Slope reinforcement and adjacent slope building deformation treatment method

Abstract

The invention discloses a side slope reinforcing and adjacent slope building deformation treatment method. The method comprises the steps that prefabricated square piles are driven into a soil body on the outer side of an existing building soil body retaining wall; the square pile and the retaining wall are connected through the upper connecting piece; the lower portion of the square pile is reinforced through a lower connecting piece; pouring a gap between the square pile and the retaining wall; the adjacent square piles are connected through the reinforcing cross beams and the conversion steel plates; in an interval defined by the upper and lower reinforcing cross beams and the square piles, transverse drilling is conducted on the retaining wall in the middle of the gap; the prefabricated pipe roofs are installed in the drill holes, and the prefabricated pipe roofs, the retaining wall and the soil body are fixed through grouting; the bag on the prefabricated pipe roofing is used for carrying out differential lifting on inclination and settlement of the existing building, and finally the bag grouting hole is blocked.

Description

Technical Field

[0001] This invention belongs to the field of slope treatment engineering, specifically relating to a method for slope reinforcement and deformation control of buildings on slopes. Background Technology

[0002] In urban development in mountainous and hilly areas with significant topographical variations, large-scale construction of buildings on slopes has become a common phenomenon. This construction often involves large-scale backfilling. While undisturbed soil typically has high density and strong bearing capacity, backfill soil, due to insufficient compaction, has weaker mechanical properties, resulting in a significant difference in bearing capacity. This difference can cause the backfill soil on the side of the diaphragm wall furthest from the existing building to fail to provide sufficient support, leading to deformation and cracking of retaining walls and other slope protection structures. Ultimately, this results in uneven deformation and eccentric settlement of the existing building, necessitating specialized remedial measures.

[0003] Uneven settlement control of buildings on slopes requires simultaneous slope reinforcement and building correction, resulting in significant overall construction challenges. For slope reinforcement, traditional techniques such as anchor bolts and soil nailing walls are commonly used, but these methods generally suffer from insufficient overall rigidity, making it difficult to fully withstand the lateral pressure of complex terrain. Regarding building correction, the mainstream technique is forced settlement correction, which has specific requirements for site space, often limited by the terrain. More importantly, forced settlement correction requires settlement control on one side of the building, where the geological conditions are typically favorable, often consisting of rock strata, further increasing the difficulty of key procedures such as drilling and grouting. Specifically: (1) Anchor / soil nail wall support: Local anchoring is achieved by implanting anchors or soil nails in the soil. However, this type of technology can only constrain the soil around the anchor point and cannot form an integral force system with the retaining wall. When faced with the difference in bearing capacity between the backfill layer and the original soil, the overall resistance to lateral displacement is weak. It is easy for the support structure to deform and crack due to uneven distribution of lateral pressure, and it cannot provide a stable reaction foundation for subsequent building correction. (2) Reinforcement of a single retaining wall: Only local treatments such as thickening and grouting are carried out on the retaining wall itself, ignoring the synergistic effect between the retaining wall, the diaphragm wall, and the surrounding soil. The problem of insufficient compaction of the backfill layer has not been solved, and the backfill on the side of the diaphragm wall away from the building still cannot provide effective support, and the risk of deep slope instability still exists.

[0004] (3) Forced settlement correction method: As the mainstream correction technology, its principle is to achieve local settlement on the side of the building with smaller settlement (mostly the hillside side of the slope site) by means of soil removal, drilling and other methods, so as to complete the repositioning of the building. However, in the slope site, the soil on the hillside side is the core support for maintaining the stability of the slope. Soil removal will directly destroy the integrity of the slope and significantly increase the risk of slope instability. Therefore, it is usually prohibited in this type of terrain and cannot meet the correction needs of the slope building. (4) Traditional jack lifting method: Single-point / multi-point lifting is carried out by setting jacks under the foundation of the building. There are three fatal defects: First, the stress concentration is serious. Single-point loading of the jack can easily lead to local pressure damage to the foundation of the building, causing new structural damage. Second, the working space requirement is large. Large-scale excavation is required under the building. However, the slope site is often restricted by the terrain and the working space is narrow, which cannot meet the construction conditions. Third, the reaction system is unreliable. The bottom of the jack often acts directly on the original soil or simple cushion layer. The bearing area is small. When facing the building load, the reaction force is insufficient, which can lead to additional settlement during the lifting process, or even cause structural instability. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned defects of the prior art and provide a method for treating deformation of buildings on slopes that integrates slope reinforcement and building correction.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: This invention provides a method for slope reinforcement and deformation control of buildings on slopes, comprising the following steps: Step 1: Drive precast square piles into the soil outside the existing building retaining wall. Step 2: Connect the square piles and the retaining wall using the upper connector; Step 3: Reinforce the lower part of the square pile using the lower connector; Step 4: Pour concrete into the gap between the square pile and the retaining wall; Step 5: Connect adjacent square piles by reinforcing the crossbeams and using conversion steel plates; Step 6: Drill holes in the reserved area of ​​the retaining wall within the section enclosed by the upper and lower reinforcing beams and square piles; Step 7: Push (or press) the precast pipe curtain into the borehole, and fix the precast pipe curtain itself and the precast pipe curtain to the retaining wall and soil by grouting; Step 8: Use the grouting bags on the precast pipe curtain to implement differentiated lifting of the tilt and settlement of the existing building. After the lifting is completed, remove the grouting pipes from the grouting bags and seal them. Then carry out curing. After the curing is completed, seal the boreholes drilled in Step 6.

