Anti-collapse comprehensive treatment construction process for tunnel crossing karst development area

Abstract

The invention relates to the technical field of tunnel engineering, in particular to an anti-collapse comprehensive treatment construction process for a tunnel to pass through a karst development area, which comprises the following steps: S1, early-stage exploration and planning: understanding a geological structure, karst development condition and underground water distribution along the tunnel in detail through drilling exploration, geological radar and seismic wave exploration; according to the anti-collapse comprehensive treatment construction process for the tunnel crossing the karst development area, the construction strategy is adjusted according to the actual geological condition, geological risks are treated more accurately, the construction progress is accelerated by adopting modern technologies and equipment such as geological radars, accidental interruption is reduced, comprehensive treatment measures are accurately controlled, and the construction efficiency is improved. The safety of the construction process is greatly improved, the influence on the surrounding environment is reduced, pollution is reduced by using environment-friendly materials and technologies, meanwhile, novel supporting materials and design are adopted in the construction technology, the novel supporting materials comprise a reinforcing mesh, anchor rods and sprayed concrete, immediate and lasting supporting is provided, and rock mass loosening and collapse are prevented.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel engineering, and in particular to a comprehensive collapse prevention and treatment construction process for a tunnel passing through a karst development area. Background Art

[0002] Karst development areas refer to areas where caves, cracks and a large number of discontinuities are widely formed in soluble rocks such as limestone and gypsum due to strong groundwater dissolution. The rock mass structure in these areas is complex, the hydrogeological conditions vary greatly, and groundwater surges and ground collapses are prone to occur. Tunnels passing through karst development areas are mainly necessary for the construction of infrastructure such as tunnels, subways, and water conservancy projects, which must pass through these geologically complex areas. Due to the special geological conditions in karst areas, the construction is difficult and the technical requirements are high, which poses higher challenges to tunnel design and construction.

[0003] Generally, the difficulty in preventing collapse lies in the difficulty of geological prediction. The geological conditions in karst development areas are discontinuous and changeable, which makes geological prediction inaccurate. The development of fissures makes it easy for groundwater and mud to break into tunnels, increasing construction risks. Due to the existence of caves and large cavities, the supporting capacity of the rocks around the tunnel is weak and prone to collapse. Traditional measures are often implemented in a fixed mode and are difficult to adapt to the rapid changes in geological conditions. Grouting and other measures consume a lot of materials and are costly. At the same time, traditional tunnel construction and prevention and control measures are difficult to combine and link, resulting in a single comprehensive anti-collapse treatment measure for construction. Only a large amount of grouting construction will have a negative impact on the surrounding hydrogeological environment. At the same time, traditional construction efficiency is limited by technology and equipment. Especially under complex geological conditions, it is impossible to effectively implement long-term anti-collapse measures and it is difficult to improve construction efficiency.

[0004] In summary, it is necessary to propose a comprehensive anti-collapse treatment construction technology for tunnels passing through karst development areas to solve the above problems. Summary of the invention

[0005] The object of the present invention is to provide a comprehensive anti-collapse treatment construction process for tunnels passing through karst development areas, so as to solve the problems raised in the above-mentioned background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A comprehensive anti-collapse treatment construction process for a tunnel passing through a karst development area comprises the following steps:

[0008] S1. Preliminary investigation and planning: Through drilling exploration, geological radar, and seismic wave survey, the geological structure, karst development, and groundwater distribution along the tunnel are understood in detail. The drilling depth is designed to be 1.5-2 times the tunnel depth according to the tunnel depth. The stability of the karst area and possible collapse risks are analyzed through geological modeling and stability analysis;

[0009] S2. Preparation before tunnel excavation: Combined with the geological survey results, numerical simulation analysis is used to formulate a construction plan, covering the excavation sequence, support plan, configuration of excavation equipment and support materials;

[0010] S3. Tunnel excavation and initial support: Use short-step method or full-section method for segmented excavation, control the length and range of each excavation, reduce the risk of collapse, single excavation length is 1-2 meters, sprayed concrete, anchor support, steel arch support, support immediately after each excavation to prevent collapse, sprayed concrete thickness is 10-15cm, anchor length is 2-4 meters, and spacing is 1-1.5 meters;

[0011] S4. Karst treatment: Use cement grouting and concrete filling to fill and reinforce karst caves to provide stable support. Determine the grouting volume and pressure according to the size and shape of the cave. Control the grouting pressure to 0.5-1.0MPa. Set up drainage pipes and precipitation wells, block groundwater sources, and prevent groundwater from affecting tunnel construction. The diameter of the drainage pipe is 100-200mm, and the depth of the precipitation well is 10-30 meters.

[0012] S5. Secondary support and lining: The final tunnel support is provided by reinforced concrete lining to ensure long-term stability. The lining thickness is 30-50cm. The lining joints are sealed by grouting to prevent water seepage.

[0013] S6. Construction monitoring and safety management: Set up monitoring points, use displacement monitors and stress strain gauges to monitor tunnel stability and geological changes in real time. The monitoring frequency is daily or after each excavation. The distance between monitoring points is 10-20 meters. Develop emergency plans, conduct regular safety training and drills to ensure construction safety, prevent accidents, and ensure that the emergency response time does not exceed 15 minutes;

[0014] S7. Construction summary and acceptance: Summarize the lessons learned during the construction process, improve the technical plan, write a construction summary report, organize expert acceptance, conduct quality inspections, ensure that the tunnel project meets the design requirements and safety standards, and conduct acceptance in accordance with national and industry standards. The pass rate should reach 100%.

[0015] Preferably, the implementation steps of step S1 are:

[0016] S1.1. Design drilling plan: Use AutoCAD software to design the drilling location and depth. The drilling depth is set to 1.5 to 2 times the tunnel burial depth to fully detect karst characteristics and groundwater distribution;

[0017] S1.2. Geological radar detection: Geological radar equipment is used to detect rock layers and cavities under the surface, with the operating frequency set at 100MHz to 1GHz to identify karst development;

[0018] S1.3. Seismic wave survey: Use seismic reflectometers to collect underground structure data and map underground structures using propagation velocity differences. The frequency range is set to 5-50 Hz.

