Construction method for water inrush section of deep and long tunnel

Abstract

The invention discloses a construction method for a water inrush section of a deep and long tunnel, and relates to the technical field of tunnel engineering.The construction method for the water inrush section of the deep and long tunnel comprises the steps that geological information of a fault, a crack and a water-rich area at the geological position is obtained through geological drilling, geological radar detection and TSP detection; fusing the multi-source data to generate a three-dimensional geological profile; based on the mechanical parameters of the surrounding rock in the three-dimensional geological section, anchor rods, grouting holes and a reinforcing mesh are arranged; advanced small pipe grouting, advanced pipe shed supporting or advanced anchor rod supporting is selected according to the fault width and the fracture density, and a supporting structure is formed; arranging double rows of grouting waterproof curtains and drainage holes in the water-rich area; the deformation rate of the surrounding rock, the underground water pressure and the strain data of the supporting structure are collected in real time through an embedded sensor, and early warning is triggered according to a preset threshold value. According to the method, integration of geological information, dynamic adaptation of supporting parameters, active prevention and control of water inrush risks and real-time guarantee of construction safety are achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tunnel engineering, in particular to a construction method for a water bursting section of a deep long tunnel. BACKGROUND

[0002] In the construction of a deep long tunnel, the geological environment of multiple faults and multiple fissures with rich water significantly increases the complexity and risk of engineering implementation.

[0003] In the existing technology, the traditional construction method generally adopts an anchor rod support strategy dominated by experience in the reinforcement of surrounding rock. In the construction of a water bursting section of a deep long tunnel, the existing technology cannot meet the comprehensive needs of accurate integration of geological information, dynamic adaptation of support parameters, active prevention and control of water bursting risks, and real-time guarantee of construction safety. SUMMARY

[0004] The main purpose of the present application is to provide a construction method for a water bursting section of a deep long tunnel, aiming to realize the integration of geological information, the dynamic adaptation of support parameters, the active prevention and control of water bursting risks, and the real-time guarantee of construction safety.

[0005] To achieve the above purpose, the construction method for a water bursting section of a deep long tunnel provided by the present application is arranged in a geological location with multiple faults and multiple fissures, and comprises the following steps: Geological drilling, geological radar detection, and TSP detection are used to obtain the geological information of the faults, fissures, and water-rich areas in the geological location, and multi-source data fusion is used to generate a three-dimensional geological profile; Based on the mechanical parameters of the surrounding rock in the three-dimensional geological profile, anchor rods, grouting holes, and steel mesh are arranged, wherein the length, spacing, and grouting pressure of the anchor rods are dynamically adjusted according to the scale of the faults and fissures; According to the width of the faults and the density of the fissures, an advanced small catheter grouting, an advanced pipe shed support, or an advanced anchor rod support is selected to form a support structure; A double-row grouting waterproof curtain and a drainage hole are arranged in the water-rich area, and grouting filling and drainage channel pre-burial are completed before excavation; Sensors are embedded to collect the deformation rate of the surrounding rock, the groundwater pressure, and the strain data of the support structure in real time, and a pre-set threshold value is used to trigger a warning.

[0006] In an embodiment, the step of obtaining the geological information of the faults, fissures, and water-rich areas in the geological location by geological drilling, geological radar detection, and TSP detection, and generating a three-dimensional geological profile by multi-source data fusion comprises: Drill holes are arranged at an interval of 1.5-2 meters between the tunnel face and the two side walls, with a drilling depth of 30-50 meters to obtain core samples. After coring, the core fissure width, inclination, and groundwater inflow are recorded to generate drilling data; An antenna of 100MHz~900MHz is moved along the tunnel face at a constant speed to scan an area of 30~50m in front at a speed of 0.5~1m / s to generate a radar reflection waveform diagram; A seismic source point and a receiving point are installed on the tunnel side wall, the distance between the seismic source points is 1.5~2m, the distance between the receiving points is 0.5~1m, seismic waves are emitted and reflected signals are collected to analyze the geological structure of 100~200m in front to generate a TSP signal; The drilling data, the radar reflection waveform diagram and the TSP signal are input into a geological information database to generate a spatial distribution diagram of the fault and the water-rich area through three-dimensional modeling.

[0007] In an embodiment, drilling holes are arranged at intervals of 1.5~2m between the tunnel face and the side walls, the drilling depth is 30~50m, rock core samples are obtained, and the core fracture width, inclination and underground water inflow are recorded after coring, and after the step of generating drilling data, the water inrush section construction method of the deep tunnel further comprises: The mineral composition of the core fracture filling of the surrounding rock is analyzed to distinguish between clay, calcite or quartz filling types; The water inflow pressure in the drilling hole is measured, and if the pressure exceeds 0.3MPa, it is marked as a high-risk water inrush area; The physical and mechanical parameters of the core samples are input into numerical simulation software to calculate the stress distribution of the surrounding rock and the potential deformation area.

[0008] In an embodiment, based on the mechanical parameters of the surrounding rock in the three-dimensional geological profile, the steps of arranging anchor rods, grouting holes and steel mesh include: Anchor rods with a length of 3~5m and a spacing of 0.8~1m are used in the fault fracture zone at the geological location, the outer insertion angle is 10°~15°, and the anchoring grouting pressure is 0.5~1MPa; Grouting holes are arranged in a quincunx pattern in the fracture zone at the geological location, the hole depth is 2~5m, the grouting material is cement slurry or chemical slurry, the grouting pressure is 1~3MPa, and the grouting amount is reduced to 10%~20% of the initial amount until the grouting amount is reduced to 10%~20% of the initial amount; Steel rods with a diameter of 6~8mm are welded into a 150mm*150mm grid, and after being welded and fixed to the end of the anchor rod, C20 or C25 concrete is sprayed, and the spraying thickness is 15~25cm.

[0009] In an embodiment, the step of arranging grouting holes in a quincunx pattern in the fracture zone at the geological location, the hole depth is 2~5m, the grouting material is cement slurry or chemical slurry, the grouting pressure is 1~3MPa, and the grouting amount is reduced to 10%~20% of the initial amount until the grouting amount is reduced to 10%~20% of the initial amount includes: Chemical slurry with rapid setting time is preferentially injected into fractures with a width greater than 5mm, and the setting time is ≤30s; After the grouting is completed, the grout filling rate of the quick-setting chemical grout is detected by using ground penetrating radar, and if the filling rate is < 90%, the grouting hole is grouted again by using the quick-setting chemical grout; The grouting area corresponding to the grouting hole is verified by drilling and coring, and the core sample compressive strength ≥ 15 MPa is considered to be qualified.

[0010] In an embodiment, according to the fault width and the fissure density, the advance small catheter grouting, the advance pipe shed support or the advance anchor rod support is selected, and the step of forming the support structure comprises: When the fault width < 50 mm and the fissure density < 3 per meter, the advance small catheter grouting is used; wherein the catheter diameter of the advance small catheter is 42 mm ~ 50 mm, the length is 3 meters ~ 5 meters, the external insertion angle is 10° ~ 15°, and the grouting pressure is 0.5 MPa ~ 1.5 MPa; When the fault width ≥ 50 mm or the fissure density ≥ 3 per meter, the advance pipe shed support is used; wherein the pipe shed diameter of the advance pipe shed is 89 mm ~ 108 mm, the interval is 300 mm ~ 500 mm, and 2 MPa ~ 4 MPa high-pressure cement mortar is injected after construction; For the area of the deep and long tunnel with a vault deformation rate > 2 mm / h, the advance anchor rod support is additionally provided; wherein the anchor rod length of the advance anchor rod support is 3 meters ~ 4 meters, the external insertion angle is 15° ~ 20°, and the anchoring grouting pressure is 0.8 MPa ~ 1.2 MPa.

[0011] In an embodiment, when the fault width < 50 mm and the fissure density < 3 per meter, the step of using the advance small catheter grouting comprises: The advance small catheter is arranged in the vault 120° range of the deep and long tunnel at an interval of 30°, and the interval of the advance small catheter is 0.5 meters ~ 0.8 meters; The advance small catheter is drilled into the surrounding rock by using an air drill, and the front end pointed cone part of the advance small catheter exceeds the excavation contour line of the deep and long tunnel by 1 meter ~ 1.5 meters; A double-liquid grout of cement and water glass is injected; wherein the water-cement ratio of the double-liquid grout is 0.8:1 ~ 1.2:1, the dosage of the water glass is 3% ~ 5%, and a reinforced ring with a thickness ≥ 200 mm is formed after grouting.

