Filling process method for filling adjacent water-containing karst cave with flow-state solidified mudstone slurry

Abstract

The invention provides a filling process method for filling an adjacent water-containing karst cave with flow-state solidified mudstone slurry, and belongs to the technical field of geotechnical engineering and foundation treatment. The method comprises the following steps: taking waste mudstone / muck generated by excavation of a tunnel near a karst area as a solid phase source, forming a composite curing system with ordinary Portland cement, slag powder, an additive and water, and preparing to obtain flow-state cured mudstone slurry; and finally, the water-containing karst cave near the pile position is filled and reinforced through the flow-state solidified mudstone slurry in a grouting mode, so that a continuous and compact solidified body is formed in the cave body. The method effectively solves the problems of pile hole instability, bearing capacity dispersion, settlement control difficulty and the like caused by uncompaction of the filling body and discontinuous plugging.

Description

Technical Field

[0001] This invention provides a filling process for filling adjacent water-bearing karst caves with fluidized solidified mudstone slurry, belonging to the field of geotechnical engineering and foundation treatment technology. Background Technology

[0002] Piling construction in karst areas often encounters complex and unfavorable conditions such as the development of karst caves, dissolution fissures, and interconnected groundwater systems, resulting in strong heterogeneity and uncertainty in the geological structure and hydrogeological conditions. When cavities or voids appear within the pile location area, the stability of the borehole wall, borehole safety, and subsequent pile quality are more easily disturbed. Karst cavities at the pile location significantly increase the construction risks of cast-in-place piles and adversely affect bearing capacity and construction safety. At the same time, the connectivity of fissures, channels, and cavities in the karst medium means that hydraulic conditions may change during construction. Phenomena such as localized water inrush and redistribution of seepage channels further amplify the coupling risks between "cavity treatment - borehole formation - pile formation." Therefore, in water-rich karst sites, pile foundation construction is often not just a simple borehole formation problem, but a comprehensive engineering project involving cavity filling and seepage disturbance control.

[0003] When performing cavity filling or grouting reinforcement under water-rich conditions, the grout is easily affected by water flow disturbance after entering the cavity, resulting in segregation, dilution, uncontrolled diffusion, or being carried away by scour. This leads to an incomplete filling and discontinuous sealing, ultimately manifesting as a problem chain of "ineffective cavity closure - unreliable cut-off of hydraulic channels - continued existence of local weak areas." For injection materials in underwater or dynamic water environments, publicly available research and reviews generally emphasize that materials should focus on key performance properties such as anti-dispersion, anti-scour, and retention rate to ensure that the grout maintains its integrity in water and forms a continuous solidified body in the target area. These performance requirements differ from the evaluation focus of conventional static or dry grouting: not only pumpability and fluidity need to be considered, but also the ability to maintain effective retention and forming capacity under the more demanding conditions of "water erosion - particle migration - grout structure stability." Therefore, for pile foundation reinforcement of water-bearing karst caves, simply relying on general cement grout or low-viscosity grout often fails to consistently achieve high-density, continuous sealing treatment results.

[0004] At the process control level, engineering practices and patent disclosures often employ sleeve valve pipes or equivalent segmented grouting structures, combined with retreating (bottom-up) segmented grouting, to improve the controllability and traceability of "fixed depth, fixed segment, and repeatable grouting." Relevant technical documents clearly indicate that the sleeve valve pipe system, by setting a valve port with a rubber sleeve on the pre-embedded pipe and using a packer to open the valve at a selected depth for injection, allows for multiple sequential re-grouting of the same segment, which is beneficial for implementing refined segmented treatment in situations with abundant water, developed fissures, or poor borehole wall conditions. The upward segmented and retreating segmented grouting approach is also considered an important organizational method to improve the controllability and quality consistency of segmentation. Correspondingly, local engineering and technical standards typically emphasize, within the overall risk management framework, that pile foundation construction in karst areas should adhere to the general principle of "treatment before construction," and establish a closed-loop control system through process recording, quality inspection, and monitoring. For example, relevant technical standards explicitly state that when cavities or sinkholes exist in karst areas, they should be backfilled or grouted before construction, and specify requirements for quality and safety control during the construction process. These standards, at the methodological level, point to the same conclusion: for water-rich karst areas, the "materials-process-monitoring-re-grouting-acceptance" process must be organized into an executable flow, rather than fragmented into unconnected individual measures.

