Treatment method for karst tunnel located in underground water vertical seepage zone and seasonal variation zone

Abstract

The invention discloses a treatment method for a karst tunnel located in an underground water vertical seepage zone and a seasonal variation zone. The treatment method comprises the following steps that firstly, field checking and treatment are conducted; step 2, karst characteristics and surface water seepage paths of disease sections; 3, extracting data features; 4, analyzing a fracture network topological structure; 5, systematic water interception and drainage measures of the drainage tunnel are taken; soil conductivity distribution data are obtained through a transient electromagnetic method, reflection coefficient data are detected through a geological radar method, a fracture-seepage characteristic spectrum is obtained through time synchronization alignment, and a quasi fracture-seepage characteristic matrix is generated for the fracture-seepage characteristic spectrum through a social range. Then the standardized fracture-seepage characteristic matrix is converted into a visible topological graph, and observation is facilitated; precise prevention and control of diseases are achieved by establishing a technical system of water detection, reason analysis, graded treatment and three-dimensional interception, and a three-level progressive technical path is constructed in the treatment stage.

Description

Technical Field

[0001] This application relates to the field of karst tunnel technology, and in particular to a method for treating karst tunnels located in the vertical seepage zone and seasonal variation zone of groundwater. Background Technology

[0002] Tunnel engineering is an underground buried project with complex and variable geological conditions. Karst tunnels are located in the vertical runoff zone and seasonal variation zone of groundwater, which is even more complex. Its geological characteristics are characterized by irregular and difficult-to-find karst cavities, dense joints and fissures, moderate karst development, and a high degree of rock fragmentation. The hydrological characteristics are mainly karst fissure water, which is significantly affected by meteorology, precipitation and surface water recharge, showing obvious seasonal differences: in the dry season, due to low precipitation and weak surface water recharge, the tunnel water output is low and the structural stability is good, with no obvious defects; in the rainy season, when the precipitation increases sharply, surface water seeps into the ground quickly, raising the pressure of fissure water, causing frequent water inrush and sand bursting at the tunnel construction joints due to the weak structure.

[0003] Existing tunnels located in areas with vertical groundwater seepage zones and seasonal groundwater fluctuation zones face complex hydrogeological challenges. The tunnel structure in these areas is susceptible to dynamic changes in groundwater, primarily manifested in the following ways: 1) The water outlets, being structurally weak points, exhibit high uncertainty. Sealing measures often fail to address all areas effectively, and after partial sealing, water flow can easily transfer to other weak points through hidden channels such as karst fissures, creating new leaks. 2) The development of karst fissure networks leads to highly uncertain seepage paths. Water outlets often form in structurally weak areas and exhibit random distribution. Conventional treatment often results in a "blocking one area and leaking another" phenomenon, where partial sealing leads to leakage in adjacent areas. The fundamental problem lies in the difficulty of accurately detecting the concealment and connectivity of the karst fissure system. 3) Even if drainage holes are constructed within the vicinity of identified water outlets, the random distribution of the fissure network may still prevent effective water diversion, leading to a "treating the symptoms but not the root cause" dilemma in water management. This presents significant technical challenges to tunnel water hazard control. If the handling methods are not appropriate, problems such as water and sand gushing in the construction joint, voids after lining, local cracks in the lining, and water leakage can easily occur.

[0004] To address the technical challenges of water hazard control in karst tunnels, current main solutions suffer from the following technical bottlenecks: First, traditional drainage tunnel projects are limited by the complexity of karst water systems. In areas where vertical runoff zones and seasonal variation zones intersect, the three-dimensional spatial distribution of karst conduits makes precise positioning difficult, hindering the effective penetration of drainage tunnel axes through karst cavities and dominant water-conducting fracture zones, resulting in a significant reduction in drainage efficiency. Second, passive grouting sealing technology has inherent flaws. High-pressure karst water easily seeps into and damages weak points in the sealing structure, inducing hydraulic fracturing effects. This not only leads to the failure of the sealing structure but also drives groundwater to expand along the weak structural surfaces to the affected areas, forming secondary leakage channels. Third, traditional trenching and drainage systems are limited by drainage capacity. Under sudden water inrush and sand-carrying conditions, the negative pressure effect generated by high-speed water flow exacerbates the erosion of the surrounding rock behind the lining, inducing delamination and damage at the structure-surrounding rock contact surface, ultimately creating a vicious cycle of lining stress imbalance and the expansion of cavities behind the lining. The aforementioned technical deficiencies make it difficult for existing treatment solutions to permanently eradicate karst water hazards, necessitating the development of a new treatment technology system based on precise detection and active regulation of karst water systems. Summary of the Invention

[0005] The main objective of this application is to provide a treatment method for karst tunnels located in the vertical seepage zone and seasonal variation zone of groundwater, so as to solve the problems in the prior art.

