Pressure relief construction method for inrush water inrush in tunnel

Abstract

The invention discloses a pressure relief construction method for water inrush in a tunnel, and relates to the technical field of water inrush treatment in the tunnel, the water inrush distribution in the tunnel is detected through a combined detection technology to obtain water inrush distribution data, and the water inrush distribution data is subjected to fusion analysis based on a multi-source data fusion method to generate a water inrush risk distribution map. According to the water inrush risk distribution diagram, pressure relief drilling parameters are determined through a dynamic pressure relief decision-making system, pressure relief operation is executed according to graded pressure relief control logic, in the pressure relief operation process, pressure relief water quantity is calculated and monitored in real time through an intelligent water quantity analysis model, and the pressure relief drilling parameters are calculated and monitored on the basis of a closed-loop disposal mechanism. The pressure relief drilling parameters are dynamically adjusted according to the monitored pressure change data and the monitored water volume data until the water inrush pressure is reduced to a safety threshold value, so that when the pressure relief device is used, rapid pressure relief treatment can be conducted on water inrush, the pressure relief treatment efficiency is improved, and the water inrush treatment effect is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of tunnel water inrush treatment technology, and in particular to a method for depressurizing water inrushes in tunnels. Background Technology

[0002] Water inrush is a common and extremely dangerous geological hazard during tunnel construction. It not only delays construction progress but also poses a serious threat to the lives of construction workers, and can even damage the tunnel structure, increasing subsequent maintenance costs.

[0003] Currently, there are many shortcomings in the methods for dealing with water inrush in tunnels. Traditional methods often lack a precise understanding of the distribution of the water inrush. They usually rely solely on limited geological survey data and the experience of construction personnel to determine the location and scale of the water inrush. This approach cannot accurately obtain detailed information on the distribution of the water inrush within the tunnel, resulting in a lack of targeted follow-up treatment measures.

[0004] In terms of pressure relief and drainage, existing methods are relatively simplistic. Generally, fixed-diameter boreholes are used for pressure relief, without selecting an appropriate borehole diameter based on the actual situation of the water inrush. For small water inrushes, excessively large-diameter boreholes may lead to unnecessary waste of resources and excessive disturbance to the surrounding rock of the tunnel; while for large water inrushes, excessively small-diameter boreholes cannot meet the pressure relief requirements and cannot effectively reduce water pressure, thus affecting the effectiveness of water inrush control. Summary of the Invention

[0005] The main objective of this invention is to propose a method for depressurizing water inrush in tunnels. This method addresses the technical problems of existing technologies that typically use fixed-diameter boreholes for depressurization during water inrush treatment, without selecting an appropriate borehole diameter based on the actual water inrush situation. For smaller water inrushes, excessively large-diameter boreholes may lead to unnecessary resource waste and excessive disturbance to the surrounding tunnel rock; while for larger water inrushes, excessively small-diameter boreholes cannot meet the depressurization requirements and effectively reduce water pressure, thus affecting the effectiveness of water inrush treatment.

[0006] To achieve the above objectives, in a first aspect, the present invention proposes a method for relieving water inrush in tunnels, comprising the following steps: The distribution of water inrush in the tunnel is detected by a combination of detection technologies to obtain water inrush distribution data. The water inrush distribution data is then fused and analyzed based on a multi-source data fusion method to generate a water inrush risk distribution map. Based on the water inrush risk distribution map, the parameters of the pressure relief borehole are determined by the dynamic pressure relief decision system, and the pressure relief operation is executed according to the staged pressure relief control logic. During the pressure relief operation, the pressure relief water volume is calculated and monitored in real time using an intelligent water volume analysis model. Based on the closed-loop treatment mechanism, the parameters of the pressure relief borehole are dynamically adjusted according to the monitored pressure change data and water volume data until the water inrush pressure drops to a safe threshold.

[0007] In one embodiment, the combined detection technology includes ground-penetrating radar scanning, distributed fiber optic sensing, and borehole inspection. The step of detecting the distribution of water inrush within the tunnel using combined detection technology and obtaining water inrush distribution data includes: Ground-penetrating radar was used to scan the surrounding rock of the tunnel to obtain ground-penetrating radar detection data; The surrounding rock humidity data is collected through a distributed optical fiber sensor network to obtain optical fiber sensing data; Drilling inspection equipment is used to inspect and explore the interior of the surrounding rock and obtain drilling inspection image data; The ground-penetrating radar detection data, the fiber optic sensing data, and the borehole observation image data are used as the water inrush distribution data.

[0008] In one embodiment, the scanning frequency of the ground-penetrating radar is 100-900MHz, and the scanning interval is 0.5-1 meter; The distributed optical fiber sensor network is arranged with a spacing of 5-10 meters along the tunnel axial direction and a spacing of 2-3 meters along the tunnel radial direction. The borehole inspection equipment can detect borehole depths of 5-10 meters.

[0009] In one embodiment, the step of fusing and analyzing the inrush water distribution data based on a multi-source data fusion method to generate an inrush water risk distribution map includes: A ground-penetrating radar risk distribution map is generated based on the ground-penetrating radar detection data, and the ground-penetrating radar risk distribution map is spatially superimposed with the humidity data in the fiber optic sensing data to obtain preliminary risk distribution data. The borehole observation image data is calibrated in three dimensions to obtain calibrated observation data. The preliminary risk distribution data and the calibrated observation data are subjected to multimodal data fusion analysis using specialized software to generate the water inrush risk distribution map.

