Construction method for integrally lifting and rectifying high-rise building foundation and structure

Abstract

The invention relates to a high-rise building foundation and structure overall lifting and inclination rectifying construction method which comprises the steps that a water accumulation pool is built on the top of a basement bottom plate of a building, a pressure relief drainage hole is formed in the basement bottom plate, and accumulated water of a soil body at the bottom of the basement bottom plate is extracted through the pressure relief drainage hole and concentrated in the water accumulation pool; pile pressing holes are formed in a foundation bottom plate of the building, a plurality of counter-force anchor rods are buried in the foundation bottom plate, and pile sinking is constructed in the pile pressing holes; a lifting frame is fixedly installed on the multiple counter-force anchor rods, a hydraulic jack is fixedly arranged at the top of the sunken pile and located below the lifting frame, and the hydraulic jack is lifted to abut against the bottom of the lifting frame so as to conduct deviation rectification on the building; and mortar is poured into the bottom of the basement bottom plate so as to fill a gap between the basement bottom plate and the soil body.

Description

Technical Field

[0001] The present invention relates to the technical field of construction engineering, and particularly refers to a construction method for integral lifting and inclination rectification of the foundation and structure of high-rise buildings. Background Art

[0003] At present, for high-rise buildings with excessive inclination, two major categories of forced settlement inclination rectification method and structural separation and jacking inclination rectification method are often adopted according to different site environments and engineering conditions. These two methods have their own advantages and disadvantages. The common point of the two methods is that the basic foundation settlement control plan is the same, and the differences are reflected in the following aspects: The forced settlement inclination rectification method has relatively poor controllability and low inclination rectification accuracy compared with the jacking inclination rectification method, and has a certain impact on the building elevation, but the construction period is short and the project cost is low; while the jacking inclination rectification method can avoid the above problems, but there are also some disadvantages, such as 1) Since the center of gravity of high-rise buildings is high and the horizontal load is large, after the structure is separated from the foundation, it will have an adverse impact on the stability of the structure; 2) The vertical members cut off the steel bars at the same level, and there are high safety risks in the structure and it is not conducive to earthquake resistance; 3) The later demolition amount of the underpinning system is large, generating a large amount of construction waste and being not environmentally friendly; 4) It involves excavation affecting the environment and the inclination of the basement itself cannot be rectified; 5) The construction period is long, the cost is high, and the social impact is large. Summary of the Invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and provide a construction method for integral lifting and inclination rectification of the foundation and structure of high-rise buildings, which reduces the construction difficulty by using hydraulic jacks to rectify the building.

[0005] The technical solution to achieve the above purpose is a construction method for integral lifting and inclination rectification of the foundation and structure of high-rise buildings, including:

[0006] Build a sump at the top of the basement floor of the building, open a pressure relief and drainage hole on the basement floor, and extract the accumulated water in the soil at the bottom of the basement floor through the pressure relief and drainage hole and concentrate it in the sump;

[0007] Open a pile pressing hole on the foundation slab of the building, bury a number of reaction anchor rods on the foundation slab, and construct a driven pile in the pile pressing hole;

[0008] Fix and install a lifting frame on a number of the reaction anchor rods, and fixedly set a hydraulic jack at the top of the driven pile. The hydraulic jack is located below the lifting frame. By lifting the hydraulic jack, the hydraulic jack is made to push against the bottom of the lifting frame to rectify the building;

[0009] Pour mortar at the bottom of the basement floor to fill the gap between the basement floor and the soil.

[0010] Further, when rectifying the building by using the hydraulic jacks, a plurality of the hydraulic jacks are provided, and the lifting amount of each hydraulic jack is provided according to the actual situation of the building.

[0011] Further, the lifting amount △hi of the hydraulic jack is:

[0012]

[0013] where li is the horizontal distance from the position of the lifting frame corresponding to the hydraulic jack to the calculated lifting point, L is the horizontal distance from the position of the lifting frame corresponding to the hydraulic jack to the maximum settlement point of the building, and Sv is the maximum designed lifting amount for rectifying the building.

[0014] Further, when opening the pile pressing holes in the foundation floor slab, the pile pressing holes are formed by using a static water drill with a slight inclination to take cores.

[0015] Further, when embedding the reaction force anchor rods in the foundation floor slab, the anchor rod holes are drilled by using a water drill to take cores, the reaction force anchor rods are arranged in the anchor rod holes, and slurry is poured into the anchor rod holes. After the slurry solidifies, the reaction force anchor rods are embedded in the foundation floor slab.

