50 results about "Karst tunnel" patented technology

The invention relates to the technical field of tunnel construction, and discloses a coal mine goaf karst tunnel construction method which comprises the following steps: S1, performing three-dimensional scanning on the axis and the periphery of a tunnel by adopting a high-frequency geological radar in combination with aerial survey of an unmanned aerial vehicle, and accurately positioning the boundary of a goaf, the development form of a karst cave and filler distribution; and S2, integrating a seismic wave reflection method, drilling and coring data and a geological sketch result, constructing a three-dimensional geological model, and dynamically predicting a potential water inrush and mud inrush risk area. According to the method, a high-frequency geological radar is combined with aerial survey of an unmanned aerial vehicle, three-dimensional scanning is conducted on the axis and the periphery of a tunnel, geological radar data, a point cloud model and tunnel design BIM are integrated, the boundary of a goaf (the error is smaller than or equal to 0.3 m) and the karst cave form are marked, and the collapse risk level is predicted based on rock mass mechanical parameters (compressive strength and fracture density) and hydrological data (seepage paths). Therefore, the method has the advantages of advanced detection, multi-source data fusion and the like, and the resolution of geological forecast is improved.

The invention discloses a karst tunnel lining quality intelligent detection and image analysis system, and relates to the technical field of image processing and defect identification, the system comprises a multispectral image acquisition module, a lining defect automatic identification engine and a defect quantitative evaluation platform, the multispectral image acquisition module acquires visible light and near infrared images and carries out fusion enhancement; the lining defect automatic recognition engine adopts a double-branch attention feature extraction network to recognize multiple types of defects, the defect quantitative evaluation platform calculates defect geometric features and evaluates severity, full-process automation of detection, recognition, evaluation and decision is achieved, the detection precision reaches the sub-millimeter level, the recognition accuracy exceeds 95%, and the method is suitable for large-scale popularization and application. And the detection efficiency is more than 10 times that of a manual method.

The invention provides a karst tunnel construction transparent intelligent decision-making system, and relates to the field of tunnel construction intellectualization, and the system comprises a dynamic risk analysis and intelligent early-warning module which constructs a dynamic working condition portrait based on karst tunnel construction site information, and uses artificial intelligence and deep learning technologies to obtain a karst tunnel construction transparent intelligent decision-making module; constructing a karst tunnel risk comprehensive evaluation system by combining fuzzy hierarchical evaluation, a user-defined rule engine and expert opinions to calculate a dynamic risk entropy value, predicting a future dynamic risk entropy value by combining a sliding time window mechanism based on a deep learning model and the dynamic working condition portrait, and determining an early warning level according to the risk entropy value; and the intelligent scheduling and decision support module performs scheduling scheme optimization according to the early warning level and the intelligent optimization objective function, continuously monitors the execution condition of the scheduling scheme, and evaluates the execution effect of the scheduling scheme. And the transparency, datamation and intelligent management level of the whole karst tunnel construction process and the early warning capability and response efficiency of sudden geological disasters are improved.

The invention relates to a knowledge-data double-drive karst tunnel construction period water inrush risk assessment method, which comprises the steps of obtaining influence factors of a target karst tunnel water inrush disaster, and constructing a risk assessment index comprehensive layering system; obtaining a comprehensive weight according to the risk evaluation index comprehensive layering system; according to the comprehensive weight and a VIKOR model, constructing a knowledge-driven water inrush risk assessment model; constructing a training sample library according to the knowledge-driven water inrush risk assessment model; a DE-GWO-ELM model is constructed, the DE-GWO-ELM model is trained according to the training sample library, and a knowledge-data dual-drive DE-GWO-ELM model is obtained; and inputting to-be-evaluated monitoring data into the DE-GWO-ELM model, and outputting a water burst risk value. According to the invention, the method can effectively and accurately achieve the risk assessment of the water inrush, and is higher in real-time performance and interpretability.