[0007] As a further technical solution, in step 1, the square pile is provided with pre-drilled holes, which are located at the vertical axis of the square pile and arranged sequentially from high to low.

[0008] As a further technical solution, the specific process of step 2 is as follows: First, holes are drilled into the retaining wall through the pre-drilled holes on the square piles. Then, the end of the upper connector is passed through the pre-drilled holes on the square piles and pushed forward until it is inserted into the retaining wall. The end of the upper connector has an expansion function, which can fit tightly against the inner wall of the hole in the retaining wall to form an initial anchor. Finally, the exposed end of the upper connector is fitted with a nut and tightened to the designed torque to ensure that there is no loose gap between the upper connector and the precast square pile, thus achieving a stable connection between the upper part of the precast square pile and the retaining wall.

[0009] As a further technical solution, the specific process of step 3 is as follows: Select a stable section where the lower part of the square pile is embedded in the original soil; use a drilling tool to drill a hole, advancing the hole from the outer soil towards the square pile until it penetrates the side wall of the square pile and penetrates into the inner original soil to a preset depth; after drilling is completed, insert the lower connector into the hole. The end of the lower connector has an expansion function. After the expansion is triggered, it can be tightly combined with the inner wall of the hole to form a reliable anchor. The exposed section of the lower connector is reinforced with steel mesh, a formwork is installed, and micro-expansion concrete is poured into the formwork. After solidification, the formwork is removed to form a reinforced concrete slab that completely encloses the lower connector. This allows the lower connector to form a synergistic force-bearing system through the reinforced concrete slab, significantly enhancing the connection stability between the lower part of the precast square pile and the soil.

[0010] As a further technical solution, the upper part of the precast tube curtain is integrated with multiple lifting bags and bag grouting pipes, and the side is integrated with cement diffusion grouting pipes. Cement diffusion outlets are provided on the side wall of the precast tube curtain, and the cement diffusion outlets are connected to the cement diffusion grouting pipes. Before bag grouting, the bag grouting pipes are connected to the lifting bags located on the innermost side of the precast tube curtain.

[0011] As a further technical solution, each bag opening on the precast tube curtain has a tightening structure to prevent slurry leakage between two bags.

[0012] As a further technical solution, the specific construction process of step 7 is as follows: The precast pipe curtain is jacked into the borehole using a pipe jacking machine. After all the precast pipe curtains are in place according to the design, the precast pipe curtain body is first grouted until the concrete fills the entire internal space of the pipe curtain. Then, using the cement diffusion grouting pipes reserved on both sides, grouting is carried out in a sequence from deep to shallow. During the grouting process, the cement diffusion grouting pipes are pulled out at a uniform speed, so that the grout can evenly penetrate into the bottom of the pipe curtain and the surrounding soil through the grout outlet gaps. When grout seepage occurs at the surface observation point, or when the cumulative grouting volume reaches the design threshold, the grouting pressure is maintained for a set time and then grouting is stopped. After the grouting is completed, curing is carried out to ensure that the grout fully solidifies and hardens, forming an expanded cement grout diffusion zone, thereby significantly improving the effective bearing area at the bottom of the pipe curtain.

[0013] As a further technical solution, the specific construction process of step 8 is as follows: During the lifting operation, the grouting pipe is inserted into the deepest sac and grouting is carried out using a backward grouting method. Grouting is performed while reversing. A high-precision real-time monitoring network is set up inside the existing building to detect the tilt angle of the existing building in real time.