[0012] In an embodiment, the step of arranging double-row grouting waterproof curtains and drainage holes in the water-rich area and completing grouting filling and drainage channel pre-burying before excavation comprises: Double-row grouting holes are arranged on both sides of the water-rich fault in the water-rich area, the hole interval is 0.8 meters ~ 1.2 meters, the grouting pressure is 2 MPa ~ 5 MPa, and the grout diffusion radius ≥ 1.5 meters; Drill the drainage hole with a diameter of 50mm-100mm at the bottom of the deep and long tunnel, the hole depth is 5-10 meters, install PVC pipe with filter screen in the hole, and connect the outlet of the drainage pipe with adjustable flow valve; Preposition the rapid-setting grouting material at the water inrush point; wherein the rapid-setting grouting material comprises polyurethane plugging agent and sulphoaluminate cement, and the response time is ≤5 minutes.

[0013] In an embodiment, the step of arranging double rows of grouting holes on both sides of the water-rich fault in the water-rich area, with a hole distance of 0.8-1.2 meters, a grouting pressure of 2-5 MPa, and a slurry diffusion radius of ≥1.5 meters, comprises: The first row of grouting holes is 0.5 meters away from the excavation contour line of the deep and long tunnel, and the second row is 0.8 meters away from the first row, arranged in a staggered pattern like a plum blossom. The segmented grouting process is adopted, with each segment being 1-1.5 meters long, and a grout stopper is arranged between segments. After grouting is completed, the permeability coefficient of the double-row grouting waterproof curtain is verified by drilling, and if the permeability coefficient is >1*10 ~6 cm / s, supplementary grouting is performed until the standard is met.

[0014] In an embodiment, the step of collecting the deformation rate of the surrounding rock, the groundwater pressure, and the strain data of the supporting structure in real time by burying sensors, and triggering an early warning according to a preset threshold value comprises: Displacement meters are buried in the surrounding rock at an interval of 2-3 meters, pore water pressure gauges are buried at an interval of 5-8 meters, and strain gauges are arranged at the nodes of the supporting structure. The data of the displacement meters, the water pressure gauges, and the strain gauges are collected every 10 minutes and transmitted wirelessly to the monitoring center. When the deformation rate of the surrounding rock is >2mm / h, the water pressure gradient is >0.1MPa / m, or the supporting strain is >80% of the yield strength, a first-level early warning is triggered. When the first-level early warning is triggered, excavation is suspended and supporting parameter adjustment is started; wherein the supporting parameter adjustment comprises increasing the grouting pressure by 10-20% or shortening the excavation footage to below 0.5 meters.

[0015] The technical scheme of the present application obtains the geological information of faults, fissures and water-rich areas through geological drilling, geological radar detection and TSP detection, and generates a three-dimensional geological profile by fusing the multi-source data, which overcomes the limitations of traditional single methods by utilizing the complementarity of various detection means, and provides a comprehensive and accurate geological model for subsequent construction decision-making. Based on the mechanical parameters of the surrounding rock in the three-dimensional geological profile, anchor rods, grouting holes and reinforcement meshes are arranged, wherein the length, spacing and grouting pressure of the anchor rods are dynamically adjusted according to the scale of the faults and fissures, to ensure that the support design accurately matches the actual geological conditions and avoid the reinforcement deficiency or resource waste caused by empiricism. Further, according to the fault width and fissure density, advanced small-diameter pipe grouting, advanced pipe roof support or advanced anchor rod support are selected to form a support structure, which flexibly selects the support method according to the specific geological parameters, effectively deals with the challenges of different scale geological defects, and avoids the failure risk of single support method under complex conditions. In the water-rich area, double-row grouting waterproof curtains and drainage holes are arranged, and grouting filling and drainage channel pre-burying are completed before excavation, to realize active prevention and systematic treatment of water inrush risk, rather than passive response, and ensure water pressure control and structure stability during excavation. Specifically, by embedding sensors to collect the deformation rate of the surrounding rock, the groundwater pressure and the strain data of the support structure in real time, and triggering an early warning according to the preset threshold, a dynamic risk monitoring mechanism is established, which can intervene in time before the risk accumulates, to ensure construction safety and efficiency. Therefore, the technical scheme systematically integrates geological detection, dynamic support design, targeted advanced support, active water inrush prevention and real-time risk monitoring, to comprehensively deal with the construction challenges of the water inrush section with multiple faults and fissures, and solves the problem of safe and efficient construction of deep long tunnels in water inrush sections under complex geological conditions. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description only constitute some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from the structures shown in the drawings without creative labor.

[0017] Figure 1 The flowchart of an embodiment of the construction method of the water inrush section of the deep long tunnel provided by the present application.

[0018] The implementation of the object of the present application, functional characteristics and advantages will be further described with reference to the embodiments and drawings. DETAILED DESCRIPTION

[0019] With reference to the accompanying drawings, the technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of the present application.

[0020] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative positional relationship, motion condition, etc. between components in a certain posture, and if the certain posture changes, the directional indications also change accordingly.

[0021] In addition, if the embodiments of the present application involve descriptions such as “first”, “second”, etc., the descriptions of “first”, “second”, etc. are only for description purposes, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by “first” and “second” can explicitly or implicitly include at least one of the features. In addition, “and / or” or “and / or” appearing throughout the text means that the three parallel schemes are included, for example, “A and / or B” includes A scheme, or B scheme, or A and B are satisfied at the same time. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the fact that a person of ordinary skill in the art can realize it, and when the combination of technical solutions contradicts each other or cannot be realized, it should be considered that the combination of technical solutions does not exist and is not within the scope of protection claimed by the present application.

[0022] In deep tunnel construction, the geological environment of multiple faults, multiple fractures and water enrichment significantly increases the complexity and risk of project implementation.

[0023] The traditional construction method generally uses an experience-oriented anchor rod support strategy in the surrounding rock reinforcement link, and the length, spacing and arrangement angle of the anchor rod lack fine analysis of the mechanical properties of the surrounding rock, resulting in a mismatch between the support system and the geological conditions. In the fault fracture zone and dense fracture zone, the surrounding rock is prone to local deformation and instability due to uneven stress distribution, causing sudden collapse accidents and seriously threatening the safety of workers. The advanced support measures have obvious limitations, and the conventional practice excessively relies on a single advanced small pipe grouting process, the grouting material type and pressure parameters are fixed, and the dynamic changes of fault width, fracture density and groundwater pressure cannot be adaptively adjusted.

[0024] When encountering large-scale faults or highly permeable fissures, the support structure cannot effectively resist water and soil pressure, causing water inrush and damage to the surrounding rock structure, leading to construction interruption and economic losses. Geological information acquisition methods are weak; geological drilling can only provide discrete data on borehole locations, and geophysical methods such as ground-penetrating radar and TSP are easily affected by signal interference in complex strata, making it difficult to accurately identify fault strikes, fissure development levels, and the spatial distribution of water-rich areas. This results in incomplete three-dimensional geological model construction and a lack of scientific basis for construction decisions. Water inrush prevention strategies lack a systematic approach. Traditional practices often involve temporary drainage and simple sealing measures after a water inrush occurs, without establishing a pre-emptive mechanism for water-stopping curtains and drainage channels. Water inrush events often induce surrounding rock strength deterioration and secondary disasters, further exacerbating safety risks. The risk monitoring system is inadequate, lacking continuous real-time monitoring of surrounding rock deformation rates, groundwater pressure, and support structure strain. It cannot trigger early warnings based on preset thresholds, and risk management is mostly in a passive response state, making it difficult to achieve proactive intervention and dynamic optimization during the construction process.

[0025] Therefore, existing technologies cannot meet the comprehensive needs of accurate integration of geological information, dynamic adaptation of support parameters, proactive prevention and control of water inrush risks, and real-time assurance of construction safety in the construction of deep and long tunnels in areas prone to water inrush.

