A grouting repair method for foundation settlement in soluble gypsum strata

Abstract

The present invention relates to a grouting repair method for foundation settlement in a soluble gypsum stratum, comprising the following steps: S1, determining the range of the stratum foundation requiring jacking treatment; S2, designing a first sequence of grouting holes and a second sequence of grouting holes, selecting survey holes, and obtaining geological information data through drilling exploration; S3, delineating different treatment sections according to stratum depth; determining a grouting scheme for the grouting holes based on the geological information data and the treatment sections; S4, performing a first drilling and a first grouting at the positions of the first and second sequence grouting holes according to the grouting scheme; S5, performing a second drilling and a second grouting at the first sequence grouting holes; S6, performing a third drilling and a third grouting at the second sequence grouting holes; and S7, sequentially performing a fourth grouting at the first and second sequence grouting holes. By dividing the grouting holes and the treatment sections, and combining the geological information data, grouting protection treatment near the foundation layer and grouting treatment of the jacking zone by region and batch are adopted to achieve grouting and lifting repair of the foundation settlement.

Description

Technical Field

[0001] The invention relates to a karst ground collapse treatment technology, in particular to a grouting repair method for foundation settlement of a soluble gypsum rock stratum, and belongs to the technical field of urban building maintenance. Background Art

[0002] Karst ground collapse is an address problem in the underground space of urban buildings. It mainly occurs in areas where the basement rock layers are soluble gypsum rocks such as carbonate rocks, calcareous clastic rocks and salt rocks. Once soluble rock dissolution occurs, the foundation on the soluble gypsum rock layer will gradually undergo uneven settlement.

[0003] The existing technology mainly adopts grouting to reinforce the foundation to solve the problem of settlement. The principle of grouting reinforcement is to make the slurry continue to diffuse in the karst fissures by drilling and grouting. As the grouting holes gradually become denser, the karst fissures are continuously filled until the settlement of the building stabilizes. The grouting reinforcement process includes drilling, grouting, slurry diffusion, filling and consolidation. Among them, the depth and distribution of the boreholes are determined according to the geological conditions and reinforcement requirements, and the slurry is injected according to the drilling situation. Usually, the slurry is a mixture of cement, lime, fly ash and other materials and water. Under the action of pressure, the slurry continues to diffuse through the karst fissures or the pores of the soil, and gradually solidifies to form a solid entity.

[0004] For example, the Chinese invention patent with publication number CN110258677A discloses a method for reinforcing and lifting the settlement of the independent foundation of an existing building. It is mainly aimed at the treatment process of collapsible loess foundation. The independent foundation is lifted through three steps: settlement measurement, foundation stabilization and foundation lifting. However, this method has a single grouting process and a single grouting material, and is not generally applicable to settlement caused by other reasons, such as the treatment of independent foundation settlement in karst areas.

[0005] The Chinese invention patent with authorization publication number CN110029999B discloses a method for grouting deep-seated soluble rocks in a closed hole with internal circulation. However, this method is mainly used to stop the sinking of buildings caused by deep karst. The grouting process and grouting materials are single, and it is not suitable for treating large-scale soluble holes with obvious connectivity.

[0006] The existing soluble gypsum strata have complex deformations. After the dissolution holes form to a certain scale, there will be local collapse sites, and then new cracks will be formed layer by layer upwards. The existing grouting repair method has the shortcomings of single process and single material, which is difficult to apply to the grouting reinforcement requirements of complex terrain. In addition, the difference in slurry fluidity during the grouting process may even lead to the risk of aggravating the lifting and tilting of the building. Summary of the Invention

[0007] The purpose of the present invention is to overcome the shortcomings of the prior art, such as single process, single material, and unsuitability for settlement grouting repair in complex underground environments, and to provide a grouting repair method for foundation settlement of soluble gypsum strata.

[0008] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0009] A grouting repair method for foundation settlement in a soluble gypsum rock formation comprises the following steps:

[0010] S1. Determine the scope of soluble gypsum rock foundation that requires jacking treatment;

[0011] S2. Designing grouting holes in the area requiring jacking treatment, the grouting holes including a first sequence of grouting holes and a second sequence of grouting holes, wherein the first sequence of grouting holes is located in the outer peripheral area of ​​the area requiring jacking treatment, and the second sequence of grouting holes is located in the inner area of ​​the area requiring jacking treatment;

[0012] Select holes from the first sequence of grouting holes as survey holes and conduct drilling exploration to obtain geological information data;

[0013] S3. Delineate different treatment sections based on stratum depth using geological information data. The treatment sections are delineated from top to bottom into a stiffness reinforcement zone, an uplift zone, and a reinforced stabilization zone. The stiffness reinforcement zone is 3 to 5 meters from the foundation bottom along the stratum depth direction, and the reinforced stabilization zone is composed of soluble gypsum. Determine the grouting plan for the grouting holes based on the geological information data and the different treatment sections.

[0014] S4. According to the grouting plan, the first drilling and the first grouting are performed at the positions of the first sequence grouting holes and the second sequence grouting holes; the drilling depth of the first drilling hole is within the depth range of the stiffness reinforcement zone, and the first grouting adopts top-down hole-sealing grouting;

[0015] S5. Perform a second drilling and second grouting of the first sequence of grouting holes. The drilling depth of the second drilling holes is within the depth range of the reinforcement and stability zone. The second grouting of the first sequence of grouting holes adopts a top-down method of sealing the grouting with a fixed depth using a sac-type grouting stopper. The second grouting depth is within the depth range of the reinforcement and stability zone.

[0016] S6. Perform a third drilling and third grouting of the second sequence of grouting holes. The drilling depth of the third drilling hole is within the depth range of the reinforcement and stabilization zone. The third grouting of the second sequence of grouting holes adopts a top-down method of using a sac-type grouting stopper to close the grouting to a fixed depth. The third grouting depth is within the depth range of the reinforcement and stabilization zone.

[0017] S7. Carry out the fourth grouting on the first sequence grouting holes and the second sequence grouting holes in sequence. The depth of the fourth grouting is within the depth range of the lifting area. The fourth grouting adopts a sac-type grouting stopper with a fixed depth to close the grouting from bottom to top.