[0014] As a further technical solution, in step 8, all the lifting bags on the pipe curtain are synchronously grouted and pressurized. At the same time, based on the real-time data fed back by the monitoring system, the lifting amount at each point is precisely controlled until the existing structure is lifted and stabilized to the design elevation.

[0015] As a further technical solution, in step 8, the lifting height at the corresponding position can be precisely adjusted by controlling the grouting volume of different bladders.

[0016] The beneficial effects of this invention are as follows: 1) The present invention has a stable structure and good synergistic stress performance: By driving dense square piles into the outside of the existing diaphragm wall, setting multiple rows of upper connectors, and pouring concrete connecting plates, a "reinforced composite support" that is tightly integrated with the original diaphragm wall is formed. This structure greatly enhances the overall stiffness, lateral displacement resistance, and stability of the diaphragm wall, providing a solid and reliable reaction foundation for subsequent jacking operations.

[0017] 2) The lifting reaction system of this invention is highly efficient and reliable: It adopts a prefabricated pipe curtain as the lifting execution channel and forms an enlarged grout solidified body by grouting at its bottom. This significantly increases the bottom bearing area, thereby providing a huge and evenly distributed counter support force that far exceeds the cross-sectional area of ​​the pipe curtain itself, effectively avoiding settlement or instability caused by insufficient reaction force during the lifting process.

[0018] 3) The lifting process of this invention is precise and controllable, causing no damage to the structure: Grouting and lifting are performed using the bladders inside the prefabricated tube curtain. The expansion of the bladders provides a gentle and uniform surface load, which can smoothly transfer the force to the building foundation, perfectly avoiding the stress concentration and local pressure damage risks that may be caused by traditional jack-type top loading. Combined with high-precision monitoring inside the building, millimeter-level fine-tuning can be achieved.

[0019] 4) The invention has good spatial adaptability and has little impact on the surrounding environment: The main working surface of the method is located outside the diaphragm wall, without the need for large-scale excavation under the building body. It is particularly suitable for complex environments with limited construction space (such as steep slopes or adjacent to important facilities), minimizing disturbance to slope stability and the surrounding environment. Attached Figure Description

[0020] To more clearly illustrate the details of this invention, the accompanying drawings used in the description will be briefly introduced below. The drawings described below are merely some structural drawings of this invention and should not be regarded as limiting the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a front view of the structure; Figure 2(a) and Figure 2(b) are the front and side cross-sectional views of the tube curtain; Figure 3(a) and Figure 3(b) are the front view and top view of the connection between the retaining wall and the reinforcing square piles; Figure 4 Diagram showing reinforcement above the bottom soil layer; Figure 5 This is a cross-sectional view before the lifting. Figure 6 This is a cross-sectional view of the entire structure after the elevation. Among them: 1-retaining wall, 2-square pile, 3-reinforced beam, 4-precast pipe curtain, 5-bag, 6-upper connector, 7-bag grouting pipe, 8-cement diffusion grouting pipe, 9-cement diffusion grout outlet, 10-cement grouting material, 11-reinforced concrete slab, 12-lower connector, 13-high-strength bolt, 14-conversion steel plate, 15-high-strength bolt washer, 16-inner soil layer, 17-waterproof membrane, 18-outer soil, 19-existing building, 20-precast pipe curtain grouting port. Detailed Implementation