[0005] On the other hand, the large amount of excavated soil, slag, and mudstone waste generated during tunnel and subway construction would not only increase disposal and transportation costs if directly transported off-site, but also impose additional environmental burdens. Recent studies have discussed combining excavated soil and mudstone solid resources with cementitious materials and mineral admixtures to prepare filling materials with certain fluidity and controllable strength for backfilling, void filling, or engineering reuse. However, for the combined condition of "tunnel proximity - water-bearing karst caves - pile foundation construction constraints," existing public discussions mostly focus on materials or single construction stages. It is still necessary to integrate the grouting system with the grouting filling process design: it must address the erosion resistance and retention requirements of water-rich environments, match a segmented, controllable, and re-grouting process organization, and meet the pre-treatment and full-process inspection and monitoring framework emphasized by standards. Against this backdrop, waste mudstone generated during tunnel excavation near karst areas is processed into a fluidized solidified mudstone slurry. This slurry is then used for segmented and sequential grouting to fill and reinforce water-bearing karst caves. This approach is expected to ensure the safety and quality of pile foundation construction while simultaneously optimizing the resource utilization and remediation costs of excavated soil. Therefore, its engineering significance and potential for wider application are even more prominent. Summary of the Invention

[0006] In water-rich karst conditions, conventional grouting materials and processes are easily affected by water erosion, dilution, and segregation, leading to incomplete filling, discontinuous sealing, and consequently, pile hole instability, bearing capacity dispersion, and difficulties in settlement control. Therefore, this invention provides a filling process for adjacent water-bearing karst caves using fluidized solidified mudstone slurry. This invention is a grouting and reinforcement process using fluidized solidified mudstone slurry as the filling medium. The method uses waste mudstone / slag from tunnel excavation near karst areas as the solid phase source, which is combined with ordinary silicate cement, slag powder, and admixtures to form a composite solidification system, preparing fluidized solidified mudstone slurry. This slurry is then used to fill and reinforce water-bearing karst caves near the pile location through grouting, forming a continuous and dense solidified body within the cave, thus providing more stable surrounding rock and foundation conditions for subsequent pile drilling and pile installation.

[0007] The mass percentages of each component in the fluidized solidified mudstone slurry of this invention are as follows: Waste mudstone / slag soil 50-65%, Ordinary Portland cement 2~7%, Slag powder 1~5%, Admixture 0.1~0.8%, The rest is water.

[0008] Preferably, the additive is an early-strength agent or a thickener.

[0009] This invention uses on-site prepared fluidized solidified mudstone slurry as the grouting filling material, and combines it with a complete process of "exploration-sealing-segmentation-filling-re-injection-inspection" to achieve controlled filling and reinforcement of water-bearing karst caves adjacent to tunnels (within the influence range of pile foundations). The reinforcement process includes the following steps: (1) Use drilling to locate the boundaries and connectivity of the tunnel, and delineate the treatment area and hole network; set up peripheral control holes when necessary to reduce the risk of grout leakage.

[0010] (2) Adopt sleeve valve pipe or equivalent segmented grouting structure, and combine shell material and sealing section to form a controlled shell breaking channel to adapt to the water-rich environment of high groundwater level.

[0011] (3) The main filling adopts a backward segmented grouting method, and can be combined with hole sequence organization such as "outer first, inner second, alternating holes, and cyclic grouting" to improve the uniformity and controllability of filling.

[0012] (4) Under conditions of water content and water flow disturbance, relying on the anti-dispersion properties of the slurry and in conjunction with segmented re-injection, segregation and scouring loss are reduced, and a continuous solidified body is gradually formed.

[0013] (5) Combine the whole process inspection and monitoring and risk management framework proposed by local standards to form an engineering closed loop of “process control - results verification - deficiencies can be supplemented”.

[0014] Compared with the prior art, the present invention has the following beneficial effects: This invention integrates the "grout system - process control - quality closed loop" into the same process framework. On the one hand, it utilizes the existing fluidized solidified mudstone grout material system to meet the requirements of pumping injection and filling fluidity while giving full play to its anti-dispersion and other working characteristics. On the other hand, it improves the controllability of injection position and injection process through segmented and sequential grouting organization, so that the grout can still achieve effective filling and continuous solidification in water-bearing karst caves and their interconnected fissures, reducing the risks of "being carried away by water" and "residual cavities".