[0018] The present invention provides a grouting repair method for foundation settlement, which divides the grouting holes within the range of jacking treatment into a first sequence of grouting holes and a second sequence of grouting holes, and then performs drilling exploration on the first sequence of grouting holes to obtain geological information data of the stratum, thereby segmenting the treatment section and providing a basis for subsequent grouting and jacking in different regions and batches; during the construction process, the first sequence of grouting holes and the second sequence of grouting holes are first drilled and grouted to reinforce the stiffness reinforcement area so that the stiffness reinforcement area forms a whole; then the first sequence of grouting holes are drilled and grouted to reinforce the stiffness reinforcement area; , realize grouting reinforcement of the peripheral area of ​​the range that needs jacking treatment, increase the bearing capacity of the stratum, reduce the uneven settlement that may occur during the lifting process of the range that needs jacking treatment, and at the same time, the peripheral reinforcement can effectively reduce the lateral pressure on the surrounding soil during the foundation lifting process, thereby reducing the impact on surrounding buildings or facilities; perform the third drilling and the third grouting on the second sequence grouting holes to realize grouting reinforcement of the inner area of ​​the range that needs jacking treatment, increase the bearing capacity of the stratum in the inner area, and finally perform the fourth grouting on the first sequence grouting holes and the second sequence grouting holes to realize grouting and lifting repair of the foundation. The present invention divides the grouting holes and the treatment sections, and combines geological information data. During the grouting process, grouting protection treatment of the near-foundation layer and grouting treatment of the jacking area in different regions and batches are adopted to realize steady grouting and lifting repair of foundation settlement.

[0019] It should be noted that the peripheral area of ​​the range requiring jacking treatment refers to the edge or outer part of the range requiring jacking treatment, the first sequence of grouting holes is arranged on the periphery of the range requiring jacking treatment, the internal area of ​​the range requiring jacking treatment refers to within the range requiring jacking treatment, and the second sequence of grouting holes is arranged on the range requiring jacking treatment.

[0020] As a preferred embodiment of the present invention, the soluble gypsum rock formation is a soluble rock (glauber's salt-gypsum) formation.

[0021] As a preferred embodiment of the present invention, the detailed steps for determining the scope of the soluble gypsum rock formation foundation requiring jacking treatment are as follows:

[0022] S11, selecting a benchmark measuring point at the foundation settlement site of the soluble gypsum stratum to be repaired, measuring the settlement of each vertical load-bearing component in the foundation settlement area based on the benchmark measuring point, and calculating the settlement difference;

[0023] S12. According to the determined settlement difference, determine the scope of foundation that needs to be jacked up.

[0024] As a preferred embodiment of the present invention, the range requiring jacking treatment is divided into individual independent foundation settlement and regional independent foundation settlement according to the settlement situation around the abnormally settled foundation. A plurality of first-sequence grouting holes are provided in the peripheral area of ​​the individual independent foundation settlement, and the plurality of first-sequence grouting holes form an outer circle in the peripheral area of ​​the individual independent foundation settlement. A plurality of second-sequence grouting holes are provided in the inner area of ​​the individual independent foundation settlement, and the plurality of second-sequence grouting holes are close to the edge of the foundation. There are multiple foundations in the regional independent foundation settlement, and a plurality of first-sequence grouting holes are provided in the peripheral area of ​​the regional independent foundation settlement, and the plurality of first-sequence grouting holes form an outer circle in the outer area of ​​the regional independent foundation settlement. A plurality of second-sequence grouting holes are provided at the edges of the plurality of foundations in the regional independent foundation settlement.

[0025] As a preferred embodiment of the present invention, the grouting holes further include a third sequence of grouting holes located within the area to be lifted. The grouting effect of the second sequence of holes is used to determine whether to proceed with the third sequence of grouting. The third sequence of grouting holes is designed to fine-tune the grouting for a more effective lifting effect. The grouting process, sequence, and stopping conditions for the third sequence of grouting holes are similar to those for the second sequence of grouting holes. Grouting parameters are fine-tuned based on the lifting effect until the lifting requirements are met.

[0026] As a more preferred embodiment of the present invention, when the range to be jacked up is divided into individual independent foundation settlement and regional independent foundation settlement, for individual independent foundation settlement, multiple third sequence grouting holes are close to the edge of the foundation, and the third sequence grouting holes are located between two adjacent second sequence grouting holes; for regional independent foundation settlement, multiple third sequence grouting holes are located between two adjacent foundations.

[0027] Preferably, the third sequence of grouting holes is located between the second sequence of grouting holes. By arranging the third sequence of grouting holes between the second sequence of holes, grouting and jacking are performed in batches and stages, and the settlement and jacking effect is better and more stable.

[0028] As a preferred embodiment of the present invention, in step S2, the method for obtaining geological information data through drilling exploration is: obtaining the geological conditions, hydrological conditions and degree of dissolution of the grouting hole through drilling underwater television and / or tracer method, and analyzing and summarizing them into geological information data.

[0029] As a preferred embodiment of the present invention, the investigation holes are selected as a representative portion of the first sequence of grouting holes. The selection principle is: based on the characteristics of building settlement and the number of foundations with abnormal settlement, the investigation holes are selected within the first sequence of grouting holes. The investigation holes are representative of the strata surrounding the reinforced foundation. More preferably, the investigation holes are selected symmetrically along both sides of the foundation with abnormal settlement.

[0030] As a preferred solution of the present invention, in S3, the soluble gypsum stratum is divided into different treatment sections according to the depth of the stratum, and is delineated from bottom to top in order: reinforced stable zone, uplift zone and stiffness reinforcement zone. The reinforced stable zone is located at the bottom, the stiffness reinforcement zone is located in the stratum where the foundation is located, the uplift zone is located between the stiffness reinforcement zone and the reinforced stable zone, and the height of the stiffness reinforcement zone is 3 to 5 meters.

[0031] Preferably, the rock layer in the reinforced stable zone is a rock layer with dissolution holes and a relatively high rock layer structural strength, such as a moderately weathered rock layer or a lowly weathered rock layer.

[0032] As a preferred embodiment of the present invention, the method for determining the grouting scheme of the grouting holes based on geological information data and different processing stages is: using simulation analysis software to perform numerical calculation simulation on the geological information data to obtain the grouting parameters and processing parameters in the grouting holes as the grouting scheme of the grouting holes.

[0033] As a preferred solution of the present invention, when the first sequence of grouting holes and the second sequence of grouting holes are first drilled, the drilling depth is 3 to 5 meters.

[0034] As a preferred embodiment of the present invention, the grouting depth of the first grouting is within the depth range of the stiffness reinforcement zone. The first grouting of the first sequence grouting holes and the second sequence grouting holes adopts the first grouting material for grouting reinforcement. The first grouting material adopts a permeable grouting material, which is required to be able to penetrate cracks with a width of more than 150 μm. The first grouting material adopts silicate cement with a water-cement ratio of 1.0 to 2.0. The setting time of the first grouting material is 6 to 12 hours.