[0010] In one embodiment, the step of determining the pressure relief borehole parameters based on the water inrush risk distribution map using a dynamic pressure relief decision system includes: The types of water inrush areas are identified based on the water inrush risk distribution map, wherein the types of water inrush areas include concentrated water inrush areas and dispersed water inrush areas; Based on the borehole diameter decision tree, the initial borehole diameter is determined according to the type of water inrush area, wherein the initial borehole diameter corresponding to the concentrated water inrush area is 100-150mm, and the initial borehole diameter corresponding to the dispersed water inrush area is 50-80mm. Obtain the surrounding rock stability coefficient, and correct the initial borehole diameter based on the surrounding rock stability coefficient to obtain the target borehole diameter, and use the target borehole diameter as the pressure relief borehole parameter.

[0011] In one embodiment, the step of performing the pressure relief operation according to the staged pressure relief control logic includes: A large-diameter borehole was used for preliminary depressurization to reduce the water inrush pressure to the first target pressure value P1. After the water inrush pressure drops to the first target pressure value P1, a fine depressurization operation is carried out using a small-diameter borehole to reduce the water inrush pressure to the second target pressure value P2, wherein the second target pressure value P2 is less than the first target pressure value P1; During the precision depressurization operation, if the detected pressure rebound value is greater than the pressure rebound threshold ΔP, the grouting and sealing operation is triggered.

[0012] In one embodiment, before the step of real-time calculation and monitoring of the depressurization water volume using an intelligent water volume analysis model, the method further includes: Water pressure-flow velocity joint measurement nodes are deployed according to the sensor networking scheme, wherein the water pressure-flow velocity joint measurement nodes are arranged at equal intervals along the pressure relief boreholes; The data acquisition cycle and data transmission protocol of the water pressure-flow velocity joint measurement node are set, wherein the data acquisition cycle is 1 minute.

[0013] In one embodiment, the step of real-time calculation and monitoring of the depressurization water volume using an intelligent water volume analysis model includes: Water pressure and flow velocity data are collected through the aforementioned water pressure-flow velocity joint measurement node; Based on the modified Bernoulli equation, the water pressure data and the flow velocity data are calculated to obtain the fluid dynamic parameters, wherein the modified Bernoulli equation includes a friction coefficient correction term; Based on the borehole diameter D, the borehole cross-sectional area A is calculated using the borehole cross-sectional flow integral algorithm, where A = π(D / 2)². The depressurization water volume Q is calculated based on the fluid dynamics parameters and the borehole cross-sectional area A.

[0014] In one embodiment, the step of dynamically adjusting the parameters of the pressure relief borehole based on the monitored pressure change data and water volume data according to the closed-loop handling mechanism includes: The pressure drop rate dP / dt is calculated using a real-time feedback adjustment module. Determine whether the pressure drop rate dP / dt exceeds the warning threshold; If the pressure drop rate dP / dt exceeds the warning threshold, the pressure relief borehole parameters are adjusted according to the dynamic adjustment rule base for borehole parameters.

[0015] In one embodiment, the method for relieving water inrush in the tunnel further includes emergency response procedures: During the pressure relief operation, if the pressure relief water volume Q is detected to be greater than 1.2 times the preset water volume threshold Y, the emergency plan for handling sudden increase in water volume will be activated. If a risk signal of surrounding rock instability is detected during the depressurization operation, the surrounding rock instability risk handling procedure is initiated. The surrounding rock instability risk handling procedure includes suspending the depressurization operation, implementing temporary support, and adjusting the depressurization strategy.

[0016] The technical solution of this invention uses combined detection technology to detect the distribution of water inrush within tunnels, acquire water inrush distribution data, and perform fusion analysis on the water inrush distribution data based on a multi-source data fusion method to generate a water inrush risk distribution map. Based on the water inrush risk distribution map, the parameters of the pressure relief borehole are determined through a dynamic pressure relief decision system, and pressure relief operations are executed according to the graded pressure relief control logic. During the pressure relief operation, the pressure relief water volume is calculated and monitored in real time through an intelligent water volume analysis model. Based on a closed-loop treatment mechanism, the parameters of the pressure relief borehole are dynamically adjusted according to the monitored pressure change data and water volume data until the water inrush pressure drops to a safe threshold. This invention enables rapid pressure relief treatment of water inrush during use, improving pressure relief efficiency and ensuring the effectiveness of water inrush treatment. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0018] Figure 1 The flowchart of the tunnel inrush water pressure relief construction method provided by the present invention.

[0019] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention 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 the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0022] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0023] During tunnel construction, the acquisition of information on water inrush distribution is limited by finite geological survey data and construction experience, resulting in an inability to accurately grasp the spatial distribution characteristics of water inrush within the tunnel. Consequently, the selection of parameters for pressure relief boreholes lacks specificity, significantly increasing the haphazardness of treatment measures. Furthermore, the simplistic approach to pressure relief is manifested in the use of fixed-diameter boreholes, failing to dynamically adjust the borehole diameter according to the actual scale of the water inrush. This leads to excessive disturbance of the surrounding rock when the water volume is small, while failing to meet pressure relief requirements when the water volume is large, thus weakening the pressure reduction effect.

[0024] For example, during the excavation of a mountain tunnel in soft rock strata, when a water inrush occurred, the water inrush distribution was incorrectly identified as a scattered area, leading to the use of small-diameter boreholes for depressurization operations in the concentrated water inrush area. As a result, the depressurization efficiency was insufficient, the water pressure failed to decrease in time, the stability of the surrounding rock was compromised, and the construction progress was forced to stop.

[0025] This invention proposes a method for relieving water pressure surges in tunnels.