[0006] To achieve the above objectives, this application provides the following technical solution: A method for treating karst tunnels located in the vertical seepage zone and seasonal variation zone of groundwater includes the following steps: Step 1: On-site inspection and handling: After the occurrence of defects in the tunnel, immediately organize professional personnel to enter the site to conduct a systematic investigation, then carry out emergency treatment for the tunnel defects, and formulate permanent measures; Step 2: Karst characteristics and surface water seepage path of the diseased section: Soil conductivity distribution data were obtained by transient electromagnetic method and reflection coefficient data were detected by ground-penetrating radar method. Soil conductivity distribution data and reflection coefficient data were spatiotemporally aligned by time synchronization to generate a fused fracture-seepage characteristic map. Step 3: Data Feature Extraction: The noise-removed soil electrical conductivity distribution data and reflection coefficient data are normalized, and data features are extracted through social scope to generate a standardized fracture-seepage feature matrix; Step 4: Fractal Network Topology Analysis: Based on the standardized fracture-seepage feature matrix, a graph theory model of the fracture network is constructed. Fracts are regarded as edges in the graph, and fracture intersections are regarded as nodes. The node degree and edge weight are calculated. The backbone path of the fracture network is extracted by the minimum spanning tree algorithm, and the seepage priority channel is determined by combining the conductivity distribution data. The connectivity parameters of the backbone path are weighted and correlated with the values ​​in the graph theory model to generate fracture permeability correction coefficients. Step 5: Implement systematic drainage measures using a spillway system: Select drainage measures based on the amount of leakage.

[0007] As a further improvement to this application, the specific steps for generating the fracture-seepage characteristic map in step two are as follows: S201. Set the detection cycle of both the electromagnetic detection device and the ground-penetrating radar to 1 second. S202. Align the collected soil electrical conductivity distribution data and reflection coefficient data, and align them according to the corresponding frequencies. S203. Cut off the ends of the uneven soil conductivity distribution data and reflection coefficient data, and then align the soil conductivity distribution data and reflection coefficient data. S204. Then, the soil electrical conductivity distribution data and reflection coefficient data are mapped and processed to achieve spatiotemporal alignment and generate a fracture-seepage characteristic map.

[0008] As a further improvement to this application, the specific steps for generating the standardized fracture-seepage feature matrix in step three are as follows: S301. Decompose the soil conductivity distribution data and reflection coefficient data using wavelet transform to extract different frequency components; set the noise frequency band range and retain the data within the frequency band as effective features; treat the remaining frequency band data as random noise and filter it out using a threshold denoising algorithm; S302. Perform minimum-maximum normalization on the noise-removed soil electrical conductivity distribution data and reflection coefficient data respectively to unify the data range to [-1,1]. S303. Standardize and restrict soil electrical conductivity distribution data and reflection coefficient data according to the social scope, that is, according to the spatial distance relationship between soil electrical conductivity distribution data and reflection coefficient data, and set a threshold, and remove soil electrical conductivity distribution data and reflection coefficient data that exceed the spatial distance of the threshold. S304. Extract the principal component features of the reflection coefficient value of the fracture intersection point and the conductivity value of adjacent fractures from the data after removal using a multi-dimensional feature mapping algorithm, and generate a standardized fracture-seepage feature matrix.

[0009] As a further improvement to this application, the spatial distance relationship is calculated using the Euclidean distance formula to determine the correlation between soil electrical conductivity distribution data and reflection coefficient data. The formula is: ; in, For spatial distance, if If the value is greater than 0.5, the data point is removed to ensure the spatial matching of fracture-seepage characteristics. and The three-dimensional coordinates of the soil electrical conductivity distribution data and the reflection coefficient data collection points are represented respectively. If the distance between the three-dimensional coordinates of the collection points is large, it indicates that there is little correlation between the collection of soil electrical conductivity distribution data and reflection coefficient data, and they need to be removed.

[0010] As a further improvement to this application, the specific steps of the fracture network topology in step four are as follows: S401. The standardized fracture-seepage characteristic matrix is ​​transformed into computable topological parameters. The node degree reflects the fracture intersection density and the edge weight reflects the fracture connectivity. S402. Extract the main path of the fracture network using the minimum spanning tree algorithm, identify the seepage priority channel, and use the region with the highest electrical conductivity in the electrical conductivity distribution data as the initial node. S403. Combining conductivity distribution data with the connectivity parameters of the main path, determine the preferred seepage channels; S404. Weight the seepage priority channel index of the main path with the data values ​​in the graph theory model to generate the fracture permeability correction coefficient. It is used to optimize grouting parameters; the correction coefficient, through a nonlinear weighting formula, combines the dynamic changes of the fracture network with the priority of the seepage path, thereby improving the model's accuracy and adaptability in predicting permeability.

[0011] As a further improvement to this application, the formula for calculating the node degree is as follows: ; in, Represented as node degree, Represented as the first The reflection coefficient value at the intersection of the fractures This is represented by the maximum value of the reflection coefficient. This represents the total number of fracture intersections; The formula for calculating the edge weight is as follows: ; in, Represented as edge weight, , Expressed as the conductivity values ​​of adjacent fractures, and These are represented as the sequence values ​​of adjacent fractures. It is represented as the gap spacing, and valid edges are filtered by spatial distance threshold.

[0012] As a further improvement to this application, the formula for determining the preferential seepage channel is as follows: ; in, This is expressed as the seepage preference channel index. This is expressed as a baseline conductivity value, such as 0.5, and the formula is used to screen for high seepage paths.

[0013] As a further improvement to this application, the drainage measures in the steps include: For minor leaks, use sealing materials for emergency sealing. When the leakage is moderate, drainage holes are drilled to release pressure and drain the water into the tunnel side ditch. When the leakage is high, the following steps are taken: drilling drainage holes, excavating pipe trenches to bury water pipes, grouting to seal the holes, and then spraying anchor mesh inside the tunnel.