The invention relates to the technical field of tunnel engineering disease treatment, in particular to a construction method of a drainage system for karst tunnel inverted arch upheaval disease treatment, which comprises the following construction steps: S1, arranging settlement monitoring points in a disease section tunnel, and arranging a reinforcing structure in a lining arch foot area; and S2, the existing disease inverted arch is broken and removed section by section according to the preset length, and temporary supporting is carried out in time. And S3, an overhaul window is dug in the lining through a water mill drill, and a supporting structure is synchronously installed. And S4, a foundation trench is excavated in the bottom of the inverted arch, a concrete strip-shaped foundation is poured to serve as a foundation of the steel corrugated pipe arch culvert, the steel corrugated pipe arch culvert is installed, the axis of the steel corrugated pipe arch culvert is consistent with the karst cave water flow direction, and the steel corrugated pipe arch culvert is in sealed butt joint with the confluence overhaul groove. And S5, a drainage pipe is pre-buried in the inverted arch reconstruction section, the confluence overhaul groove and the central drainage ditch are connected, and finally concrete is poured to seal the inverted arch structure. The method effectively solves the problem of upheaval of the inverted arch caused by water burst of the deeply-buried karst cave, reduces the damage of the lining structure, and improves the long-term stability of the tunnel.

According to the advanced drilling-based complex terrain karst tunnel disaster identification method and system provided by the invention, the target karst tunnel risk level is determined by integrating geological conditions, hydrological conditions and structural mechanical response, and then the target karst tunnel advanced prediction detection scheme is determined, so that the target karst tunnel disaster identification method and system can be realized according to the target karst tunnel risk condition. An advanced forecasting detection scheme is reasonably selected; according to the method, dynamic weights of different advanced prediction and detection methods are determined based on matching degrees of different advanced prediction and detection methods for target karst tunnel types, historical accuracy rates and quality of target karst tunnel related data currently acquired by the advanced prediction and detection methods, so that the more accurate advanced prediction and detection methods can be effectively utilized; and the subsequent identification accuracy is improved.

The present invention discloses an anti-siltation and anti-impact water-dividing structure for the intersection of a karst tunnel and an underground river. The structure utilizes an upstream water-dividing weir, a downstream force-dissipating weir, a porous box culvert-type V-shaped inverted siphon water pipe and an open overflow channel, so that the karst tunnel structure divides the underground river intersecting therewith into upper and lower water-passing sections; the lower water-passing section is a porous box culvert-type V-shaped inverted siphon water pipe, and the upper water-passing section is an open overflow channel. The water-dividing structure of the present invention diverts the underground river through the karst tunnel according to the dry season and the flood season. The buried depth of the V-shaped inverted siphon hole water pipe is shallow, and there is no need to adjust the water flow gradient of the underground river. In addition, the V-shaped inverted siphon hole water pipe solves the problem of siltation on the upstream side of the lining structure of the upstream karst tunnel. At the same time, the water-dividing weir reduces the impact load of the water flow on the lining structure during the flood season, so that the upper and lower diverted water loads achieve a certain degree of balance.

This invention belongs to the field of tunnel construction technology. It discloses a karst tunnel surrounding rock reinforcement device and method, comprising at least one set of outer support members. The outer walls of the outer support members are fixed to the tunnel roof surrounding rock, and the inner walls of the two outer support members are fixed to the two ends of a top support plate. An inner support member is disposed on the inner wall of the top support plate and located at the connection point of two adjacent top support plates. The inner support member passes through the top support plate and the outer support members and is fixed to the tunnel roof surrounding rock. A side wall reinforcement component includes support piles and side support plates. The side walls of the side support plates, the ends of the inner support members, and the ends of the outer support members are all cast and fixed within the support piles. The outer support member is an outer arc-shaped rib. Several first anchor rods are fixedly installed on the top support plate, with the ends of the first anchor rods penetrating the outer arc-shaped ribs and extending into the tunnel roof surrounding rock. The ends of second anchor rods penetrate the inner arc-shaped ribs, the top support plate, and the outer arc-shaped ribs, extending into the tunnel roof surrounding rock. This invention simplifies construction and improves tunnel construction efficiency while ensuring support effectiveness.