[0035] As a preferred embodiment of the present invention, the first grouting adopts top-down hole-sealing grouting, and the specific steps are as follows:

[0036] After the first drilling of the first sequence grouting holes or the second sequence grouting holes is completed to form the grouting holes, a waterproof plate is set on the upper surface of the grouting hole, an orifice pipe is arranged in the grouting hole, and an orifice sealing material is used to fill the space between the grouting hole and the orifice pipe; an orifice sealer is installed at the orifice of the orifice pipe; a return liquid pipe is set at the upper end of the orifice pipe, the return liquid pipe is connected to the orifice pipe, and a return slurry valve is set on the return liquid pipe for controlling the opening and closing of the return liquid pipe away from the orifice pipe;

[0037] Place the slurry inlet pipe into the orifice pipe, open the return slurry valve to connect the return liquid pipe; turn on the grouting equipment, pass the slurry of the first grouting material into the grouting hole through the slurry inlet pipe, and control the grouting pressure and speed; after the slurry diffuses in the grouting hole and the grouting pressure reaches the end standard pressure, stop grouting, close the return slurry valve, rotate the slurry inlet pipe, and then pull out the slurry inlet pipe.

[0038] As a preferred embodiment of the present invention, a second drilling is performed on the first sequence of grouting holes based on the first drilling hole to obtain a first sequence of grouting holes, the depth of the first sequence of grouting holes exceeds the depth of the hard rock where obvious dissolution holes and cavities exist, and the first sequence of grouting holes are vertical grouting holes; a third drilling is performed on the first drilling hole of the second sequence of grouting holes to obtain a second sequence of grouting holes, the depth of the second sequence of grouting holes exceeds the depth of the hard rock where obvious dissolution holes and cavities exist, and the second sequence of grouting holes are vertical grouting holes.

[0039] As a preferred embodiment of the present invention, the second grouting of the first sequence grouting holes adopts a second grouting material for grouting reinforcement, the second grouting material adopts a fast-setting, highly corrosion-resistant grouting material, the second grouting material is a mixture of sulfate-resistant Portland cement and an accelerating agent, the water-cement ratio of the sulfate-resistant Portland cement is 1:0.8-1.5, the content of tricalcium aluminate in the sulfate-resistant Portland cement does not exceed 3%, and the amount of the accelerating agent added is determined according to the connectivity of the corrosion pores of the grouting holes and for different degrees of corrosion and connectivity. The amount of the accelerating agent added is 0.8-1.5‰ of the dry weight of the sulfate-resistant Portland cement, the initial setting time of the second grouting material is 15-30 minutes, and the accelerating agent is polyacrylamide or water glass.

[0040] As a preferred embodiment of the present invention, the third grouting of the second sequence grouting holes uses a third grouting material for grouting reinforcement. The third grouting material uses a permeable grouting material. The third grouting material uses silicate cement with a water-cement ratio of 1.0 to 2.0. The setting time of the third grouting material is 6 to 12 hours.

[0041] As a preferred embodiment of the present invention, the second grouting or the third grouting adopts a sac-type grouting stopper with a fixed depth for closed grouting from top to bottom, and the specific steps are as follows:

[0042] S51. Install a waterproof plate on the upper surface of the grouting hole, insert an orifice pipe into the grouting hole, and fill the space between the grouting hole and the orifice pipe with orifice sealing material; connect the slurry inlet pipe and the slurry stopper in sequence;

[0043] S52, installing the capsule grouting plug at the upper end of the depth range of the reinforcement stabilization zone in the grouting hole;

[0044] S53, injecting pressure into the bladder stopper, so that the bladder stopper expands and presses against the inner wall of the grouting hole to form an in-hole grouting system; starting the grouting equipment, and injecting the slurry of the second grouting material or the third grouting material into the grouting hole through the grouting pipe; after the grouting pressure reaches the end standard pressure, stopping the grouting and depressurizing the bladder stopper;

[0045] S54: After the second grouting material or the third grouting material is initially set, the grouting pipe is rotated to adjust the position of the bag-type grouting plug downward, and step S53 is repeated until the grouting within the depth range of the reinforced stable zone is completed.

[0046] As a preferred embodiment of the present invention, during the second or third grouting process, grouting is performed in the depth range of the reinforced stable zone, and the grouting parameters of each section are adjusted according to the fact that there is no obvious deformation or uplift of the foundation. Grouting is stopped when deformation or uplift occurs, and then grouting is continued after adjusting the grouting parameters.

[0047] As a preferred embodiment of the present invention, the grouting depth of the fourth grouting is within the depth range of the lifting zone, and the fourth grouting of the first sequence grouting holes and the second sequence grouting holes adopts the fourth grouting material for grouting reinforcement. The fourth grouting material adopts the permeable grouting material. The fourth grouting material is the existing permeable grouting material. For example, the fourth grouting material adopts silicate cement with a water-cement ratio of 1.0 to 2.0, and the setting time of the fourth grouting material is 6 to 12 hours.

[0048] As a preferred embodiment of the present invention, the fourth grouting adopts a bottom-up method with a sac-type stopper to close the grouting to a fixed depth, and the specific steps are as follows:

[0049] S71. Install a waterproof plate on the upper surface of the grouting hole, insert an orifice pipe into the grouting hole, and fill the space between the grouting hole and the orifice pipe with orifice sealing material; connect the slurry inlet pipe and the slurry stopper in sequence;

[0050] S72, installing the capsule grout stopper at the bottom end of the depth range of the lifting area in the grouting hole;

[0051] S73, injecting pressure into the bladder stopper, so that the bladder stopper expands and presses against the inner wall of the grouting hole to form an in-hole grouting system; starting the grouting equipment, and injecting the slurry of the fourth grouting material into the grouting hole through the grouting inlet pipe; after the grouting pressure reaches the end standard pressure, stopping the grouting and depressurizing the bladder stopper;

[0052] S74: Rotate the slurry inlet pipe to adjust the position of the bag-type slurry stopper upwards, and repeat step S73 until the grouting in the depth range of the lifting area is completed.

[0053] As a preferred embodiment of the present invention, in the fourth grouting process, grouting is performed in the depth range of the lifting zone, and the grouting parameters of each section of the lifting zone are adjusted based on the fact that there are no obvious cracks in the foundation.