[0019] S1.4. Data collection and collation: Import the data of drilling, geological radar and seismic wave survey into the GIS system for integration and analysis, and record the geological samples and test results of each drilling hole in detail;

[0020] S1.5. Establishment of geological model: Use Rocksc i ence software to establish a detailed three-dimensional geological model based on the collected data to simulate the geological structure and karst development characteristics;

[0021] S1.6. Stability analysis: Use GeoStud io software to perform stability analysis. By setting the physical and mechanical parameters of the formation, determine whether the geological density of the karst area is 2.5-3.0 g / cm 3 , shear strength 50-300kPa, assessing the possible collapse risk in karst areas;

[0022] S1.7. Risk assessment report preparation: Integrate the above analysis results and prepare a detailed risk assessment report, including geological structure, karst development and potential risk areas;

[0023] S1.8. Plan revision and final confirmation: Adjust the tunnel design plan based on the risk assessment results, confirm the final construction plan and preventive measures, and ensure the safety of the tunnel crossing the karst area.

[0024] Preferably, the implementation steps of step S2 are:

[0025] S2.1. Formulate the excavation sequence: Use PLAXI S 3D numerical simulation software to simulate the tunnel excavation process and its impact on the surrounding environment based on the geological survey results. Set the soil model parameters: cohesion 15kPa, internal friction angle 30 degrees;

[0026] S2.2. Design support scheme: Use ABAQUS software to perform structural analysis and design support structures, including precast concrete lining and anchor rods. The diameter of the anchor rods is set to 32 mm, and the length is set to 3-6 meters according to geological conditions;

[0027] S2.3. Configure excavation equipment: Select appropriate excavation equipment according to tunnel size and geological conditions, including shield machines and excavators. The shield diameter of the shield machine is determined by the tunnel diameter and is usually set to 1.05 times the tunnel diameter;

[0028] S2.4. Select support materials: Select support materials according to the support scheme requirements, including 12mm diameter steel bars and C30 grade concrete;

[0029] S2.5. Install monitoring equipment: Deploy tunnel deformation monitoring equipment, including inclinometers and stress sensors, to ensure real-time monitoring of tunnel stability during excavation;

[0030] S2.6. Develop emergency response measures: Develop emergency response plans including flooding and collapse to ensure rapid response and handling of emergencies;

[0031] S2.7. Construction plan review meeting: Organize a construction plan review meeting and invite engineers and experts to review and discuss the excavation plan to ensure that all technical details and safety measures are fully considered;

[0032] S2.8. Training of construction personnel: Provide professional training to construction personnel to ensure that they understand the construction plan, safety regulations and emergency measures, and improve construction efficiency and safety.

[0033] Preferably, the implementation steps of step S3 are:

[0034] S3.1. Select excavation method: select short step method or full section method according to geological conditions and tunnel size, use GeoStud io software to simulate the impact of different excavation methods on tunnel stability and optimize excavation strategy;

[0035] S3.2. Determine excavation parameters: Set the maximum length of each excavation to 2 meters to reduce the risk of collapse. Use ABAQUS software simulation analysis to confirm the safety of this parameter under specific geological conditions;

[0036] S3.3. Shotcrete construction: After each excavation, the shotcrete machine is used for initial support immediately. The thickness of the shotcrete is set to 15cm to ensure full support coverage;

[0037] S3.4. Anchor bolt installation: After the shotcrete is stabilized, the anchor bolts are installed with a length of 4 meters, a diameter of 25 mm, and a spacing of 1.5 meters. Drilling equipment is used for installation;

[0038] S3.5. Steel arch installation: Steel arches are installed in specific sections to provide additional support. The arch spacing is 2 meters. The arch profile specifications are determined based on structural analysis.

[0039] S3.6. Real-time monitoring and adjustment: Install displacement and pressure sensors to monitor the deformation and pressure of the tunnel during excavation and support, and use the real-time data feedback system to adjust the construction parameters;

[0040] S3.7. Safety inspection: After each excavation and support, a safety inspection is carried out to ensure that there are no cracks or looseness, and the inspection is recorded and evaluated through a digital monitoring system;

[0041] S3.8. Construction records and data analysis: Record the data of each excavation and support in detail, including the excavation length, thickness of shotcrete, and use of anchor rods, and use data analysis software to conduct construction quality assessment and risk prediction.

[0042] Preferably, the implementation steps of step S4 are:

[0043] S4.1. Karst cave survey: Use geological radar and underground detection technology to accurately identify the location, size and shape of karst caves, process data through professional geological analysis software, and draw detailed geological profiles;

[0044] S4.2. Grouting scheme design: According to the size and shape of the cave, use the FLAC3D model to simulate the effects of different grouting amounts and pressures, optimize the grouting scheme, determine the grouting amount and grouting pressure of each cave, and control it within 0.5-1.0MPa;

[0045] S4.3. Cement grouting preparation: prepare special cement slurry suitable for karst filling, adjust the ratio of cement to water to achieve ideal fluidity and curing time, and use a concrete mixer truck for mixing;

[0046] S4.4. Grouting execution: Grouting is carried out by high-pressure grouting pumps to ensure that the grouting evenly fills the karst space. The pressure monitoring system is used to monitor the grouting pressure in real time to ensure that it does not exceed the design pressure;

[0047] S4.5. Drainage system setting: Design drainage pipes and precipitation wells according to geological conditions and hydrogeological survey results. The diameter of the drainage pipes should be 150 mm and the depth of the precipitation wells should be 20 meters to effectively control groundwater flow.

[0048] S4.6. Blocking groundwater sources: Set up cement blocking walls in important water source areas to prevent groundwater from flowing into the tunnel area, and use special waterproof materials to ensure the durability and effectiveness of the blocking;

[0049] S4.7. Safety inspection and adjustment: After completing the grouting and drainage system setting, conduct a detailed safety inspection to check the quality of the grouting and whether the drainage system is operating normally;

[0050] S4.8. Data recording and subsequent monitoring: Record all detailed data of grouting and drainage, including grouting volume, grouting pressure, specifications and location of drainage system, and set up long-term monitoring equipment, including displacement sensors and pressure gauges, to continuously monitor the stability of karst areas.