[0015] Furthermore, this invention strives to achieve a balance between engineering feasibility and economic and environmental benefits. By utilizing tunnel spoil and waste mudstone locally (or nearby), this invention transforms them into a source of grouting filling materials with controllable performance, reducing the costs and environmental burden associated with off-site disposal and the procurement of new materials. Simultaneously, by employing a process-oriented and streamlined filling and reinforcement method, a repeatable, verifiable, and traceable construction path is formed, enabling the treatment of water-bearing karst caves and pile foundation construction to be integrated within the same technical system. This further enhances the safety, stability, and consistency of construction quality in pile foundation engineering in karst areas. Attached Figure Description

[0016] Figure 1 This represents the underwater manifestation of fluidized solidified mudstone slurry. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the preferred embodiments of this invention will be described in further detail below with reference to the examples. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0018] "Water-bearing karst caves" refer to karst spaces containing still water or connected to fissures or groundwater systems and capable of seepage replenishment; "adjacent water-bearing karst pile foundations" refer to karst caves or dissolution fissures located at the pile position or within the influence range of the pile tip, which need to be filled with grout before pile foundation construction to form a stable reinforced body to improve bearing capacity and water-stopping conditions.

[0019] The present invention specifically includes the following steps: I. Construction Preparation and Investigation Verification (Phase A) (1) Data verification: Summarize the tunnel construction findings, advanced geological forecasts, existing exploration results, groundwater level and recharge conditions, pile location and stress requirements, etc., to form a spatial relationship diagram of "karst cave-tunnel-pile location".

[0020] (2) Site survey and risk zoning: Mark sensitive areas of surface subsidence, existing structures, sensitive sections of tunnel structure, underground pipelines, etc., and determine the key monitoring areas and prohibited areas for grouting operations.

[0021] (3) Drilling to find the boundary: Drill holes in the suspected karst area according to the grid pattern of squares or strips, and comprehensively determine the boundary, filling status and connectivity of the cave by means of leakage, backflow, core sampling and in-hole imaging (if available). This method of “drilling to find the boundary of the cave” is clearly defined as the first step in the published patent.

[0022] (4) Treatment Scope and Hole Network: Based on the boundary of the tunnel and the influence range of the pile foundation, a reinforcement zone is formed by expanding outward; an outer control zone is set for the development direction of the connecting cracks to reduce the risk of grout escaping along the dominant channel. The hole spacing, hole depth, and zoning scale are determined by the design and field test section. This invention emphasizes that it should meet the construction closed loop of "controllable, verifiable, and reinforceable".

[0023] II. Equipment Composition and Construction Organization (Phase B) To ensure the continuity and controllability of grouting under water-rich conditions, an integrated construction organization encompassing "mixing-storage-pumping-monitoring-emergency response" is recommended. Equipment configuration can be selected based on the project scale, but typically includes at least: (1) Mixing system: metering device, forced mixer (or equivalent high-efficiency mixing equipment), and slurry storage tank with mixing function; (2) Pumping and Piping: Grouting pump, grouting pipeline, pressure / flow monitoring device, check valve and pressure relief assembly; (3) Grouting assembly: sleeve valve tube, grouting core tube, grout stop plug / packer, orifice sealing and grout collection device; (4) Estimate the amount of grouting required for the karst caves being investigated; estimate the time required for one mixing of the mixing equipment and the volume that can be mixed; test and record the performance of different materials under different working conditions, ensuring that the pumpability of the Pearl River material is met, and record the rheological time window of the grout; connect all the above times and volumes to ensure that the grout is mixed and pumped in a timely manner as much as possible.

[0024] (5) Monitoring and recording: Real-time recording of grouting parameters (pressure, flow rate, cumulative volume, time), and monitoring of surrounding deformation / leakage; (6) Emergency and cleaning: backup pump, backup power supply (if available), pipeline flushing and waste slurry collection facilities.

[0025] (7) Estimate the amount of grouting required for the karst caves being investigated; estimate the time required for one mixing operation of the mixing equipment and the volume that can be mixed; test and record the performance of different materials under different working conditions, ensuring that the pumpability of the Pearl River material is met, and record the rheological time window of the grout; connect all the above times and volumes to ensure that the grout is mixed and pumped in a timely manner as much as possible.