[0014] As a further improvement to this application, the specific steps of the drainage measure are as follows: S501 Emergency Handling: Based on the size of the water output, emergency handling can be carried out at the water outlet; When the water flow is small: use sealing materials such as baffles or baffle blocks for emergency sealing; When the water volume is large: use cement mortar or chemical grout to line the leaking area and then grout to seal it. Drainage holes are drilled in the sidewalls to drain and relieve pressure, and the water is discharged to the tunnel side ditch. S502. Formulate permanent measures: Based on the site conditions, permanent remediation measures inside the tunnel will be adopted first, and the measures are as follows: Drainage holes are drilled and water pipes are installed in grooves: When there is a single point of linear flow, stream flow or jet flow in the arch or sidewall, and the water volume is large, it is not easy to use water blocking measures such as grouting, plastering or caulking. Drainage is carried out. Depending on the water discharge of the defective section, 2-3 rows of drainage holes are drilled at different heights from the bottom plate. One row is drilled at intervals of 3-5m along the tunnel direction. Water pipes are installed in grooves in the sidewall and water is diverted into the drainage ditch. Grouting and sealing: Grouting is carried out inside the lining at construction joints of the arch wall, lining cracks, and individual water outlets where the water volume inside the tunnel is small, the water flow is scattered and inconvenient to drain, in order to seal the water flow channels and lining cracks, or to make the water flow relatively concentrated for easy drainage. S503, Anchor Mesh Shotcrete: For serious defects such as cracks, fissures, and misalignments in tunnel lining, the method of strengthening and treating the tunnel by reinforcing the structure inside the tunnel is adopted. Specifically, the anchor mesh shotcrete is installed inside the tunnel lining, and water channels are set at the leakage points for drainage. S504. Verify the effect: Is the leakage inside the cave still serious during the rainy season? Observe for 1-2 rainy seasons. If the leakage stops, no further measures will be taken. If the treatment effect is not good and water is still seeping, consider adding a drainage tunnel.

[0015] As a further improvement to this application, the grouting and sealing are classified according to whether the leakage is point leakage, surface leakage, or crack leakage: Point Leakage: The central grouting pipe for point leakage should be aligned with the water outlet point. When installing the grouting pipe, concrete debris on the hole wall should be cleaned. The grouting pipe should be tightly against the water outlet point at the bottom of the hole. The gap between the hole and the pipe should be tightly filled with sealing and pipe fixing material. The hole opening should be compacted and smoothed with a trowel. The peripheral grouting pipes should be set within a range of 20cm-30cm around the water outlet point. The installation method is the same as that of the central grouting pipe. Surface leakage: Locate the main leakage points on the lining surface. If the leakage points are difficult to find with the naked eye, sprinkle dry cement on the lining surface. The first place with wet stains is the leakage point. Drill holes for the leakage points and evenly distribute holes around the leakage surface, with a hole spacing of 30-50cm. After drilling, clean the hole walls, tightly fill the gaps between the holes and pipes with sealing and sealing material, and then apply cement-based penetrating crystalline waterproof coating. For crack leakage: First, chisel a 6cm wide and 8cm deep "V" shaped groove along the crack. The top of the groove should be directly opposite the leaking crack. After chiseling the groove, use high-pressure water to clean the groove wall and remove mud, sand, loose concrete blocks, and debris. Depending on the size of the crack and the amount of water, install grouting pipes at certain intervals along the groove and tightly fill the gaps between the pipes with sealing material. Then, compact the grouting pipes with a trowel. The grouting pipes should be tightly against the leaking crack. The spacing should be about 60-100cm when the crack is large and the amount of water is large, and about 30-50cm when the crack is small and the amount of water is small.

[0016] The beneficial effects of this invention are: This application acquires soil conductivity distribution data using transient electromagnetic methods and detects reflection coefficient data using ground-penetrating radar. Through time synchronization alignment, a fracture-seepage feature map is obtained. For this fracture-seepage feature map, a standardized fracture-seepage feature matrix is ​​generated based on the distance between the soil conductivity distribution data and the reflection coefficient data acquisition points (i.e., the distance between the three-dimensional coordinates of the acquisition points). A large distance indicates a weak correlation between the soil conductivity distribution data and the reflection coefficient data, and these data points need to be removed. This effectively improves the correlation between the soil conductivity distribution data and the reflection coefficient data. The standardized fracture-seepage feature matrix is ​​then converted into a visual topological graph for easy observation. Furthermore, identifying seepage points and the main paths of cracks facilitates subsequent sealing, grouting path determination, and provides data support for constructing trenches, improving accuracy and enhancing construction efficiency and effectiveness. The correlation is primarily determined through spatial distance, facilitating the location determination of aligned soil conductivity distribution and reflection coefficient data, improving correspondence and data correlation. Multiple processing steps are performed on the matrix data to construct a topology graph, treating cracks as edges and crack intersections as nodes. The relationship between node degree and edge weight, with node degree reflecting crack intersection density and edge weight reflecting crack connectivity, allows for the determination of preferred seepage channels through density and connectivity, providing data support for grouting paths. This invention achieves precise prevention and control of diseases by establishing a technical system of "water exploration - cause analysis - graded treatment - three-dimensional interception". It constructs a multi-dimensional water exploration system, integrating transient electromagnetic method, ground radar and disease display map to accurately locate cavities, fissures and seepage paths; the treatment stage constructs a three-level progressive technical path: the first stage implements emergency water stoppage, the middle stage carries out grouting reinforcement and drainage system transformation in the tunnel, and finally achieves active interception and drainage through the layout of drainage tunnels. The breakthrough lies in the pioneering three-dimensional interception and drainage network based on seepage path tracking, using a variety of water exploration methods to accurately locate cavities, fissures and seepage paths, and optimizing the spatial layout of drainage tunnels in real time to form a "interception-guidance-drainage" collaborative working mechanism. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the steps in the treatment method of karst tunnels located in the vertical seepage zone and seasonal variation zone of groundwater according to this application. Figure 2 This is a schematic diagram illustrating the specific steps involved in generating a fracture-seepage characteristic map, as part of an embodiment of a treatment method for karst tunnels located in vertical seepage zones and seasonal variation zones of groundwater according to this application. Figure 3 This is a schematic diagram illustrating the steps of generating a standardized fracture-seepage feature matrix in one embodiment of a treatment method for karst tunnels located in the vertical seepage zone and seasonal variation zone of groundwater according to this application. Figure 4 This is a schematic diagram of the steps of a fracture network topology structure in an embodiment of a treatment method for karst tunnels located in the vertical seepage zone and seasonal variation zone of groundwater according to this application. Detailed Implementation