[0022] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0023] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, unless otherwise expressly indicated by the invention, the singular form is also intended to include the plural form. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof. As described in the background section, existing slope reinforcement methods commonly employ traditional techniques such as anchor bolt support and soil nailing walls. However, these methods generally suffer from insufficient overall rigidity, making it difficult to fully withstand the lateral pressure of complex terrain. Regarding building correction, the mainstream technique is forced settlement correction, which has specific requirements for construction site space. However, on-site work often suffers from insufficient space due to the limited terrain of the adjacent slope. More importantly, forced settlement correction requires settlement control on one side of the building, where the geological conditions are usually better, often consisting of rock strata, further increasing the difficulty of key procedures such as drilling and grouting. To address these issues, this embodiment provides a slope reinforcement and adjacent building deformation control method, specifically including the following steps: Step 1: Driving precast square piles into the soil outside the existing building retaining wall; Step 2: Connecting the square piles and the retaining wall using upper connectors; Step 3: Inserting the lower part of the square piles into the soil using lower connectors. Step 4: Pour concrete into the gap between the square piles and the retaining wall; Step 5: Connect adjacent square piles using reinforcing beams and transfer steel plates; Step 6: Drill holes in the reserved area of ​​the retaining wall within the space enclosed by the upper and lower reinforcing beams and square piles; Step 7: Jack (or press) precast pipe curtains into the holes and fix them to the retaining wall and soil through grouting; Step 8: Use the bladders on the precast pipe curtains to differentially lift the existing building to address tilt and settlement, and finally seal the holes drilled in Step 6. By driving denser square piles into the outside of the existing diaphragm wall, setting multiple rows of upper connectors, and pouring concrete connecting plates, a "reinforced composite support" tightly integrated with the original diaphragm wall is formed. This structure greatly enhances the overall stiffness, lateral displacement resistance, and stability of the diaphragm wall, providing a solid and reliable reaction foundation for subsequent jacking operations. Using precast tubular walls as the lifting channel, and grouting at their bottom to form an expanded grout consolidation body, significantly increases the bottom bearing area. This provides a massive, evenly distributed counter-support force far exceeding the cross-sectional area of ​​the tubular walls themselves, effectively preventing settlement or instability caused by insufficient counter-force during lifting. Grouting and lifting are achieved using bladders inside the precast tubular walls. The expansion of these bladders provides a gentle, uniform surface load, smoothly transferring force to the building foundation and perfectly avoiding the stress concentration and localized foundation damage risks that can occur with traditional jack-type top loading. Combined with high-precision monitoring inside the building, millimeter-level fine-tuning can be achieved.

[0024] The slope reinforcement and deformation control method for adjacent buildings proposed in this embodiment will be described in detail below with reference to the specific accompanying drawings: Step 1: As Figure 1 As shown, precast square piles 2 are driven into the soil outside the existing building retaining wall 1. First, ground-penetrating radar is used to detect the soil outside the retaining wall to determine the soil distribution, density, and presence of underground pipelines. The construction area outside the diaphragm wall corresponding to the inclined section of the building is then delineated to ensure that construction does not damage surrounding concealed facilities.

[0025] Precast reinforced concrete square piles 2 are selected and driven into the soil outside the diaphragm wall in sequence using static pressure pile driving technology. The spacing of the square piles 2 is strictly controlled at 2 meters. The pile length of the square piles 2 needs to penetrate the fill layer to the original soil layer to ensure that the vertical bearing capacity of the square piles 2 meets the requirements of subsequent reinforcement and jacking. In addition, there are reserved holes pre-processed on the square piles 2. In this embodiment, there are four reserved holes on the square piles 2, located at the vertical axis of the square piles 2, arranged in descending order. Step 2: Connect the square pile 2 and the retaining wall 1 using the upper connector 6; First, holes are drilled into the retaining wall 1 through the four pre-drilled holes on the square pile 2. Then, the upper connector 6 is inserted into the holes of the square pile 2 and the retaining wall 1. The end of the upper connector 6 has an expansion effect and is reinforced with a high-strength nut at the outer end. This ultimately reinforces the square pile 2 and the retaining wall 1, and the upper connector 6 connects the precast square pile 2 and the retaining wall 1. The upper connector 6 can be made of anchor bolts. Specifically, four pre-reserved holes are pre-set on the square pile 2. All the pre-reserved holes are linearly distributed along the vertical axis of the square pile and arranged sequentially from top to bottom. Before construction, a high-pressure air gun is used to clean the dust, debris, and concrete residue in the reserved holes to ensure that the inner walls of the reserved holes are flat and free of obstructions. Then, holes are drilled in the retaining wall 1 through the four reserved holes on the square pile 2. Next, an upper connector 6 that is precisely matched to the size of the reserved hole is selected and slowly inserted into the reserved hole. The end of the upper connector 6 passes through the bottom of the reserved hole on the square pile 2 and continues to move forward until it is inserted into the retaining wall 1. The end of the upper connector 6 has an expansion function. After expansion is triggered by a special tool, it can fit tightly against the inner wall of the hole in the retaining wall 1 to form an initial anchor. Finally, a high-strength flat washer is fitted on the exposed end of the upper connector 6 and tightened with a high-strength nut to the designed torque to ensure that there is no loose gap between the upper connector 6 and the precast square pile 2, and finally a stable connection between the upper part of the precast square pile 2 and the retaining wall 1 is achieved.