[0051] Preferably, the implementation steps of step S5 are:

[0052] S5.1. Lining design: Use AutoCAD and SAP2000 software to design the lining structure, ensure that the reinforced concrete lining meets the mechanical and structural stability requirements, and determine the lining thickness to be 40 cm to adapt to the expected ground pressure and environmental conditions;

[0053] S5.2. Rebar production and installation: Cut and bend the rebar according to the design drawings. The diameter of the rebar is 16mm. Use a rebar tying machine to assemble and install the rebar cage.

[0054] S5.3. Formwork installation: Install the steel formwork for pouring concrete, ensuring that the formwork is flat, stable, and evenly arranged along the tunnel perimeter, and that the gaps between the formwork are tightly sealed to prevent concrete leakage;

[0055] S5.4. Concrete pouring: Use C30 concrete and pour it by concrete pump truck. The concrete should be poured evenly to prevent voids or insufficiently filled areas. Use a vibrating rod during pouring to ensure the concrete is dense.

[0056] S5.5. Initial curing: After the concrete is poured, cover and maintain it with a covering cloth and curing film for 7 days to prevent the concrete from drying out too quickly and causing cracks;

[0057] S5.6. Joint treatment: The lining joints are sealed with polyurethane grouting material, which is injected through a grouting pump to ensure that there is no water seepage at the joints. This step is carried out 28 days after the concrete reaches the design strength;

[0058] S5.7. Quality inspection: Use ultrasonic detector to check the integrity of concrete to ensure there are no defects. The position and coverage depth of steel bars are checked by magnetic detector.

[0059] S5.8. Safety Assessment: After all construction is completed, a professional engineering team will conduct a structural safety assessment using STAAD.Pro software to ensure long-term stability and safety compliance.

[0060] Preferably, the implementation steps of step S6 are:

[0061] S6.1. Arrange monitoring points: Arrange monitoring points inside and outside the tunnel, with a spacing of one every 15 meters to ensure comprehensive monitoring coverage and accurate positioning of monitoring points. Use GPS and laser scanners to determine the exact coordinates of the monitoring points;

[0062] S6.2. Install monitoring equipment: Install displacement monitors and stress strain gauges at each monitoring point, using equipment with high precision and high sensitivity to ensure the accuracy and reliability of the data;

[0063] S6.3. Develop a monitoring plan: Develop a detailed monitoring plan that specifies daily monitoring and additional monitoring immediately after each excavation, set the monitoring frequency and data recording method, and use dedicated software including GeoMoS to automatically record and analyze data;

[0064] S6.4. Data analysis and evaluation: Use GeoStud io or Rocscience to analyze data, evaluate the stability and geological changes of the tunnel, and adjust the construction strategy based on the analysis results;

[0065] S6.5. Develop emergency response plan: Based on monitoring data and risk assessment results, develop a detailed emergency response plan, including key information such as emergency evacuation routes, contact list, and location of rescue equipment;

[0066] S6.6. Safety training and drills: Conduct safety training and emergency response drills regularly, and conduct safety training and drills for all construction personnel at least once a month to ensure that every employee is proficient in emergency procedures;

[0067] S6.7. Real-time monitoring and alarm system: Set up a real-time monitoring system and automatic alarm function. When the monitoring data exceeds the safety threshold, the system automatically issues an alarm and notifies relevant personnel and management via SMS or email;

[0068] S6.8. Safety review and assessment: Conduct a safety review every week to evaluate the monitoring data and the implementation of safety measures during the construction process, and use Safeti or Riskcurves to conduct risk assessment and safety analysis.

[0069] Preferably, the implementation steps of step S7 are:

[0070] S7.1. Summarize lessons learned: Collect key data from the entire construction process through Microsoft Project, including cost overruns and time delays, analyze the causes and summarize lessons learned;

[0071] S7.2. Improve the technical solution;

[0072] S7.3. Prepare a construction summary report;

[0073] S7.4. Organize expert acceptance;

[0074] S7.5. Conduct quality inspection;

[0075] S7.6. Ensure compliance with design requirements and safety standards;

[0076] S7.7. Acceptance shall be conducted in accordance with national and industry standards;

[0077] S7.8. Ensure 100% pass rate: Through comprehensive quality assurance and control processes, ensure that each test indicator meets the acceptance criteria and achieve 100% pass rate.

[0078] Preferably, the implementation steps of step S7.1 are:

[0079] S7.1.1. Data collection: Use SAP ERP to collect data from each construction stage, including manpower, material consumption, and equipment operating status;

[0080] S7.1.2.Data analysis: Conduct in-depth analysis of the collected data using SPSS to identify the root causes of the problem;

[0081] S7.1.3. Lessons learned document preparation: Prepare a lessons learned report based on the analysis results, and record in detail the construction links that can be improved and the recommended operating methods.

[0082] Preferably, in step S7.7, the final project acceptance is organized according to GB 50010-2010 national building standards and industry specifications.

[0083] Compared with the prior art, the beneficial effects of the present invention are as follows: the comprehensive anti-collapse treatment construction process for tunnels crossing karst development areas of the present invention adjusts the construction strategy according to the actual geological conditions, handles geological risks more accurately, and accelerates the construction progress and reduces unexpected interruptions by adopting modern technologies and equipment, such as geological radar. The comprehensive treatment measures can greatly improve the safety of the construction process through precise control, reduce the impact on the surrounding environment, and reduce pollution by using environmentally friendly materials and technologies. At the same time, the construction process of the present invention adopts new support materials and designs, including steel mesh, anchor rods and shotcrete, to provide immediate and lasting support to prevent rock loosening and collapse. BRIEF DESCRIPTION OF THE DRAWINGS

[0084] Figure 1 The present invention is a construction process flow chart of a comprehensive anti-collapse treatment method for a tunnel passing through a karst development area. DETAILED DESCRIPTION

[0085] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0086] Example 1

[0087] See also Figure 1 The present invention proposes a comprehensive anti-collapse treatment construction process for tunnels passing through karst development areas, comprising the following steps:

[0088] S1. Preliminary investigation and planning:

[0089] S1.1. Design drilling plan: Use AutoCAD software to design the drilling location and depth. The drilling depth is set to 1.5 to 2 times the tunnel burial depth to fully detect karst characteristics and groundwater distribution;

[0090] S1.2. Geological radar detection: Geological radar equipment is used to detect rock layers and cavities under the surface, with the operating frequency set at 100MHz to 1GHz to identify karst development;

[0091] S1.3. Seismic wave survey: Use seismic reflectometers to collect underground structure data and map underground structures using propagation velocity differences. The frequency range is set to 5-50 Hz.