[0026] To address this technical problem, this invention proposes a construction method for water inrush sections of deep and long tunnels.

[0027] Please see Figure 1 In one embodiment of the present invention, the water inrush section is located in a geological area with multiple faults and fissures, and the construction method for the water inrush section of the deep and long tunnel includes: S10, geological information of faults, fissures and water-rich areas at the geological site is obtained through geological drilling, ground-penetrating radar detection and TSP detection, and multi-source data is fused to generate a three-dimensional geological profile. S20, based on the mechanical parameters of the surrounding rock in the three-dimensional geological profile, anchor bolts, grouting holes and steel mesh are arranged; wherein, the length, spacing and grouting pressure of the anchor bolts are dynamically adjusted according to the scale of the fault and fracture; S30, depending on the fault width and fracture density, select advanced small pipe grouting, advanced pipe roof support or advanced anchor bolt support to form a support structure; S40, a double-row grouting water-stopping curtain and drainage holes are set in the water-rich area, and grouting filling and drainage channel pre-embedding are completed before excavation; S50: The deformation rate of the surrounding rock, the groundwater pressure, and the strain data of the support structure are collected in real time by burying sensors, and an early warning is triggered according to a preset threshold.

[0028] In practical applications, geological drilling can be understood as the process of drilling holes in geological bodies using mechanical equipment to obtain core samples. For example, rotary drilling rigs or percussion drilling rigs are used for drilling operations, primarily to achieve direct observation and analysis of the internal structure of the geological body. Ground-penetrating radar (GPR) detection refers to the technology of scanning geological bodies using high-frequency electromagnetic waves and recording reflected signals. For example, antennas of different frequencies are moved along the detection area to obtain reflected waveforms of underground structures, aiming to reveal the distribution of faults and fissures within the geological body. Transient seismic wave propagation (TSP) detection is a detection technology based on the principle of seismic wave reflection. For example, by placing source and receiver points on the tunnel sidewalls, seismic waves are emitted and reflected signals are collected to analyze the geological structure ahead, which is used to generate a spatial distribution model of the geological body.

[0029] Furthermore, the generation of three-dimensional geological profiles can be achieved in various ways. For example, borehole data, radar reflection waveforms, and TSP signals can be input into geological modeling software, and interpolation algorithms can be used to generate continuous geological profiles. Alternatively, simplified geological profiles can be generated by manually drawing data from multiple sources, primarily for providing a visual model of geological conditions. The arrangement of anchor bolts can be tailored to the mechanical properties of the surrounding rock, using methods such as expansion bolts or mechanical bolts. Their length and spacing can be adjusted according to the specific scale of faults and fractures. Grouting holes can be arranged in a straight line or staggered pattern. The grouting material can be cement grout, chemical grout, or other materials with consolidation properties, and the grouting pressure can be dynamically adjusted according to changes in geological conditions.

[0030] Specifically, advanced small-diameter pipe grouting can be achieved by arranging pipes at regular intervals within the tunnel arch area and injecting grout, for example, using single-component or double-component grout as the grouting material. Its purpose is to form a reinforcing ring before excavation to improve the stability of the surrounding rock. Advanced pipe roof support can be achieved by arranging steel pipes at the tunnel roof and injecting mortar, for example, using high-pressure grouting technology to ensure the grout fully fills the voids around the pipe roof, thus enhancing the overall strength of the support structure. Advanced anchor bolt support can be achieved by driving anchor bolts into the surrounding rock and applying prestress, for example, using threaded steel or fiberglass reinforcement as anchor bolt materials. Its purpose is to provide immediate support during excavation.

[0031] Furthermore, the double-row grouting water-stop curtain can be implemented by arranging grouting holes on both sides of the water-rich area and injecting grout, for example, by using a segmented grouting process to ensure uniform grout diffusion. The purpose is to form a water-stop barrier before excavation to reduce the risk of water inrush. Drainage holes can be installed by drilling holes at the bottom of the tunnel and installing drainage pipes, for example, using PVC pipes with filters as drainage channels to guide groundwater out and reduce water pressure.

[0032] The innovation of this application lies in the systematic integration of multiple geological exploration methods to generate a three-dimensional geological profile, overcoming the limitations of traditional single exploration methods. Furthermore, it dynamically adjusts support design parameters based on the geological profile, avoiding insufficient reinforcement or resource waste caused by reliance on experience. In addition, the proactive implementation of a double-row grouting water-stop curtain and drainage holes achieves preventative treatment of water inrush risks, rather than reactive measures, thereby improving the safety and efficiency of the construction process.

[0033] The working principle of this application embodiment is as follows: Geological information on faults, fissures, and water-rich areas is obtained through geological drilling, ground-penetrating radar, and TSP detection. Multi-source data is then fused to generate a three-dimensional geological profile. This process utilizes the complementarity of multiple detection methods, overcoming the limitations of traditional single methods and providing a comprehensive and accurate geological model for subsequent construction decisions. Based on the mechanical parameters of the surrounding rock in the three-dimensional geological profile, anchor bolts, grouting holes, and steel mesh are arranged. The length, spacing, and grouting pressure of the anchor bolts are dynamically adjusted according to the scale of the faults and fissures, ensuring that the support design accurately matches the actual geological conditions and avoiding insufficient reinforcement or waste of resources due to empiricism. Furthermore, advanced small-diameter pipe grouting, advanced pipe roof support, or advanced anchor bolt support are selected based on the fault width and fissure density to form a support structure. This method flexibly selects the support method based on specific geological parameters, effectively addressing the challenges of geological defects of different scales and avoiding the failure risk of a single support method under complex conditions. In water-rich areas, a double-row grouting water-stop curtain and drainage holes were installed. Grouting and drainage channels were pre-embedded before excavation, enabling proactive prevention and systematic handling of water inrush risks, rather than passive response. This ensured water pressure control and structural stability during excavation. Specifically, sensors were installed to collect real-time data on the deformation rate of the surrounding rock, groundwater pressure, and strain of the support structure. Early warnings were triggered based on preset thresholds, establishing a dynamic risk monitoring mechanism that allows for timely intervention before risks accumulate, ensuring construction safety and efficiency. Thus, this technical solution, through the systematic integration of geological exploration, dynamic support design, targeted advanced support, proactive water inrush prevention, and real-time risk monitoring, comprehensively addresses the construction challenges of water inrush sections with multiple faults and fissures, solving the problem of safe and efficient construction of deep, long tunnels in complex geological conditions with water inrush zones.

[0034] In an embodiment of the present invention, the step of obtaining geological information on faults, fissures, and water-rich areas at the geological location through geological drilling, ground-penetrating radar detection, and TSP detection, and fusing multi-source data to generate a three-dimensional geological profile includes: S11, boreholes are arranged at intervals of 1.5 meters to 2 meters at the tunnel face and both sidewalls, with a drilling depth of 30 to 50 meters, to obtain rock core samples. After core sampling, the rock core fracture width, dip angle and groundwater inflow are recorded to generate borehole data. S12, using an antenna of 100MHz~900MHz, moves at a constant speed along the tunnel face, scanning the area 30m~50m ahead at a speed of 0.5m / s~1m / s, and generating a radar reflection waveform. S13, install seismic source points and receiver points on the tunnel sidewall, with a distance of 1.5 to 2 meters between seismic source points and a distance of 0.5 to 1 meter between receiver points, emit seismic waves and collect reflected signals, analyze the geological structure 100 to 200 meters ahead, and generate TSP signals; S14, input the borehole data, the radar reflection waveform and the TSP signal into the geological information database, and generate a spatial distribution map of the fault and the water-rich area through three-dimensional modeling.

[0035] Specifically, drilling refers to exploratory excavation at predetermined intervals and depths at the tunnel face and sidewalls. This can be achieved using geological drilling rigs with drill bits of different specifications. The borehole spacing is set at 1.5 to 2 meters. This range is chosen to balance coverage and resource utilization efficiency, avoiding geological blind spots due to excessive spacing or resource waste due to insufficient spacing. The borehole depth is set at 30 to 50 meters to meet the engineering needs of deep and long tunnels, ensuring the acquisition of rock core samples at sufficient depth, thereby providing a continuous and accurate data foundation for surrounding rock mechanics analysis.