[0026] Please see Figure 1 To facilitate understanding, this method for relieving water inrush in tunnels includes the following steps: S100. The distribution of water inrush in the tunnel is detected by combined detection technology to obtain water inrush distribution data, and the water inrush distribution data is fused and analyzed based on the multi-source data fusion method to generate a water inrush risk distribution map. S200. Based on the water inrush risk distribution map, the pressure relief drilling parameters are determined through the dynamic pressure relief decision system, and the pressure relief operation is executed according to the graded pressure relief control logic. S300. During the pressure relief operation, the pressure relief water volume is calculated and monitored in real time using an intelligent water volume analysis model. S400: Based on the closed-loop treatment mechanism, the parameters of the pressure relief borehole are dynamically adjusted according to the monitored pressure change data and water volume data until the water inrush pressure drops to a safe threshold.

[0027] In practical applications, combined detection technologies can be implemented in various ways. For example, a series of simple geological exploration devices, such as resistivity meters and acoustic detectors, can be deployed to conduct preliminary scans of the tunnel surrounding rock to identify potential water-rich areas. Simultaneously, manual drilling and visual inspection can be used to obtain more direct groundwater information. These detection methods each provide different types of data, such as resistivity data, acoustic velocity data, and water content information from geological samples, which together constitute data on the distribution of water inrush.

[0028] After acquiring the water inrush distribution data, a multi-source data fusion method is used to perform fusion analysis on this data to generate a water inrush risk distribution map. In one implementation, data acquired by different detection methods can be simply overlaid or displayed side-by-side. For example, resistivity anomaly area maps and low-velocity acoustic wave area maps can be placed directly together, allowing experienced engineers to manually interpret and comprehensively evaluate them, thereby roughly determining the water inrush risk area. While this method can initially identify risks, its accuracy and efficiency are limited by human experience and the amount of data available.

[0029] Based on the water inrush risk distribution map, pressure relief borehole parameters are determined using a dynamic pressure relief decision-making system. In one implementation, a fixed set of pressure relief borehole parameters can be preset based on the high-risk areas identified on the risk distribution map. For example, for all areas marked as "high-risk," boreholes with a diameter of 80mm and a depth of 5m are uniformly used for pressure relief. This method is simple to operate, but it may not be fully adaptable to the actual conditions of different water inrush areas, resulting in low pressure relief efficiency or unnecessary disturbance to the surrounding rock.

[0030] After determining the parameters for the pressure relief borehole, the pressure relief operation is executed according to the staged pressure relief control logic. In one implementation, the pressure relief strategy can be manually adjusted based on the progress of the operation. For example, in the initial stage of pressure relief, a larger borehole can be used for rapid pressure relief; once the water pressure has initially decreased, the process can be switched to a smaller borehole for continuous pressure relief. This staged approach relies on the operator's experience and judgment, and may suffer from issues such as delayed response or inaccurate adjustments.

[0031] During this pressure relief operation, the pressure relief water volume is calculated and monitored in real time using an intelligent water volume analysis model. In one implementation, a simple flow meter can be installed at the pressure relief borehole outlet to periodically read and manually record the flow data. While this method can obtain water volume information, it may not achieve true real-time monitoring and intelligent analysis, making it difficult to immediately assess the pressure relief effect.

[0032] Based on a closed-loop response mechanism, the parameters of the pressure relief borehole are dynamically adjusted according to monitored pressure and water volume data until the inrush pressure drops to a safe threshold. In one implementation, field engineers can use their experience to determine whether adjustments to the pressure relief borehole parameters are necessary based on flow meter and pressure gauge readings. For example, if a slow pressure drop or persistently excessive water volume is detected, a manual decision can be made regarding increasing the number of boreholes or adjusting their diameter. While this mechanism offers some flexibility, its response speed and adjustment accuracy are limited by human intervention, making it difficult to achieve efficient and precise closed-loop control.

[0033] In this embodiment, a combined detection technology is used to detect the distribution of water inrush within the tunnel, acquiring water inrush distribution data. This data is then fused and analyzed using a multi-source data fusion method to generate a water inrush risk distribution map. Based on this map, a dynamic pressure relief decision system determines the parameters of the pressure relief borehole, and pressure relief operations are executed according to a graded pressure relief control logic. During the pressure relief operation, an intelligent water volume analysis model is used to calculate and monitor the pressure relief water volume in real time. Based on a closed-loop treatment mechanism, the pressure relief borehole parameters are dynamically adjusted according to the monitored pressure change data and water volume data until the water inrush pressure drops to a safe threshold. This allows the invention to quickly relieve water inrush during use, improving pressure relief efficiency and ensuring the effectiveness of water inrush treatment.

[0034] In one embodiment, the combined detection technology includes ground-penetrating radar scanning, distributed fiber optic sensing, and borehole inspection. The step of detecting the distribution of water inrush within the tunnel using combined detection technology and obtaining water inrush distribution data includes: Ground-penetrating radar was used to scan the surrounding rock of the tunnel to obtain ground-penetrating radar detection data; The surrounding rock humidity data is collected through a distributed optical fiber sensor network to obtain optical fiber sensing data; Drilling inspection equipment is used to inspect and explore the interior of the surrounding rock and obtain drilling inspection image data; The ground-penetrating radar detection data, the fiber optic sensing data, and the borehole observation image data are used as the water inrush distribution data.