[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0019] like Figure 1-4 As shown, this embodiment provides a treatment method for karst tunnels located in the vertical seepage zone and seasonal variation zone of groundwater. This embodiment includes the following steps: Step 1: On-site inspection and handling: After the occurrence of defects in the tunnel, immediately organize professional personnel to enter the site to conduct a systematic investigation, then carry out emergency treatment for the tunnel defects, and formulate permanent measures; Inspect the site and collect information on defects: Once defects occur inside the tunnel, professional personnel should be immediately organized to enter the site to conduct a systematic investigation; It should be noted that, firstly, the width, depth, and direction of the cracks should be accurately measured to determine whether the cracks are active; simultaneously, the flow rate, water pressure, and water quality characteristics of the leakage points should be recorded; and the distribution of voids behind the lining should be preliminarily determined by tapping. Preliminarily determine the start and end mileage of the disease occurrence section, and trace the time of disease occurrence and development process by combining monitoring data or consulting relevant technical personnel; Finally, environmental parameters such as on-site rainfall and groundwater level were collected simultaneously before and after the occurrence of the disease, the causes of the disease were analyzed, and an on-site investigation report was generated. By promptly investigating and taking emergency measures when tunnel defects occur, the impact of water leakage and seepage on the tunnel can be reduced. Step 2: Karst characteristics and surface water seepage path of the diseased section: Soil conductivity distribution data were obtained by transient electromagnetic method and reflection coefficient data were detected by ground-penetrating radar method. Soil conductivity distribution data and reflection coefficient data were spatiotemporally aligned by time synchronization to generate a fused fracture-seepage characteristic map. It should be noted that multiple sets of electromagnetic detection devices are deployed around the tunnel using the transient electromagnetic method to obtain soil conductivity distribution data. The electromagnetic detection devices are arranged along the two sidewalls of the tunnel along the route, with seven detection lines at angles of 45° downward, 0° horizontal, 45° upward, and at the tunnel roof. Furthermore, the low-resistivity anomaly zone within 50m of the tunnel is of particular importance, as it represents a water-bearing cavity. Simultaneously, ground-penetrating radar emits high-frequency electromagnetic waves into the tunnel excavation face and surrounding rock mass, and receives reflected signals to calculate the reflection coefficient distribution of internal rock fissures. The ground-penetrating radar is arranged along the two sidewalls of the tunnel along the route, with two horizontal detection lines. This allows for the identification of erosion inclusions, fissures, and cavities within 30m of the tunnel. The specific steps for generating the fracture-seepage characteristic map are as follows: S201. Set the detection cycle of both the electromagnetic detection device and the ground-penetrating radar to 1 second. S202. Align the collected soil electrical conductivity distribution data and reflection coefficient data, and align them according to the corresponding frequencies. S203. Cut off the ends of the uneven soil conductivity distribution data and reflection coefficient data, and then align the soil conductivity distribution data and reflection coefficient data. S204. Then, the soil electrical conductivity distribution data and reflection coefficient data are mapped and processed to achieve spatiotemporal alignment and generate a fracture-seepage characteristic map. It should be noted that by setting the detection cycle of both the electromagnetic detection device and the ground-penetrating radar to 1 second, high-frequency synchronous acquisition of the two detection technologies is ensured in the time dimension, thereby capturing the instantaneous dynamic correlation between fracture development and seepage changes. Soil electrical conductivity distribution data and reflectance coefficient data are aligned using timestamps, and anomalous data segments with mismatches at both ends are removed to ensure that the two sets of data correspond completely on the time and spatial axes. Through data integrity verification, invalid data caused by equipment synchronization errors or environmental interference is eliminated, improving the spatiotemporal consistency of the fracture-seepage feature map and providing a reliable data foundation for subsequent modeling. Spatial coordinate mapping is performed on the removed soil electrical conductivity distribution data and reflectance coefficient data, and the measurement results of the two detection technologies are correlated in a unified three-dimensional coordinate system to form a spatial coupling relationship between fracture location and seepage characteristics. Through spatial alignment of multi-source data, the accurate correspondence between fracture development location and seepage path is ensured, providing a high-precision spatial reference for dynamic prediction. By fusing multi-dimensional features of the aligned soil electrical conductivity data and reflectance coefficient data, a fracture-seepage feature map is generated.