[0036] In practical applications, the choice of an antenna frequency range of 100MHz to 900MHz is based on considerations of the complexity of the tunnel environment. This can be achieved using broadband antennas or multi-band antenna combinations. This frequency range can effectively penetrate different rock strata while reducing signal attenuation, thereby improving detection accuracy. Furthermore, the antenna's uniform movement speed along the tunnel face is controlled within the range of 0.5 m / s to 1 m / s. This speed range is designed to avoid waveform distortion caused by speed fluctuations, while focusing on the critical influence zone 30 to 50 meters ahead of the excavation face, significantly improving the identification accuracy of shallow fractures and water-rich areas.

[0037] The arrangement of the source and receiver points is designed to enhance the resolution and noise immunity of TSP detection, which can be achieved by optimizing the signal acquisition density. A source point spacing of 1.5 to 2 meters and a receiver point spacing of 0.5 to 1 meter can improve the accuracy of signal analysis while ensuring detection depth, thereby more accurately capturing the fault strike and scale and compensating for the limitations of radar detection depth.

[0038] Specifically, the aforementioned technical solution addresses the issues of incomplete and inaccurate geological information acquisition by systematically standardizing the specific parameters and data fusion processes for geological exploration. Firstly, by accurately controlling the spacing and depth of boreholes at the tunnel face and sidewalls, it avoids blind spots caused by excessive spacing in traditional drilling methods, while preventing resource waste due to insufficient spacing. Simultaneously, it ensures the acquisition of core samples at sufficient depth, providing a reliable data foundation for subsequent rock mechanics analysis. Secondly, by employing an antenna frequency range and uniform movement speed adapted to the tunnel environment, the accuracy of identifying shallow fractures and water-rich areas using ground-penetrating radar (PTZ) is significantly improved, overcoming the susceptibility to interference in complex geological conditions inherent in traditional radar detection. Thirdly, by optimizing the arrangement of the source and receiver points, the resolution and noise resistance of TSP detection are enhanced, enabling more accurate analysis of the geological structure 100-200 meters ahead, providing a reliable basis for long-distance geological forecasting. Finally, the borehole data, radar reflection waveforms, and TSP signals were input into the geological information database and a spatial distribution map of faults and water-rich areas was generated through 3D modeling. This process eliminated the one-sidedness of a single detection method by fusing multi-source data, integrated point details, shallow continuity, and deep structural information, and formed an intuitive spatial distribution map, providing a comprehensive and accurate geological basis for subsequent support design and water inrush prevention.

[0039] The above technical solutions not only solve the problems of fragmented, inaccurate, and severely interfered geological information acquisition, but also significantly improve the reliability of three-dimensional geological profiles, providing a scientific basis for support design and water inrush prevention in deep and long tunnel construction, thereby reducing construction safety risks.

[0040] In an embodiment of the present invention, boreholes are arranged at intervals of 1.5 meters to 2 meters at the tunnel face and both sidewalls, with a drilling depth of 30 to 50 meters to obtain core samples. After core sampling, the width and dip angle of the core fractures and the groundwater inflow are recorded to generate borehole data. Following this step, the construction method for water-rush sections of the deep and long tunnel further includes: S121, Mineral composition analysis is performed on the core fracture filling material of the surrounding rock to distinguish the filling type of clay, calcite or quartz; S122, Measure the water inrush pressure inside the borehole. If the pressure exceeds 0.3 MPa, mark it as a high-risk water inrush area; S123, input the physical and mechanical parameters of the core sample into numerical simulation software to calculate the stress distribution and potential deformation area of ​​the surrounding rock.

[0041] Specifically, core fracture filler refers to mineral materials existing in the fractures of the surrounding rock, and its composition directly affects the stability of the surrounding rock. In practical applications, X-ray diffraction analysis, scanning electron microscopy, and other techniques can be used to identify and classify mineral components, aiming to reveal the differences in behavior of different fillers under water conditions, thereby accurately assessing the stability of the surrounding rock. Water inrush pressure refers to the pressure value of groundwater within the borehole, which can be measured using pressure sensors or gauges. The purpose is to identify potential threats from high-pressure water sources in a timely manner by setting a threshold (e.g., 0.3 MPa), avoiding water inrush accidents caused by insufficient pressure assessment. Surrounding rock stress distribution refers to the changes in internal stress of the surrounding rock during excavation. Its calculation can be performed using finite element analysis software, aiming to predict the mechanical response and deformation trend during excavation, providing a scientific basis for support design.

[0042] Specifically, after generating borehole data, mineral composition analysis of the core fracture filler can distinguish between clay, calcite, and quartz filler types. This operation reveals the differences in behavior of different fillers under water conditions. For example, clay fillers tend to cause softening and instability of the surrounding rock, while calcite or quartz fillers provide stronger structural support, thus accurately determining the specific impact of water inrush on the stability of the surrounding rock. Simultaneously, by measuring the inrush water pressure within the borehole and marking areas exceeding 0.3 MPa as high-risk water inrush areas, the potential threat of high-pressure water sources can be reliably identified based on actual pressure thresholds rather than solely relying on inrush volume records. Furthermore, the physical and mechanical parameters of the core samples are input into numerical simulation software to calculate the stress distribution and potential deformation areas of the surrounding rock. Using measured parameters to simulate the mechanical response during excavation, the deformation trend of the surrounding rock is predicted, providing a scientific basis for support design and effectively preventing the risk of collapse caused by localized stress concentration. These features work together to elevate geological information from basic recording to the level of risk quantification and prediction, significantly enhancing the safety and controllability of construction in water-prone areas.

[0043] Building upon this foundation, the aforementioned scheme enhances the depth and specificity of geological risk assessment by incorporating mineral composition analysis, water inrush pressure measurement, and numerical simulation. Analysis of core fracture filling materials clarifies the impact of different filling types on surrounding rock stability; water inrush pressure measurement allows for the timely marking of high-risk water inrush areas; and numerical simulation calculates the stress distribution and potential deformation zones of the surrounding rock, providing a scientific basis for support design. These steps work together to form a systematic geological risk assessment system, enabling construction decisions to be based on more comprehensive geological information, thereby significantly reducing the risk of water inrush and localized collapse.

[0044] In an embodiment of the present invention, the steps of arranging anchor bolts, grouting holes, and reinforcing mesh based on the mechanical parameters of the surrounding rock in the three-dimensional geological profile include: S21, in the fault fracture zone at the geological location, anchor bolts with a length of 3 to 5 meters and a spacing of 0.8 to 1 meter are used, with an external insertion angle of 10° to 15° and an anchoring grouting pressure of 0.5 MPa to 1 MPa; S22, in the fractured area of ​​the geological site, grouting holes are arranged in a quincunx pattern, with a hole depth of 2 to 5 meters. The grouting material is cement grout or chemical grout, and the grouting pressure is 1 MPa to 3 MPa, until the grouting volume drops to 10% to 20% of the initial volume. S23 uses steel bars with a diameter of 6mm to 8mm welded into a 150mm*150mm grid, which is then welded and fixed to the end of the anchor rod before spraying C20 or C25 concrete with a spray thickness of 15cm to 25cm.

[0045] Specifically, an anchor bolt is a rod-shaped component used to reinforce surrounding rock. It can be made of threaded steel or fiberglass reinforced plastic, and its purpose is to enhance the integrity of the surrounding rock by transmitting stress through deep penetration into stable rock strata. The anchor bolt's external insertion angle refers to the angle between the anchor bolt's axis and the horizontal plane, which can be optimized and adjusted according to the stress direction of the surrounding rock to reduce the accumulation of deformation caused by excavation. In practical applications, a grouting hole is a drilled hole used to inject grout into the surrounding rock. It can be formed by mechanical drilling or hydraulic drilling to effectively fill the fissures with grout. The cement grout in the grouting material can be ordinary silicate cement grout, while the chemical grout can be epoxy resin or polyurethane-based materials, with the selection based on an adaptive decision made according to the fissure width and water inflow conditions.