[0035] In this embodiment, three technologies with different detection principles and advantages—ground-penetrating radar scanning, distributed fiber optic sensing, and borehole inspection—are organically combined to form a multi-dimensional, multi-layered detection system. Ground-penetrating radar scanning can quickly acquire macroscopic structural information and the distribution of potential anomalies in the tunnel surrounding rock, providing a preliminary assessment over a wide area. Distributed fiber optic sensing can continuously monitor changes in the humidity of the surrounding rock along the tunnel route, accurately indicating the dynamic information of water accumulation and migration. Borehole inspection provides intuitive images of the microscopic geological structures such as fissures and filling materials within the surrounding rock, verifying and refining the detection results of the former two. These three detection technologies complement and verify each other, jointly constructing comprehensive and accurate water inrush distribution data, effectively overcoming the limitations of single detection technologies under complex geological conditions, and providing a solid data foundation for subsequent water inrush risk assessment and pressure relief decisions.

[0036] In one embodiment, the scanning frequency of the ground-penetrating radar is 100-900MHz, and the scanning interval is 0.5-1 meter; The distributed optical fiber sensor network is arranged with a spacing of 5-10 meters along the tunnel axial direction and a spacing of 2-3 meters along the tunnel radial direction. The borehole inspection equipment can detect borehole depths of 5-10 meters.

[0037] In this embodiment, the scanning frequency of the ground-penetrating radar (GPR) determines the penetration depth and resolution of the radar waves. Lower frequencies generally have stronger penetration capabilities and are suitable for detecting deep geological structures, but the resolution is relatively low; higher frequencies have higher resolution and are suitable for detecting shallow, fine structures. Setting the scanning frequency in the range of 100-900MHz can balance penetration depth and detection accuracy, effectively identifying water-rich structures and fracture zones within the tunnel surrounding rock. The scanning spacing refers to the distance between adjacent measurement points on the GPR scanning path. Smaller scanning spacing provides denser detection data, thereby improving the precision and reliability of the detection results, but increasing the workload; larger scanning spacing improves detection efficiency, but may miss local details. Setting the scanning spacing to 0.5-1 meter aims to balance detection efficiency and data accuracy, ensuring effective capture of water inrush distribution characteristics. The distributed fiber optic sensor network senses the water distribution within the surrounding rock by monitoring changes in temperature, strain, or humidity along the fiber optic cable. Its arrangement, especially the spacing of the sensors along the tunnel's axial and radial directions, directly affects the spatial resolution and coverage of the monitoring data. The sensor network is spaced 5-10 meters apart along the tunnel's axial direction to ensure continuous monitoring of longitudinal hydrogeological anomalies and avoid missing large-scale water inrush areas. The radial spacing is 2-3 meters apart to focus on capturing moisture changes at different depths and in different directions within the surrounding rock, such as the radial extension of water-rich fissures, thus providing a more comprehensive reflection of the lateral distribution of water inrush risk. Appropriate spacing improves the monitoring sensitivity and positioning accuracy of the sensor network. Borehole inspection equipment, by inserting probes into the borehole, directly acquires images or video data of the surrounding rock, providing a direct understanding of the rock structure, fissure development, filling materials, and groundwater conditions. A borehole depth of 5-10 meters means that the inspection can penetrate to a certain depth into the tunnel's surrounding rock, covering key areas potentially at risk of water inrush, such as the surrounding rock behind the initial support, potential water-rich faults, or fissure zones. If the detection depth is too shallow, it may fail to reach deep water inrush hazards; if the detection depth is too deep, it may increase construction difficulty and cost. Therefore, the detection depth is set at 5-10 meters to obtain sufficient information about the interior of the surrounding rock to support an accurate assessment of the risk of water inrush.

[0038] By optimizing the specific parameters of the combined detection technologies—penetrating radar (GPR) scanning, distributed fiber optic sensor network, and borehole inspection equipment—significant improvements were achieved in spatial coverage, detection accuracy, and information depth for GPR data, fiber optic sensor data, and borehole inspection image data. The GPR scanning employs a scanning frequency of 100-900MHz and a scanning interval of 0.5-1 meter, enabling the GPR data to simultaneously penetrate deep geological structures and identify shallow, fine structures, thus effectively identifying water-rich areas and fracture development within the surrounding rock. Simultaneously, the distributed fiber optic sensor network is arranged at intervals of 5-10 meters along the tunnel axis and 2-3 meters along the tunnel radial direction. This refined arrangement allows the sensor network to comprehensively and continuously collect surrounding rock moisture data, accurately reflecting the distribution and changes of moisture within the surrounding rock and avoiding monitoring blind spots. Furthermore, the borehole inspection equipment, with a drilling depth set at 5-10 meters, ensures that the inspection can penetrate deep into key areas within the surrounding rock, directly acquiring high-resolution surrounding rock structure and hydrogeological image data. The optimized settings of these parameters lay a solid foundation for subsequent fusion analysis of water inrush distribution data based on multi-source data fusion methods, generating accurate and reliable water inrush risk distribution maps. This effectively supports the dynamic pressure relief decision system in determining pressure relief borehole parameters and guides the smooth progress of pressure relief operations.

[0039] In one embodiment, the step of fusing and analyzing the inrush water distribution data based on a multi-source data fusion method to generate an inrush water risk distribution map includes: A ground-penetrating radar risk distribution map is generated based on the ground-penetrating radar detection data, and the ground-penetrating radar risk distribution map is spatially superimposed with the humidity data in the fiber optic sensing data to obtain preliminary risk distribution data. The borehole observation image data is calibrated in three dimensions to obtain calibrated observation data. The preliminary risk distribution data and the calibrated observation data are subjected to multimodal data fusion analysis using specialized software to generate the water inrush risk distribution map.