[0016] Further, after the slurry solidifies, the slurry is cured and the anti-pulling force test is carried out on the reaction force anchor rods.

[0017] Further, before rectifying the building, a plurality of horizontal cross bars are arranged in the basement of the building, and a plurality of emergency steel supports are arranged between the horizontal cross bars and the foundation floor slab.

[0018] Further, before rectifying the building, displacement sensors are arranged on the hydraulic jacks.

[0019] Further, when grouting the bottom of the basement floor slab, a grouting test is carried out to determine the grouting construction process parameters.

[0020] Further, when constructing the pile sinking, the pile sinking is kept vertically arranged.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] By using hydraulic jacks to rectify the building, the construction difficulty is reduced. By using hydraulic jacks, the rectifying height can be accurately controlled. The construction rectifying has a wide application range, strong controllability, high precision, and is safe and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1It is the effect diagram before deviation rectification of a construction method for integral lifting and inclination rectification of high-rise building foundation and structure;

[0024] Figure 2 It is the effect diagram after deviation rectification of a construction method for integral lifting and inclination rectification of high-rise building foundation and structure;

[0025] Legend: 1. Lifting frame; 2. Pressed pile; 3. Foundation slab. Specific implementation mode

[0026] The present invention will be further described below in conjunction with the attached drawings and specific embodiments.

[0027] Refer to Figure 1 , a construction method for integral lifting and inclination rectification of high-rise building foundation and structure, including: building a water accumulation pool at the top of the basement floor slab of the building, opening pressure relief and drainage holes on the basement floor slab, and pumping and concentrating the accumulated water in the soil at the bottom of the basement floor slab through the pressure relief and drainage holes into the water accumulation pool; opening pressed pile holes on the foundation slab 3 of the building, burying a number of reaction anchor rods on the foundation slab 3, and constructing pressed piles 2 in the pressed pile holes; fixedly installing a lifting frame 1 on a number of the reaction anchor rods, and fixedly setting hydraulic jacks at the top of the pressed piles 2, the hydraulic jacks are located below the lifting frame 1, and by lifting the hydraulic jacks, the hydraulic jacks are made to push against the bottom of the lifting frame 1 to rectify the inclination of the building; grouting mortar at the bottom of the basement floor slab to fill the gap between the basement floor slab and the soil.

[0028] In the present invention, a preferred implementation mode is: using the self-weight load of the existing building as the reaction force for pressing piles, pressing the pressed piles 2 into the pile position holes, then using the supplemented pressed piles 2 as support points, installing a lifting device, and implementing integral synchronous lifting and inclination rectification of the foundation and structure. During the inclination rectification process, the base of the basement floor slab where there is void at the bottom is synchronously grouted with cement slurry to make it dense. After the inclination rectification is in place, the piles are cut off and sealed in batches.

[0029] Further, when rectifying the inclination of the building through the hydraulic jacks, a number of the hydraulic jacks are provided, and according to the actual situation of the building, the lifting amount of each hydraulic jack is provided.

[0030] Further, the lifting amount △hi of the hydraulic jack is:

[0031]

[0032] Where li is the horizontal distance from the position of the lifting frame 1 corresponding to the hydraulic jack to the calculated lifting point, L is the horizontal distance from the position of the lifting frame 1 corresponding to the hydraulic jack to the maximum settlement point of the building, and Sv is the maximum designed lifting amount for inclination rectification of the building.

[0033] Further, when forming the pile pressing holes in the foundation bottom plate 3, a static water drill is used to slightly incline and take cores to form the pile pressing holes.

[0034] Further, when embedding the reaction force anchor rods in the foundation bottom plate 3, water drilling is used to take cores and drill the anchor rod holes, the reaction force anchor rods are arranged in the anchor rod holes, and slurry is poured into the anchor rod holes. After the slurry solidifies, the reaction force anchor rods are embedded in the foundation bottom plate 3.

[0035] Further, after the slurry solidifies, the slurry is cured, and a pull-out resistance test is carried out on the reaction force anchor rods.

[0036] Further, before rectifying the building, a number of horizontal cross bars are arranged in the basement of the building, and a number of emergency steel supports are arranged between the horizontal cross bars and the foundation bottom plate 3.