[0054] Compared with the prior art, the present invention has the following beneficial effects:

[0055] 1. The grouting repair method for foundation settlement of the present invention divides the grouting holes within the range of jacking treatment into the first sequence grouting holes and the second sequence grouting holes, and then conducts drilling exploration on the first sequence grouting holes to obtain geological information data of the stratum, thereby segmenting the treatment section and providing a basis for subsequent grouting and jacking in different regions and batches; during the construction process, the first sequence grouting holes and the second sequence grouting holes are first drilled and grouted to reinforce the stiffness reinforcement area so that the stiffness reinforcement area forms a whole; then the first sequence grouting holes are drilled and the second sequence grouting holes are drilled and the second sequence grouting holes are drilled to reinforce the stiffness reinforcement area; then the first sequence grouting holes are drilled and the second sequence grouting holes are drilled to reinforce the stiffness reinforcement area; The third drilling and the second grouting of the second sequence of grouting holes are carried out to realize the grouting reinforcement of the peripheral areas of the range that needs to be jacked up, increase the bearing capacity of the stratum, and reduce the uneven settlement that may occur during the lifting process of the range that needs to be jacked up. At the same time, the peripheral reinforcement can effectively reduce the lateral pressure on the surrounding soil during the foundation lifting process, thereby reducing the impact on surrounding buildings or facilities; the third drilling and the third grouting of the second sequence of grouting holes are carried out to realize the grouting reinforcement of the inner area of ​​the range that needs to be jacked up, increase the bearing capacity of the stratum in the inner area, and finally the fourth grouting of the first sequence of grouting holes and the second sequence of grouting holes is carried out. The present invention is more targeted at the grouting repair of independent foundation settlement in soluble rock (glauber's salt-gypsum) strata, and the quality of grouting repair treatment of settlement is better than that of traditional grouting technology.

[0056] 2. The grouting repair method of the present invention adopts quick-setting grouting materials for deep grouting in the reinforced stable zone of the first sequence grouting holes according to the settlement structure characteristics of different strata. This method can ensure both the setting time and the diffusion performance, and avoid the grouting materials from being lost with groundwater or pores, resulting in waste of grouting materials. There are non-obvious connected cracks in the stratum of the uplift zone. According to the characteristics that the non-continuous settlement pore structure is not easy to be filled with grouting, the deep grouting in the uplift zone of the first sequence grouting holes and the second sequence grouting holes adopts permeable grouting materials, which can meet the requirements of permeability and water seepage rate, improve the quality of grouting repair, and avoid the defects of insufficient grouting repair, external closure, and a large number of residual pores inside. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 Delineate schematic diagrams for uplift treatment depths;

[0058] Figure 2 It is the settlement of individual independent foundation.

[0059] Figure 3 It is the regional independent foundation settlement.

[0060] Figure 4 Schematic diagram of grouting in the stiffness reinforcement area.

[0061] Figure 5 Schematic diagram of grouting in the reinforced stable area.

[0062] Markings in the figure: 1-water-proof plate, 2-orifice pipe, 3-grouting hole, 4-slurry inlet pipe, 5-pressure gauge, 6-slurry inlet valve, 7-orifice sealing material, 8-bladder type slurry stopper, 9-return liquid pipe, 10-return slurry valve, 11-return slurry pressure gauge. DETAILED DESCRIPTION

[0063] The present invention will be further described in detail below in conjunction with test examples and specific embodiments. However, this should not be understood as limiting the scope of the present invention to the following embodiments, and all technologies implemented based on the present invention fall within the scope of the present invention.

[0064] Unless otherwise specified, in the description of the specific embodiments of the present invention, the terms indicating orientation or positional relationships such as "upper," "lower," "left," "right," "center," "inside," and "outside" are based on the orientation or positional relationships shown in the accompanying drawings, or are the orientation or positional relationships in which the inventive product / device / apparatus is typically placed when in use. These terms indicating orientation or positional relationships are merely for the purpose of facilitating the description of the present invention or simplifying the description of the specific embodiments to facilitate a quick understanding of the solutions by technicians. They do not indicate or imply that a particular device / component / element must have a specific orientation or be constructed and operated in a specific positional relationship, and therefore should not be construed as limiting the present invention.

[0065] In addition, the expressions "first", "second", "third", etc. that appear in the terms are merely descriptions used to distinguish the same or similar components and should not be understood as emphasizing or implying the relative importance of specific components.

[0066] In addition, in the description of the embodiments of the present invention, "several," "plurality," and "a number" represent at least two. It can also be any number such as two, three, four, five, six, seven, eight, nine, or even more than nine.

[0067] Furthermore, in the description of the technical solution of the present invention, unless otherwise expressly specified, defined, or limited, the terms "disposed," "installed," "connected," "connected," "provided with," "laid," and "arranged" should be understood broadly. For example, they may refer to fixed connections, detachable connections, or integral connections. They may be welded, riveted, bolted, threaded, or other commonly used connection methods in the art. Such connections may be mechanical, electrical, or communicative; they may be direct, indirect via an intermediate medium, or internally connected between two components.

[0068] Example 1

[0069] like Figure 1As shown, the building is located on a soluble gypsum stratum. The upper layer of the stratum is a non-gypsum stratum, and below the non-gypsum stratum is a gypsum stratum. The foundation of the building is a pile, located within the non-gypsum stratum. In addition to gypsum (CaSO4·2H2O) and anhydrite (CaSO4), the gypsum stratum is locally associated with sodium sulfate (Na2SO4) or calcium sulfate (Na2SO4·CaSO4), forming a sodium sulfate-gypsum stratum structure. After the sodium sulfate-gypsum stratum structure is affected by long-term erosion by flowing water, the gypsum stratum gradually dissolves, causing deformation of the upper building basement wall. In order to repair the settlement of the building, a grouting repair method for the settlement of the soluble gypsum stratum foundation is proposed, which includes the following steps:

[0070] S1. Determine the scope of soluble gypsum stratum foundation that requires jacking treatment;

[0071] S2. Designing grouting holes in the area requiring jacking treatment, the grouting holes including a first sequence of grouting holes and a second sequence of grouting holes, wherein the first sequence of grouting holes are located in the outer peripheral area of ​​the area requiring jacking treatment, and the second sequence of grouting holes are located in the inner area of ​​the area requiring jacking treatment; selecting holes in the first sequence of grouting holes as survey holes, and conducting drilling exploration to obtain geological information data;

[0072] S3. Delineate different treatment sections based on stratum depth using geological information data. The treatment sections are delineated from top to bottom into a stiffness reinforcement zone, an uplift zone, and a reinforced stabilization zone. The stiffness reinforcement zone is 3 to 5 meters from the foundation bottom along the stratum depth direction, and the reinforced stabilization zone is composed of soluble gypsum. Determine the grouting plan for the grouting holes based on the geological information data and the different treatment sections.

[0073] S4. According to the grouting plan, the first drilling and the first grouting are performed at the positions of the first sequence grouting holes and the second sequence grouting holes; the drilling depth of the first drilling hole is within the depth range of the stiffness reinforcement zone, and the first grouting adopts top-down hole-sealing grouting;

[0074] S5. Perform a second drilling and second grouting of the first sequence of grouting holes. The drilling depth of the second drilling holes is within the depth range of the reinforcement and stability zone. The second grouting of the first sequence of grouting holes adopts a top-down method of sealing the grouting with a fixed depth using a sac-type grouting stopper. The second grouting depth is within the depth range of the reinforcement and stability zone.