[0092] S1.4. Data collection and collation: Import the data of drilling, geological radar and seismic wave survey into the GIS system for integration and analysis, and record the geological samples and test results of each drilling hole in detail;

[0093] S1.5. Establishment of geological model: Use Rocksc i ence software to establish a detailed three-dimensional geological model based on the collected data to simulate the geological structure and karst development characteristics;

[0094] S1.6. Stability analysis: Use GeoStud io software to perform stability analysis. By setting the physical and mechanical parameters of the formation, determine whether the geological density of the karst area is 2.5-3.0 g / cm 3 , shear strength 50-300kPa, assessing the possible collapse risk in karst areas;

[0095] S1.7. Risk assessment report preparation: Integrate the above analysis results and prepare a detailed risk assessment report, including geological structure, karst development and potential risk areas;

[0096] S1.8. Plan revision and final confirmation: adjust the tunnel design plan according to the risk assessment results, confirm the final construction plan and preventive measures, and ensure the safety of the tunnel crossing the karst area;

[0097] S2. Preparation before tunnel excavation:

[0098] S2.1. Formulate the excavation sequence: Use PLAXI S 3D numerical simulation software to simulate the tunnel excavation process and its impact on the surrounding environment based on the geological survey results. Set the soil model parameters: cohesion 15kPa, internal friction angle 30 degrees;

[0099] S2.2. Design support scheme: Use ABAQUS software to perform structural analysis and design support structures, including precast concrete lining and anchor rods. The diameter of the anchor rods is set to 32 mm, and the length is set to 3-6 meters according to geological conditions;

[0100] S2.3. Configure excavation equipment: Select appropriate excavation equipment according to tunnel size and geological conditions, including shield machines and excavators. The shield diameter of the shield machine is determined by the tunnel diameter and is usually set to 1.05 times the tunnel diameter;

[0101] S2.4. Select support materials: Select support materials according to the support scheme requirements, including 12mm diameter steel bars and C30 grade concrete;

[0102] S2.5. Install monitoring equipment: Deploy tunnel deformation monitoring equipment, including inclinometers and stress sensors, to ensure real-time monitoring of tunnel stability during excavation;

[0103] S2.6. Develop emergency response measures: Develop emergency response plans including flooding and collapse to ensure rapid response and handling of emergencies;

[0104] S2.7. Construction plan review meeting: Organize a construction plan review meeting and invite engineers and experts to review and discuss the excavation plan to ensure that all technical details and safety measures are fully considered;

[0105] S2.8. Training construction personnel: Provide professional training to construction personnel to ensure that they understand the construction plan, safety regulations and emergency measures, and improve construction efficiency and safety;

[0106] S3. Tunnel excavation and initial support:

[0107] S3.1. Select excavation method: select short step method or full section method according to geological conditions and tunnel size, use GeoStud io software to simulate the impact of different excavation methods on tunnel stability and optimize excavation strategy;

[0108] S3.2. Determine excavation parameters: Set the maximum length of each excavation to 2 meters to reduce the risk of collapse. Use ABAQUS software simulation analysis to confirm the safety of this parameter under specific geological conditions;

[0109] S3.3. Shotcrete construction: After each excavation, the shotcrete machine is used for initial support immediately. The thickness of the shotcrete is set to 15cm to ensure full support coverage;

[0110] S3.4. Anchor bolt installation: After the shotcrete is stabilized, the anchor bolts are installed with a length of 4 meters, a diameter of 25 mm, and a spacing of 1.5 meters. Drilling equipment is used for installation;

[0111] S3.5. Steel arch installation: Steel arches are installed in specific sections to provide additional support. The arch spacing is 2 meters. The arch profile specifications are determined based on structural analysis.

[0112] S3.6. Real-time monitoring and adjustment: Install displacement and pressure sensors to monitor the deformation and pressure of the tunnel during excavation and support, and use the real-time data feedback system to adjust the construction parameters;

[0113] S3.7. Safety inspection: After each excavation and support, a safety inspection is carried out to ensure that there are no cracks or looseness, and the inspection is recorded and evaluated through a digital monitoring system;

[0114] S3.8. Construction records and data analysis: Record the data of each excavation and support in detail, including the excavation length, thickness of shotcrete, and use of anchor rods, and use data analysis software to conduct construction quality assessment and risk prediction;

[0115] S4. Karst treatment:

[0116] S4.1. Karst cave survey: Use geological radar and underground detection technology to accurately identify the location, size and shape of karst caves, process data through professional geological analysis software, and draw detailed geological profiles;

[0117] S4.2. Grouting scheme design: According to the size and shape of the cave, use the FLAC3D model to simulate the effects of different grouting amounts and pressures, optimize the grouting scheme, determine the grouting amount and grouting pressure of each cave, and control it within 0.5-1.0MPa;

[0118] S4.3. Cement grouting preparation: prepare special cement slurry suitable for karst filling, adjust the ratio of cement to water to achieve ideal fluidity and curing time, and use a concrete mixer truck for mixing;

[0119] S4.4. Grouting execution: Grouting is carried out by high-pressure grouting pumps to ensure that the grouting evenly fills the karst space. The pressure monitoring system is used to monitor the grouting pressure in real time to ensure that it does not exceed the design pressure;

[0120] S4.5. Drainage system setting: Design drainage pipes and precipitation wells according to geological conditions and hydrogeological survey results. The diameter of the drainage pipes should be 150 mm and the depth of the precipitation wells should be 20 meters to effectively control groundwater flow.

[0121] S4.6. Blocking groundwater sources: Set up cement blocking walls in important water source areas to prevent groundwater from flowing into the tunnel area, and use special waterproof materials to ensure the durability and effectiveness of the blocking;

[0122] S4.7. Safety inspection and adjustment: After completing the grouting and drainage system setting, conduct a detailed safety inspection to check the quality of the grouting and whether the drainage system is operating normally;

[0123] S4.8. Data recording and subsequent monitoring: Record all detailed data of grouting and drainage, including grouting volume, grouting pressure, specifications and location of drainage system, and set up long-term monitoring equipment, including displacement sensors and pressure gauges, to continuously monitor the stability of karst areas;

[0124] S5. Secondary support and lining:

[0125] S5.1. Lining design: Use AutoCAD and SAP2000 software to design the lining structure, ensure that the reinforced concrete lining meets the mechanical and structural stability requirements, and determine the lining thickness to be 40 cm to adapt to the expected ground pressure and environmental conditions;

[0126] S5.2. Rebar production and installation: Cut and bend the rebar according to the design drawings. The diameter of the rebar is 16mm. Use a rebar tying machine to assemble and install the rebar cage.