[0020] Step 3: Data Feature Extraction: The noise-removed soil electrical conductivity distribution data and reflection coefficient data are normalized, and data features are extracted through social scope to generate a standardized fracture-seepage feature matrix; It should be noted that by denoising and normalizing the soil electrical conductivity distribution data and reflectance coefficient data, the differences in dimensions, sampling frequency and spatial resolution of different detection technologies are eliminated, enabling the data to be compared and analyzed on a unified scale; ensuring the numerical stability of the fracture-seepage feature matrix, avoiding model bias caused by inconsistent data scales, improving the calculation accuracy of subsequent dynamic equations, and constructing the relationship between fractures on a social scale, which facilitates the generation of a standardized fracture-seepage feature matrix; The specific steps for generating the standardized fracture-seepage characteristic matrix are as follows: S301. Decompose the soil conductivity distribution data and reflection coefficient data using wavelet transform to extract different frequency components; set the noise frequency band range and retain the data within the frequency band as effective features; treat the remaining frequency band data as random noise and filter it out using a threshold denoising algorithm; S302. The noise-removed soil electrical conductivity distribution data and reflectance coefficient data are respectively subjected to minimum-maximum normalization to unify the data range to [-1,1], so as to eliminate the dimensional differences between different detection technologies; the normalized data are further processed by Z-score standardization to calculate the mean and standard deviation of each data point to ensure the statistical comparability of the data. S303. Standardize and restrict soil electrical conductivity distribution data and reflection coefficient data according to the social scope, that is, according to the spatial distance relationship between soil electrical conductivity distribution data and reflection coefficient data, and set a threshold, and remove soil electrical conductivity distribution data and reflection coefficient data that exceed the spatial distance of the threshold. The correlation between soil electrical conductivity distribution data and reflection coefficient data was calculated using the Euclidean distance formula. The formula is: ; in, For spatial distance, if If the value is greater than 0.5, the data point is removed to ensure the spatial matching of fracture-seepage characteristics. and The three-dimensional coordinates of the soil conductivity distribution data and the reflection coefficient data collection points are represented respectively. By calculating the spatial distance, if the three-dimensional coordinates of the collection points are far apart, it indicates that there is little correlation between the collection of soil conductivity distribution data and reflection coefficient data, and they need to be removed. S304. Extract the principal component features of the reflection coefficient value of the fracture intersection point and the conductivity value of the adjacent fractures from the data after the removal through the multi-dimensional feature mapping algorithm, and generate a standardized fracture-seepage feature matrix. It should be noted that wavelet transform is used to decompose the soil conductivity distribution data and reflection coefficient data into multiple scales, dividing the data into different frequency components. This preserves the dynamic characteristics of fracture propagation, avoids model bias caused by noise interference, and uses min-max normalization to eliminate dimensional differences between different detection technologies, thus improving data compatibility. Thresholds are set to remove uncorrelated data between the soil conductivity distribution data and reflection coefficient data in space. Principal component analysis is used to extract the principal component features of the reflection coefficient values ​​at fracture intersections and the conductivity values ​​of adjacent fractures, achieving dimensionality reduction of multidimensional data while retaining key feature information.

[0021] Step 4: Fractal Network Topology Analysis: Based on the standardized fracture-seepage feature matrix, a graph theory model of the fracture network is constructed. Fracts are regarded as edges in the graph, and fracture intersections are regarded as nodes. The node degree and edge weight are calculated. The backbone path of the fracture network is extracted by the minimum spanning tree algorithm, and the seepage priority channel is determined by combining the conductivity distribution data. The connectivity parameters of the backbone path are weighted and correlated with the values ​​in the graph theory model to generate fracture permeability correction coefficients. It should be noted that by constructing a graph theory model of the fracture network, fractures are regarded as nodes and fracture intersections as edges, the connectivity and permeability characteristics of the fracture network are quantified, providing a structured decision-making basis for grouting path optimization. The minimum spanning tree algorithm is used to extract the main path, and combined with conductivity distribution data, the seepage priority channel is determined to achieve dynamic matching of fracture-seepage paths, avoiding blind grouting and resource waste. By calculating the node degree and edge weight, a fracture permeability correction coefficient is generated to improve the dynamic adaptability of grouting parameters and ensure sealing efficiency and construction safety.

[0022] The specific steps for constructing a gap network topology are as follows: S401. The standardized fracture-seepage characteristic matrix is ​​transformed into computable topological parameters. The node degree reflects the fracture intersection density and the edge weight reflects the fracture connectivity. Formula for calculating node degree: ; in, Represented as node degree, Represented as the first The reflection coefficient value at the intersection of the fractures This is represented by the maximum value of the reflection coefficient. This represents the total number of fracture intersections; Edge weight calculation formula: ; in, Represented as edge weight, , Expressed as the conductivity values ​​of adjacent fractures, and These are represented as the sequence values ​​of adjacent fractures. Represented as the crack spacing, valid edges are filtered out using a spatial distance threshold. Represented as the crack spacing, valid edges are filtered using a spatial distance threshold; S402. Extract the main path of the fracture network using the minimum spanning tree algorithm, identify the seepage priority channel, and use the region with the highest conductivity in the conductivity distribution data as the initial node, such as the region with conductivity value greater than 0.8; set the edge weight threshold to 0.5, and only retain the fracture connection relationship with edge weight greater than 0.5. S403. Combining conductivity distribution data with the connectivity parameters of the main path, determine the preferred seepage channels; Formula for determining preferential seepage channels: ; in, This is expressed as the seepage preference channel index. This is expressed as a baseline conductivity value, such as 0.5, and high-permeability pathways are selected using this formula. S404. Weight the seepage priority channel index of the main path with the data values ​​in the graph theory model to generate the fracture permeability correction coefficient. It is used to optimize grouting parameters; the correction coefficient, through a nonlinear weighting formula, combines the dynamic changes of the fracture network with the priority of the seepage path, thereby improving the model's accuracy and adaptability in predicting permeability. Correction factor calculation formula: ; in, , , Represented as a weighting coefficient, its value range is 0.3-0.5, calibrated experimentally. Weighting coefficient settings: The focus is on the effect of nodal density on permeability, such as the increased permeability at fracture junctions; The focus is on the contribution of edge weights to the seepage path, such as the higher permeability of highly connected fractures; The focus is on the dynamic adjustment of seepage priority channels, such as path changes caused by seasonal rainfall.