[0075] S6. Perform a third drilling and third grouting of the second sequence of grouting holes. The drilling depth of the third drilling hole is within the depth range of the reinforcement and stabilization zone. The third grouting of the second sequence of grouting holes adopts a top-down method of using a sac-type grouting stopper to close the grouting to a fixed depth. The third grouting depth is within the depth range of the reinforcement and stabilization zone.

[0076] S7. Carry out the fourth grouting on the first sequence grouting holes and the second sequence grouting holes in sequence. The depth of the fourth grouting is within the depth range of the lifting area. The fourth grouting adopts a sac-type grouting stopper with a fixed depth to close the grouting from bottom to top.

[0077] When the repair construction unit enters the site, it first conducts settlement observation: select benchmark measuring points on the site, measure the settlement of each vertical load-bearing component, record the settlement data, calculate the settlement difference, and determine the scope that needs to be jacked up. Based on the observation results, the settlement characteristics of the building and the number of abnormally settled foundations, the scope that needs to be jacked up is determined. According to the settlement situation around the abnormally settled foundations, it is divided into two situations: individual independent foundation settlement and regional independent foundation settlement. Figure 2 Individual independent foundation settlements occurred in individual vertical load-bearing components as shown; Figure 3 The multiple vertical load-bearing components shown have undergone regional independent foundation settlement, which is named regional independent foundation settlement.

[0078] like Figure 2 and Figure 3 As shown, the first sequence of grouting holes is planned in the peripheral area of ​​the area to be jacked up. Figure 2 Mark Ii, i=1,2,3,...8, Figure 3 Similarly, multiple first-sequence grouting holes form an outer circle in the peripheral area of ​​the area to be jacked up; and second-sequence grouting holes are planned in the inner area of ​​the area to be jacked up. Figure 2 The mark is II-j, j = 1, 2, 3, 4, Figure 3 Similarly, for individual independent foundation settlement, multiple second-sequence grouting holes are close to the edge of the foundation; for regional independent foundation settlement, there are multiple foundations within the regional independent foundation settlement, and multiple second-sequence grouting holes are set on the edges of the multiple foundations.

[0079] In some embodiments, in addition to the first and second sequence grouting holes, a third sequence grouting hole is also planned. The third sequence grouting holes need to lift the inner area of ​​the treatment range. For individual independent foundation settlement, multiple third sequence grouting holes are close to the edge of the foundation. The third sequence grouting holes are located between two adjacent first sequence grouting holes. Figure 2 Marked as III-k, k = 1, 2, 3, 4; for regional independent foundation settlement, multiple third sequence grouting holes are located between two adjacent foundations. The third sequence grouting holes are grouting holes adjacent to vertical load-bearing components, such as Figure 3 shown.

[0080] The survey holes are selected as some representative holes in the first sequence of grouting holes. The selection principle is as follows: the survey holes are selected from the first sequence of grouting holes based on the characteristics of building settlement and the number of abnormally settled foundations. The survey holes can represent the strata surrounding the reinforced foundation. In some embodiments, the survey holes are selected symmetrically along both sides of the foundation with abnormal settlement. The geological conditions, hydrological conditions and degree of dissolution of the grouting holes are obtained by drilling underwater television and / or tracer method, and analyzed and summarized as geological information data. The underwater television is an HX-JD-04A high-definition underwater television. The HX-JD-04A full-HD intelligent drilling television imager uses a high-definition horizontal 180-degree wide-angle lens or a 360-degree rotating lens, equipped with an underwater super-strong light source, and uses GPS to locate the route and scan the underwater conditions according to the specified route. The imaging effect is clear and is widely used in aquaculture, underwater surveys, underwater operations, diving exploration, underwater project acceptance, underground observation and other fields.

[0081] In S3, the soluble gypsum stratum is divided into different treatment sections according to the stratum depth, which are delineated from bottom to top: reinforcement stabilization zone, lifting zone and stiffness reinforcement zone, e.g. Figure 1 As shown, the stiffness reinforcement zone is in the uppermost layer L1, which is 3m to 5m away from the bottom of the foundation along the depth of the stratum, that is, the height of the stiffness reinforcement zone is 3 to 5m; the reinforced stable zone is located at the bottom, which is L3. The stratum in the reinforced stable zone is soluble gypsum, which is a dissolution layer with many dissolution holes. The uplift zone is located between the stiffness reinforcement zone and the reinforced stable zone, which is L2. The uplift zone is a (slightly soluble but not dissolved) fracture layer with many fractures.

[0082] The method for determining the grouting scheme for grouting holes based on geological information data and different treatment sections is to use simulation analysis software to perform numerical calculations on the geological information data to obtain grouting parameters (such as grouting pressure and grouting flow rate) and treatment parameters (such as the spacing, number, and arrangement of grouting holes) in the grouting holes, which serve as the grouting scheme for the grouting holes. The simulation analysis software can use existing analysis software, such as ABAQUS, to simulate the entire process of post-bored grouting piles, simulate the diffusion shape of the grouting, and analyze the bearing capacity of the piles formed after grouting.

[0083] After numerical simulation analysis, grouting parameters and treatment parameters for the grouting holes can be obtained, such as grouting flow rate, grouting pressure, slurry ratio, grouting time, slurry diffusion model, grouting depth and location, formation deformation parameters, and risk assessment. The optimal grouting pressure is determined by simulating the diffusion range and effect of slurry in the formation under different grouting pressures. Based on the simulation results, the ratio of cement, water, and other additives in the slurry is adjusted to achieve the desired mechanical properties and the slurry ratio. The slurry diffusion model is used to determine the optimal depth and location of the grouting points to achieve the best reinforcement effect. Post-grouting formation deformation, including displacement, settlement, and crack development, is simulated to obtain formation deformation parameters. Potential risks during the grouting process, such as slurry loss and ground uplift, are assessed, and corresponding preventive measures are proposed. These parameters help reduce uncertainty and risk in actual projects and facilitate the design of more scientific and reasonable grouting plans.

[0084] During the first drilling of the first and second sequence grouting holes, the obtained drilling depth is the first drilling depth, and the first drilling depth is 3 to 5 meters. In this embodiment, during the first drilling of the first and second sequence grouting holes, alternate hole drilling is used. The grouting holes formed after the first drilling are located within the depth range of the stiffness reinforcement zone. The first drilling depth is 3 meters, and vertical grouting holes are arranged. The length of the orifice pipe is approximately 3 meters.