[0127] S5.3. Formwork installation: Install the steel formwork for pouring concrete, ensuring that the formwork is flat, stable, and evenly arranged along the tunnel perimeter, and that the gaps between the formwork are tightly sealed to prevent concrete leakage;

[0128] S5.4. Concrete pouring: Use C30 concrete and pour it by concrete pump truck. The concrete should be poured evenly to prevent voids or insufficiently filled areas. Use a vibrating rod during pouring to ensure the concrete is dense.

[0129] S5.5. Initial curing: After the concrete is poured, cover and maintain it with a covering cloth and curing film for 7 days to prevent the concrete from drying out too quickly and causing cracks;

[0130] S5.6. Joint treatment: The lining joints are sealed with polyurethane grouting material, which is injected through a grouting pump to ensure that there is no water seepage at the joints. This step is carried out 28 days after the concrete reaches the design strength;

[0131] S5.7. Quality inspection: Use ultrasonic detector to check the integrity of concrete to ensure there are no defects. The position and coverage depth of steel bars are checked by magnetic detector.

[0132] S5.8. Safety assessment: After all construction is completed, a professional engineering team will use STAAD.Pro software to conduct a structural safety assessment to ensure long-term stability and safety compliance;

[0133] S6. Construction monitoring and safety management:

[0134] S6.1. Arrange monitoring points: Arrange monitoring points inside and outside the tunnel, with a spacing of one every 15 meters to ensure comprehensive monitoring coverage and accurate positioning of monitoring points. Use GPS and laser scanners to determine the exact coordinates of the monitoring points;

[0135] S6.2. Install monitoring equipment: Install displacement monitors and stress strain gauges at each monitoring point, using equipment with high precision and high sensitivity to ensure the accuracy and reliability of the data;

[0136] S6.3. Develop a monitoring plan: Develop a detailed monitoring plan that specifies daily monitoring and additional monitoring immediately after each excavation, set the monitoring frequency and data recording method, and use dedicated software including GeoMoS to automatically record and analyze data;

[0137] S6.4. Data analysis and evaluation: Use GeoStud io or Rocscience to analyze data, evaluate the stability and geological changes of the tunnel, and adjust the construction strategy based on the analysis results;

[0138] S6.5. Develop emergency response plan: Based on monitoring data and risk assessment results, develop a detailed emergency response plan, including key information such as emergency evacuation routes, contact list, and location of rescue equipment;

[0139] S6.6. Safety training and drills: Conduct safety training and emergency response drills regularly, and conduct safety training and drills for all construction personnel at least once a month to ensure that every employee is proficient in emergency procedures;

[0140] S6.7. Real-time monitoring and alarm system: Set up a real-time monitoring system and automatic alarm function. When the monitoring data exceeds the safety threshold, the system automatically issues an alarm and notifies relevant personnel and management via SMS or email;

[0141] S6.8. Safety review and assessment: Conduct a safety review every week to evaluate the monitoring data and the implementation of safety measures during the construction process, and use Safeti or Riskcurves to conduct risk assessment and safety analysis;

[0142] S7. Construction summary and acceptance:

[0143] S7.1 Summarize lessons learned: Collect key data from the entire construction process through Microsoft Project, including cost overruns and time delays, analyze the causes and summarize lessons learned;

[0144] S7.1.1 Data collection: Use SAP ERP to collect data from each construction stage, including manpower, material consumption, and equipment operating status;

[0145] S7.1.2 Data Analysis: Conduct in-depth analysis of the collected data using SPSS to identify the root causes of the problem;

[0146] S7.1.3 Lessons learned document preparation: Prepare lessons learned report based on the analysis results, and record in detail the construction links that can be improved and the recommended operating methods;

[0147] S7.2 Improve the technical plan: adjust and optimize the construction technical plan based on the lessons learned, redraw the construction drawings using AutoCAD and Revit design tools, and ensure that all design corrections comply with safety regulations;

[0148] S7.2.1 Technical review: Organize an engineering team to conduct three-dimensional simulation and collision testing on the adjusted design plan by using BIM software;

[0149] S7.2.2 Plan update: Adjust construction drawings and construction plans based on simulation results, and use project management software to update project timelines and resource allocations;

[0150] S7.3 Prepare a construction summary report: Use Microsoft Word to summarize the key activities, implementation details and results of the entire construction process to form a detailed construction summary report;

[0151] S7.3.1 Report review: Invite senior engineers and managers related to the project to review the report to ensure that all information is accurate;

[0152] S7.4 Organize expert acceptance: Invite external and internal engineering experts to use quality inspection instruments to conduct acceptance review of the completed project;

[0153] S7.4.1 Acceptance preparation: Prepare all technical documents and construction records required for acceptance to ensure that the project details can be fully presented during acceptance;

[0154] S7.5 Conduct quality inspection: Use ultrasonic flaw detectors to conduct quality inspections on key parts of the tunnel project to ensure there are no defects;

[0155] S7.5.1 Quality data recording: Record test results through quality management software under ISO 9001 standard to ensure data traceability;

[0156] S7.6 Ensure compliance with design requirements and safety standards: Compare the design specifications with the actual project conditions, perform structural analysis using SAP2000, and verify that the project complies with the design and safety standards;

[0157] S7.6.1 Safety Assessment Report: Prepare a detailed safety assessment report to record the analysis process and results for future review;

[0158] S7.7 Acceptance in accordance with national and industry standards: Organize the final project acceptance in accordance with GB 50010-2010 national building standards and industry specifications;

[0159] S7.7.1 Standard comparison: List in detail each standard that the project must comply with, and compare it with the actual construction results to confirm that each standard has been met;

[0160] S7.8 Ensure 100% pass rate: Through a comprehensive quality assurance and control process, ensure that each test indicator meets the acceptance criteria and achieve a 100% pass rate.

