A low-disturbance deformation recovery method for old buildings

Abstract

The present invention relates to a method for low-disturbance deformation restoration of old buildings. First, an information monitoring system is arranged to real-time control the attitude of the old building. High-frequency hydraulic vibration hammers without resonance are used to drive steel pipe piles along the perimeter of the building. Loose soil is dug by rotary excavation inside the pipe piles to form a loosening groove conducive to subsequent building deformation adjustment, and it also plays a role in retaining to avoid the occurrence of uncontrollable large deformations. Casing pipes are distributed obliquely into the foundation from the bottom plate position, and the insertion of the bladder pipes and the extraction of the casing pipes are completed. On the side where the settlement of the old building is relatively small, the steel pipe piles are extracted, and at the same time, dewatering is carried out on the indoor bottom plate. On the side where the settlement of the old building is relatively large, high-pressure grouting is carried out on the pre-embedded bladder pipes, and the lifting effect on this side is achieved by the volume expansion of the bladder pipes. Combining the monitoring data, the fine rectification and leveling of the old building are dynamically completed. The soil in the rotary excavation loosening area is grouted and reinforced, and at the same time, the remaining steel pipe piles are extracted. Finally, supplementary grouting is carried out to ensure the stiffness balance around the formation, and finally the bottom plate is sealed.

Description

Technical Field

[0001] The present invention belongs to the technical field of building construction, and particularly relates to a method for low-disturbance deformation restoration of old buildings. Background Art

[0002] Under the background of urban renewal, the number of renovation projects for historical and cultural protection residential areas is increasing continuously, especially for the protection and deformation control of low-rise and multi-story old buildings. The complex surrounding environment and narrow construction space faced by old buildings require that the implementation of rectification must meet the requirements of low disturbance and low space. Secondly, due to the long age of old buildings, the structural performance shows insufficient toughness, and general repair schemes are difficult to effectively ensure the safety of the buildings themselves. It is necessary to fully combine information-based construction methods to achieve micro-iteration, refined control, and dynamic deformation restoration.

[0003] Generally, the methods for controlling the deformation of foundation bases often adopt high-pressure grouting reinforcement operations. Due to the complex and uncertain geological conditions, the diffusion mode of the slurry in the formation is random and disorderly, which is difficult to meet the requirements of precise deformation control. At the same time, for repeated rectification control, repeated grouting often requires splitting grouting of the existing solidified body, and the grouting effect is more difficult to control.

[0004] Therefore, how to provide a method for low-disturbance deformation restoration of old buildings is a technical problem that needs to be solved urgently by those skilled in the art.

[0005] The information disclosed in this background art section is only intended to enhance the overall understanding of the present invention and should not be regarded as an admission or any form of implication that this information is prior art known to those of ordinary skill in the art. Summary of the Invention

[0006] The present invention provides a method for low-disturbance deformation restoration of old buildings, which is used to solve the problems of uneven settlement and structural cracking damage of old buildings in the renovation projects of historical and cultural protection residential areas under the background of urban renewal due to changes in groundwater level, long-term soil consolidation, and recent adjacent construction disturbances; thereby ensuring the structural safety during the protective restoration of old buildings and their subsequent normal use.

[0007] To solve the above technical problems, the present invention includes the following technical solutions:

[0008] A method for low-disturbance deformation restoration of old buildings includes the following steps:

[0009] Step S1: Arrange an information-based monitoring system for the old building, complete the installation of sensing devices, complete the layout of monitoring points, calculate the actual deformation of the old building, and ensure the accurate calculation and control of the inclination and displacement of the old building in real time, and control the attitude of the old building.

[0010] Step S2: Drive steel pipe piles around the old building using a non-resonant high-frequency hydraulic vibratory hammer, and drill obliquely downward and drive casing pipes at the position of the bottom slab of the old building to provide hole positions for subsequent bladder pipe layout;

[0011] Step S3: According to the monitoring data, on the side of the old building with less settlement, use a rotary drilling rig to agitate and loosen the soil inside the steel pipe piles to form a loosening groove, reduce the soil pressure level on this side, and extract part of the soil according to the degree of differential settlement to ensure the sustainable progress of subsequent rectification; at the same time, on the side of the old building with larger settlement, complete the operation of inserting bladder pipes and removing casing pipes under the indoor bottom slab;

[0012] Step S4: According to the monitoring data, on the side of the old building with less settlement, use a non-resonant device to remove the steel pipe piles to form a relatively weak side of the formation stiffness, so as to facilitate the overall natural deflection trend towards the weak side, and at the same time use dewatering and drying on the indoor bottom slab to achieve the forced settlement effect on this side; on the side of the old building with larger settlement, perform high-pressure grouting on the pre-embedded bladder pipes indoors, and use the volume expansion of the bladder pipes to achieve the lifting effect on this side;

[0013] Step S5: According to the monitoring data, complete the overall rectification and leveling of the old building through the bladder pipes arranged at the bottom. After the leveling is completed, grout and reinforce the soil in the rotary drilling loosening area, and at the same time remove the remaining steel pipe piles;

[0014] Step S6: Carry out supplementary grouting on the steel pipe piles removed later to ensure the stiffness balance around the formation. After all the work is completed, finally complete the sealing of the bottom hole.