[0085] The grouting depth of the first grouting is within the depth range of the stiffness reinforcement zone. The first grouting of the first sequence grouting holes and the second sequence grouting holes adopts the first grouting material for grouting reinforcement. The first grouting material adopts a permeable grouting material, which is required to be able to penetrate cracks with a width of more than 150μm. The first grouting material is an existing permeable grouting material. For example, the first grouting material adopts silicate cement with a water-cement ratio of 1.0 to 2.0. The setting time of the first grouting material is 6 to 12h.

[0086] The first grouting adopts the top-down hole sealing grouting, such as Figure 4 The structure of the stiffness reinforcement zone grouting device shown in the figure has the following specific steps:

[0087] After the first drilling of the first sequence grouting holes or the second sequence grouting holes is completed to form the grouting holes 3, a waterproof plate 1 is set on the upper surface of the grouting hole, an orifice pipe 2 is arranged in the grouting hole 3, and an orifice sealing material 7 is used to fill the space between the grouting hole 3 and the orifice pipe 2; an orifice sealer is installed at the orifice of the orifice pipe; a return liquid pipe 9 is set at the upper end of the orifice pipe 2, and the return liquid pipe 9 is connected to the orifice pipe 2. A return liquid valve 10 and a return liquid pressure gauge 11 are provided on the return liquid pipe 9. The return liquid valve 10 is used to control the opening and closing of the end of the return liquid pipe 9 away from the orifice pipe 2;

[0088] Place the slurry inlet pipe 4 into the orifice pipe 2. Install a pressure gauge 5 and a slurry inlet valve 6 on the slurry inlet pipe 4. Open the slurry inlet valve 6 and the return valve 10 to connect the return pipe 9. Start the grouting equipment and inject the first grouting material slurry into the grouting hole through the slurry inlet pipe 4, controlling the grouting pressure and speed. Once the slurry diffuses in the grouting hole and the grouting pressure reaches the end pressure, stop grouting, close the return valve 10, rotate the slurry inlet pipe 4, and then pull it out. During the grouting process, the grouting pressure is controlled to not exceed 0.5 MPa.

[0089] On the basis of the first borehole, a second borehole is drilled for the first sequence of grouting holes to obtain a first sequence of grouting holes. The depth of the first sequence of grouting holes exceeds the depth of the hard rock with obvious dissolution holes. The first sequence of grouting holes is a vertical grouting hole. The third borehole is drilled for the second sequence of grouting holes to obtain a second sequence of grouting holes. The depth of the second sequence of grouting holes exceeds the depth of the hard rock with obvious dissolution holes. The second and third boreholes are drilled to the depth range of the reinforced stable zone using spacer holes. The second sequence of grouting holes is a vertical grouting hole. The depth of the first sequence of grouting holes and the depth of the second sequence of grouting holes are set according to the situation of the stratum structure and can be the same or different, which is not limited here. In this embodiment, the hard rock is a moderately weathered rock layer or a slightly weathered rock layer. Whether there are obvious dissolution holes in the hard rock is obtained based on geological information data. The drilling depth of the first sequence of grouting holes or the second sequence of grouting holes is determined based on the geological information data obtained in step S2. More specifically, the bottom of the first sequence of grouting holes or the second sequence of grouting holes is located in sandy mudstone.

[0090] The grouting depth of the second grouting is within the depth range of the reinforced stable zone. The second grouting of the first sequence grouting holes adopts the second grouting material for grouting reinforcement. The second grouting material adopts a fast-setting, highly corrosion-resistant grouting material, the purpose of which is to seal the corrosion holes with strong connectivity. The second grouting material is an existing fast-setting grouting material. For example, the second grouting material is a mixture of sulfate-resistant silicate cement and a quick-setting agent. The water-cement ratio of the sulfate-resistant silicate cement is 1:0.8-1.5, and the content of tricalcium aluminate in the sulfate-resistant silicate cement does not exceed 3%. According to the connectivity of the corrosion holes of the grouting holes, the amount of the quick-setting agent added is determined for different degrees of dissolution and connectivity. The amount of the quick-setting agent added is 0.8-1.5‰ of the dry weight of the sulfate-resistant silicate cement. The initial setting time of the second grouting material is 15-30 minutes, and the quick-setting agent is polyacrylamide or water glass. Preferably, the initial setting time of the second grouting material is 20 minutes, which can ensure both the rapid setting time and the diffusion performance. The accelerating setting agent used is polyacrylamide, and the amount of the accelerating setting agent added is 1‰ of the dry weight of the sulfate-resistant Portland cement.

[0091] The third grouting depth is within the reinforcement and stabilization zone. The third grouting of the second sequence of grouting holes uses a third grouting material for grouting reinforcement. This third grouting material is a permeable grouting material, typically a conventional permeable grouting material. For example, the third grouting material uses Portland cement with a water-cement ratio of 1.0 to 2.0, and a setting time of 6 to 12 hours. The internal holes of the stiffness reinforcement zone, lifting zone, and reinforcement and stabilization zone all use permeable grouting material, while the peripheral holes of the reinforcement and stabilization zone use a quick-setting grouting material.

[0092] The second or third grouting is done from top to bottom with a sac-type stopper to a fixed depth. Figure 5 The grouting diagram shown in the figure has the following specific steps:

[0093] S51. Install a waterproof plate 1 on the upper surface of the grouting hole 3, insert an orifice pipe 2 into the grouting hole 3, and fill the space between the grouting hole 3 and the orifice pipe 2 with an orifice sealing material 7; connect the slurry inlet pipe 4 and the slurry stopper 8 in sequence; the slurry stopper 8 is composed of a steel tube and an expansion rubber plug, and the steel tube is provided with a slurry overflow hole; install a pressure gauge 5 and a slurry inlet valve 6 on the slurry inlet pipe 4;

[0094] S52, installing the capsule stopper 8 at the upper end of the depth range of the reinforcement stability zone in the grouting hole 3;

[0095] S53, injecting pressure into the bladder stopper 8, so that the bladder stopper 8 expands and presses against the inner wall of the grouting hole 3 to form an in-hole grouting system; starting the grouting equipment, and injecting the slurry of the second grouting material or the third grouting material into the grouting hole through the grouting pipe 4; after the grouting pressure reaches the end standard pressure, stopping the grouting and depressurizing the bladder stopper;

[0096] S54: After the second grouting material or the third grouting material is initially set, the grouting pipe 4 is rotated to adjust the position of the bag-type grouting plug 8 downward, and step S53 is repeated until the grouting in the depth range of the reinforced stable zone is completed.

[0097] During the second grouting process, grouting is performed within the depth range of the reinforced stable zone of the first sequence of grouting holes. Grouting parameters are adjusted for each section to ensure there is no noticeable deformation or heave of the foundation. Grouting is stopped if deformation or heave appears, and then the grouting parameters are adjusted and continued. To monitor foundation deformation, sensors and geological radar detection technologies can be used. The grouting pressure during the second grouting process is 1.0 to 1.5 MPa.