The invention provides a karst tunnel cavity self-adaptive filling method and system, and relates to the field of tunnel construction intellectualization. Constructing a three-dimensional geologic model of the karst tunnel cavity; according to the cavity filler performance demand matrix, the cavity geometrical morphology, the geological condition, the tunnel structure load condition and the engineering demand, a dynamic mapping relation model between the foam light soil performance parameters and the raw material proportion under the multi-target constraint is established, and a foam light soil proportion scheme is calculated according to the dynamic mapping relation model; a cavity grouting filling scheme is generated according to different working condition requirements, so that a grouting hole site sequence, a diffusion radius, a grouting path, a filling mode, a flow parameter, a pressure parameter and a vibration parameter are dynamically optimized, regulated and controlled on a construction site according to the cavity grouting filling scheme. The intelligent degree, the reliability, the economical efficiency and the environmental protection level of karst tunnel cavity treatment are remarkably improved.

The application discloses a karst tunnel lining quality intelligent detection and image analysis system, relates to the technical field of image processing and defect identification, and comprises a multispectral image acquisition module, a lining defect automatic identification engine and a defect quantitative evaluation platform.The multispectral image acquisition module acquires visible light and near-infrared images and performs fusion enhancement, the lining defect automatic identification engine adopts a double-branch attention feature extraction network to identify multiple types of defects, and the defect quantitative evaluation platform calculates defect geometric features and evaluates the severity, so that the whole process of detection, identification and evaluation decision is automatically realized.The detection precision of the application reaches a sub-millimeter level, the identification accuracy is more than 95%, and the detection efficiency is more than 10 times that of the artificial method.

The application provides a high-position water discharge branch hole setting height determination method and a monitoring point water pressure analysis method, and the high-position water discharge branch hole setting height determination method comprises the following steps: S1, determining that the most important factor affecting the tunnel operation safety in a karst area is the seepage water pressure finally acting on the lining; S2, determining the influencing factors of the seepage water pressure finally acting on the lining; the influencing factors comprise an initial seepage water pressure of a solution cavity, a reduction of the seepage water pressure by surrounding rock and a drainage condition of a water discharge hole; and S3, designing the high-position water discharge branch hole height according to the influencing factors in a water-rich filled solution cavity. The application can effectively solve the drainage problem of a solution cavity not yet found in a karst area or a drainage channel formed again in the later period, ensures the operation safety, speeds up the tunnel construction progress, can safely and quickly pass through a high-pressure water-rich solution cavity in the karst tunnel construction, and avoids the risk of water and mud inrush.

The invention provides a karst tunnel excavation support pressure reliability design method based on threshold gradient. According to the method, aiming at three random variables in an HB constitutive model, firstly, center composite sampling is carried out in a standard normal space to obtain seven test points, coordinates of the test points are converted into an original parameter space, a failure threshold value of each test point is obtained through calculation by establishing a numerical model, then a secondary response surface agent model without cross terms is established, and the failure threshold value of each test point is calculated. And establishing a tunnel face support force dominant threshold function by solving a linear equation set and determining seven coefficients of the proxy model, on this basis, proposing a standard normal space target reliability isoline checking point iteration method, performing checking point iteration on a sphere with the radius being the target reliability, and updating checking points in a gradient manner by adopting the threshold function. And calculating the collapse load of the design point during iterative convergence, so that the collapse load meets the requirement of a target reliable index. According to the method, the design complexity is reduced, and the design efficiency is improved.