[0161] Example 2

[0162] Based on the above construction technology, the practical application in the construction project of tunnel crossing the karst development area to prevent the comprehensive treatment of collapse, this embodiment describes the application examples and construction standards before construction:

[0163] After exploring the on-site environment, the geological environment was finally measured as follows:

[0164] Average annual rainfall: 1,200 mm; Average groundwater level: 20 meters; Rock types: limestone (60%), shale (20%), sandstone (20%); Density of geological fissures and cavities: high;

[0165] Based on the construction process in Example 1, the project construction is carried out:

[0166] Real-time monitoring of equipment parameters (see Table 1) and engineering parameters (Table 2) before construction, as well as pre-excavation geological assessment, tunnel deformation monitoring and lining integrity testing (Table 3);

[0167] Table 1: Equipment parameters

[0168] Device Name model Function Main parameters Geological radar GRD-20 Underground Detection Frequency: 100-1000MHz Drilling equipment DRX-5 sampling Drilling depth: up to 500 meters Shield Machine TBM-80 Tunnel Excavation Diameter: 10 meters, speed: 20 meters / day Jet SJ-40 Shotcrete <![CDATA[Flow rate: 10m 3 / h]]> Anchor drilling rig AM-50 Install anchor rods Depth: 50m, Diameter: 150mm

[0169] Table 2: Engineering parameters

[0170] step Key Parameters Target value Geological Assessment Crack density <10％ Grouting reinforcement Grouting pressure 2000kPa Tunnel Excavation Excavation speed 20m / day Primary lining thickness 25cm Secondary lining thickness 50cm

[0171] Table 3 Pre-excavation geological assessment, tunnel deformation monitoring and lining integrity testing

[0172]

[0173]

[0174] During construction, real-time monitoring of equipment operation performance (see Table 4), environment and health and safety (see Table 5), and safety facilities (see Table 6) is performed;

[0175] Table 4 Operational performance test

[0176] Test items Preset Standards Simulation test results Eligibility Shield machine speed 3.5RPM 3.5RPM yes Advance speed 15m / day 15m / day yes Tunnel axis deviation ≤3cm 2cm yes

[0177] Table 5 Environmental and health safety testing

[0178] Test items Preset Standards Simulation test results Eligibility Air quality (PM2.5) <![CDATA[≤35μg / m 3 ]]> <![CDATA[30μg / m 3 ]]> yes Noise Level ≤75dB 70dB yes Groundwater contamination No pollution index growth No growth yes Rock subsidence rate ≤1cm / year 0.5cm / year yes

[0179] Table 6 Safety facility inspection

[0180]

[0181]

[0182] After the construction of the above projects is completed, the structure and material quality inspection will be carried out during the acceptance stage (see Table 7);

[0183] Table 7: Structural and material quality inspection

[0184] Test items Preset Standards Simulation test results Eligibility Primary lining thickness ≥30cm 32cm yes Secondary lining thickness ≥50cm 51cm yes Lining concrete strength ≥30MPa 35MPa yes Rebar Spacing ≤20cm 18cm yes Waterproof layer integrity No leakage No leakage yes

[0185] So far, the practical application of the comprehensive anti-collapse treatment construction technology for tunnels crossing karst development areas in this project has been completed. It should be noted that in the above construction process, each link is implemented in accordance with the following standards:

[0186] Code for Construction of Tunnel Engineering (GB 50218-2018);

[0187] "Geotechnical Engineering Investigation Code" (GB 50021-2001);

[0188] Urban Rail Transit Engineering Construction Standard (CJJ / T 186-2009);

[0189] "Highway Tunnel Design Specification" (JTG 3370.1-2018);

[0190] Technical Regulations for Safety in Tunnel Construction (AQ 1031-2007);

[0191] In summary, the invention discloses a comprehensive anti-collapse treatment construction process for tunnels crossing karst development areas, adjusts construction strategies according to actual geological conditions, handles geological risks more accurately, and accelerates construction progress and reduces unexpected interruptions by adopting modern technologies and equipment, such as geological radar. Comprehensive treatment measures can greatly improve the safety of the construction process through precise control, reduce the impact on the surrounding environment, and reduce pollution by using environmentally friendly materials and technologies. At the same time, the construction process of the invention adopts new support materials and designs, including steel mesh, anchor rods and shotcrete, to provide immediate and lasting support to prevent rock loosening and collapse.

[0192] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A comprehensive anti-collapse treatment construction process for tunnels passing through karst development areas, characterized in that: The following steps are involved: S1. Preliminary investigation and planning: Through drilling exploration, geological radar, and seismic wave survey, the geological structure, karst development, and groundwater distribution along the tunnel are understood in detail. The drilling depth is designed to be 1.5-2 times the tunnel depth according to the tunnel depth. The stability of the karst area and possible collapse risks are analyzed through geological modeling and stability analysis; S2. Preparation before tunnel excavation: Combined with the geological survey results, numerical simulation analysis is used to formulate a construction plan, covering the excavation sequence, support plan, configuration of excavation equipment and support materials; S3. Tunnel excavation and initial support: Use short-step method or full-section method for segmented excavation, control the length and range of each excavation, reduce the risk of collapse, single excavation length is 1-2 meters, sprayed concrete, anchor support, steel arch support, support immediately after each excavation to prevent collapse, sprayed concrete thickness is 10-15cm, anchor length is 2-4 meters, and spacing is 1-1.5 meters; S4. Karst treatment: Use cement grouting and concrete filling to fill and reinforce karst caves to provide stable support. Determine the grouting volume and pressure according to the size and shape of the cave. Control the grouting pressure to 0.5-1.0MPa. Set up drainage pipes and precipitation wells, block groundwater sources, and prevent groundwater from affecting tunnel construction. The diameter of the drainage pipe is 100-200mm, and the depth of the precipitation well is 10-30 meters. S5. Secondary support and lining: The final tunnel support is provided by reinforced concrete lining to ensure long-term stability. The lining thickness is 30-50cm. The lining joints are sealed by grouting to prevent water seepage. S6. Construction monitoring and safety management: Set up monitoring points, use displacement monitors and stress strain gauges to monitor tunnel stability and geological changes in real time. The monitoring frequency is daily or after each excavation. The distance between monitoring points is 10-20 meters. Develop emergency plans, conduct regular safety training and drills to ensure construction safety, prevent accidents, and ensure that the emergency response time does not exceed 15 minutes; S7. Construction summary and acceptance: Summarize the lessons learned during the construction process, improve the technical plan, write a construction summary report, organize expert acceptance, conduct quality inspections, ensure that the tunnel project meets the design requirements and safety standards, and conduct acceptance in accordance with national and industry standards. The pass rate should reach 100%.