[0015] Further, the sensing equipment includes a static level, an inclinometer, and an automatic total station.

[0016] Further, the old building includes an upper space structure and an underground structure foundation, and the underground structure foundation includes a strip foundation or a raft foundation.

[0017] Further, the height of the upper space structure is about 20m.

[0018] Further, a slow-setting material is used as the grouting material in the bladder pipes.

[0019] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0020] The low-disturbance deformation repair method for old buildings provided by the present invention utilizes the low-disturbance characteristics of high-frequency non-resonant construction of steel pipe piles, combines the rotation of the auger in the pipe pile to loosen the soil to establish an asymmetric formation stiffness condition, which is beneficial to the building deformation recovery operation under limited jacking force, and combines the information monitoring data to gradually, slightly and dynamically complete the attitude adjustment of the existing structure, avoiding the uncontrollable and irrecoverable damage of the existing building caused by large deformation; at the same time, due to the use of the method of lifting the soil by grouting in the capsule to compact the soil, it effectively avoids the requirement of precise deformation control caused by the random and disorderly diffusion of the grout during the ordinary grouting process. With the help of the retarder material, the slurry in each capsule pipe can be continuously adjusted reciprocally, realizing the fine leveling of the uneven settlement of the old building, so as to effectively cope with the construction accuracy of rectifying and straightening under the complex structure configuration mode. The low-disturbance deformation recovery method for low-rise and multi-storey (about 20m) old buildings formed by the present invention ensures the structural safety during the repair process of the old building and its subsequent normal use. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of an old building in the low-disturbance deformation recovery method for old buildings in an embodiment of the present invention;

[0022] Figures 2 to 7 It is a flowchart of the low-disturbance deformation recovery method for old buildings in an embodiment of the present invention.

[0023] In the figure:

[0024] 11 - upper space structure, 12 - underground structure foundation; 21 - precision level, 22 - inclinometer, 23 - total station; 31 - steel pipe pile, 32 - bottom plate drilling; 41 - loosening groove, 42 - casing, 43 - capsule pipe; 51 - dewatering and drainage, 52 - high-pressure grouting, 53 - supplementary grouting, 54 - bottom plate hole sealing. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The following further describes in detail a low-disturbance deformation recovery method for old buildings provided by the present invention with reference to the accompanying drawings and specific embodiments. According to the following description, the advantages and features of the present invention will be clearer. It should be noted that the drawings are all in a very simplified form and use non-precise scales, only for the purpose of facilitating and clearly assisting in explaining the purpose of the embodiments of the present invention. For the convenience of description, the "upper" and "lower" described below are in the same direction as the upper and lower of the drawings, but this cannot be a limitation to the technical solution of the present invention.

[0026] Embodiment 1

[0027] Please refer to Figure 1, The old buildings along the street are generally low-rise or multi-story buildings, usually around 20m in height, including the upper space structure 11 and the underground structure foundation 12. The underground structure foundation 12 generally adopts strip foundation or raft foundation. Affected by the changes in the surrounding environment, long-term consolidation of the stratum, and the influence of adjacent construction disturbances, uneven settlement is likely to occur, causing the old building to tilt to one side, reducing the building's lifespan and affecting its normal use.

[0028] Please refer to Figures 2 to 7 , A low-disturbance deformation recovery method for old buildings, comprising the following steps:

[0029] Step S1: Install an information monitoring system for the old building, complete the installation of sensing devices, complete the layout of monitoring points, calculate the actual deformation of the old building, and ensure the accurate calculation and control of the inclination and displacement of the old building in real time, and control the attitude of the old building;

[0030] Step S2: Drive steel pipe piles 31 around the old building using a non-resonant high-frequency hydraulic vibratory hammer. Due to the low-disturbance characteristics of the non-resonant pile driving process, the impact on the building itself during pile formation is reduced. Drill holes 32 obliquely downward at the bottom plate position of the old building and drive in sleeves 42 to provide hole positions for subsequent bladder pipe layout;

[0031] Step S3: According to the monitoring data, on the side of the old building with less settlement, use a rotary drilling rig to agitate and loosen the soil inside the steel pipe pile to form a loosening groove 41, reducing the soil pressure level on this side. Extract part of the soil according to the degree of differential settlement to ensure the sustainable progress of subsequent rectification; at the same time, on the side of the old building with larger settlement, complete the operation of inserting the bladder pipe 43 under the indoor bottom plate and removing the sleeve;

[0032] Step S4: According to the monitoring data, on the side of the old building with less settlement, use a non-resonant device to remove the steel pipe pile to form a relatively weak side of the formation stiffness, so as to facilitate the overall natural deflection trend towards the weak side. At the same time, carry out dewatering and drying 51 on the indoor bottom plate to achieve the forced settlement effect on this side; on the side of the old building with larger settlement, inject high-pressure grout 52 into the pre-embedded bladder pipe indoors, and use the volume expansion of the bladder pipe 43 to achieve the lifting effect on this side;

[0033] Step S5: According to the monitoring data, complete the overall rectification and leveling of the old building through the bladder pipe 43 arranged at the bottom. After the leveling is completed, grout and reinforce the soil in the rotary drilling loosening area, and at the same time remove the remaining steel pipe piles 31;

[0034] Step S6: Carry out supplementary grouting 53 on the steel pipe piles removed later to ensure the stiffness balance around the formation. After all the work is completed, finally complete the bottom plate hole sealing 54.