[0023] Correction factor range: The value range is 0.6-1.2; It should be noted that by treating cracks as edges in a graph and crack intersections as nodes, a graph theory model of the crack network is constructed to visualize the crack structure. Furthermore, the minimum spanning tree algorithm is used to extract the main path of the crack network and identify the seepage priority channels, providing key path basis for grouting path planning. This determines the seepage priority channels and provides accurate path planning for grouting material injection, which can effectively improve grouting efficiency. Finally, a correction coefficient is generated by multi-parameter weighting (node ​​degree, edge weight, priority channel) to improve prediction accuracy.

[0024] Step 5: Implement systematic drainage measures using a spillway system: Select drainage methods based on the amount of leakage. For minor leaks, use sealing materials for emergency sealing. When the leakage is moderate, drainage holes are drilled to release pressure and drain the water into the tunnel side ditch. When the leakage is high, the following steps are taken: drilling drainage holes, excavating pipe trenches to bury water pipes, grouting to seal the holes, and then spraying anchor mesh inside the tunnel. The specific steps are as follows: S502 Emergency handling: Based on the size of the water output, emergency handling can be carried out at the water outlet; When the water flow is small: use sealing materials such as baffles or baffle blocks for emergency sealing; When the water volume is large: use cement mortar or chemical grout to line the leaking area and then grout to seal it. Drainage holes are drilled in the side wall to drain and relieve pressure, and the water is discharged to the tunnel side ditch.

[0025] S503. Formulate permanent measures: Based on the site conditions, permanent internal remediation measures should be adopted first, which may include the following: Drainage holes and drainage pipes are installed by chiseling trenches: When there is a large volume of water flowing from a single point in the arch or sidewalls, and grouting, plastering, or sealing are not suitable for blocking the water, drainage is carried out. Depending on the water discharge situation in the affected section, 2-3 rows of drainage holes are installed at different heights from the floor slab, with one row installed every 3-5 meters along the tunnel direction. Drainage pipes are installed in trenches in the sidewalls to divert water into drainage ditches.

[0026] Grouting and sealing: Grouting is carried out inside the lining at construction joints of the arch wall, lining cracks, and individual water outlets (surfaces) where the water volume inside the tunnel is small, the water flow is dispersed and inconvenient to drain, in order to seal the water flow channels and lining cracks, or to make the water flow relatively concentrated for easy drainage. Leaks can be classified according to whether they are point leaks, surface leaks, or seam leaks: Point Leakage: The central grouting pipe for point leakage should be aligned with the water outlet point. When installing the grouting pipe, concrete debris on the hole wall should be cleaned. The grouting pipe should be tightly against the water outlet point at the bottom of the hole. The gap between the hole and the pipe should be tightly filled with sealing and pipe fixing material. The hole opening should be compacted and smoothed with a trowel. The peripheral grouting pipes should be set within a range of 20cm-30cm around the water outlet point. The installation method is the same as that of the central grouting pipe. Surface leakage: Locate the main leakage points on the lining surface. If the leakage points are difficult to find with the naked eye, sprinkle dry cement on the lining surface. The first place with wet stains is the leakage point. Drill holes for the leakage points and evenly distribute holes around the leakage surface, with a hole spacing of 30-50cm. After drilling, clean the hole walls, tightly fill the gaps between the holes and pipes with sealing and sealing material, and then apply cement-based penetrating crystalline waterproof coating. For crack leakage: First, chisel a 6cm wide and 8cm deep "V" shaped groove along the crack. The top of the groove should be directly opposite the leaking crack. After chiseling the groove, use high-pressure water to clean the groove wall and remove mud, sand, loose concrete blocks, and debris. Depending on the size of the crack and the amount of water, install grouting pipes at certain intervals along the groove and tightly fill the gaps between the pipes with sealing material. Then, compact the grouting pipes with a trowel. The grouting pipes should be tightly against the leaking crack. The spacing should be about 60-100cm when the crack is large and the amount of water is large (such as construction joints), and about 30-50cm when the crack is small and the amount of water is small.

[0027] S504, Anchor Mesh Shotcrete: For serious defects such as cracks, fissures, and misalignments in tunnel lining, the method of strengthening and treating the tunnel by reinforcing the structure inside the tunnel is adopted. Specifically, the anchor mesh shotcrete is installed in the tunnel lining, and water channels are set at the leakage points for drainage. S505. Verify the effect: Is the leakage inside the cave still serious during the rainy season? Observe for 1-2 rainy seasons. If the leakage stops, no further measures will be taken. If the treatment effect is not good and water is still seeping, consider adding a drainage tunnel.

[0028] Furthermore, the storage medium in this application embodiment stores program instructions capable of implementing all the above methods. These program instructions can be stored in the storage medium in the form of a software product, including several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks, or terminal devices such as computers, servers, mobile phones, and tablets.