[0046] In detail, the above scheme, by specifying the parameters and layout of the surrounding rock reinforcement process, makes dynamic adjustments based on three-dimensional geological profiles feasible, thereby solving the problem of unstable reinforcement effects. In fault fracture zones, the anchor bolt length range is set based on fault scale and surrounding rock strength data to ensure that it can penetrate deep into stable rock strata to transfer stress, avoiding insufficient reinforcement due to excessive length or increased construction difficulty due to excessive length; the dense arrangement of anchor bolt spacing is dynamically adjusted according to fracture density to form a uniform support network and prevent local loosening and collapse of the surrounding rock; the design of the outer corner is combined with the stress direction of the surrounding rock to optimize the stress path and reduce the accumulation of deformation caused by excavation; the anchor grouting pressure is controlled according to groundwater pressure and rock permeability to ensure that the grout fully fills the anchoring area while avoiding high pressure damage to the surrounding rock structure. In fractured areas, grouting holes are arranged in a quincunx pattern to achieve comprehensive coverage based on fracture orientation and density data, eliminating reinforcement blind spots. Hole depth is dynamically determined based on fracture depth information to ensure effective grout penetration into deep fractures. Grouting pressure is set in conjunction with surrounding rock strength and fracture connectivity to provide sufficient driving force for grout diffusion. Grouting volume is reduced to 10%–20% of the initial volume as a termination condition, with real-time monitoring data used to assess filling adequacy, avoiding material waste while ensuring complete fracture closure. For the reinforcing mesh system, its dimensions are determined based on surrounding rock deformation prediction data, providing appropriate stiffness to accommodate micro-deformation. It is welded to the ends of anchor bolts to enhance connection strength, forming a synergistic load-bearing system. The shotcrete strength grade is dynamically selected based on surrounding rock load to ensure stable surface bearing capacity. The shotcrete thickness, combined with deformation rate monitoring data, forms an effective protective layer, preventing spalling of the excavation face and transferring loads to deeper support structures.

[0047] Based on this, the above-mentioned scheme achieves precise analysis and dynamic adjustment of the surrounding rock mechanical properties by taking targeted reinforcement measures for fault fracture zones and fissure areas, significantly improving the stability of the reinforcement effect. By combining the surrounding rock mechanical parameters in the three-dimensional geological profile, this scheme can effectively cope with complex working conditions under multiple faults and fissures, thereby reducing the risk of water inrush and ensuring construction safety.

[0048] In an embodiment of the present invention, grouting holes are arranged in a quincunx pattern in the fracture area of ​​the geological site, with a hole depth of 2 to 5 meters. The grouting material is cement grout or chemical grout, and the grouting pressure is 1 MPa to 3 MPa. The step of grouting until the grouting volume decreases to 10% to 20% of the initial volume includes: S221, For cracks wider than 5mm, inject quick-setting chemical grout first, with a setting time ≤30 seconds; S222 After grouting is completed, the filling rate of the quick-setting chemical grout is detected by ground penetrating radar. If the filling rate is <90%, the quick-setting chemical grout is used to perform secondary grouting on the grouting hole. S223, Drill core samples to verify the grouting area corresponding to the grouting hole. A core sample with a compressive strength ≥15MPa is considered qualified.

[0049] Specifically, rapid-setting chemical grout refers to chemical materials that can quickly solidify and form a stable structure within a short time. It can be achieved using polyurethane, epoxy resin, or other chemical grouts with rapid reaction characteristics. Its purpose is to quickly seal water flow channels in wide fissures and prevent water inrush events. Ground-penetrating radar (GPR) is a detection device based on the principle of electromagnetic wave reflection. It can emit high-frequency electromagnetic waves and receive reflected signals to obtain real-time data on the grouting filling status, aiming to accurately assess the actual filling effect after grouting. Core drilling verification involves drilling core samples from the grouting area and conducting physical and mechanical tests. This can be achieved using hydraulic drilling rigs or diamond drill bits, aiming to objectively verify the actual bearing capacity of the reinforced surrounding rock and ensure that the strength standards required for safe construction are met.

[0050] In detail, based on the quincunx arrangement of grouting holes in the fracture area, rapid-setting chemical grout is first injected into fractures wider than 5mm. Since wide fractures are prone to rapid groundwater inflow, the short setting time of the rapid-setting chemical grout can quickly form an effective barrier, thus avoiding the risk of water inrush. After grouting, the grout filling rate is monitored in real time using ground-penetrating radar. If insufficient filling is detected, secondary grouting is performed using rapid-setting chemical grout. This process effectively compensates for weak areas caused by insufficient initial grouting, ensuring that the grout fully fills the fracture cavities. Subsequently, core sampling is performed on the grouting area for verification. The compressive strength test results of the core samples determine whether the grouting quality meets the standards, thus forming a closed-loop quality control system. Overall, this scheme organically combines the priority treatment of wide fissures, real-time filling rate monitoring and secondary grouting mechanism, and strength verification, which significantly improves the reliability and adaptability of the grouting process. At the same time, combined with the aforementioned grouting hole arrangement method in the fissure area, it further enhances the overall effect of surrounding rock reinforcement and solves the technical problems of insufficient treatment of wide fissures, difficulty in monitoring the filling rate, and lack of strength verification mechanism.

[0051] In embodiments of the present invention, the steps of selecting advanced small-diameter grouting, advanced pipe roof support, or advanced anchor bolt support based on the fault width and fracture density to form a support structure include: S31, when the fault width is less than 50 mm and the fracture density is less than 3 fractures / meter, the advanced small guide pipe is used for grouting; wherein, the diameter of the advanced small guide pipe is 42 mm to 50 mm, the length is 3 to 5 meters, the external insertion angle is 10° to 15°, and the grouting pressure is 0.5 MPa to 1.5 MPa; S32, when the fault width is ≥50mm or the fracture density is ≥3 fractures / meter, the advanced pipe roof support is adopted; wherein, the diameter of the advanced pipe roof is 89mm~108mm, the spacing is 300mm~500mm, and 2MPa~4MPa high-pressure cement mortar is injected after construction. S33, for the area where the arch deformation rate of the deep and long tunnel is >2mm / h, the advanced anchor bolt support is added; wherein, the length of the advanced anchor bolt support is 3 meters to 4 meters, the external insertion angle is 15° to 20°, and the anchoring grouting pressure is 0.8MPa to 1.2MPa.

[0052] Specifically, advanced small guide pipes refer to slender metal pipes used for shallow rock reinforcement. They can be made of steel pipes or high-strength composite materials, and their purpose is to stabilize the surrounding rock by grouting through micro-fractures. Advanced pipe roofs are larger-scale support structures that can be constructed using multi-segment spliced ​​steel pipes or integrally formed steel pipes, aiming to provide higher compressive strength to cope with complex geological conditions. Advanced anchor bolts are components used for deep rock reinforcement, made of threaded steel or glass fiber reinforced plastic, and their purpose is to disperse crown stress and enhance local stability.

[0053] In detail, this technical solution achieves precise adaptation of support methods by quantifying geological parameter thresholds and dynamic monitoring data. When the fault width is less than 50 mm and the fracture density is less than 3 fractures per meter, advanced small-diameter pipe grouting is selected. This setting is based on the accurate identification of minor geological defects, ensuring that an economical and efficient support method is used in relatively stable surrounding rock areas. The diameter range of the pipes balances construction convenience and structural bearing capacity, the length design covers the shallow area in front of typical excavation faces, the optimized insertion angle allows the pipes to effectively extend beyond the excavation outline, and the grouting pressure setting ensures that the grout fully penetrates without damaging the integrity of the surrounding rock. When the fault width reaches or exceeds 50 mm or the fracture density reaches or exceeds 3 fractures per meter, the system switches to advanced pipe roof support. This condition is designed for complex geological features, providing higher compressive strength through larger-sized pipe roofs, controlling the spacing to ensure the continuity of the support structure, and injecting high-pressure cement mortar to enhance the overall stability of the fractured zone. For areas where the arch deformation rate exceeds 2 mm per hour, advanced anchor bolt support is added. This mechanism dynamically responds to local risks based on real-time deformation data. The anchor bolt length adapts to the depth requirements of the rapidly deforming area, the outward angle adjustment enhances stress dispersion, and precise control of grouting pressure ensures reliable bonding between the anchor bolt and the surrounding rock. Overall, the specific ranges of these parameters are derived from quantitative analysis of geological conditions, shifting support selection from experience-based to data-driven, significantly improving the safety and adaptability of construction in complex water-rush areas.