[0026] III. Preparation and On-site Consistency Control of Fluidized Solidified Mudstone Slurry (Phase C) (1) Mudstone pretreatment: The tunnel waste soil is sorted and screened to remove organic impurities, plastics, wood chips, metals, etc. If necessary, the mudstone blocks are crushed and then passed through a 4.5mm screen to reduce the risk of pump blockage and improve the uniformity of the slurry.

[0027] (2) Other raw materials: The ordinary Portland cement used is 42.5 grade ordinary Portland cement with a specific surface area of ​​352 m². 2 / kg, initial setting time 188min, final setting time 239min; the mineral powder used is S105 grade mineral powder with a density of 2.93g / cm³. 3 Specific surface area 628m² 2 / kg, fluidity ratio 102%, water content 0.2%; admixtures include early strength agent and thickener. According to different working conditions and construction site requirements for grouting materials, performance ratio adjustments are made in the laboratory to determine the optimal ratio required for specific working conditions and the engineering site. Materials are then prepared according to the optimal ratio and the estimated volume required for the karst cave.

[0028] (3) Feeding and mixing sequence: It is recommended to use forced mixing equipment. Generally, the admixture can be dissolved in metered water first, then cement and mineral powder can be added to form a uniform slurry, and then the pretreated waste soil can be added in batches and mixed until uniform. The specific sequence can be optimized according to the on-site equipment and flow stability, but uniformity and pumpability should be the goal. For the preparation and construction points of fluid self-compacting backfill materials, please refer to the principle description of mixing, transportation and quality control in the relevant technical reports of CLSM.

[0029] (4) On-site workability verification: After each batch is mixed, rapid workability observation and necessary simple tests (such as expansion, bleeding, and segregation trend) should be carried out to ensure that the grout has continuous filling and anti-dispersion stability in water-rich tunnels. For grouting materials in underwater karst environments, attention should be paid to the underwater workability of the material, such as its anti-dispersion and anti-erosion properties and retention rate.

[0030] (5) Storage and transportation: After mixing, the slurry should be stored in a slurry tank with a stirring device for short-term turnover. The pipeline should be arranged with as few bends as possible and easy to disassemble and clean. When pumping is interrupted, long-term standing should be avoided to prevent sedimentation.

[0031] IV. Drilling, Sealing, and Grouting Channel Construction (Phase D) In water-rich karst conditions, the stability of the sealing and grouting channels directly determines whether the grout can diffuse along predetermined sections. To improve controllability, this invention preferably employs a segmented grouting system with sleeve valves; in cases of poor borehole wall stability or high groundwater levels, casing material can be introduced to form a controlled shell-breaking channel with the sealing section.

[0032] (1) Drilling and cleaning: Drill to the designed depth according to the hole location. After drilling, clean the hole to reduce the impact of sediment at the bottom of the hole and mud on the hole wall on the sealing quality.

[0033] (2) Lowering the pipe: Lower the sleeve valve pipe to the bottom of the hole, with the valve port section corresponding to the section to be grouted; if there is a significant difference between the tunnel section and the overlying soil layer section, the density of key valve ports can be set for the tunnel section to facilitate the filling of the tunnel space.

[0034] (3) Shelling and sealing: In the shelling process, the shelling material can be pressed into the bottom of the hole to replace the mud in the hole and fill the gap between the pipe wall and the hole wall, thereby forming a filling layer with a certain strength, providing a controlled channel for the subsequent grout to "break the shell laterally"; a sealing section is set at the top to prevent the grout from flowing out along the annular gap. Similar organization of "pressing in shelling material - lower sleeve valve pipe - segmented grouting" has been disclosed in published patents.

[0035] (4) Sealing verification: After sealing, necessary waiting and pressure testing verification are carried out (in accordance with the principle that no obvious grout leakage occurs). After meeting the requirements, the grouting stage is entered.

[0036] V. Segmented and sequential grouting and filling (E stage, core process) This invention uses fluidized solidified mudstone slurry as the main filling material, employs a retreating segmented grouting method, and combines a strategy of "edge control priority - main filling follow-up - alternating / circular grouting with alternate holes - re-grouting and compaction" to adapt to the irregular morphology and hydraulic connectivity of water-bearing karst caves. Published patents propose typical organizational methods for the treatment of karst and soil caves, including "outer side first, then inner side, alternating or circular grouting with alternate holes" and "retreating segmented grouting"; the retreating segmented grouting method is also clearly described in grouting method patents.