[0026] Step 3 as follows Figure 4 As shown, the lower part of the square pile 2 is reinforced; First, the reinforcement location is determined by selecting a stable section where the lower part of the precast square pile 2 is embedded in the undisturbed soil. A diamond water-cooled drill bit is used for drilling. The drill bit is equipped with a water circulation cooling system, continuously supplying clean circulating water during drilling. The water flow cools the drill bit and removes drill cuttings, preventing cracking of the square pile concrete due to high temperatures or impact loads from dry drilling. Drilling should proceed from the outer soil 18 towards the square pile until it penetrates the sidewall of the square pile and reaches the predetermined depth in the outer undisturbed soil. After drilling, residual drill cuttings are flushed out of the hole with a high-pressure water gun. Once the hole is dry, a lower connector 12 suitable for the hole size is selected and slowly inserted into the hole. The connector end has an expansion function; after expansion, it can tightly bond with the inner wall of the hole, forming a reliable anchor. The lower connector 12 can be an existing anchor rod. Rust removal treatment was carried out on the exposed sections of the three lower connectors 12, and then steel mesh was tied according to the design requirements. Steel formwork was installed, and water-swellable waterstop strips were pasted on the contact surfaces between the steel formwork and the side wall of the square pile and the outer soil to prevent grout leakage during pouring. C35 micro-expansion concrete was poured into the formwork and compacted in layers using an immersion vibrator. After the concrete was poured, it was covered with geotextile and watered to cure until the design strength was reached. After the steel formwork was removed, a reinforced concrete slab 11 was formed that completely wrapped the three lower connectors 12, so that the lower connectors 12 formed a cooperative force-bearing system through the concrete slab, which significantly enhanced the connection stability between the lower part of the precast square pile and the soil.

[0027] Step 4: The gap between the opposing pile 2 and the retaining wall 1 is filled with cement grout 10; First, the gap at the connection point of the two parts is pre-treated: a high-pressure air gun is used to blow along the direction of the gap to thoroughly remove floating dust, soil debris and loose debris in the gap, ensuring that the inner wall of the gap is clean and free of foreign objects that would hinder the filling of the grout.

[0028] Then, the template installation work is carried out: 5mm thick steel templates are selected and tightly attached to the outer walls of the diaphragm wall and square piles. Water-swellable rubber sealing strips with a width of 20mm and a thickness of 5mm are pasted on the contact surfaces of the templates with the diaphragm wall and square piles. The templates are fixed to the diaphragm wall and square piles with expansion bolts to ensure that the templates are firmly installed and reliably sealed, and to prevent grout leakage during the grouting process.

[0029] After the template is fixed, cement grout material 10 is used for grouting. The grouting operation is carried out from the bottom to the top in layers from the grouting port reserved at the bottom of the gap. The height of each layer of grouting is controlled at 300-500mm to avoid segregation of the grout due to excessive grouting height in a single grouting operation. At the same time, a small hand-held vibrator is used to set up vibration points at 500mm intervals along the direction of the gap on the outside of the template. The vibration time of each vibration point is controlled at 10-15 seconds. During the vibration process, the surface of the grout on the inside of the template is observed until no air bubbles continue to overflow and the surface of the grout tends to be flat, ensuring that the grout fully fills all the tiny pores in the gap without voids or missing grout.

[0030] After all grouting work is completed, curing measures should be taken immediately for the grouting area: cover the outside of the formwork with geotextile and use water spraying for curing, with a curing period of no less than 7 days; during the curing period, the formwork, diaphragm wall, and square pile structure must not be disturbed. After the curing period is over, and after visual inspection confirms that there are no cracks or leakage marks on the surface of the grouting body, the formwork can be removed and subsequent construction procedures can begin.

[0031] Step 5: As shown in Figures 3(a) and 3(b), the adjacent precast square piles 2 are connected by the reinforcing beam 3 and the conversion steel plate 14; Q355B grade steel is selected as the reinforcing beam 3. Simultaneously, a conversion steel plate 14, compatible with the precast square pile 2 and the reinforcing beam, is prefabricated. The thickness of the conversion steel plate 14 is 10-12mm (adjusted according to the connection stress requirements), and its dimensions must cover the contact surface between the side wall of the square pile and the end of the steel section. Bolt holes matching the high-strength bolts 13 are pre-set on the conversion steel plate 14. The flanges of the steel section and the surface of the conversion steel plate 14 are sandblasted to remove rust and then coated with epoxy anti-rust paint to prevent future corrosion from affecting the connection strength.

[0032] One end of the conversion steel plate 14 is attached to the pre-set connection position on the side wall of the square pile, and the other end is tightly connected to the end of the steel section to ensure that there is no gap between the steel plate and the contact surface of the square pile and the steel section. M24 grade high-strength bolts are used to penetrate the pre-set bolt holes of the conversion steel plate 14 and the precast square pile 2 and the steel section. The bolt spacing is controlled at 150-200mm, and at least 2 sets of bolts are set at each connection point. The bolts are tightened with a torque wrench according to the design torque. During the tightening process, the "diagonal tightening" method is used to avoid uneven local stress that may cause the connection to loosen.