[0040] Specifically, generating ground-penetrating radar (GPR) risk distribution maps from GPR data aims to transform raw GPR signals into images or models that intuitively reflect the risk of water inrush. This can be achieved through advanced processing and interpretation of GPR signals. For example, by analyzing parameters such as radar wave attenuation, reflection intensity, and propagation speed, groundwater bodies, water-rich fracture zones, or areas of geological anomalies can be identified. Methods for generating risk distribution maps include: using specialized geophysical interpretation software to process GPR profiles and extract the boundaries and distribution of high-risk areas; or, by establishing a mapping relationship between GPR signal characteristics and water inrush risk levels, directly converting the detection data into regional delineation maps with different risk levels.

[0041] Spatially overlaying ground-penetrating radar (GPR) risk distribution maps with humidity data from fiber optic sensing data yields preliminary risk distribution data. This approach integrates two different but complementary types of detection information. GPR primarily provides information on subsurface structures, while fiber optic sensing data directly reflects the water-bearing state of the surrounding rock. Spatial overlay can be achieved using Geographic Information System (GIS) technology, aligning and fusing the two datasets within a unified coordinate system. For example, methods such as weighted averaging, logical judgment, or fuzzy comprehensive evaluation can be employed to combine the structural risks identified by GPR with the actual humidity levels monitored by fiber optic sensors, thereby generating a more comprehensive and preliminary assessment of water inrush risk.

[0042] Three-dimensional coordinate calibration of borehole inspection images is performed to obtain calibrated inspection data, which is essential for accurately locating detailed visual information about the borehole interior into the three-dimensional spatial model of the tunnel. Borehole inspection images provide direct evidence of microscopic features such as rock fissures, joints, and seepage points, but the raw data lacks spatial coordinates. Three-dimensional coordinate calibration can be achieved in the following ways: by combining measurement data such as the precise location, depth, dip angle, and azimuth of the borehole, mapping each frame or specific feature in the image to the tunnel's three-dimensional coordinate system; or by using image processing techniques to identify known geological markers in the image and calibrating them using their known coordinates in the tunnel model.

[0043] The core step in the entire data fusion process is to perform multimodal data fusion analysis on preliminary risk distribution data and calibrated surveillance data to generate a water inrush risk distribution map. Specialized software can process and integrate data from different sensors and in different formats, and use advanced algorithms for comprehensive analysis. For example, the software can use machine learning algorithms (such as support vector machines and neural networks) to train and perform pattern recognition on preliminary risk distribution data (macroscopic structure and humidity information) and calibrated surveillance data (microscopic geological features), thereby identifying potential water inrush areas and assessing their risk levels. Furthermore, uncertainty reasoning methods such as Bayesian networks and Dempster-Shafer evidence theory can be used to fuse evidence from different data sources, ultimately generating a comprehensive and highly accurate water inrush risk distribution map.

[0044] First, ground-penetrating radar (GPR) data is converted into a GPR risk distribution map to initially identify potential structural water inrush risk areas. Then, this risk map is spatially overlaid with humidity data acquired by distributed fiber optic sensors, combining structural risks with actual water content to form more reliable preliminary risk distribution data. Based on this, precise three-dimensional coordinate calibration is performed on borehole inspection image data, integrating high-resolution local geological details into the overall risk assessment. Finally, multimodal fusion analysis is performed on these multi-source, multi-scale preliminary risk data and calibrated inspection data using specialized software to generate a comprehensive, detailed, and accurate water inrush risk distribution map. This systematic data fusion method effectively integrates the advantages of different detection technologies, compensates for the limitations of single detection methods, and provides a deeper and more accurate understanding of water inrush distribution within tunnels, offering a solid data foundation for subsequent pressure relief operations.

[0045] In one embodiment, the step of determining the pressure relief borehole parameters based on the water inrush risk distribution map using a dynamic pressure relief decision system includes: The types of water inrush areas are identified based on the water inrush risk distribution map, wherein the types of water inrush areas include concentrated water inrush areas and dispersed water inrush areas; Based on the borehole diameter decision tree, the initial borehole diameter is determined according to the type of water inrush area, wherein the initial borehole diameter corresponding to the concentrated water inrush area is 100-150mm, and the initial borehole diameter corresponding to the dispersed water inrush area is 50-80mm. Obtain the surrounding rock stability coefficient, and correct the initial borehole diameter based on the surrounding rock stability coefficient to obtain the target borehole diameter, and use the target borehole diameter as the pressure relief borehole parameter.

[0046] In this embodiment, firstly, the dynamic pressure relief decision system, based on a water inrush risk distribution map generated by multi-source data fusion, refines the identification of water inrush areas within the tunnel, classifying them into concentrated or dispersed water inrush areas. This classification forms the basis for differentiated pressure relief strategies. Subsequently, the system invokes a preset borehole diameter decision tree to quickly determine a preliminary initial borehole diameter range based on the identified water inrush area type. For example, for high-risk concentrated water inrush areas, the decision tree recommends a larger initial diameter to cope with high water pressure and large inflows; while for dispersed water inrush areas, it recommends a smaller initial diameter to avoid excessive water discharge and unnecessary disturbance to the surrounding rock. Based on this, the system further obtains the surrounding rock stability coefficient for the area. This coefficient, as an important safety verification parameter, is used to correct the initial borehole diameter. If the surrounding rock stability is poor, even in concentrated water inrush areas, it may be necessary to appropriately reduce the borehole diameter to prevent instability induced by excessively large boreholes; conversely, in cases of good surrounding rock stability, the initial diameter can be maintained or slightly adjusted to maximize the pressure relief effect. Through this dynamic, hierarchical decision-making process that considers the stability of the surrounding rock, the final target borehole diameter can accurately match the actual needs and surrounding rock conditions of different water inrush areas, thereby optimizing the efficiency and safety of pressure relief operations. Based on the generation of a water inrush risk distribution map, this scheme further refines the process of determining pressure relief borehole parameters, making pressure relief operations more targeted and safer.