The invention provides a small-section karst tunnel long-distance pipe jacking construction method based on a depth Q network, and relates to the technical field of pipe jacking construction. Comprising the following steps: collecting pipe jacking data in a pipe jacking construction process in real time; the pipe jacking data are preprocessed, and construction state features are constructed; constructing a deep Q network according to the construction state features to construct a construction decision model, and changing hard update of a target network in the deep Q network into soft update by using a target network soft update algorithm to obtain a preliminary training model; inputting the preprocessed pipe jacking data into the preliminary training model to obtain an optimal construction parameter decision; and collecting construction feedback data of the optimal construction parameter decision application, updating construction state characteristics, and driving the model to dynamically adjust the decision strategy. According to the method, the deep Q network is optimized by using the target network soft update algorithm, and the deep Q network construction decision model is constructed according to the construction state characteristics, so that the construction efficiency is improved, and the negative influence on the surrounding environment is reduced.

The utility model discloses a water collecting well circulating water dust fall device for karst tunnel engineering, including water suction device, water collecting well and fixed together's mobile water tank and sewage collection tank, and water suction device, water collecting well and mobile water tank are communicated in proper order through water pipe, and water pump A is installed to the water inlet of water pipe, and the below and the top of water suction device are all installed with propeller A and drive motor, and the vertically installed telescopic stainless steel bellows of mobile water tank, one end of telescopic stainless steel bellows is located inside mobile water tank, and water pump B is installed to the port, and the other end is located outside mobile water tank, and the port is installed with the shower nozzle, and the periphery of shower nozzle is installed with the fender, and the adjacent fender side fixed connection, and the water inlet of sewage collection tank is located inside fender, and the water outlet of sewage collection tank and water collecting well water inlet are communicated through the backwater pipe. The utility model is used in karst tunnel engineering, not only solves the problem of water accumulation in the cave, but also improves the dust fall efficiency and improves the construction environment.

The invention discloses a karst area shield tunnel face outburst prevention rock mass safety thickness prediction method, and belongs to the field of karst tunnel outburst prevention rock mass thickness predication.The method comprises the steps that environmental parameters in an area where tunnel engineering is located are collected, an orthogonal test table is established according to the environmental parameters, and according to the environmental parameters and the orthogonal test table, an outburst prevention rock mass safety thickness prediction method is established. Performing numerical simulation by using discrete element software 3DEC to obtain a plurality of working condition combined data; fitting a random forest model and a multiple linear regression equation which are used for predicting the safety thickness of the outburst prevention rock mass according to the combined data of each working condition; predicting a to-be-measured working condition by using the random forest model and the multiple linear regression equation to obtain a first prediction result and a second prediction result; and determining a final prediction result of the safety thickness of the outburst prevention rock mass according to the first prediction result and the second prediction result. The technical problems that an existing outburst prevention rock mass safety thickness prediction analysis result is low in accuracy and large in error are solved.

A karst tunnel construction period water gushing well flooding accident treatment method, comprising the following steps, 1) predicting the maximum water inflow of the well flooding section; 2) setting the reserved safety rock disc thickness according to the overall stability of the surrounding rock; 3) forming upper, middle and lower three steps according to the step design parameters; 4) according to the design parameters of the advanced drill hole, the advanced drill hole drainage is made in the middle step; 5) reinforcing the reserved safety rock disc; 6) when the well flooding water level drops to the middle step drainage hole, the upper step of the tunnel is excavated; 7) after the upper step is completely penetrated, the well flooding water body of the tunnel is directly pumped out. The karst tunnel construction period water gushing well flooding accident treatment method can maintain the overall stability of the safety rock disc surrounding rock, efficiently pump out the water of the karst tunnel construction period water gushing well flooding, restore the site construction as soon as possible, and ensure the construction safety.

The application discloses a kind of ventilation parameter processing method and system for the whole world water-rich karst tunnel small section multi-shaft, comprising the following steps: determining small section shaft clearance diameter D And single well ventilation capacity, and determine the upper limit of main hole design wind speed to obtain the maximum wind capacity of main hole;Select control need air volume index, calculate the air volume and establish relative index, determine the critical distance L 1 when relative index reaches limit value L First exhaust shaft is arranged near L 1 And downstream air supply shaft constitutes "one exhaust one supply" ventilation unit, according to different section relative index check and iterative arrangement of multiple groups of shafts form shaft group, so that downstream available air volume meets the next partition air volume.The application replaces the traditional large-diameter ventilation shaft by adopting small-section shaft group suitable for mechanized construction, which can reduce the construction risk of shaft in the whole water-rich karst section, reduce the exposure of underground personnel, and improve the engineering applicability and construction safety.