[0037] Further, before rectifying the building, a displacement sensor is arranged on the hydraulic jack.

[0038] Further, when grouting the bottom of the basement floor slab, a grouting test is carried out to determine the grouting construction process parameters

[0039] Further, when constructing the driven pile 2, the driven pile 2 is kept vertically arranged.

[0040] The usage process of a construction method for integral lifting and rectifying inclination of a high-rise building foundation and structure according to the present invention will be described below.

[0041] 1. For the construction of the basement floor, first be familiar with the design drawings and relevant documents of the building; prepare a special construction plan, submit it to the design and supervision for review, and conduct safety technical briefing after modifying and improving the plan according to the review opinions; conduct a comprehensive inspection and evaluation of the working stress conditions of the existing building, understand the impact of the damaged condition of the building on the structure itself, and propose safety measures to ensure the lifting construction; establish a monitoring system on site to ensure information-based construction; check whether the relevant pipelines and underground pipelines are separated; conduct a comprehensive inspection of the raw materials, mechanical equipment, etc. entering the site, especially the calibration of pile driving and hydraulic jacks; communicate and negotiate with the power supply department in advance to ensure normal power supply during the lifting stage, or prepare dual-circuit power supply; directly open a pressure relief drainage hole on the basement floor, and if necessary, pre-drill an outdoor precipitation deep well and an indoor drainage well; open a pressure relief and drainage hole on the basement floor with a diameter of Φ60~100mm and a depth of 0.2~0.3m below the bottom of the basement floor. First, open a pressure relief drainage hole with a diameter of Φ60 to drain water, and then gradually expand the pressure relief hole diameter according to the water discharge situation. Before drilling, a water collection pool of about 1.2m high is set up in the area of about 1m×1m outside the area. The water collection pool is made of bricks or steel plates welded around and built on the bottom plate structure surface (if there is a leveling layer, the leveling layer needs to be cut off after cutting the edge line). The wall thickness of the masonry water collection pool is 240mm, the mortar is full, and the inner side and surface of the pool wall are brushed with 20-30mm thick mortar for anti-seepage. Then a self-priming pump and a submersible pump are set up in the water collection pool to pump and drain water. After the water is drained below the basement floor, the hole is expanded and replaced with a self-priming pump to absorb water, ensuring that the groundwater level is below the basement floor during construction; during the tilt correction and reinforcement construction, two sets of manual and automatic monitoring systems are established, and the main monitoring content is: house settlement and tilt. The data of the two monitoring systems should be checked against each other every day. If the data is abnormal, the cause should be found out before the next process can be constructed; when opening the pile hole on the existing foundation floor 3, a static water drill micro-tilt coring and hole-making process should be used to reduce damage to the existing floor. If the opening and cutting of the steel bars affect the bearing capacity of the foundation slab 3, the foundation slab 3 should be reinforced by bonding steel reinforcement on the surface; the reaction anchors use ΦT25~ΦT40 prestressed threaded steel bars (fpyk=785~1080MPa), and use a water drill to drill holes on the foundation slab 3, with a hole diameter of Φ50~Φ100mm and a hole depth of 500~1200mm. Pour C40~C80 anchoring grouting material in the holes and maintain for 2~3 days. And perform pull-out resistance tests in advance according to the specifications. The bearing capacity of the reaction anchor group near each pile should be no less than twice the maximum lifting force;

[0042] 2. For the construction of the driven pile 2, first check the anchor rods and pile driving machine, clean the pile hole, and clean the wall of the pile hole thoroughly. The lifting frame 1 should be kept vertical, and the nuts of the anchor bolts should be tightened evenly. During the pile driving construction process, the loosened nuts should be tightened at any time. The pile section should be placed vertically to align the jack with the pile section and the axis of the pile driving hole, and no eccentric pressing is allowed. The pile sections should be driven in separately, and the driving of the pile sections and the welding of the pile sections should be carried out alternately. The first three sections should be slowly pressed in, and good verticality must be maintained, with the inclination rate < 1%. For subsequent connections, the pile body must be kept straight up and down. Straightening the pile during driving is prohibited, and lapping with shims is prohibited. The pile driving construction should not stop halfway and should be completed in one go. The welding quality of the pile sections is particularly important. Each set of pile driving machinery is specially equipped with 1-2 professional welders to be responsible for the welding operation of the precast piles. The weld quality grade is 2. During the pile driving process, a special person should be assigned to command the operation, and a special person should record the pressure gauge readings and draw the pressure curve. In case of any abnormality, the relevant record should be immediately reported to the technician to determine whether the quality of the driven pile 2 meets the requirements. The pile driving termination standard: Adopt a double control standard, that is, control both the pile length of the driven pile and the final pile driving force, and it is necessary to re-press 3-6 times before final sinking. The driven pile 2 should be constructed in batches with informationization to reduce the disturbance of the foundation and strictly control the additional settlement, so as to achieve immediate loading after driving. For the temporary protection and reinforcement of the raft, prestressed elastic supports are added during the lifting stage for the protective reinforcement of the raft. The method is as follows: First, fix the horizontal steel beam on the vertical members in the basement, and then apply vertical load to the raft with prestressed steel supports to balance part of the lifting force and reduce the internal force of the raft. It is also possible to symmetrically add inclined supports with shear walls or frame columns as the fulcrums to pre-reinforce the bottom plate to ensure the safety of force transfer during the lifting and inclination correction process;