[0037] (1) Edge control grouting (peripheral holes, curtain holes): Grouting should be prioritized at the boundary of the tunnel and the fracture development zone to form flow restriction and boundary constraint, reducing the probability of grout escaping to the distant dominant channel during subsequent main filling. Edge control grouting should be carried out by alternating holes to avoid local concentrated lifting or cross-flow of grout.

[0038] (2) Main filling grouting (internal holes): After the initial constraint is formed by the control of the edge, the internal filling of the tunnel is carried out. The hole sequence can be alternated by alternating holes or organized in a "center-periphery-center" cycle to take into account both the continuity of filling and the sealing of the boundary.

[0039] (3) Retreating segmented grouting: Segmented grouting from bottom to top within a single hole. After each segment is completed, the grouting core tube is lifted to enter the next segment and continue grouting until the segment within the hole is completed. The core of this method is to achieve inter-segment isolation through grout stop plugs or valves, thereby achieving segmented quantitative grouting, controlling diffusion, and supporting re-grouting.

[0040] (4) Grouting rhythm under water-rich conditions: When there is obvious water in the tunnel and water flow disturbance, priority should be given to ensuring that the grout forms a stable diffusion and initial sealing in the injection section before advancing the main filling; if necessary, the rhythm of "segmented short-time injection - intermittent observation - re-injection and compaction" can be adopted to reduce the risk of grout run-out and dilution caused by a large amount of injection at one time.

[0041] (5) Termination and Re-grouting Judgment (Principles): Termination and re-grouting should not be determined solely by the cumulative grouting volume. Instead, they should be determined by comprehensively considering the pressure-flow response, grout return, grout cross-contamination between adjacent boreholes, surface / tunnel structure monitoring, and verification results from supplementary boreholes. For areas where cavities or connecting channels are suspected to still exist, re-grouting can be carried out using a sleeve valve pipe system to gradually fill and compact the area.

[0042] (6) Connection with pile foundation construction: After grouting is completed, the time for entering the pile foundation hole drilling or re-drilling is determined according to the design requirements and the hardening law of the grout; this connection needs to take into account both "formation of an effective solidified body" and "feasibility of pile foundation construction". In the study on the preparation of grouting materials using drill cuttings / spoil for karst pile foundation reinforcement, the influence of grout fluidity, stability and strength control on construction adaptability is also emphasized.

[0043] VI. Process Monitoring, Recording, and Information Feedback (Phase F) Grouting is a process-dependent procedure. It is recommended to establish a four-level ledger: borehole-segment-batch-parameter, including borehole coordinates and depth, valve port location for each segment, corresponding grout batch number, pressure / flow rate over time curve, cumulative grouting volume, grouting stop and re-grouting times, and abnormal phenomena (grout leakage, grout overflow, surface uplift, tunnel seepage, etc.).

[0044] Information feedback and process adjustments should be triggered when the monitored or process parameters exhibit the following trends: (1) Pressure rises rapidly and flow drops significantly (suspected blockage or compaction within the section); (2) The pressure is low but the amount of grout suction is abnormally large (suspected grout leakage or connection of cavities). (3) If grout leakage occurs at a distance or in the tunnel, grouting must be stopped immediately for investigation. (4) Abnormal surface / structure deformation (the hole sequence and grouting rhythm need to be adjusted).

[0045] VII. Filling and Re-grouting and Final Grouting Control (Phase G) (1) Triggering conditions for hole repair: When the construction log shows abnormal grout absorption or grout leakage at a distance, or when the exploratory borehole still reveals obvious cavities / high permeability channels, or when the monitoring data indicates an increased risk, hole repair or re-grouting should be carried out.

[0046] (2) Reinforcement strategy: Prioritize refilling the control zone to improve boundary sealing, and then refill the insufficiently filled internal areas; for the dominant channels of connecting fractures, the connectivity can be gradually weakened by densifying the hole network and refilling in segments.

[0047] (3) Closed-loop requirements: This invention emphasizes the formation of a closed loop of “verification-reinforcement-re-verification”; local standards emphasize that construction in karst areas should follow the principle of treatment before construction, and regard inspection and monitoring and risk management as important links.