2. The comprehensive anti-collapse treatment construction process for tunnels passing through karst development areas according to claim 1 is characterized in that , the implementation steps of step S1 are: S1.

1. Design drilling plan: Use AutoCAD software to design the drilling location and depth. The drilling depth is set to 1.5 to 2 times the tunnel burial depth to fully detect karst characteristics and groundwater distribution; S1.

2. Geological radar detection: Geological radar equipment is used to detect rock layers and cavities under the surface, with the operating frequency set at 100MHz to 1GHz to identify karst development; S1.

3. Seismic wave survey: Use seismic reflectometers to collect underground structure data and map underground structures using propagation velocity differences. The frequency range is set to 5-50 Hz. S1.

4. Data collection and collation: Import the data of drilling, geological radar and seismic wave survey into the GIS system for integration and analysis, and record the geological samples and test results of each drilling hole in detail; S1.

5. Establishment of geological model: Use Rockscience software to establish a detailed three-dimensional geological model based on the collected data to simulate the geological structure and karst development characteristics; S1.

6. Stability analysis: Use GeoStudio software to perform stability analysis and determine whether the geological density of the karst area is 2.5-3.0 g / cm by setting the physical and mechanical parameters of the formation. 3 , shear strength 50-300kPa, assessing the possible collapse risk in karst areas; S1.

7. Risk assessment report preparation: Integrate the above analysis results and prepare a detailed risk assessment report, including geological structure, karst development and potential risk areas; S1.

8. Plan revision and final confirmation: Adjust the tunnel design plan based on the risk assessment results, confirm the final construction plan and preventive measures, and ensure the safety of the tunnel crossing the karst area.

3. The comprehensive anti-collapse treatment construction process for tunnels passing through karst development areas according to claim 2 is characterized in that: The implementation steps of step S2 are: S2.

1. Formulate the excavation sequence: Use PLAXIS 3D numerical simulation software to simulate the tunnel excavation process and its impact on the surrounding environment based on geological survey results. Set the soil model parameters: cohesion 15kPa, internal friction angle 30 degrees; S2.

2. Design support scheme: Use ABAQUS software to perform structural analysis and design support structures, including precast concrete lining and anchor rods. The diameter of the anchor rods is set to 32 mm, and the length is set to 3-6 meters according to geological conditions; S2.

3. Configure excavation equipment: Select appropriate excavation equipment according to tunnel size and geological conditions, including shield machines and excavators. The shield diameter of the shield machine is determined by the tunnel diameter and is usually set to 1.05 times the tunnel diameter; S2.

4. Select support materials: Select support materials according to the support scheme requirements, including 12mm diameter steel bars and C30 grade concrete; S2.

5. Install monitoring equipment: Deploy tunnel deformation monitoring equipment, including inclinometers and stress sensors, to ensure real-time monitoring of tunnel stability during excavation; S2.

6. Develop emergency response measures: Develop emergency response plans including flooding and collapse to ensure rapid response and handling of emergencies; S2.

7. Construction plan review meeting: Organize a construction plan review meeting and invite engineers and experts to review and discuss the excavation plan to ensure that all technical details and safety measures are fully considered; S2.

8. Training of construction personnel: Provide professional training to construction personnel to ensure that they understand the construction plan, safety regulations and emergency measures, and improve construction efficiency and safety.

4. The comprehensive anti-collapse treatment construction process for tunnels passing through karst development areas according to claim 3 is characterized in that: The implementation steps of step S3 are: S3.

1. Select excavation method: select short-step method or full-section method according to geological conditions and tunnel size, use GeoStudio software to simulate the impact of different excavation methods on tunnel stability, and optimize the excavation strategy; S3.

2. Determine excavation parameters: Set the maximum length of each excavation to 2 meters to reduce the risk of collapse. Use ABAQUS software simulation analysis to confirm the safety of this parameter under specific geological conditions; S3.

3. Shotcrete construction: After each excavation, the shotcrete machine is used for initial support immediately. The thickness of the shotcrete is set to 15cm to ensure full support coverage; S3.

4. Anchor bolt installation: After the shotcrete is stabilized, the anchor bolts are installed with a length of 4 meters, a diameter of 25 mm, and a spacing of 1.5 meters. Drilling equipment is used for installation; S3.

5. Steel arch installation: Steel arches are installed in specific sections to provide additional support. The arch spacing is 2 meters. The arch profile specifications are determined based on structural analysis. S3.

6. Real-time monitoring and adjustment: Install displacement and pressure sensors to monitor the deformation and pressure of the tunnel during excavation and support, and use the real-time data feedback system to adjust the construction parameters; S3.

7. Safety inspection: After each excavation and support, a safety inspection is carried out to ensure that there are no cracks or looseness, and the inspection is recorded and evaluated through a digital monitoring system; S3.

8. Construction records and data analysis: Record the data of each excavation and support in detail, including the excavation length, thickness of shotcrete, and use of anchor rods, and use data analysis software to conduct construction quality assessment and risk prediction.

5. The construction process for comprehensive anti-collapse treatment of a tunnel passing through a karst development area according to claim 4 is characterized in that: The implementation steps of step S4 are: S4.

1. Karst cave survey: Use geological radar and underground detection technology to accurately identify the location, size and shape of karst caves, process data through professional geological analysis software, and draw detailed geological profiles; S4.

2. Grouting scheme design: According to the size and shape of the cave, use the FLAC3D model to simulate the effects of different grouting amounts and pressures, optimize the grouting scheme, determine the grouting amount and grouting pressure of each cave, and control it within 0.5-1.0MPa; S4.

3. Cement grouting preparation: prepare special cement slurry suitable for karst filling, adjust the ratio of cement to water to achieve ideal fluidity and curing time, and use a concrete mixer truck for mixing; S4.