[0098] During the third grouting process, grouting is performed on the reinforced and stabilized areas of the second sequence of grouting holes. Grouting parameters are adjusted for each section based on the absence of significant deformation or heave in the foundation. Grouting is stopped if deformation or heave appears, and grouting is then continued after adjusting the grouting parameters. During the third grouting process, the grouting pressure is 1.5-2.5 MPa.

[0099] The third grouting is performed on the reinforced and stabilized area. After the grouting in the reinforced and stabilized area has solidified, the uplifted area is treated from the outside inward. The fourth grouting depth is within the depth range of the uplifted area. The fourth grouting of the first and second sequence grouting holes is reinforced with a fourth grouting material. The fourth grouting material is a permeable grouting material. The fourth grouting material is an existing permeable grouting material, for example, silicate cement with a water-cement ratio of 1.0 to 2.0. The setting time of the fourth grouting material is 6 to 12 hours.

[0100] The fourth grouting adopts grouting from bottom to top with a sac-type stopper to set the depth. The specific steps are as follows:

[0101] S71. Install a waterproof plate on the upper surface of the grouting hole, insert an orifice pipe into the grouting hole, and fill the space between the grouting hole and the orifice pipe with orifice sealing material; connect the slurry inlet pipe and the slurry stopper in sequence;

[0102] S72, installing the capsule grout stopper at the bottom end of the depth range of the lifting area in the grouting hole;

[0103] S73, injecting pressure into the bladder stopper, so that the bladder stopper expands and presses against the inner wall of the grouting hole to form an in-hole grouting system; starting the grouting equipment, and injecting the slurry of the fourth grouting material into the grouting hole through the grouting inlet pipe; after the grouting pressure reaches the end standard pressure, stopping the grouting and depressurizing the bladder stopper;

[0104] S74: Rotate the slurry inlet pipe to adjust the position of the bag-type slurry stopper upwards, and repeat step S73 until the grouting in the depth range of the lifting area is completed.

[0105] During the fourth grouting process, grouting is performed within the depth range of the lifting area. The grouting parameters of each section of the lifting area are adjusted based on the absence of obvious cracks in the foundation. The grouting pressure during the fourth grouting process is 1.0-2.5 MPa.

[0106] The grouting effect of the second sequence grouting holes is used to judge whether to carry out grouting of the third sequence grouting holes. The setting of the third sequence grouting holes is to fine-tune the grouting for the lifting effect. The third sequence grouting holes are inclined holes. The grouting process, sequence, and stop conditions of the third sequence grouting holes are similar to those of the second sequence grouting holes. The grouting parameters are fine-tuned according to the lifting effect until the lifting requirements are met.

[0107] During the grouting process, the grouting pressure is calculated according to the following formula:

[0108]

[0109] Where: P cis the grouting pressure (MPa); τ is the yield shear stress (MPa); r is the distance from any position in the slurry migration zone to the center of the grouting hole (m); q is the grouting flow rate (t); b is the crack opening (m); μ is the viscosity time function; r t is the slurry diffusion front at time t (m); P w is the groundwater pressure (MPa), and r0 is the borehole radius (m). The grouting pressures calculated above and those in the grouting schemes determined based on geological information and different treatment sections are all theoretical values. The smaller of the two can be selected and adjusted based on actual on-site results and feedback.

[0110] The present invention is a grouting repair method for independent foundation settlement. Through monitoring measures, numerical simulation, obvious dissolution layer sealing, stabilization treatment (rapid setting, high corrosion resistance grouting material), near-foundation layer grouting protection treatment, and regional and batch grouting of lifting areas (permeable grouting material), a grouting and lifting repair of independent foundation settlement in Glauber's salt-gypsum stratum is achieved.

[0111] For those skilled in the art, when understanding the solutions described in the specific embodiments of the present invention, they can refer to conventional technical manuals in the field. At the same time, for the places where the above-mentioned terms appear, they can make appropriate understanding or adjustments for reference, and deduce the implementation of the same or similar technical solutions without paying any creative work.

[0112] The above embodiments describe only the basic principles, main features and / or advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and the invention content of the specification only describe the principles or specific cases of the present invention. Without departing from the essence of the innovative ideas of the present invention, the innovative solutions of the present invention may be subject to various changes and improvements, and these changes and improvements all fall within the scope of protection claimed by the present invention.

Claims

1. A grouting repair method for foundation settlement of soluble gypsum rock formation, characterized in that: The following steps are involved: S1. Determine the scope of the foundation of the soluble gypsum formation that requires jacking treatment. The soluble gypsum formation is the mirabilite-gypsum formation; S2. Design grouting holes in the area requiring jacking treatment, including a first sequence of grouting holes and a second sequence of grouting holes. The first sequence of grouting holes is located in the outer peripheral area of ​​the area requiring jacking treatment, and the second sequence of grouting holes is located in the inner area of ​​the area requiring jacking treatment. The area requiring jacking treatment is divided into individual independent foundation settlements and regional independent foundation settlements. Multiple first sequence grouting holes form an outer ring in the outer peripheral area of ​​the individual independent foundation settlements, and multiple second sequence grouting holes are close to the edge of the foundation. There are multiple foundations in the regional independent foundation settlement, multiple first-sequence grouting holes form an outer circle in the outer area of ​​the regional independent foundation settlement, and multiple second-sequence grouting holes are set on the edges of the multiple foundations in the regional independent foundation settlement; Select holes from the first sequence of grouting holes as survey holes and conduct drilling exploration to obtain geological information data; S3. Delineate different treatment sections based on stratum depth using geological data. The treatment sections are delineated from top to bottom into a stiffness reinforcement zone, an uplift zone, and a reinforced stabilization zone. The stiffness reinforcement zone is 3 to 5 meters from the foundation bottom along the stratum depth direction, and the reinforced stabilization zone consists of soluble gypsum. Determine the grouting plan for the grouting holes based on the geological data and the different treatment sections. S4. According to the grouting plan, first drilling and first grouting are performed at the positions of the first sequence grouting holes and the second sequence grouting holes; the drilling depth of the first drilling hole is within the depth range of the stiffness reinforcement zone; the first grouting is performed on the first drilling hole, and the first grouting adopts top-down hole-sealing grouting; S5. Perform a second drilling and second grouting of the first sequence of grouting holes. The drilling depth of the second drilling holes is within the depth range of the reinforcement and stability zone. The second grouting of the first sequence of grouting holes adopts a top-down method of sealing the grouting with a fixed depth using a sac-type grouting stopper. The second grouting depth is within the depth range of the reinforcement and stability zone. S6. Perform a third drilling and third grouting of the second sequence of grouting holes. The drilling depth of the third drilling hole is within the depth range of the reinforcement and stabilization zone. The third grouting of the second sequence of grouting holes adopts a top-down method of using a sac-type grouting stopper to close the grouting to a fixed depth. The third grouting depth is within the depth range of the reinforcement and stabilization zone. S7, performing a fourth grouting operation on the first and second sequence grouting holes in sequence, wherein the depth of the fourth grouting operation is within the depth range of the lifting zone, and the fourth grouting operation is performed from bottom to top using a sac-type grout stopper to close the grouting operation at a fixed depth; The first grouting of the first sequence grouting holes and the second sequence grouting holes adopts the first grouting material for grouting reinforcement. The first grouting material adopts the permeable grouting material. The permeable grouting material is required to be able to penetrate cracks with a width of more than 150μm. The first grouting material adopts silicate cement with a water-cement ratio of 1.0 to 2.