The invention discloses a grouting model test system and method under karst tunnel water-rock interaction, and belongs to the field of grouting construction simulation.The system comprises a test workbench, an extension supporting frame is arranged on one side of the test workbench, a rotating support is rotationally arranged in a lifting frame on one side of the extension supporting frame, and a mold frame is arranged at the top of the rotating support; a grouting groove body is formed in a karst module in the mold frame, and solidified slurry can be taken out along with splitting of the module; the first driving assembly drives the lifting frame to enable the mold frame to be immersed in water to detect the sealing performance; the grouting pump conveys slurry in the slurry storage barrel to the grouting groove body, and the booster water pump forms water circulation through the drainage pipeline to simulate karst seepage; the second driving assembly drives the mold frame to rotate to change the grouting flow direction; the system can simulate the grouting and water-rock action under different working conditions to solve the problems that when a traditional grouting model test device is used for rock mass simulation, module installation is tedious, solidified slurry is difficult to take out, angle adjustment is limited, and the grouting simulation effect is poor.

The application provides a karst tunnel large cave automatic water discharge pressure reduction device and method under heavy rainfall conditions, which comprises a filtering mechanism, the top end of the filtering mechanism extends into the cave, the bottom end of the filtering mechanism is connected with a cylindrical mechanism, the end of the cylindrical mechanism away from the filtering mechanism is fixedly connected with the top end of a tunnel mechanism, the high end of the cylindrical mechanism is connected with the inlet of a fine drain pipe, the outlet of the fine drain pipe is connected with the tunnel mechanism, the low end of the cylindrical mechanism is connected with a coarse drain mechanism, and the other end of the coarse drain mechanism is connected with the tunnel mechanism. On the one hand, the hydrogeological environment of the tunnel is not damaged, the underground water balance is protected, the automatic grading discharge of the cave underground water is realized, the water pressure outside the tunnel structure is reduced, the tunnel structure performance is protected, and the unreasonable stress of the tunnel structure caused by excessive water pressure is avoided to prevent the structure damage. On the other hand, the integrity of the secondary lining structure of the tunnel is not damaged, and the structure performance reduction caused by local stress concentration is avoided.

The utility model relates to the technical field of tunnel collapse early warning, and discloses karst area tunnel collapse early warning equipment which comprises a supporting frame, a winding mechanism and an early warning mechanism. The supporting frame is installed over a hole in a tunnel, a limiting block is fixedly connected to the middle of the top end of the supporting frame, an inner pipe is fixedly connected to the middle of the limiting block, the inner pipe is arranged in the middle of the hole, a top plate is fixedly connected to the middle of the top end of the supporting frame, and a winding mechanism is fixedly connected to the top plate and used for adapting to vertical displacement of an early warning mechanism in the inner pipe. Under the linkage cooperation of the early warning mechanism and the winding mechanism, the floating ball at the bottom end can always make contact with underground water, the height displacement change of the underground water is monitored through buoyancy, and under the action of the bottom end floating ball turbidity sensor, the underground water turbidity degree is monitored.

This utility model provides a rigid reinforced skeleton structure for karst tunnels, including a grid steel frame, a pressure dispersion component distributed at two arched feet of the grid steel frame to disperse the pressure of the grid steel frame on the tunnel floor, and a limiting component disposed between the pressure dispersion component and the grid steel frame to constrain the installation position of the arched feet of the grid steel frame. This utility model relates to the field of skeleton structure technology. The convex and concave plates bear the weight of the grid steel frame and the surrounding rock load. The convex and concave plates have a surface contact with the tunnel floor to prevent stress concentration. When multiple grid steel frames are arranged and installed, they are all supported by convex and concave plates. The snap-fit ​​grooves of adjacent convex and concave plates are inserted into the outer periphery of the corresponding snap-fit ​​blocks. Multiple convex and concave plates form a long strip-shaped bearing surface, increasing the contact area with the tunnel floor and increasing the stability of the grid steel frame in the event of tunnel collapse or surrounding rock deformation.