[0035] Specifically, for the low-disturbance deformation recovery method of old buildings provided by the present invention, first, an information monitoring system is arranged to continuously monitor the attitude of the old building; high-frequency hydraulic vibration hammers without resonance are used to drive steel pipe piles 31 along the periphery of the building. Loose soil is rotary dug inside the steel pipe piles 31 to form a loose groove 41 conducive to subsequent building deformation adjustment, and it also serves as a retaining structure to prevent uncontrollable large deformations; sleeves 42 are distributed and driven obliquely into the foundation from the bottom plate position, and then the bladder pipes 43 are inserted and the sleeves 42 are pulled out; on the side of the old building with less settlement, the steel pipe piles 31 are pulled out, and at the same time, dewatering and drying 51 are carried out on the indoor bottom plate; on the side of the old building with larger settlement, high-pressure grouting 52 is carried out on the pre-embedded bladder pipes 43, and the volume expansion of the bladder pipes 43 is used to lift this side. Combining the monitoring data, the fine rectification and leveling of the old building are dynamically completed; the soil in the rotary dug loose area is grouted and reinforced, and the remaining steel pipe piles are pulled out; finally, supplementary grouting 53 is carried out to ensure the stiffness balance around the formation, and finally the bottom plate is sealed 54.

[0036] In this embodiment, more preferably, the sensing devices include a static level 21, an inclinometer 22, and an automatic total station 23. Through the sensing devices, the actual deformation of the old building is calculated to always ensure the accurate calculation and real-time monitoring of the inclination and displacement of the old building.

[0037] In this embodiment, more preferably, a retarder is used as the grouting material inside the bladder pipes 43.

[0038] Particularly, compared with the existing high-pressure grouting reinforcement and lifting rectification process, in this embodiment, monitoring and early warning are carried out, and timely realignment and repeated adjustment are made to achieve real-time deformation control of the old building.

[0039] The above examples are the preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above examples. The above-described embodiments only represent several embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the invention patent should be subject to the appended claims.

Claims

1. A method for low-disturbance deformation restoration of old buildings, characterized in that, it includes the following steps: Step S1: Install an information monitoring system for the old building, complete the installation of sensing devices, complete the layout of monitoring points, calculate the actual deformation of the old building, and ensure the accurate calculation and control of the inclination and displacement of the old building in real time, and control the attitude of the old building; Step S2: Drive steel pipe piles around the old building using a non-resonant high-frequency hydraulic vibratory hammer, and drill obliquely downward and drive sleeves at the bottom plate position of the old building to provide hole positions for subsequent bladder tube layout; Step S3: According to the monitoring data, on the side of the old building with less settlement, use a rotary drilling rig to agitate and loosen the soil inside the steel pipe pile to form a loosening groove, reduce the soil pressure level on this side, and extract part of the soil according to the degree of differential settlement to ensure the sustainable progress of subsequent rectification; at the same time, on the side of the old building with greater settlement, complete the operation of inserting the bladder tube and removing the sleeve under the indoor floor slab; Step S4: According to the monitoring data, on the side of the old building with less settlement, use a non-resonant device to remove the steel pipe pile to form a relatively weak side of the formation stiffness, so as to facilitate the overall natural deflection trend towards the weak side, and at the same time use dewatering to achieve the forced settlement effect on this side on the indoor floor slab; On the side of the old building with greater settlement, conduct high-pressure grouting of the pre-embedded bladder tube indoors, and use the volume expansion of the bladder tube to achieve the lifting effect on this side; Step S5: According to the monitoring data, complete the overall rectification and leveling of the old building through the bladder tubes arranged at the bottom. After the leveling is completed, grout and reinforce the soil in the rotary drilling loosening area, and at the same time remove the remaining steel pipe piles; Step S6: Carry out supplementary grouting on the steel pipe piles removed later to ensure the stiffness balance around the formation. After all the work is completed, finally complete the sealing of the bottom hole.

2. The method according to claim 1, characterized in that, the sensing devices include static level gauges, inclinometers and total station theodolites.

3. The method according to claim 1, characterized in that, the old building includes an upper space structure and an underground structural foundation, and the underground structural foundation includes a strip foundation or a raft foundation.

4. The method according to claim 3, characterized in that, the height of the upper space structure is about 20m.

5. The method according to claim 1, characterized in that, a retarder material is used as the grouting material inside the bladder tube.

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