0. The setting time of the first grouting material is 6 to 12min. The second grouting of the first sequence grouting holes adopts the second grouting material for grouting reinforcement. The second grouting material adopts the quick-setting grouting material. The second grouting material is a mixture of sulfate-resistant silicate cement and quick-setting agent. The water-cement ratio of the Portland sulfate cement is 1:0.8-1.5, the content of tricalcium aluminate in the sulfate-resistant Portland cement does not exceed 3%, the amount of the accelerator added is 0.8-1.5‰ of the dry weight of the sulfate-resistant Portland cement, and the initial setting time of the second grouting material is 15-30 minutes; the third grouting of the second sequence grouting holes is grouting reinforced with a third grouting material, and the third grouting material is a permeable grouting material; the fourth grouting of the first sequence grouting holes and the second sequence grouting holes is grouting reinforced with a fourth grouting material, and the fourth grouting material is a permeable grouting material; During the second or third grouting process, grouting is performed within the depth range of the reinforced stable zone. The grouting parameters of each section are adjusted according to the fact that there is no obvious deformation or uplift of the foundation. Grouting is stopped when deformation or uplift occurs, and then grouting is continued after adjusting the grouting parameters. In the fourth grouting process, grouting is carried out in the depth range of the lifting area, and the grouting parameters of each section of the lifting area are adjusted based on the fact that there is no obvious cracking of the foundation; The second or third grouting is carried out from top to bottom, with a sac-type stopper to set the depth for closed grouting. The specific steps are as follows: S51. Install a waterproof plate on the upper surface of the grouting hole, insert an orifice pipe into the grouting hole, and fill the space between the grouting hole and the orifice pipe with an orifice sealing material; connect the slurry inlet pipe and the slurry stopper in sequence; S52, installing the capsule grouting plug at the upper end of the depth range of the reinforcement stability zone in the grouting hole; S53, injecting pressure into the bladder stopper, so that the bladder stopper expands and presses against the inner wall of the grouting hole to form an in-hole grouting system; starting the grouting equipment, and injecting the slurry of the second grouting material or the third grouting material into the grouting hole through the grouting pipe; after the grouting pressure reaches the end standard pressure, stopping the grouting and depressurizing the bladder stopper; S54: After the second grouting material or the third grouting material has initially set, the grouting pipe is rotated to adjust the position of the capsule grouting plug downward, and step S53 is repeated until the grouting within the depth range of the reinforced stable zone is completed; The fourth grouting adopts grouting from bottom to top with a sac-type stopper to set the depth. The specific steps are as follows: S71. Install a waterproof plate on the upper surface of the grouting hole, insert an orifice pipe into the grouting hole, and fill the space between the grouting hole and the orifice pipe with orifice sealing material; connect the slurry inlet pipe and the slurry stopper in sequence; S72, installing the capsule grout stopper at the bottom end of the depth range of the lifting area in the grouting hole; S73, injecting pressure into the bladder stopper, so that the bladder stopper expands and presses against the inner wall of the grouting hole to form an in-hole grouting system; starting the grouting equipment, and injecting the slurry of the fourth grouting material into the grouting hole through the grouting inlet pipe; after the grouting pressure reaches the end standard pressure, stopping the grouting and depressurizing the bladder stopper; S74: Rotate the slurry inlet pipe to adjust the position of the bag-type slurry stopper upwards, and repeat step S73 until the grouting in the depth range of the lifting area is completed.

2. The grouting repair method for foundation settlement of soluble gypsum rock formation according to claim 1, characterized in that: The detailed steps to determine the scope of soluble gypsum formation foundation that requires jacking treatment are as follows: S11. Selecting a benchmark measuring point at the foundation settlement site of the soluble gypsum stratum to be repaired, measuring the settlement of each vertical load-bearing component in the foundation settlement area based on the benchmark measuring point, and calculating the settlement difference; S12. According to the determined settlement difference, determine the scope of foundation that needs to be jacked up.

3. The grouting repair method for foundation settlement of soluble gypsum rock formation according to claim 1, characterized in that: The grouting holes also include the third sequence of grouting holes, which are located in the inner area of ​​the range to be jacked up. When the range to be jacked up is divided into individual independent foundation settlement and regional independent foundation settlement, For individual independent foundation settlement, multiple third-sequence grouting holes are close to the edge of the foundation, and the third-sequence grouting holes are located between two adjacent second-sequence grouting holes; For regional independent foundation settlement, multiple third sequence grouting holes are located between two adjacent foundations.

4. The grouting repair method for foundation settlement of soluble gypsum rock formation according to claim 1, characterized in that: In step S2, the method for obtaining geological information data through drilling exploration is: obtaining the geological conditions, hydrological conditions and degree of dissolution of the grouting hole through drilling underwater television and / or tracer method, and analyzing and summarizing them into geological information data.

5. The grouting repair method for foundation settlement of soluble gypsum rock formation according to claim 1, characterized in that: The method for determining the grouting scheme of the grouting holes based on geological information data and different processing stages is: using simulation analysis software to perform numerical calculation simulation on the geological information data, and obtaining the grouting parameters and processing parameters of the grouting holes as the grouting scheme of the grouting holes.

6. The grouting repair method for foundation settlement of soluble gypsum strata according to claim 1, characterized in that: On the basis of the first drilling holes, a second drilling is continued for the first sequence of grouting holes to obtain a first sequence of grouting holes, wherein the depth of the first sequence of grouting holes exceeds the depth of the hard rock where obvious dissolution holes exist; Based on the first drilling foundation of the second sequence of grouting holes, the third drilling is continued to obtain the second sequence of grouting holes. The depth of the second sequence of grouting holes exceeds the depth of the hard rock where obvious dissolution holes exist.

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