[0033] The steel flange should fit tightly against the outer wall of the diaphragm wall (fitting surface error ≤ 2mm). A 10mm thick high-strength bolt washer 15 should be installed on the contact surface between the flange and the diaphragm wall (to prevent damage to the diaphragm wall surface when tightening the bolts). Similarly, M24 grade high-strength bolts should be used to pass through the bolt holes of the flange and the diaphragm wall, and tightened to the torque requirements mentioned above. After the bolts are installed, check the fit between the flange and the diaphragm wall. If there are any small gaps, fill them with non-shrink cement-based grout to ensure a reliable connection.

[0034] Step 6: Within the area enclosed by the upper and lower reinforcing beams 3 and the precast square piles 2, drill holes into the soil inside the retaining wall 1. According to the requirements of precast pipe curtain layout, an opening point is evenly marked between the two reinforced crossbeams 3 and in the interval between every two square piles. Before opening the hole, a steel bar scanner is used to detect the position of the steel bars inside the diaphragm wall, avoiding areas with dense steel bars, and ensuring that the opening does not damage the load-bearing structure of the diaphragm wall.

[0035] Water drilling is used to form holes, with the drill speed controlled at 800-1000 r / min and the drilling speed ≤50 mm / min to avoid impact and vibration causing cracks in the diaphragm wall. After drilling, concrete debris is cleaned from the hole, and the inner wall of the hole is ground smooth with an angle grinder to ensure that the flatness deviation of the inner wall is ≤2 mm / m.

[0036] Cut the polymer waterproof membrane to a size 200mm larger than the perimeter of the hole. Use a special waterproof adhesive to attach the membrane to the soil-facing side of the hole and around the opening. Use a hot air gun to heat and compact the overlaps to ensure there are no voids or damage, forming the first waterproof seal layer. Then, apply a 2mm thick cement-based penetrating crystalline waterproof coating to the inside of the opening to further enhance the waterproof effect.

[0037] Step 7: As Figure 5 As shown, a precast pipe curtain is installed inside the borehole, and the precast pipe curtain is fixed to the retaining wall and soil by grouting; The precast pipe curtain in this step is made of steel, as shown in Figures 2(a) and 2(b). The upper part of the precast pipe curtain is integrated with multiple lifting bags 5 and a bag grouting pipe 7, and the side is integrated with a cement diffusion grouting pipe 8. The side wall of the precast pipe curtain is provided with a cement diffusion outlet 9, which is connected to the cement diffusion grouting pipe 8. Before the bag 5 is grouted, the bag grouting pipe 7 is connected to the lifting bag 5 located on the innermost side of the precast pipe curtain. Each bag 5 on the precast pipe curtain 4 has a tightening structure at its opening, so that there will be no grout leakage between two bags 5.

[0038] The jacking operation of the precast pipe jacking 4 was carried out using a hydraulic pipe jacking machine. Before jacking, steel pads were placed between the pipe jacking machine and the precast pipe jacking 4 to evenly transfer the load. During the jacking process, a laser collimator was used to monitor the deviation of the pipe jacking axis in real time to ensure that its linear deviation was controlled within 10 mm per meter. After the jacking was completed, the soil inside the pipe jacking was removed by a horizontal auger drill.

[0039] After all the precast pipe curtains are jacked into place according to the design, grouting is carried out through the pre-set grouting holes on the pipe body. First, the soil inside the precast pipe curtain is transported out using a spiral soil removal device, and grout is injected into the precast pipe curtain body until the concrete fills the entire internal space of the pipe curtain. Then, using the cement diffusion grouting pipes 8 reserved on both sides, grouting is carried out in the same order from deep to shallow. During the grouting process, the grouting pipes are pulled out at a uniform speed, allowing the grout to permeate evenly to the bottom of the pipe curtain and the surrounding soil through the grout outlet gaps. The total amount of grout is controlled to be consistent with the design value. When grout seepage occurs at the surface observation point, or when the cumulative grouting volume reaches the design threshold, the grouting pressure is maintained for 3 to 5 minutes before grouting can be stopped. After grouting is completed, curing is required for no less than 7 days to ensure that the grout fully solidifies and hardens, forming an expanded cement grout diffusion zone, thereby significantly increasing the effective bearing area at the bottom of the pipe curtain.