The application discloses a karst tunnel anti-slope drainage device, belongs to the technical field of karst tunnels, is installed in a water collecting groove which is arranged at the bottom of the karst tunnel at equal intervals, and comprises a filtering assembly, an automatic water pumping assembly and a flushing assembly. The filtering assembly comprises a lifting plate, a supporting ring, a filter plate, a water receiving cylinder, a spring and a bottom plate. The automatic water pumping assembly comprises a water outlet pipe, a water pump, a straight plate and a liquid level detection device. The flushing assembly comprises a driving member and a flushing assembly. The driving member intermittently drives the flushing assembly to rotate the input end of the water pump. The filter plate can be shaken up and down, so that shaking filtration is realized, sand and stones and other impurities are prevented from being accumulated and blocked in the filter holes of the filter plate, and the filtering effect is improved. The flushing assembly is arranged, the input end of the water pump can be flushed, the deposition of the sand in the input end of the water pump during the pumping and draining process is avoided, and the working efficiency of the water pump is improved.

The present application relates to the technical field of geological disaster prediction, and more particularly to a method for identifying microseismic precursor information of karst tunnel collapse disaster. The technical solution comprises constructing a microseismic monitoring system integrating multi-source data, processing and analyzing based on machine learning, establishing a multi-factor coupling analysis and early warning model, and real-time early warning and dynamic feedback. The present application can accurately remove noise by wavelet transform, retain the key features of microseismic signals, improve the quality of data, and extract multi-dimensional features including frequency, amplitude, phase, etc. from microseismic signals, achieving multi-dimensional feature extraction and improving the accuracy of capturing precursor information related to collapse disaster. In addition, the present application utilizes machine learning algorithms to comprehensively classify and judge various factors such as geological conditions and construction progress, making the identification results more consistent with actual situations and avoiding misjudgments caused by single factors, thereby improving the accuracy and efficiency of identification.

The invention belongs to the technical field of disaster simulation, and particularly discloses a test system and a test method for simulating water and mud bursting disasters of a karst tunnel, and the system comprises a seepage simulation box, a tunnel test unit, a water pressure monitoring device, a mud and sand flow monitoring device, a water tank water supply system and an atomization spraying device. The seepage simulation box comprises a box body, a first cover plate and universal wheels; a tunnel hole is formed in the front plate surface of the box body and is used for mounting a tunnel test unit; the interior of the box body is filled with different materials in a layered mode to simulate karst rock geologic bodies and non-karst rock geologic bodies, and rock stratum permeability parameters are regulated and controlled so as to reproduce evolution of a corrosion channel and the waterproof characteristic of a non-karst rock layer. The test system disclosed by the invention combines accurate water supply, extreme rainfall simulation, karst boundary difference modeling and double-hole coupling monitoring means, reveals critical conditions and a propagation mechanism of water inrush and mud inrush disasters caused when a tunnel passes through soluble and non-soluble rock mass interfaces, and provides a reliable test basis for disaster chain prevention and control in karst area tunnel construction and operation.

The invention discloses a wheel-paddle composite propelling robot for karst pipeline detection, and relates to the technical field of karst tunnel site area refined detection, the wheel-paddle composite propelling robot comprises an integrated hollow machine body, a tilting mounting seat and a wheel-paddle composite body, the integrated hollow machine body is formed by integrally forming a machine body and four symmetrically arranged hollow machine arms, a master control and master control management board, a four-in-one electric adjusting board, a rotation driving control board and a battery pack are sequentially arranged in the machine arm, the end of the machine arm is connected with a tilting installation base through a metal force bearing ring, the tilting installation base is connected with the machine body in a tilting mode through a slewing bearing, and a propelling motor, a tilting motor and a limiting switch are installed. And the wheel-paddle composite body is mounted at the outer end of the tilting mounting seat, is used as a wheel for rolling walking in a land walking mode, and is used as a propeller for underwater propulsion after tilting. The device has the advantages of being compact in structure, high in integration degree, low in energy consumption and high in environmental adaptability.