[0047] In one embodiment, the step of performing the pressure relief operation according to the staged pressure relief control logic includes: A large-diameter borehole was used for preliminary depressurization to reduce the water inrush pressure to the first target pressure value P1. After the water inrush pressure drops to the first target pressure value P1, a fine depressurization operation is carried out using a small-diameter borehole to reduce the water inrush pressure to the second target pressure value P2, wherein the second target pressure value P2 is less than the first target pressure value P1; During the precision depressurization operation, if the detected pressure rebound value is greater than the pressure rebound threshold ΔP, the grouting and sealing operation is triggered.

[0048] In this embodiment, a tiered pressure relief control logic is introduced to achieve refined and dynamic management of tunnel water inrush pressure relief operations. In the initial stage of the pressure relief operation, due to the typically high pressure of the inrush water, a large-diameter borehole is used for preliminary pressure relief, which can quickly and efficiently release most of the water pressure, rapidly reducing the inrush pressure to the first target pressure value P1. This stage primarily addresses the impact risk caused by the initial high pressure, creating safe conditions for subsequent operations. Subsequently, once the pressure drops to P1, a smaller-diameter borehole is used for fine pressure relief, further reducing the pressure in a slower and more controllable manner until the second target pressure value P2 is reached. This tiered strategy avoids the problems of over- or under-pressure relief that may occur with a single borehole diameter, resulting in a smoother pressure reduction process and effectively protecting the stability of the surrounding rock. Furthermore, during the fine pressure relief operation, a pressure rebound monitoring mechanism is also introduced. If the pressure rebound value detected in real time exceeds the preset pressure rebound threshold ΔP, grouting and sealing operations are immediately triggered. This closed-loop feedback mechanism can promptly respond to dynamic changes in the water inrush channel or potential risks within the surrounding rock. By rapidly sealing or mitigating the water inrush through grouting, it effectively prevents pressure from rising again, thereby avoiding secondary disasters such as surrounding rock instability that may result from pressure rebound. Through the strategy of combining graded pressure relief with dynamic emergency response, the proposed solution can more safely, efficiently, and accurately complete tunnel water inrush pressure relief operations, significantly improving the risk control capabilities and operational adaptability during construction.

[0049] In one embodiment, before the step of real-time calculation and monitoring of the depressurization water volume using an intelligent water volume analysis model, the method further includes: Water pressure-flow velocity joint measurement nodes are deployed according to the sensor networking scheme, wherein the water pressure-flow velocity joint measurement nodes are arranged at equal intervals along the pressure relief boreholes; The data acquisition cycle and data transmission protocol of the water pressure-flow velocity joint measurement node are set, wherein the data acquisition cycle is 1 minute.

[0050] In this embodiment, a reliable data foundation for the intelligent water volume analysis model is provided by pre-deploying a sensor network scheme and water pressure-flow velocity joint measurement nodes before real-time calculation and monitoring of the depressurization water volume. Specifically, according to the preset sensor network scheme, multiple water pressure-flow velocity joint measurement nodes are arranged at equal intervals along the depressurization borehole, enabling distributed and synchronous water pressure and flow velocity data acquisition throughout the entire effective range of the depressurization borehole. This evenly spaced arrangement ensures the comprehensiveness and representativeness of the data acquisition, avoiding the problem of missing or inaccurate data in local areas. At the same time, by setting a fixed data acquisition cycle (e.g., 1 minute), the real-time updating of data is guaranteed, enabling the intelligent water volume analysis model to obtain the latest hydraulic parameters in a timely manner. In addition, a clear data transmission protocol ensures that the water pressure and flow velocity data collected from each measurement node can be stably, efficiently, and accurately transmitted to the central processing system, providing high-quality input for the subsequent intelligent water volume analysis model. This systematic pre-acquisition step effectively solves the problem of obtaining accurate and real-time hydraulic data in complex tunnel environments, laying a solid foundation for subsequent depressurization water volume calculation and dynamic adjustment of depressurization borehole parameters.

[0051] In one embodiment, the step of real-time calculation and monitoring of the depressurization water volume using an intelligent water volume analysis model includes: Water pressure and flow velocity data are collected through the aforementioned water pressure-flow velocity joint measurement node; Based on the modified Bernoulli equation, the water pressure data and the flow velocity data are calculated to obtain the fluid dynamic parameters, wherein the modified Bernoulli equation includes a friction coefficient correction term; Based on the borehole diameter D, the borehole cross-sectional area A is calculated using the borehole cross-sectional flow integral algorithm, where A = π(D / 2)². The depressurization water volume Q is calculated based on the fluid dynamics parameters and the borehole cross-sectional area A.