[0054] In an embodiment of the present invention, when the fault width is <50mm and the fracture density is <3 fractures / meter, the step of grouting using the advanced small guide pipe includes: S311, the advanced small guide pipes are arranged at 30° intervals within a 120° range of the arch of the deep and long tunnel, and the spacing between the advanced small guide pipes is 0.5 meters to 0.8 meters; S312, the advanced small guide pipe is driven into the surrounding rock using a pneumatic drill, and the pointed tip of the advanced small guide pipe extends 1 meter to 1.5 meters beyond the excavation outline of the deep and long tunnel; S313, a two-component grout consisting of cement and water glass; wherein the water-cement ratio of the two-component grout is 0.8:1 to 1.2:1, the amount of water glass is 3% to 5%, and a reinforcing ring with a thickness of ≥200mm is formed after grouting.

[0055] Specifically, advanced small guide pipes refer to slender steel pipes used for advanced support in tunnel construction, which can be made of seamless or welded steel pipes. In practical applications, the arrangement of advanced small guide pipes needs to be adjusted according to geological conditions. The purpose is to ensure uniform coverage and continuity of the support structure and avoid rock instability caused by local weak points.

[0056] Among them, a pneumatic drill is an impact drilling device driven by compressed air, which can be a handheld pneumatic drill or a frame-mounted pneumatic drill. Using a pneumatic drill to drive a pre-excavated guide pipe into the surrounding rock can ensure construction efficiency, while ensuring that the pointed tip of the pre-excavated guide pipe effectively extends beyond the excavation outline, thereby stabilizing the surrounding rock in advance.

[0057] In practical applications, two-component grout refers to a grout composed of two different components, which can be achieved by combining cement grout and water glass grout. Accurate control of the water-cement ratio and water glass content in two-component grout aims to ensure a balance between grout fluidity and setting time, rapidly forming a high-strength sealing layer and effectively blocking groundwater channels.

[0058] Specifically, pre-cast small guide pipes are arranged at 30° intervals within a 120° range of the tunnel arch. This arrangement, tailored to small-scale faults and low fracture density, ensures uniform coverage and continuity of the support structure, preventing rock instability caused by localized weak points. The spacing of the pre-cast small guide pipes is set at 0.5 to 0.8 meters. This parameter selection is based on the analysis of the mechanical properties of the surrounding rock, optimizing material usage while ensuring support effectiveness.

[0059] Based on this, a pre-drilled guide pipe is driven into the surrounding rock using a pneumatic drill. The pointed tip of the guide pipe extends 1 to 1.5 meters beyond the excavation outline of the deep and long tunnel. The key to this step is to stabilize the surrounding rock in advance to prevent water inrush caused by loosening of the surrounding rock during excavation. In this way, an effective reinforced area can be formed before excavation, significantly reducing construction risks.

[0060] Furthermore, a two-component grout consisting of cement and water glass is injected, with a water-cement ratio of 0.8:1 to 1.2:1 and a water glass content of 3% to 5%. After grouting, a reinforcement ring with a thickness of ≥200mm is formed. This grout mix ratio and parameters ensure a balance between grout fluidity and setting time, rapidly forming a high-strength sealing layer that effectively blocks groundwater channels and prevents the risk of water inrush. This technical solution solves the problem of unstable support performance under geological conditions with narrow fault width and low fracture density, establishing a scientific and systematic construction method that ensures construction safety and progress.

[0061] In an embodiment of the present invention, the steps of setting up a double-row grouting water-stop curtain and drainage holes in the water-rich area, and completing the grouting filling and drainage channel pre-embedding before excavation include: S41, double rows of grouting holes are arranged on both sides of the water-rich fault in the water-rich area, with a hole spacing of 0.8 m to 1.2 m, a grouting pressure of 2 MPa to 5 MPa, and a grout diffusion radius of ≥1.5 m; S42, Drill drainage holes with a diameter of 50mm to 100mm at the bottom of the deep tunnel, with a depth of 5m to 10m, install PVC pipes with filters inside the holes, and connect adjustable flow valves to the outlet of the drainage pipes. S43, Pre-install quick-setting grouting material at the water inrush point; wherein, the quick-setting grouting material includes polyurethane sealing agent and sulfoaluminate cement, with a response time ≤ 5 minutes.

[0062] Specifically, double-row grouting holes refer to two rows of grouting holes symmetrically arranged on both sides of a water-rich fault. The hole spacing is strictly controlled within the range of 0.8 meters to 1.2 meters, which can be achieved in practical applications through accurate measurement and positioning equipment. The purpose is to ensure that the grout diffuses seamlessly, forming a continuous curtain and avoiding blind spots due to excessive hole spacing. The grouting pressure can be dynamically adjusted by the grouting pump, with a set range of 2MPa to 5MPa. The specific pressure can be optimized according to the geological strength of the water-rich area to prevent insufficient filling of fractures due to low pressure or ground disturbance due to excessive pressure. The grout diffusion radius refers to the effective diffusion range of the grout in the formation, which is required to be no less than 1.5 meters. This is to ensure that the curtain thickness is sufficient to resist groundwater seepage pressure, thereby constructing a stable water-stopping barrier.

[0063] The drainage holes, drilled at the bottom of deep tunnels, are for drainage. Their diameter ranges from 50mm to 100mm, and the appropriate diameter can be selected based on the surrounding rock conditions using drilling equipment. The hole depth is set at 5 to 10 meters to ensure penetration of potential water-rich layers and effectively reduce deep water pressure. The PVC pipe with a filter screen is a pipe structure installed inside the drainage holes. The filter screen prevents sediment from entering and clogging the channel. Different sizes of filter screens can be selected to accommodate varying sediment content. The adjustable flow valve is a device connected to the drainage pipe outlet. It dynamically adjusts the drainage rate based on real-time water pressure, preventing rock instability due to excessively rapid drainage or water accumulation due to excessively slow drainage, thus maintaining the long-term stable operation of the drainage system.

[0064] In practical applications, quick-setting grouting materials refer to grouting materials that can cure rapidly in a short time, including combinations of polyurethane sealants and sulfoaluminate cement. The polyurethane sealant expands quickly to seal water flow channels, while the sulfoaluminate cement provides subsequent strength support. Response time refers to the time interval from the occurrence of a water inrush to the complete sealing by the grouting material, which should not exceed 5 minutes. In practical applications, this goal can be achieved by optimizing material ratios and construction techniques, with the aim of significantly improving emergency response efficiency.

[0065] Specifically, when arranging double rows of grouting holes on both sides of a water-rich fault in a water-rich area, symmetrical arrangement and precise control of hole spacing ensure that the grout diffuses to form a continuous curtain, effectively preventing groundwater infiltration. Dynamic adjustment of grouting pressure, combined with the requirements of grout diffusion radius, ensures the water-stopping curtain has sufficient thickness and strength to cope with complex geological conditions. When drilling drainage holes at the bottom of deep and long tunnels, reasonable selection of hole diameter and depth balances drainage efficiency and surrounding rock stability. The design of PVC pipes with filters and adjustable flow valves further enhances the reliability of the drainage system. Pre-installing quick-setting grouting material at the water inrush point enables immediate response to water inrush events. Through the synergistic effect of polyurethane sealing agent and sulfoaluminate cement, the water flow channel is quickly sealed and long-term strength support is provided, effectively controlling the risk of water inrush.

[0066] Based on the above technical solutions, the core problems of insufficient cutoff wall integrity, poor drainage system reliability, and slow emergency response to water inrush were systematically solved by refining the layout parameters of the double-row grouting cutoff wall, optimizing the drainage hole structure, and pre-setting quick-setting grouting materials. This proactive water inrush prevention barrier, constructed before excavation, not only significantly improved construction safety but also provided reliable technical support for deep and long tunnel construction under complex geological conditions.