4. Grouting execution: Grouting is carried out by high-pressure grouting pumps to ensure that the grouting evenly fills the karst space. The pressure monitoring system is used to monitor the grouting pressure in real time to ensure that it does not exceed the design pressure; S4.

5. Drainage system setting: Design drainage pipes and precipitation wells according to geological conditions and hydrogeological survey results. The diameter of the drainage pipes should be 150 mm and the depth of the precipitation wells should be 20 meters to effectively control groundwater flow. S4.

6. Blocking groundwater sources: Set up cement blocking walls in important water source areas to prevent groundwater from flowing into the tunnel area, and use special waterproof materials to ensure the durability and effectiveness of the blocking; S4.

7. Safety inspection and adjustment: After completing the grouting and drainage system setting, conduct a detailed safety inspection to check the quality of the grouting and whether the drainage system is operating normally; S4.

8. Data recording and subsequent monitoring: Record all detailed data of grouting and drainage, including grouting volume, grouting pressure, specifications and location of drainage system, and set up long-term monitoring equipment, including displacement sensors and pressure gauges, to continuously monitor the stability of karst areas.

6. The construction process for comprehensive anti-collapse treatment of a tunnel passing through a karst development area according to claim 5 is characterized in that: The implementation steps of step S5 are: S5.

1. Lining design: Use AutoCAD and SAP2000 software to design the lining structure, ensure that the reinforced concrete lining meets the mechanical and structural stability requirements, and determine the lining thickness to be 40 cm to adapt to the expected ground pressure and environmental conditions; S5.

2. Rebar production and installation: Cut and bend the rebar according to the design drawings. The diameter of the rebar is 16mm. Use a rebar tying machine to assemble and install the rebar cage. S5.

3. Formwork installation: Install the steel formwork for pouring concrete, ensuring that the formwork is flat, stable, and evenly arranged along the tunnel perimeter, and that the gaps between the formwork are tightly sealed to prevent concrete leakage; S5.

4. Concrete pouring: Use C30 concrete and pour it by concrete pump truck. The concrete should be poured evenly to prevent voids or insufficiently filled areas. Use a vibrating rod during pouring to ensure the concrete is dense. S5.

5. Initial curing: After the concrete is poured, cover and maintain it with a covering cloth and curing film for 7 days to prevent the concrete from drying out too quickly and causing cracks; S5.

6. Joint treatment: The lining joints are sealed with polyurethane grouting material, which is injected through a grouting pump to ensure that there is no water seepage at the joints. This step is carried out 28 days after the concrete reaches the design strength; S5.

7. Quality inspection: Use ultrasonic detector to check the integrity of concrete to ensure there are no defects. The position and coverage depth of steel bars are checked by magnetic detector. S5.

8. Safety Assessment: After all construction is completed, a professional engineering team will conduct a structural safety assessment using STAAD.Pro software to ensure long-term stability and safety compliance.

7. The construction process for comprehensive anti-collapse treatment of a tunnel passing through a karst development area according to claim 6 is characterized in that: The implementation steps of step S6 are: S6.

1. Arrange monitoring points: Arrange monitoring points inside and outside the tunnel, with a spacing of one every 15 meters to ensure comprehensive monitoring coverage and accurate positioning of monitoring points. Use GPS and laser scanners to determine the exact coordinates of the monitoring points; S6.

2. Install monitoring equipment: Install displacement monitors and stress strain gauges at each monitoring point, using equipment with high precision and high sensitivity to ensure the accuracy and reliability of the data; S6.

3. Develop a monitoring plan: Develop a detailed monitoring plan that specifies daily monitoring and additional monitoring immediately after each excavation, set the monitoring frequency and data recording method, and use dedicated software including GeoMoS to automatically record and analyze data; S6.

4. Data analysis and evaluation: Use GeoStudio or Rocscience to analyze data, evaluate tunnel stability and geological changes, and adjust construction strategies based on the analysis results; S6.

5. Develop emergency response plan: Based on monitoring data and risk assessment results, develop a detailed emergency response plan, including key information such as emergency evacuation routes, contact list, and location of rescue equipment; S6.

6. Safety training and drills: Conduct safety training and emergency response drills regularly, and conduct safety training and drills for all construction personnel at least once a month to ensure that every employee is proficient in emergency procedures; S6.

7. Real-time monitoring and alarm system: Set up a real-time monitoring system and automatic alarm function. When the monitoring data exceeds the safety threshold, the system automatically issues an alarm and notifies relevant personnel and management via SMS or email; S6.

8. Safety review and assessment: Conduct a safety review every week to evaluate the monitoring data and the implementation of safety measures during the construction process, and use Safeti or Riskcurves to conduct risk assessment and safety analysis.

8. The construction process for comprehensive anti-collapse treatment of a tunnel passing through a karst development area according to claim 7 is characterized in that: The implementation steps of step S7 are: S7.

1. Summarize lessons learned: Collect key data from the entire construction process, including cost overruns and time delays, analyze the causes and summarize lessons learned through Microsoft Project; S7.

2. Improve the technical solution; S7.

3. Prepare a construction summary report; S7.

4. Organize expert acceptance; S7.

5. Conduct quality inspection; S7.

6. Ensure compliance with design requirements and safety standards; S7.

7. Acceptance shall be conducted in accordance with national and industry standards; S7.

8. Ensure 100% pass rate: Through comprehensive quality assurance and control processes, ensure that each test indicator meets the acceptance criteria and achieve 100% pass rate.

9. The comprehensive anti-collapse treatment construction process for tunnels passing through karst development areas according to claim 8 is characterized in that: The implementation steps of step S7.1 are: S7.1.

1. Data collection: Use SAP ERP to collect data from each construction stage, including manpower, material consumption, and equipment operating status; S7.1.2.Data analysis: Conduct in-depth analysis of the collected data using SPSS to identify the root causes of the problem; S7.1.

3. Lessons learned document preparation: Prepare a lessons learned report based on the analysis results, and record in detail the construction links that can be improved and the recommended operating methods.

10. The construction process for comprehensive anti-collapse treatment of a tunnel passing through a karst development area according to claim 9, characterized in that: In step S7.7, the final project acceptance is organized according to GB 50010-2010 national building standards and industry specifications.

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