[0052] In this embodiment, water pressure and velocity joint measurement nodes are deployed in the pressure relief borehole to collect water pressure and velocity data in real time. This raw data is then input into an intelligent water volume analysis model. The model first uses a modified Bernoulli equation to perform precise calculations on the collected water pressure and velocity data. Specifically, the friction coefficient correction term included in this equation accurately compensates for energy losses caused by friction during fluid flow within the borehole, thus obtaining more realistic fluid dynamic parameters. Simultaneously, based on the known diameter D of the pressure relief borehole, the cross-sectional area A of the borehole is accurately calculated using a borehole cross-sectional flow integral algorithm. Finally, by combining these accurate fluid dynamic parameters with the calculated borehole cross-sectional area A, the real-time pressure relief water volume Q can be accurately calculated. This method ensures that the calculated pressure relief water volume Q is not only a theoretical value but also reliable data that fully considers actual flow conditions (including friction losses), providing a solid foundation for subsequent dynamic adjustments. In this way, the proposed solution overcomes the calculation errors caused by neglecting friction losses in traditional methods, significantly improving the accuracy of pressure relief water volume monitoring.

[0053] In one embodiment, the step of dynamically adjusting the parameters of the pressure relief borehole based on the monitored pressure change data and water volume data according to the closed-loop handling mechanism includes: The pressure drop rate dP / dt is calculated using a real-time feedback adjustment module. Determine whether the pressure drop rate dP / dt exceeds the warning threshold; If the pressure drop rate dP / dt exceeds the warning threshold, the pressure relief borehole parameters are adjusted according to the dynamic adjustment rule base for borehole parameters.

[0054] In this embodiment, a real-time feedback adjustment module continuously receives monitored pressure change data and water volume data, and accurately calculates the pressure drop rate dP / dt. Then, the calculated pressure drop rate dP / dt is compared with a preset warning threshold. Once the pressure drop rate dP / dt exceeds the warning threshold, it indicates that the pressure relief process may be abnormal or deviate from expectations, and the system immediately triggers an adjustment mechanism. At this time, the dynamic adjustment rule base for borehole parameters is activated, and dynamic adjustments to the pressure relief borehole parameters are quickly determined and executed according to preset rules or intelligent algorithms. This closed-loop control mechanism ensures that the pressure relief operation is no longer statically executed, but can intelligently respond and optimize based on the real-time dynamic changes in the water inrush pressure inside the tunnel, thereby ensuring that the pressure relief process is always under control and effectively avoiding risks caused by excessively rapid or slow pressure changes. By combining this with the aforementioned combined detection technology, multi-source data fusion method, dynamic pressure relief decision-making system, and intelligent water volume analysis model, this solution can achieve refined management and efficient control of tunnel water inrush pressure relief construction within a framework of comprehensive perception, intelligent decision-making, and precise execution.

[0055] In one embodiment, the method for relieving water inrush in the tunnel further includes emergency response procedures: During the pressure relief operation, if the pressure relief water volume Q is detected to be greater than 1.2 times the preset water volume threshold Y, the emergency plan for handling sudden increase in water volume will be activated. If a risk signal of surrounding rock instability is detected during the depressurization operation, the surrounding rock instability risk handling procedure is initiated. The surrounding rock instability risk handling procedure includes suspending the depressurization operation, implementing temporary support, and adjusting the depressurization strategy.

[0056] In this embodiment, an emergency response mechanism is introduced on top of conventional pressure relief operations to address potential sudden risks during construction. When the intelligent water volume analysis model calculates and monitors an abnormal increase in the pressure relief water volume Q, exceeding 1.2 times the preset water volume threshold Y, the system can quickly identify this anomaly and automatically or manually trigger the emergency response plan for sudden water volume increases. This plan aims to quickly control the water volume through a series of preset emergency measures, such as enhanced drainage and temporary sealing, to prevent flooding and ensure construction safety. Simultaneously, during pressure relief operations, the surrounding rock condition is continuously monitored. Once a risk signal of surrounding rock instability is detected, such as deformation or crack propagation, the system immediately initiates the surrounding rock instability risk handling process. This process first requires suspending pressure relief operations to avoid further disturbance to the surrounding rock, followed by rapid implementation of temporary support to reinforce unstable areas and buy time for subsequent treatment. Based on this, the pressure relief strategy is dynamically adjusted according to the actual stability of the surrounding rock, such as changing drilling parameters or adjusting the pressure relief area, to continue the pressure relief operation while ensuring safety. This emergency response mechanism, together with the aforementioned steps of combined detection, dynamic decision-making, real-time monitoring, and closed-loop adjustment, forms a more complete and safer construction system. It can not only effectively manage conventional water inrush risks, but also provide rapid and powerful response measures in the face of sudden emergencies, significantly improving the safety and controllability of tunnel depressurization construction.

[0057] The above description is merely an exemplary embodiment of the present invention and does not limit the scope of the present invention. Any equivalent structural transformations made based on the technical concept of the present invention and the contents of the specification and drawings of the present invention, or direct / indirect applications in other related technical fields, are included within the protection scope of the present invention.

Claims

1. A method for relieving water inrush pressure in a tunnel, characterized in that, Includes the following steps: The distribution of water inrush in the tunnel is detected by a combination of detection technologies to obtain water inrush distribution data. The water inrush distribution data is then fused and analyzed based on a multi-source data fusion method to generate a water inrush risk distribution map. Based on the water inrush risk distribution map, the parameters of the pressure relief borehole are determined by the dynamic pressure relief decision system, and the pressure relief operation is executed according to the staged pressure relief control logic. During the pressure relief operation, the pressure relief water volume is calculated and monitored in real time using an intelligent water volume analysis model. Based on the closed-loop treatment mechanism, the parameters of the pressure relief borehole are dynamically adjusted according to the monitored pressure change data and water volume data until the water inrush pressure drops to a safe threshold.