[0067] In an embodiment of the present invention, the steps of arranging double rows of grouting holes on both sides of the water-rich fault in the water-rich region, with a hole spacing of 0.8 m to 1.2 m, a grouting pressure of 2 MPa to 5 MPa, and a grout diffusion radius ≥ 1.5 m include: S411, the first row of grouting holes is 0.5 meters away from the excavation outline of the deep and long tunnel, and the second row is 0.8 meters away from the first row, arranged in a staggered quincunx pattern; S412 adopts a segmented grouting process, with each segment having a length of 1 to 1.5 meters, and grout stop plugs installed between segments; S413, After grouting is completed, the permeability coefficient of the double-row grouting water-stop curtain is verified by drilling. If the permeability coefficient is > 1*10 ~6 cm / s, continue grouting until the target is met.

[0068] Specifically, the first row of grouting holes refers to the row of grouting holes close to the excavation outline of a deep and long tunnel. Their position is determined based on the stress distribution characteristics of the surrounding rock, aiming to ensure timely reinforcement of the surrounding rock near the excavation face and prevent local instability caused by excavation disturbance. In practical applications, the position of the first row of grouting holes can be fine-tuned according to specific geological conditions. For example, in cases where the surrounding rock is relatively fractured, the distance from the excavation outline can be appropriately shortened to enhance the reinforcement effect. The second row of grouting holes is arranged in a staggered, quincunx pattern with the first row. This layout is designed based on the spatial distribution of fractures, aiming to ensure that the grouting areas overlap, eliminating potential blind spots that may exist in traditional uniform arrangements, and forming a continuous and dense water-stopping barrier. The staggered, quincunx arrangement can be understood as an optimized spatial layout, aimed at improving grouting efficiency and coverage.

[0069] Furthermore, segmented grouting refers to a technique that breaks down the grouting process into several controllable units. Its core lies in controlling the length of each grouting segment and using inter-segment stop plugs. In practical applications, the segmented grouting length can be adjusted according to the degree of fracture development and the dynamic changes in grouting pressure. For example, in areas with denser fractures, the length of each grouting segment can be appropriately shortened to prevent grout from flowing long distances along the fractures. The stop plugs maintain stable grouting pressure, ensuring that the grout fully diffuses and fills the target area. This method effectively avoids uneven grout diffusion, thereby improving grouting quality.

[0070] In detail, the above technical solution has a clear execution sequence and triggering conditions for each key step. First, the arrangement of the first and second rows of grouting holes is based on the stress distribution characteristics and fracture spatial distribution patterns of the surrounding rock. This layout not only considers the stability of the surrounding rock near the excavation face but also achieves full coverage of the grouting area through a staggered, quincunx arrangement, fundamentally solving the problem of grouting blind spots. Second, the introduction of segmented grouting technology makes the grouting process more refined. By controlling the length of each grouting segment and setting grout stoppers, it is possible to effectively prevent grout from flowing away along fractures over long distances while maintaining the stability of the grouting pressure, ensuring that the grout fully diffuses and fills the target area. Finally, after grouting, the permeability coefficient is verified by drilling, and a threshold standard of 1*10~6 cm / s is set. This step forms a closed-loop quality control mechanism, which can quantitatively evaluate the water-stopping effect according to the actual geological conditions. If the standard is not met, supplementary grouting is implemented, fundamentally ensuring the seepage prevention performance of the water-stop curtain.

[0071] Building upon this foundation, the aforementioned technical solutions, working in conjunction with the preceding content, further enhance the safety and reliability of construction. For example, by optimizing the specific spatial layout of the grouting holes, combined with segmented grouting technology and a permeability coefficient verification mechanism, the problems of uneven grout diffusion, blind spots in grout coverage, and the inability to quantify and confirm the water-stopping effect can be effectively solved. This not only improves the reliability of the water-stop curtain but also significantly reduces the probability of water inrush hazards, thus providing a scientific and systematic solution for the construction of deep, long tunnels in multi-fault, multi-fissure water-rush sections.

[0072] In an embodiment of the present invention, the step of collecting real-time data on the deformation rate of the surrounding rock, groundwater pressure, and strain of the support structure by embedding sensors, and triggering an early warning based on a preset threshold, includes: S51, displacement gauges are installed at intervals of 2 to 3 meters and pore water pressure gauges are installed at intervals of 5 to 8 meters in the surrounding rock, and strain gauges are arranged at the nodes of the support structure. S52 collects data from the displacement gauge, the hydraulic gauge, and the strain gauge every 10 minutes and transmits the data wirelessly to the monitoring center; S53, a Level I warning is triggered when the surrounding rock deformation rate is greater than 2 mm / h, the water pressure gradient is greater than 0.1 MPa / m, or the support strain is greater than 80% of the yield strength; S54, when the first-level warning is triggered, the excavation is suspended and the support parameter adjustment is initiated; wherein, the support parameter adjustment includes increasing the grouting pressure by 10% to 20% or shortening the excavation advance to less than 0.5 meters.

[0073] Specifically, a displacement gauge is a sensing device used to monitor local deformation of surrounding rock. It can be implemented using a vibrating wire displacement gauge or a fiber optic displacement gauge, with the aim of accurately capturing minute deformation signals of the surrounding rock. A pore water pressure gauge is a device used to measure changes in groundwater pressure. It can be implemented using a piezoresistive or capacitive pore water pressure gauge, with the aim of promptly detecting abnormal fluctuations in water pressure. A strain gauge is an element attached to the surface of a support structure to monitor its stress state. It can be implemented using a resistance strain gauge or a semiconductor strain gauge, with the aim of assessing whether the bearing capacity of the support structure is approaching its limit.

[0074] In detail, the above technical solution achieves dynamic closed-loop control of tunnel construction risks by constructing a multi-layered monitoring network. First, displacement gauges and pore water pressure gauges are arranged at specific intervals within the surrounding rock. This layout, based on the deformation patterns of the surrounding rock and the distribution characteristics of groundwater pressure, ensures that monitoring points cover potential risk areas to avoid blind spots, while also avoiding excessive density that would waste resources. Second, the high-frequency data acquisition cycle combined with wireless transmission technology overcomes the data delay defects of traditional manual monitoring, enabling the monitoring center to continuously acquire dynamic information from the site. Third, scientifically set early warning thresholds accurately identify the critical state of surrounding rock instability, avoiding the subjectivity of experience-based judgments. Finally, when an early warning is triggered, the grouting pressure is dynamically adjusted to enhance the surrounding rock reinforcement effect, or the excavation advance is reduced to decrease surrounding rock disturbance, effectively curbing the trend of risk escalation.

[0075] Based on this, the proposed scheme is organically linked with the aforementioned methods for constructing deep and long tunnels in areas prone to water inrush, including steps such as geological information acquisition, surrounding rock reinforcement, and advanced support. Real-time monitoring of surrounding rock deformation and water pressure changes allows for timely verification of the effectiveness of early support measures and provides a basis for adjusting subsequent construction parameters, thereby ensuring the safety and continuity of construction.

[0076] The above description is merely an exemplary embodiment of the present invention and does not limit the scope of protection 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 scope of protection of the present invention.

Claims

1. A construction method for a deep and long tunnel in a water inrush section, characterized in that, The water inrush section is located in a geological area with multiple faults and fissures. The construction method for the water inrush section of the deep and long tunnel includes: Geological information on faults, fissures and water-rich areas at the geological site was obtained through geological drilling, ground-penetrating radar and TSP detection, and multi-source data were fused to generate a three-dimensional geological profile. Based on the mechanical parameters of the surrounding rock in the three-dimensional geological profile, anchor bolts, grouting holes, and steel mesh are arranged; wherein, the length, spacing, and grouting pressure of the anchor bolts are dynamically adjusted according to the scale of the fault and fracture. Based on the fault width and fracture density, select advanced small pipe grouting, advanced pipe roof support or advanced anchor bolt support to form a support structure; Double-row grouting water-stop curtain and drainage holes are set in the water-rich area, and grouting filling and drainage channel pre-embedding are completed before excavation; By embedding sensors, the deformation rate of the surrounding rock, groundwater pressure, and strain data of the support structure are collected in real time, and an early warning is triggered according to a preset threshold.