[0048] VIII. Verification and Acceptance Data of Treatment Effectiveness (H Phase) To avoid relying solely on grouting volume or a single indicator for judgment, the treatment effect should be comprehensively confirmed through "process records + supplementary exploration and verification". Supplementary exploration and verification can be carried out by re-drilling inspection, in-hole observation (when available), and commonly used engineering methods such as core sampling, water injection / pressure water injection, etc., to corroborate changes in filling density and permeability (specific indicators and methods are determined by project design and supervision requirements).

[0049] Acceptance documentation should include at least the following: borehole location layout and change records, material batch and mix ratio records (within the established range), grouting parameter curves and logs, abnormal event handling records, monitoring data and analysis, and supplementary exploration / verification data.

[0050] IX. Key Points and Precautions for Construction (Facing Water-Rich Karst and Adjacent Tunnels) (1) Deformation and leakage risk control of adjacent tunnel structures: During grouting, the tunnel structure and surrounding surface are monitored. If any abnormality occurs, the hole sequence and grouting rhythm are adjusted in time to avoid local uplift or grout leakage to the back of the tunnel lining.

[0051] (2) Prioritize edge control and alternate between grouting: Prioritize edge control grouting of the tunnel boundary and connecting fracture zone to reduce the probability of grout leakage during main filling; alternating between grouting / circular organization can reduce concentrated disturbance.

[0052] (3) Prioritize sealing quality: Under high groundwater conditions, measures such as casing material + sealing section should be adopted to form a controlled shell breaking channel to prevent slurry from flowing out along the annular gap of the pipe wall.

[0053] (4) Preventing pipe blockage: Pre-treatment of waste soil (sorting, screening, and necessary crushing) and easy-to-disassemble and clean pipeline design are the key to reducing the risk of pipe blockage; when the pump is stopped for a long time, circulation stirring or pipeline flushing should be carried out.

[0054] (5) Material consistency: When the source of the waste soil changes, a quick workability check should be carried out. If necessary, the amount of water or admixture should be adjusted slightly within the established ratio range to ensure flowability and stability.

[0055] (6) Environmental and civilized construction: The resource utilization of waste soil should meet the environmental protection management requirements of the project. Wastewater from slurry mixing and cleaning should be collected and treated to avoid direct discharge into surface water bodies or drainage systems.

[0056] The embodiments described above are some, but not all, embodiments of the present invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A filling process for adjacent water-bearing karst caves using fluidized solidified mudstone slurry, characterized in that, Using waste mudstone / slag from tunnel excavation near karst areas as the solid phase source, a composite solidification system is formed with ordinary silicate cement, slag powder, additives, and water to prepare a fluidized solidified mudstone slurry. Finally, the fluidized solidified mudstone slurry is injected to fill and reinforce water-bearing karst caves near the pile locations to form a continuous and dense solidified body within the cave.

2. The filling process method for filling adjacent water-bearing karst caves with fluidized solidified mudstone slurry as described in claim 1, characterized in that, The mass percentages of each component in the fluidized solidified mudstone slurry are as follows: Waste mudstone / slag soil 50-65%, Ordinary Portland cement 2~7%, Slag powder 1~5%, Admixture 0.1~0.8%, The rest is water.

3. The filling process method for filling adjacent water-bearing karst caves with fluidized solidified mudstone slurry as described in claim 1, characterized in that, The additives are early-strength agents and thickeners.

4. The filling process method for filling adjacent water-bearing karst caves with fluidized solidified mudstone slurry as described in claim 1, characterized in that, The reinforcement method includes the following steps: (1) Use drilling to locate the boundaries and connectivity of the cavity, and delineate the treatment area and borehole network; (2) Adopt sleeve valve pipe or equivalent segmented grouting structure, and combine shell material and sealing section to form a controlled shell breaking channel to adapt to the water-rich environment of high groundwater level; (3) The main filling adopts a backward segmented grouting method, and can be combined with hole sequence organization such as "outer first, inner later, alternating holes, and circulating grouting" to improve the uniformity and controllability of filling; (4) Under conditions of moisture and water flow disturbance, relying on the anti-dispersion properties of the slurry and in conjunction with segmented re-injection, segregation and scouring loss are reduced, and a continuous solidified body is gradually formed; (5) Combine the whole process inspection and monitoring and risk management framework proposed by local standards to form an engineering closed loop of "process control - results verification - deficiencies can be supplemented".

5. The filling process method for filling adjacent water-bearing karst caves with fluidized solidified mudstone slurry as described in claim 4, characterized in that, Step (1) can be set with peripheral control holes to reduce the risk of slurry leakage.

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