[0040] Step 8: As Figure 6 As shown, the precast tube curtain 4 is used to implement differentiated lifting for the tilt and settlement of the existing building. To implement differentiated lifting for the tilt and settlement of existing buildings, four sets of grouting bags are installed along the depth direction on the upper part of the precast pipe curtain. During the lifting operation, the grouting pipe is inserted into the deepest bag 5, and grouting is carried out using a backward grouting method, while grouting is being done backward. A high-precision real-time monitoring network is set up inside the existing building to detect the tilt angle of the existing building in real time.

[0041] After the first grouting bag 5 is fully lifted, it is lowered into the second grouting bag 5. Each grouting bag 5 has a tightening structure (such as an elastic rope that can tighten automatically) at its opening. After the grouting pipe 7 is pulled out, it can automatically tighten, preventing grout leakage between the two grouting bags 16. The same operation is repeated until all grouting is completed, and then the grouting holes are sealed with sealing material. By adjusting the grouting volume of different bags 5, the lifting height at the corresponding position can be precisely adjusted, thereby achieving precise correction of tunnel deformation. After the grouting of the bags 5 is completed, the insertion port of the grouting pipe 7 is immediately sealed with adhesive material to prevent grout backflow or seepage.

[0042] Throughout the lifting process, the aforementioned lifting pipe curtain was repeatedly installed in the entire inclined and subsided section of the existing underground structure. A high-precision monitoring system was deployed inside the existing underground structure, and the bladders 5 inside all the pipe curtains were simultaneously grouted and pressurized. Based on real-time data from the monitoring system, the lifting amount at each point was precisely controlled until the existing structure was lifted and stabilized at the design elevation. After the lifting was completed, high-strength micro-expansion grouting material, i.e., existing rubber-based sealing plugs, was used to permanently seal the cavities.

[0043] The aforementioned structure is robust and exhibits excellent load-bearing performance: by driving dense square piles into the outer side of the existing diaphragm wall, installing multiple rows of anchor rods, and pouring concrete connecting plates, a "reinforced composite support" tightly integrated with the original diaphragm wall is formed. This structure greatly enhances the overall stiffness, lateral displacement resistance, and stability of the diaphragm wall, providing a solid and reliable reaction foundation for subsequent jacking operations.

[0044] The above-mentioned jacking reaction system is highly efficient and reliable: it uses prefabricated pipe curtains as the jacking execution channel, and forms an expanded grout solidified body through grouting at its bottom. This significantly increases the bottom bearing area, thereby providing a huge, evenly distributed counter-support force that far exceeds the cross-sectional area of ​​the pipe curtain itself, effectively avoiding settlement or instability caused by insufficient reaction force during the jacking process.

[0045] The aforementioned lifting process is precise and controllable, causing no damage to the structure: grouting and lifting are performed using bladders inside the precast tube curtain. The expansion of these bladders provides a gentle and uniform surface load, smoothly transferring force to the building foundation. This perfectly avoids the stress concentration and localized foundation damage risks that can occur with traditional jack-type top loading. Combined with high-precision monitoring inside the building, millimeter-level fine-tuning can be achieved.

[0046] The above-mentioned method has good spatial adaptability and minimal impact on the surrounding environment: the main working surface of the method is located outside the diaphragm wall, without the need for large-scale excavation under the building body. It is particularly suitable for complex environments with limited construction space (such as steep slopes or adjacent to important facilities), minimizing disturbance to slope stability and the surrounding environment.

Claims

1. A method for slope reinforcement and deformation control of buildings on slopes, characterized in that, Includes the following steps: Step 1: Drive precast square piles into the soil outside the existing building retaining wall. Step 2: Connect the square piles and the retaining wall using the upper connector; Step 3: Reinforce the lower part of the square pile using the lower connector; Step 4: Pour concrete into the gap between the square pile and the retaining wall; Step 5: Connect adjacent square piles by reinforcing the crossbeams and using conversion steel plates; Step 6: Drill holes in the reserved area of ​​the retaining wall within the section enclosed by the upper and lower reinforcing beams and square piles; Step 7: Install the precast pipe curtain inside the borehole, and fix the precast pipe curtain itself and the precast pipe curtain to the retaining wall and soil by grouting; Step 8: Use the grouting bags on the precast pipe curtain to implement differentiated lifting of the tilt and settlement of the existing building. After the lifting is completed, remove the grouting pipes from the grouting bags and seal them. Then carry out curing. After the curing is completed, seal the boreholes drilled in Step 6.