[0043] 3. Fix the lifting frame 1 with reaction force anchor bolts. Arrange a self-locking hydraulic jack at the top of the pile sinking 2. Group the hydraulic jacks according to engineering conditions such as the load at each jacking point, the configuration of the variable-frequency speed control hydraulic pump station, the layout of the monitoring system, and the indoor and outdoor environment. Set a monitoring point for each group, and install a displacement sensor at each monitoring point; conduct reliability inspection of the lifting system; establish a on-site leading group for the lifting project, conduct pre-service training and safety technical disclosure for the operating personnel; check the structural part of the lifting system; the commissioning of the lifting system mainly includes the inspection of the hydraulic system, the control system, the monitoring system, the setting and reading of the initial value. The lifting construction monitoring refers to the monitoring carried out during the lifting process to ensure the overall posture of the building, including the translation, torsion, inclination, stress, and cracks of the structure, etc. Its monitoring points are mainly arranged on the first-floor floor. To ensure the synchronous progress of the lifting process, the actual load at each lifting point should be measured before lifting. When weighing, according to the calculated lifting load, the step-by-step loading method is adopted. Within a certain lifting height (1 - 10 mm), by repeatedly adjusting the oil pressure of each group, a set of lifting oil pressure values can be set so that the lifting pressure at each vertex is basically balanced with its upper load. Compare the measured value of each point with the theoretical calculated value, calculate the difference, jointly analyze the reasons by the hydraulic engineer and the structural engineer, and finally determine by the leading group whether the measured value of this point can be used as the reference value during lifting. If the difference is large, corresponding adjustments will be made. Conduct a trial lift before the formal lift. The trial lift is mainly to eliminate the pile body compression deformation of the precast pile and park for several hours for observation. Only when there is no change can the overall lift start. After the trial lift, if there is no problem, start the formal lift. The lifting stroke can be formulated according to the specific lifting height of the project. After jacking up one section (one set safety stroke), lock the mechanical lock nut of the jack, then install the stroke-changing support pad, and carry out the lifting of the next stroke, and cycle in turn until the lifting and inclination correction are in place. The lifting should be carried out in a graded and synchronous coordination manner. The maximum lifting amount of a single-stage stroke should not be greater than 10 mm. There should be a certain interval time after each stage of lifting amount. The next stage of lifting can only be carried out after the top back-tilt amount is coordinated with the current stage of lifting amount;

[0044] 4. Base tracking grouting. The first purpose of grouting is to prevent the deflection and cracking of the bottom plate caused by the "hanging in the air" of the bottom plate during the overall lifting of the basement. The second purpose is to fill the voids generated during the rectification process due to the lifting of the bottom plate and maintain the stress state of the existing foundation. The grouting parameters use a cement slurry with a water-cement ratio of 0.6 - 0.7:1 (mixed with 5% water glass), and 42.5-grade composite Portland cement is used. Before the formal grouting construction, a grouting test is carried out to determine the appropriate grouting construction process parameters. To prevent the loss of slurry, the grouting sequence should be from the periphery to the middle first, and the grouting pressure should be increased from small to large. The grouting pressure and speed should be controlled according to the rectification speed and effect of the pool body. There are 2 grouting pumps (grouting pressure 0 - 5 MPa) and 2 medium and low-pressure grouting pumps (grouting pressure less than 0 - 2.0 MPa). First, optimize the pile sealing process. The number of piles sealed in each batch should not be more than 3, and construction should be carried out at intervals. The holding load value should be taken as ≥1.0Ra. Before pile sealing, the inner wall of the pile pressing hole must be roughened and wetted to ensure the cleanliness of the hole. The roughening of the hole wall can be completed before the second pile driving; after pile sealing, good maintenance work should be done. The pile sealing material uses non-shrinking grouting material and is poured in two times. After the strength of the first pile sealing concrete reaches the design strength, the pile sealing reaction frame can be removed, but it should be noted that the prerequisite must be met, that is, the shear bearing capacity of the first pile sealing concrete should be more than 1.2 times the preloading value.