2. The method for relieving water inrush in tunnels as described in claim 1, characterized in that, The combined detection technology includes ground-penetrating radar scanning, distributed fiber optic sensing, and borehole inspection. The step of detecting the distribution of water inrush within the tunnel using combined detection technology and obtaining water inrush distribution data includes: Ground-penetrating radar was used to scan the surrounding rock of the tunnel to obtain ground-penetrating radar detection data; The surrounding rock humidity data is collected through a distributed optical fiber sensor network to obtain optical fiber sensing data; Drilling inspection equipment is used to inspect and explore the interior of the surrounding rock and obtain drilling inspection image data; The ground-penetrating radar detection data, the fiber optic sensing data, and the borehole observation image data are used as the water inrush distribution data.

3. The method for relieving water inrush in tunnels as described in claim 2, characterized in that, The scanning frequency of the ground-penetrating radar is 100-900MHz, and the scanning interval is 0.5-1 meter; The distributed optical fiber sensor network is arranged with a spacing of 5-10 meters along the tunnel axial direction and a spacing of 2-3 meters along the tunnel radial direction. The borehole inspection equipment can detect borehole depths of 5-10 meters.

4. The method for relieving water inrush in tunnels as described in claim 2, characterized in that, The step of fusing and analyzing the water inrush distribution data based on a multi-source data fusion method to generate a water inrush risk distribution map includes: A ground-penetrating radar risk distribution map is generated based on the ground-penetrating radar detection data, and the ground-penetrating radar risk distribution map is spatially superimposed with the humidity data in the fiber optic sensing data to obtain preliminary risk distribution data. The borehole observation image data is calibrated in three dimensions to obtain calibrated observation data. The preliminary risk distribution data and the calibrated observation data are subjected to multimodal data fusion analysis using specialized software to generate the water inrush risk distribution map.

5. The tunnel inrush water pressure relief construction method according to any one of claims 1 to 4, characterized in that, The step of determining the pressure relief borehole parameters based on the water inrush risk distribution map using a dynamic pressure relief decision system includes: The types of water inrush areas are identified based on the water inrush risk distribution map, wherein the types of water inrush areas include concentrated water inrush areas and dispersed water inrush areas; Based on the borehole diameter decision tree, the initial borehole diameter is determined according to the type of water inrush area, wherein the initial borehole diameter corresponding to the concentrated water inrush area is 100-150mm, and the initial borehole diameter corresponding to the dispersed water inrush area is 50-80mm. Obtain the surrounding rock stability coefficient, and correct the initial borehole diameter based on the surrounding rock stability coefficient to obtain the target borehole diameter, and use the target borehole diameter as the pressure relief borehole parameter.

6. The method for relieving water inrush in tunnels as described in claim 5, characterized in that, The steps for performing the pressure relief operation according to the graded pressure relief control logic include: A large-diameter borehole was used for preliminary depressurization to reduce the water inrush pressure to the first target pressure value P1. After the water inrush pressure drops to the first target pressure value P1, a fine depressurization operation is carried out using a small-diameter borehole to reduce the water inrush pressure to the second target pressure value P2, wherein the second target pressure value P2 is less than the first target pressure value P1; During the precision depressurization operation, if the detected pressure rebound value is greater than the pressure rebound threshold ΔP, the grouting and sealing operation is triggered.

7. The tunnel inrush water pressure relief construction method according to any one of claims 1 to 4, characterized in that, Before the step of calculating and monitoring the pressure relief water volume in real time using an intelligent water volume analysis model, the following steps are also included: Water pressure-flow velocity joint measurement nodes are deployed according to the sensor networking scheme, wherein the water pressure-flow velocity joint measurement nodes are arranged at equal intervals along the pressure relief boreholes; The data acquisition cycle and data transmission protocol of the water pressure-flow velocity joint measurement node are set, wherein the data acquisition cycle is 1 minute.

8. The method for relieving water inrush in tunnels as described in claim 7, characterized in that, The steps for real-time calculation and monitoring of the pressure relief water volume using an intelligent water volume analysis model include: Water pressure and flow velocity data are collected through the aforementioned water pressure-flow velocity joint measurement node; Based on the modified Bernoulli equation, the water pressure data and the flow velocity data are calculated to obtain the fluid dynamic parameters, wherein the modified Bernoulli equation includes a friction coefficient correction term; Based on the borehole diameter D, the borehole cross-sectional area A is calculated using the borehole cross-sectional flow integral algorithm, where A = π(D / 2)². The depressurization water volume Q is calculated based on the fluid dynamics parameters and the borehole cross-sectional area A.

9. The method for relieving water inrush pressure in a tunnel as described in any one of claims 1 to 4, characterized in that, The step of dynamically adjusting the parameters of the pressure relief borehole based on the monitored pressure change data and water volume data according to the closed-loop treatment mechanism includes: The pressure drop rate dP / dt is calculated using a real-time feedback adjustment module. Determine whether the pressure drop rate dP / dt exceeds the warning threshold; If the pressure drop rate dP / dt exceeds the warning threshold, the pressure relief borehole parameters are adjusted according to the dynamic adjustment rule base for borehole parameters.

10. The method for relieving water inrush in tunnels as described in claim 9, characterized in that, The method for relieving water inrush in tunnels also includes emergency response procedures: During the pressure relief operation, if the pressure relief water volume Q is detected to be greater than 1.2 times the preset water volume threshold Y, the emergency plan for handling sudden increase in water volume will be activated. If a risk signal of surrounding rock instability is detected during the depressurization operation, the surrounding rock instability risk handling procedure is initiated. The surrounding rock instability risk handling procedure includes suspending the depressurization operation, implementing temporary support, and adjusting the depressurization strategy.

Images