2. The method for slope reinforcement and deformation control of adjacent buildings as described in claim 1, characterized in that, In step 1, pre-drilled holes are made on the square pile. The pre-drilled holes are located on the vertical axis of the square pile and are arranged in descending order of height.

3. The method for slope reinforcement and deformation control of adjacent buildings as described in claim 1, characterized in that, The specific process of step 2 is as follows: First, holes are drilled into the retaining wall through the pre-drilled holes on the square piles. Then, the end of the upper connector is passed through the pre-drilled holes on the square piles and pushed forward until it is inserted into the retaining wall. The end of the upper connector has an expansion function, which can fit tightly against the inner wall of the hole in the retaining wall to form an initial anchor. Finally, the exposed end of the upper connector is fitted with a nut and tightened to the designed torque to ensure that there is no loose gap between the upper connector and the precast square pile, thus achieving a stable connection between the upper part of the precast square pile and the retaining wall.

4. The method for slope reinforcement and deformation control of adjacent buildings as described in claim 1, characterized in that, The specific process of step 3 is as follows: Select a stable section where the lower part of the square pile is embedded in the original soil; use a drilling tool to drill a hole, advancing the hole from the outer soil towards the square pile until it penetrates the side wall of the square pile and penetrates into the retaining wall to a preset depth; after drilling is completed, insert the lower connector into the hole. The end of the lower connector has an expansion function. After the expansion is triggered, it can be tightly combined with the inner wall of the hole to form a reliable anchor. The exposed section of the lower connector is reinforced with steel mesh, a formwork is installed, and micro-expansion concrete is poured into the formwork. After solidification, the formwork is removed to form a reinforced concrete slab that completely encloses the lower connector. This allows the lower connector to form a synergistic force-bearing system through the reinforced concrete slab, significantly enhancing the connection stability between the lower part of the precast square pile and the soil.

5. The method for slope reinforcement and deformation control of adjacent buildings as described in claim 1, characterized in that, The upper part of the precast tube curtain is integrated with multiple lifting bags and bag grouting pipes, and the side is integrated with cement diffusion grouting pipes. Cement diffusion grout outlets are provided on the side wall of the precast tube curtain, and the cement diffusion grout outlets are connected to the cement diffusion grouting pipes. Before bag grouting, the bag grouting pipes are connected to the lifting bags located on the innermost side of the precast tube curtain.

6. The method for slope reinforcement and deformation control of adjacent buildings as described in claim 5, characterized in that, Each of the precast tube curtains has a tightening structure at its opening to prevent slurry leakage between two tubes.

7. The method for slope reinforcement and deformation control of adjacent buildings as described in claim 6, characterized in that, The specific construction process of step 7 is as follows: The precast pipe curtain is jacked into the borehole by a pipe jacking machine. After all the precast pipe curtains are jacked into place according to the design position, the precast pipe curtain body is first grouted until the concrete fills the entire internal space of the pipe curtain. Then, using the cement diffusion grouting pipes reserved on both sides, grouting is carried out in a sequence from deep to shallow. During the grouting process, the cement diffusion grouting pipes are pulled out at a uniform speed, so that the grout can evenly penetrate into the bottom of the pipe curtain and the surrounding soil through the grout outlet gap. When grout seepage occurs at the surface observation point, or when the cumulative grouting volume reaches the design threshold, the grouting pressure is maintained for a set time and then the grouting is stopped. After grouting is completed, curing is carried out to ensure that the grout fully solidifies and hardens, forming an expanded cement grout diffusion zone, thereby significantly increasing the effective load-bearing area at the bottom of the pipe curtain.

8. The method for slope reinforcement and deformation control of adjacent buildings as described in claim 1, characterized in that, In step 8 During the lifting operation, the grouting pipe is inserted into the deepest sac and grouting is carried out using a backward grouting method. Grouting is performed while reversing. A high-precision real-time monitoring network is set up inside the existing building to detect the tilt angle of the existing building in real time.

9. The method for slope reinforcement and deformation control of adjacent buildings as described in claim 1, characterized in that, In step 8, all the lifting bags on the pipe curtain are simultaneously grouted and pressurized. At the same time, based on the real-time data fed back by the monitoring system, the lifting amount at each point is precisely controlled until the existing structure is lifted and stabilized to the design elevation.

10. The method for slope reinforcement and deformation control of adjacent buildings as described in claim 1, characterized in that, In step 8, the lifting height at the corresponding position can be precisely adjusted by controlling the grouting volume of different bladders.

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