[0045] The present invention has been described in detail in combination with the accompanying drawings and embodiments. Those of ordinary skill in the art can make various variations of the present invention according to the above description. Therefore, some details in the embodiments should not constitute a limitation to the present invention, and the protection scope of the present invention will be defined by the scope defined in the appended claims.

Claims

1. A construction method for the overall lifting and inclination correction of the foundation and structure of a high-rise building, characterized in that, Including: Construct a water accumulation pool on the top of the basement floor slab of the building. Open pressure relief and drainage holes on the basement floor slab, and pump out the accumulated water in the soil at the bottom of the basement floor slab through the pressure relief and drainage holes and concentrate it in the water accumulation pool; Open pile pressing holes on the foundation floor slab of the building. Bury a number of reaction force anchor rods in the foundation floor slab, and construct pile sinking in the pile pressing holes; Fix and install a lifting frame on a number of the reaction force anchor rods, and fixedly set a hydraulic jack at the top of the pile sunk. The hydraulic jack is located below the lifting frame. By lifting the hydraulic jack, the hydraulic jack is made to push against the bottom of the lifting frame to correct the deviation of the building; Pour mortar at the bottom of the basement floor slab to fill the gap between the basement floor slab and the soil; 2. A construction method for integral lifting and inclination rectification of a high-rise building foundation and structure according to claim 1, characterized in that: at When correcting the deviation of the building through the hydraulic jack, a number of the hydraulic jacks are provided, and the lifting amount of each hydraulic jack is provided according to the actual situation of the building; 3. A construction method for integral lifting and inclination rectification of the foundation and structure of a high-rise building according to claim 2, characterized in that: The lifting amount △hi of the hydraulic jack is: Where li is the horizontal distance from the position of the lifting frame corresponding to the hydraulic jack to the calculated lifting point, L is the horizontal distance from the position of the lifting frame corresponding to the hydraulic jack to the point with the maximum settlement of the building, and Sv is the maximum designed lifting amount for correcting the deviation of the building; 4. A construction method for integral lifting and inclination rectification of a high-rise building foundation and structure according to claim 1, characterized in that: When opening the pile pressing holes in the foundation floor slab, use a static water drill to take core with a slight inclination to form the pile pressing holes; 5. A construction method for integral lifting and inclination rectification of the foundation and structure of a high-rise building according to claim 1, characterized in that: When burying the reaction force anchor rods in the foundation floor slab, use a water drill to take core and drill anchor rod holes, set the reaction force anchor rods in the anchor rod holes, pour slurry into the anchor rod holes, and after the slurry solidifies, the reaction force anchor rods are buried in the foundation floor slab; 6. A construction method for integral lifting and inclination rectification of the foundation and structure of a high-rise building according to claim 5, characterized in that: After the slurry solidifies, cure the slurry and conduct a pull-out resistance test on the reaction force anchor rods; 7. A construction method for integral lifting and inclination rectification of a high-rise building foundation and structure according to claim 1, characterized in that: at Before correcting the deviation of the building, set a number of horizontal crossbars in the basement of the building, and set a number of emergency steel supports between the horizontal crossbars and the foundation floor slab; 8. A construction method for integral lifting and inclination rectification of a high-rise building foundation and structure according to claim 1, characterized in that: Before correcting the deviation of the building, set displacement sensors on the hydraulic jacks; 9. A construction method for integral lifting and inclination rectification of the foundation and structure of a high-rise building according to claim 1, characterized in that: When pouring mortar at the bottom of the basement floor slab, conduct a grouting test to determine the grouting construction process parameters; 10. A construction method for integral lifting and inclination rectification of the foundation and structure of a high-rise building according to claim 1, characterized in that: When constructing the pile sunk, keep the pile sunk vertically set.

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