[0029] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces, or indirect coupling or communication connection between apparatuses or units, and may be electrical, mechanical, or other forms.

[0030] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated units described above can be implemented in hardware or as software functional units. The above are merely embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made based on the description and drawings of this application, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

[0031] The specific embodiments of the invention have been described in detail above, but they are only examples, and this application is not limited to the specific embodiments described above. For those skilled in the art, any equivalent modifications or substitutions to the invention are also within the scope of this application. Therefore, all equivalent changes, modifications, and improvements made without departing from the spirit and principles of this application should be covered within the scope of this application.

Claims

1. A method for treating karst tunnels located in the vertical seepage zone and seasonal variation zone of groundwater, characterized in that, It includes the following steps: Step 1: On-site inspection and handling: After the occurrence of defects in the tunnel, immediately organize professional personnel to enter the site to conduct a systematic investigation, then carry out emergency treatment for the tunnel defects, and formulate permanent measures; Step 2: Karst characteristics and surface water seepage path of the diseased section: Soil conductivity distribution data were obtained by transient electromagnetic method and reflection coefficient data were detected by ground-penetrating radar method. Soil conductivity distribution data and reflection coefficient data were spatiotemporally aligned by time synchronization to generate a fused fracture-seepage characteristic map. Step 3: Data Feature Extraction: The noise-removed soil electrical conductivity distribution data and reflection coefficient data are normalized, and data features are extracted through social scope to generate a standardized fracture-seepage feature matrix; Step 4: Fractal Network Topology Analysis: Based on the standardized fracture-seepage feature matrix, a graph theory model of the fracture network is constructed. Fracts are regarded as edges in the graph, and fracture intersections are regarded as nodes. The node degree and edge weight are calculated. The backbone path of the fracture network is extracted by the minimum spanning tree algorithm, and the seepage priority channel is determined by combining the conductivity distribution data. The connectivity parameters of the backbone path are weighted and correlated with the values ​​in the graph theory model to generate fracture permeability correction coefficients. Step 5: Implement systematic drainage measures using a spillway system: Select drainage measures based on the amount of leakage.

2. The treatment method for karst tunnels located in the vertical seepage zone and seasonal variation zone of groundwater according to claim 1, characterized in that, The specific steps for generating the fracture-seepage characteristic map in step two are as follows: S201. Set the detection cycle of both the electromagnetic detection device and the ground-penetrating radar to 1 second. S202. Align the collected soil electrical conductivity distribution data and reflection coefficient data, and align them according to the corresponding frequencies. S203. Cut off the ends of the uneven soil conductivity distribution data and reflection coefficient data, and then align the soil conductivity distribution data and reflection coefficient data. S204. Then, the soil electrical conductivity distribution data and reflection coefficient data are mapped and processed to achieve spatiotemporal alignment and generate a fracture-seepage characteristic map.

3. The treatment method for karst tunnels located in the vertical seepage zone and seasonal variation zone of groundwater according to claim 2, characterized in that, The specific steps for generating the standardized fracture-seepage feature matrix in step three are as follows: S301. Decompose the soil conductivity distribution data and reflection coefficient data using wavelet transform to extract different frequency components; set the noise frequency band range and retain the data within the frequency band as effective features; treat the remaining frequency band data as random noise and filter it out using a threshold denoising algorithm; S302. Perform minimum-maximum normalization on the noise-removed soil electrical conductivity distribution data and reflection coefficient data respectively to unify the data range to [-1,1]. S303. Standardize and restrict soil electrical conductivity distribution data and reflection coefficient data according to the social scope, that is, according to the spatial distance relationship between soil electrical conductivity distribution data and reflection coefficient data, and set a threshold, and remove soil electrical conductivity distribution data and reflection coefficient data that exceed the spatial distance of the threshold. S304. Extract the principal component features of the reflection coefficient value of the fracture intersection point and the conductivity value of adjacent fractures from the data after removal using a multi-dimensional feature mapping algorithm, and generate a standardized fracture-seepage feature matrix.

4. The treatment method for karst tunnels located in the vertical seepage zone and seasonal variation zone of groundwater according to claim 3, characterized in that, The spatial distance relationship was calculated using the Euclidean distance formula to correlate soil electrical conductivity distribution data with reflectance coefficient data. The formula is: ; in, For spatial distance, if If the value is greater than 0.5, the data point is removed to ensure the spatial matching of fracture-seepage characteristics. and The three-dimensional coordinates of the soil electrical conductivity distribution data and the reflection coefficient data collection points are represented respectively. If the distance between the three-dimensional coordinates of the collection points is large, it indicates that there is little correlation between the collection of soil electrical conductivity distribution data and reflection coefficient data, and they need to be removed.

5. The treatment method for karst tunnels located in the vertical seepage zone and seasonal variation zone of groundwater according to claim 1, characterized in that, The specific steps for constructing the gap network topology in step four are as follows: S401. The standardized fracture-seepage characteristic matrix is ​​transformed into computable topological parameters. The node degree reflects the fracture intersection density and the edge weight reflects the fracture connectivity. S402. Extract the main path of the fracture network using the minimum spanning tree algorithm, identify the seepage priority channel, and use the region with the highest electrical conductivity in the electrical conductivity distribution data as the initial node. S403. Combining conductivity distribution data with the connectivity parameters of the main path, determine the preferred seepage channels; S404. Weight the seepage priority channel index of the main path with the data values ​​in the graph theory model to generate the fracture permeability correction coefficient. Used to optimize grouting parameters; The correction coefficients, through a nonlinear weighting formula, combine the dynamic changes of the fracture network with the priority of seepage paths, thereby improving the model's accuracy and adaptability in predicting permeability.

