lifting when the preset displacement is reached; Step 7, perform wall column construction in the lifting section between the basement and the upper lifting layer, remove the lifting devices after the construction is completed, and seal the bracket holes opened before lifting.

2. The top-down hybrid building lifting method according to claim 1, wherein, The specific steps of step 6 are as follows: Step 6.1, according to the load values of the basement roof to be lifted and the upper auxiliary structure, set multiple lifting positions and multiple lifting levels through the computer control system, and make the vertical displacement of each lifting position per level not exceed 3 mm; Step 6.2, send instructions to the oil pump pressure system through the computer control system, and control the jacks to lift and tension the steel strands, so that the jacks are lifted upward; Step 6.3, the electronic displacement sensors at each lifting position collect real-time data of the lifting height, analyze the numerical deviation between the actual lifting height and the preset lifting height, and transmit the numerical deviation to the computer control system; Step 6.4, the computer control system adjusts the pressure value of the oil pump pressure system according to the numerical deviation, so that the vertical displacement of each lifting position is consistent; Step 6.5, lock the force value of each jack and stop lifting when the preset displacement is reached.

3. The top-down hybrid building lifting method according to claim 1, wherein: In step 6, the number of lifting positions is not less than 80, the jacks at each lifting position are controlled synchronously by the computer control system, and the vertical displacement per level of lifting is 1 mm. In step 2, the steel brackets of the lifting device are three, two of which are used to be fixed with the jacks, and the other one passes through the bracket hole at the bottom of the ring beam and is used for lifting the ring beam.

4. The top-down hybrid building lifting method according to claim 1, wherein: In step 3, vertical supports are arranged between the steel columns, and horizontal supports are arranged at the top in the longitudinal and transverse directions.

5. The top-down hybrid building lifting method according to claim 1, wherein: In step 6.2, the jacks are of the front clamping type. When lifting, the jack piston and the tensioning bush are stationary, the outer cylinder sleeve, the through sleeve and the tool anchor move backward relative to the jack piston, the tool anchor and the tool clamp hold the steel strands for tensioning, and the outer cylinder sleeve and the through sleeve reset after the required prestress value is reached, and the working clamp and the working anchor are automatically anchored.

6. The top-down hybrid building lifting method according to claim 2, wherein: ​ 7. The top-down hybrid building lifting method according to claim 1, wherein: In the step 4, each to be lifted point position is pasted with a chord strain gauge, and is connected to a strain tester and a computer control system; the strain tester is used for monitoring whether the data is abnormal, and the computer control system is used for analyzing abnormal data and adjusting the lifting scheme.

8. The top-down hybrid building lifting method according to claim 1, wherein: The multi-storey building is provided with heavy electrical equipment.

9. The top-down hybrid building lifting method according to claim 1, wherein: The step 7 further comprises a step of arranging a mezzanine between the basement and the lifted layer of the upper part.

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