2. The construction method for deep and long tunnels in water-rush sections as described in claim 1, characterized in that, The steps of obtaining geological information on faults, fissures, and water-rich areas at the geological location through geological drilling, ground-penetrating radar, and TSP detection, and then fusing multi-source data to generate a three-dimensional geological profile, include: Drill holes are arranged at intervals of 1.5 to 2 meters at the tunnel face and both sidewalls, with a drilling depth of 30 to 50 meters, to obtain rock core samples. After core sampling, the rock core fracture width, dip angle and groundwater inflow are recorded to generate borehole data. An antenna with a frequency of 100MHz to 900MHz is moved at a constant speed along the tunnel face to scan an area of ​​30 to 50 meters ahead at a speed of 0.5 m / s to 1 m / s, generating a radar reflection waveform. Seismic source points and receiver points are installed on the tunnel sidewalls, with a distance of 1.5 to 2 meters between the seismic source points and a distance of 0.5 to 1 meter between the receiver points. Seismic waves are emitted and reflected signals are collected. The geological structure 100 to 200 meters ahead is analyzed to generate TSP signals. The borehole data, radar reflection waveform, and TSP signal are input into a geological information database, and a spatial distribution map of the fault and the water-rich area is generated through three-dimensional modeling.

3. The construction method for deep and long tunnels in water-rush sections as described in claim 2, characterized in that, After drilling holes at intervals of 1.5 to 2 meters at the tunnel face and both sidewalls, with a drilling depth of 30 to 50 meters, to obtain core samples, and recording the core fracture width, dip angle, and groundwater inflow to generate borehole data, the construction method for water inrush sections of the deep and long tunnel further includes: Mineral composition analysis was performed on the core fracture filling material of the surrounding rock to distinguish the filling types of clay, calcite, or quartz. Measure the water pressure inside the borehole; if the pressure exceeds 0.3 MPa, mark it as a high-risk water inrush area. The physical and mechanical parameters of the core sample are input into numerical simulation software to calculate the stress distribution and potential deformation zone of the surrounding rock.

4. The construction method for water inrush sections of deep and long tunnels as described in claim 1, characterized in that, Based on the mechanical parameters of the surrounding rock in the three-dimensional geological profile, the steps for arranging anchor bolts, grouting holes, and reinforcing mesh include: In the fault fracture zone of the geological location, anchor bolts with a length of 3 to 5 meters and a spacing of 0.8 to 1 meter are used, with an external insertion angle of 10° to 15° and an anchoring grouting pressure of 0.5 MPa to 1 MPa. In the fractured area of ​​the geological site, grouting holes are arranged in a quincunx pattern, with a hole depth of 2 to 5 meters. The grouting material is cement grout or chemical grout, and the grouting pressure is 1 to 3 MPa until the grouting volume drops to 10% to 20% of the initial volume. Use steel bars with a diameter of 6mm to 8mm to weld into a 150mm*150mm grid, weld and fix it to the end of the anchor rod, and then spray C20 or C25 concrete with a spray thickness of 15cm to 25cm.

5. The construction method for water inrush sections of deep and long tunnels as described in claim 4, characterized in that, In the fractured area of ​​the geological site, grouting holes are arranged in a quincunx pattern, with a hole depth of 2 to 5 meters. The grouting material is cement grout or chemical grout, and the grouting pressure is 1 MPa to 3 MPa. The steps include: For cracks wider than 5 mm, inject quick-setting chemical grout first, with a setting time ≤ 30 seconds; After grouting is completed, ground-penetrating radar is used to detect the grout filling rate of the quick-setting chemical grout. If the filling rate is <90%, the quick-setting chemical grout is used to perform secondary grouting on the grouting hole. Core sampling was performed on the grouting area corresponding to the grouting hole. A core sample with a compressive strength ≥15MPa was considered qualified.

6. The construction method for water inrush sections of deep and long tunnels as described in claim 1, characterized in that, Based on the fault width and fracture density, the steps for selecting advanced small-diameter grouting, advanced pipe roof support, or advanced anchor bolt support to form a support structure include: When the fault width is less than 50 mm and the fracture density is less than 3 fractures / meter, the advanced small guide pipe is used for grouting; wherein, the diameter of the advanced small guide pipe is 42 mm to 50 mm, the length is 3 m to 5 m, the external insertion angle is 10° to 15°, and the grouting pressure is 0.5 MPa to 1.5 MPa; When the fault width is ≥50mm or the fracture density is ≥3 fractures / meter, the advanced pipe roof support is adopted; wherein, the diameter of the advanced pipe roof is 89mm~108mm, the spacing is 300mm~500mm, and 2MPa~4MPa high-pressure cement mortar is injected after construction. For areas where the arch deformation rate of the deep and long tunnel is greater than 2 mm / h, the advanced anchor bolt support is added; wherein, the length of the advanced anchor bolt support is 3 to 4 meters, the external insertion angle is 15° to 20°, and the anchoring grouting pressure is 0.8 MPa to 1.2 MPa.

7. The construction method for deep and long tunnels in water-rush sections as described in claim 6, characterized in that, When the fault width is less than 50 mm and the fracture density is less than 3 fractures / meter, the steps for grouting using the advanced small-diameter guide pipe include: The advanced small guide pipes are arranged at 30° intervals within a 120° range of the arch of the deep and long tunnel, with the spacing between the advanced small guide pipes being 0.5 meters to 0.8 meters; The advanced small guide pipe is driven into the surrounding rock using a pneumatic drill, with the pointed tip of the advanced small guide pipe extending 1 to 1.5 meters beyond the excavation outline of the deep and long tunnel. A two-component grout consisting of cement and water glass is injected; wherein the water-cement ratio of the two-component grout is 0.8:1 to 1.2:1, and the amount of water glass is 3% to 5%, forming a reinforcing ring with a thickness of ≥200mm after grouting.

8. The construction method for deep and long tunnels in water-rush sections as described in claim 1, characterized in that, The steps of setting up a double-row grouting water-stop curtain and drainage holes in the water-rich area, and completing grouting filling and pre-embedding of drainage channels before excavation include: Double rows of grouting holes are arranged on both sides of the water-rich fault in the water-rich area, with a hole spacing of 0.8 m to 1.2 m, a grouting pressure of 2 MPa to 5 MPa, and a grout diffusion radius of ≥1.5 m. Drainage holes with a diameter of 50mm to 100mm are drilled at the bottom of the deep tunnel, with a depth of 5 meters to 10 meters. PVC pipes with filter screens are installed inside the holes, and an adjustable flow valve is connected to the outlet of the drainage pipe. Pre-place quick-setting grouting material at the water inrush point; wherein, the quick-setting grouting material includes polyurethane sealing agent and sulfoaluminate cement, with a response time ≤ 5 minutes.

9. The construction method for water inrush sections of deep and long tunnels as described in claim 8, characterized in that, The steps of arranging double rows of grouting holes on both sides of the water-rich fault in the water-rich area, with a hole spacing of 0.8 meters to 1.2 meters, a grouting pressure of 2 MPa to 5 MPa, and a grout diffusion radius ≥ 1.5 meters, include: The first row of grouting holes is 0.5 meters away from the excavation outline of the deep and long tunnel, and the second row is 0.8 meters away from the first row, arranged in a staggered quincunx pattern; A segmented grouting process is adopted, with each segment having a length of 1 to 1.5 meters, and grout stop plugs are installed between segments; After grouting is completed, the permeability coefficient of the double-row grouting water-stop curtain is verified by drilling. If the permeability coefficient is >1*10 ~6 cm / s, continue grouting until the target is met.

10. The construction method for water inrush sections of deep and long tunnels as described in any one of claims 1 to 9, characterized in that, The steps of collecting real-time data on the deformation rate of the surrounding rock, groundwater pressure, and strain of the support structure by embedding sensors, and triggering an early warning based on a preset threshold, include: Displacement gauges are installed at intervals of 2 to 3 meters and pore water pressure gauges at intervals of 5 to 8 meters within the surrounding rock, and strain gauges are arranged at the nodes of the support structure. Data from the displacement gauge, the hydraulic gauge, and the strain gauge are collected every 10 minutes and transmitted wirelessly to the monitoring center. A Level I warning is triggered when the surrounding rock deformation rate is greater than 2 mm / h, the water pressure gradient is greater than 0.1 MPa / m, or the support strain is greater than 80% of the yield strength. When the first-level warning is triggered, excavation is suspended and support parameter adjustment is initiated; wherein, the support parameter adjustment includes increasing the grouting pressure by 10% to 20% or shortening the excavation advance to less than 0.5 meters.

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