This invention discloses a karst tunnel cave simulation experimental device for applying different gradient stresses. The device includes a first loading chamber, a second loading chamber, a third loading chamber, a top cover, a first oil pump, a second oil pump, a third oil pump, a first pressure regulating valve, a second pressure regulating valve, a third pressure regulating valve, a first strain gauge, a second strain gauge, a third strain gauge, and a high-speed camera mounted on the top cover. This karst tunnel cave simulation experimental device can apply different pressures to the lower, middle, and upper parts of a hollow rock specimen, thereby simulating the force exerted by different soil pressures at different burial depths on the cave. It can also observe and record the deformation and failure of the specimen using strain sensors and a high-speed camera. This device can conveniently simulate the structural changes of caves under stress gradients in engineering projects.

The utility model provides a karst tunnel anti-seepage lining structure which is characterized in that a tunnel outer lining is arranged on the outer side of a tunnel inner lining, a drainage pipe communicated with an underground river is arranged at the bottom of a side wall on the underground river side of the tunnel outer lining, and the end, located in a tunnel, of the drainage pipe is connected with a gate valve when the tunnel outer lining is lined. When lining is conducted on the lining tunnel, the end, located in the tunnel, of the drainage pipe is connected with a sealing plate, and a water passing culvert pipe communicated with an underground river is transversely arranged below the tunnel in a penetrating mode. According to the structure, the tunnel structure can be prevented from being damaged by underground external water, and meanwhile construction safety and construction quality are guaranteed.

The invention belongs to the field of tunnel safety construction risk assessment under complex geological conditions, and particularly discloses a composite stratum karst tunnel construction risk assessment model construction method comprising the following steps: constructing a tunnel construction risk assessment index system comprising a plurality of first-level indexes and corresponding second-level indexes; respectively determining the weight of each index by using an analytic hierarchy process and an entropy weight method, and combining the weights obtained by the analytic hierarchy process and the entropy weight method by using a combined weighting method to obtain the combined weight of each first-level index and each second-level index; constructing a matter element to be evaluated, determining a node domain and a classic domain of the matter element to be evaluated, and calculating the node domain and the classic domain of each index of the project; and calculating the membership degree of the first-level indexes, determining risk levels, and judging the risk level to which each evaluation matter element belongs by calculating the membership degree of each first-level index on different risk levels and adopting a maximum membership degree criterion. The construction risk assessment accuracy of the karst tunnel in the composite stratum can be effectively improved.

This invention relates to a system and method for balancing the bearing capacity and external water pressure of karst tunnel lining, belonging to the field of tunnel lining disaster prevention. It includes two drainage lines located below and on both sides of a karst cavity. Each drainage line comprises multiple water pressure regulating chambers connected sequentially from top to bottom. The uppermost water pressure regulating chamber is connected to the bottom of the karst cavity via a pipe, adjacent water pressure regulating chambers are connected via pipes, and the lowermost water pressure regulating chamber is connected to a drainage ditch via a pipe. All pipes are equipped with electromagnetic valves. The water pressure regulating chambers are located at key points in the lining, including between the tunnel arch lining and the surrounding rock, the tunnel sidewall lining and the surrounding rock, and the tunnel arch foot lining and the surrounding rock. The electromagnetic valves control the water flow dispersion in each water pressure regulating chamber. This solution can evenly distribute local water pressure behind the tunnel lining throughout the entire lining ring, reducing stress concentration, protecting the lining structure, and ensuring the safe operation of the tunnel.