6. The treatment method for karst tunnels located in the vertical seepage zone and seasonal variation zone of groundwater according to claim 5, characterized in that, The formula for calculating the node degree is as follows: ； in, Represented as node degree, Represented as the first The reflection coefficient value at the intersection of the fractures This is represented by the maximum value of the reflection coefficient. This represents the total number of fracture intersections; The formula for calculating the edge weight is as follows: ； in, Represented as edge weight, , Expressed as the conductivity values ​​of adjacent fractures, and These are represented as the sequence values ​​of adjacent fractures. It is represented as the gap spacing, and valid edges are filtered by spatial distance threshold.

7. The treatment method for karst tunnels located in the vertical seepage zone and seasonal variation zone of groundwater according to claim 5, characterized in that, The formula for determining preferential seepage channels is as follows: ； in, This is expressed as the seepage preference channel index. This is expressed as a baseline conductivity value, such as 0.5, and the formula is used to screen for high seepage paths.

8. The treatment method for karst tunnels located in the vertical seepage zone and seasonal variation zone of groundwater according to claim 1, characterized in that, The drainage measures in the aforementioned steps include: For minor leaks, use sealing materials for emergency sealing. When the leakage is moderate, drainage holes are drilled to release pressure and drain the water into the tunnel side ditch. When the leakage is high, the following steps are taken: drilling drainage holes, excavating pipe trenches to bury water pipes, grouting to seal the holes, and then spraying anchor mesh inside the tunnel.

9. A method for treating karst tunnels located in vertical seepage zones and seasonal variation zones of groundwater according to claim 8, characterized in that, The specific steps of the drainage measures are as follows: S501 Emergency Handling: Based on the size of the water output, emergency handling can be carried out at the water outlet; When the water flow is small: use sealing materials such as baffles or baffle blocks for emergency sealing; When the water volume is large: use cement mortar or chemical grout to line the leaking area and then grout to seal it. Drainage holes are drilled in the sidewalls to drain and relieve pressure, and the water is discharged to the tunnel side ditch. S502. Formulate permanent measures: Based on the site conditions, permanent remediation measures inside the tunnel will be adopted first, and the measures are as follows: Drainage holes are drilled and water pipes are installed in grooves: When there is a single point of linear flow, stream flow or jet flow in the arch or sidewall, and the water volume is large, it is not easy to use water blocking measures such as grouting, plastering or caulking. Drainage is carried out. Depending on the water discharge of the defective section, 2-3 rows of drainage holes are drilled at different heights from the bottom plate. One row is drilled at intervals of 3-5m along the tunnel direction. Water pipes are installed in grooves in the sidewall and water is diverted into the drainage ditch. Grouting and sealing: Grouting is carried out inside the lining at construction joints of the arch wall, lining cracks, and individual water outlets where the water volume inside the tunnel is small, the water flow is scattered and inconvenient to drain, in order to seal the water flow channels and lining cracks, or to make the water flow relatively concentrated for easy drainage. S503, Anchor Mesh Shotcrete: For serious defects such as cracks, fissures, and misalignments in tunnel lining, the method of strengthening and treating the tunnel by reinforcing the structure inside the tunnel is adopted. Specifically, the anchor mesh shotcrete is installed inside the tunnel lining, and water channels are set at the leakage points for drainage. S504. Verify the effect: Is the leakage inside the cave still serious during the rainy season? Observe for 1-2 rainy seasons. If the leakage stops, no further measures will be taken. If the treatment effect is not good and water is still seeping, consider adding a drainage tunnel.

10. A method for treating karst tunnels located in vertical seepage zones and seasonal variation zones of groundwater according to claim 9, characterized in that, The grouting and sealing methods are classified according to whether the leakage is point leakage, surface leakage, or crack leakage: Point Leakage: The central grouting pipe for point leakage should be aligned with the water outlet point. When installing the grouting pipe, concrete debris on the hole wall should be cleaned. The grouting pipe should be tightly against the water outlet point at the bottom of the hole. The gap between the hole and the pipe should be tightly filled with sealing and pipe fixing material. The hole opening should be compacted and smoothed with a trowel. The peripheral grouting pipes should be set within a range of 20cm-30cm around the water outlet point. The installation method is the same as that of the central grouting pipe. Surface leakage: Locate the main leakage points on the lining surface. If the leakage points are difficult to find with the naked eye, sprinkle dry cement on the lining surface. The first place with wet stains is the leakage point. Drill holes for the leakage points and evenly distribute holes around the leakage surface, with a hole spacing of 30-50cm. After drilling, clean the hole walls, tightly fill the gaps between the holes and pipes with sealing and sealing material, and then apply cement-based penetrating crystalline waterproof coating. For crack leakage: First, chisel a "V" shaped groove 6cm wide and 8cm deep along the crack. The top of the groove should be directly opposite the leaking crack. After chiseling the groove, use high-pressure water to clean the groove wall and remove mud, sand, loose concrete blocks, and debris. Depending on the size of the crack and the amount of water, install grouting pipes at certain intervals along the groove and tightly fill the gaps between the pipes with sealing material. Then, compact the grouting pipes with a trowel. The grouting pipes should be tightly against the leaking crack. The spacing should be about 60-100cm when the crack is large and the amount of water is large, and about 30-50cm when the crack is small and the amount of water is small.

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