Surrounding rock excavation response comparison monitoring method based on TBM method and drilling and blasting method

Abstract

The invention discloses a TBM method and drilling and blasting method surrounding rock excavation response comparison monitoring method, and relates to the field of high-level radioactive waste dispose.The method comprises the steps that firstly, the positions and section sizes of a TBM test roadway, a special monitoring roadway and a drilling and blasting test roadway are determined on the basis of an underground engineering main body structure; a plurality of excavation response monitoring systems are arranged in advance by utilizing a special monitoring roadway, and comprise a micro-seismic and / or acoustic emission monitoring system, a surrounding rock internal displacement monitoring system and a disturbance stress monitoring system; in the drilling and blasting method and TBM method excavation process, various excavation response monitoring systems are adopted to monitor the surrounding rock response of a drilling and blasting test roadway and a TBM test roadway; and contrastively analyzing the surrounding rock response characteristics and evolution laws of the TBM test roadway and the drilling and blasting test roadway, and guiding the excavation process of the TBM method and the drilling and blasting method according to an analysis result. Through comprehensive interpretation and comparison verification of various excavation response monitoring methods, a scientific basis can be provided for guiding the excavation process of the TBM method and the drilling and blasting method.

Description

Technical Field

[0001] The present application relates to the technical field of high-level radioactive waste disposal, and in particular to a method for comparative monitoring of surrounding rock excavation responses using a TBM method and a drilling and blasting method. Background Art

[0002] High-level radioactive waste (abbreviated as HLW) has the characteristics of strong radioactivity, high toxicity and long half-life. It is extremely difficult to dispose of it safely and faces a series of scientific, technological and engineering challenges. Whether HLW can be safely disposed of is a strategic issue related to the sustainable development of the nuclear industry and environmental protection. At present, it is generally believed that the technically feasible way to dispose of HLW is deep geological disposal, that is, burying HLW in a stable geological body within a depth range of 500m to 1000m. The geological disposal repository for HLW has the characteristics of complex construction conditions, high safety level and long service life (tens of thousands of years), which makes it very difficult to develop. Therefore, based on previous research experience, it is necessary to first build an underground laboratory for HLW disposal at the depth of the repository, conduct site characteristic evaluation, field test and verification of disposal technology, and provide the necessary scientific research foundation and practical experience for the construction of the repository.

[0003] TBM and drilling and blasting are two commonly used methods in underground engineering construction. They each have their own characteristics and are suitable for different geological conditions and engineering requirements. The TBM method uses a special tunnel boring machine for excavation. It has the advantages of high efficiency and high degree of automation, and is suitable for long-distance and large-section tunnel projects. The drilling and blasting method is a traditional construction method that excavates by drilling and blasting. It is suitable for various geological conditions, but the construction efficiency is relatively low. In the excavation process of underground laboratories and disposal repositories, the TBM method is often used in combination with the drilling and blasting method. However, there is a lack of comparative experiments in this field to clarify the specific performance of the two methods in different geological conditions, engineering scales, safety performance, etc., making it difficult to provide engineers and decision makers with more specific and practical information. Summary of the invention

[0004] The purpose of this application is to provide a comparative monitoring method for surrounding rock excavation responses of TBM and drilling and blasting methods, and to provide a scientific basis for guiding the excavation process of TBM and drilling and blasting methods through comprehensive interpretation and comparative verification of multiple excavation response monitoring methods.

[0005] To achieve the above objectives, this application provides the following solutions.

[0006] The present application provides a method for comparative monitoring of surrounding rock excavation response using a TBM method and a drilling and blasting method, including:

[0007] Determine the location and cross-sectional dimensions of the TBM test tunnel, dedicated monitoring tunnel, and drilling and blasting test tunnel based on the main structure of the underground project;

[0008] Use special monitoring tunnels to deploy multiple excavation response monitoring systems in advance, including microseismic and / or acoustic emission monitoring systems, surrounding rock internal displacement monitoring systems, and disturbance stress monitoring systems;

[0009] During the drilling and blasting excavation process, various excavation response monitoring systems are used to monitor the surrounding rock response of the drilling and blasting test tunnel;

[0010] During the TBM excavation process, various excavation response monitoring systems are used to monitor the surrounding rock response of the TBM test tunnel;

[0011] The surrounding rock response characteristics and evolution laws of the TBM test tunnel and the drilling and blasting test tunnel were compared and analyzed, and the TBM and drilling and blasting excavation processes were guided according to the analysis results.

[0012] Optionally, the determining of the location and cross-sectional dimensions of the TBM test tunnel, the dedicated monitoring tunnel, and the drilling and blasting test tunnel based on the main structure of the underground project specifically includes:

[0013] Determine the location of the TBM test tunnel based on the excavation progress of the main structure of the underground project;

[0014] Based on the location of the TBM test tunnel, one tunnel is selected from the excavated tunnels as a dedicated monitoring tunnel, and the drilling and blasting test tunnel and the TBM test tunnel are arranged symmetrically with respect to the dedicated monitoring tunnel.

[0015] Based on the cross-sectional dimensions of the TBM test tunnel, the cross-sectional dimensions of the drilling and blasting test tunnel are designed as a rectangular straight wall + horseshoe, circular, semicircular or three-center arch vault structure and the corresponding cross-sectional dimensions are determined;

[0016] The relative position of the drilling and blasting test tunnel and the connecting tunnel is determined based on the cross-sectional dimensions of the drilling and blasting test tunnel, the cross-sectional dimensions of the connecting tunnel between the dedicated monitoring tunnel and the drilling and blasting test tunnel, and the layout positions of the key monitoring boreholes.

[0017] Optionally, the use of a dedicated monitoring tunnel to pre-arrange multiple excavation response monitoring systems specifically includes:

[0018] Drill holes from the dedicated monitoring tunnel toward the drilling and blasting test tunnel and the TBM test tunnel, and install microseismic sensors and / or acoustic emission sensors in the holes to form a microseismic and / or acoustic emission monitoring system;

[0019] One or more of a multi-point displacement meter, a fiber Bragg grating (FRP) intelligent reinforcement and a sliding micrometer are buried in the borehole to form a surrounding rock internal displacement monitoring system;

[0020] Install multiple stress gauges in the borehole to form a disturbance stress monitoring system.

[0021] Optionally, during the drilling and blasting excavation process, a variety of excavation response monitoring systems are used to monitor the surrounding rock response of the drilling and blasting test tunnel, specifically including:

[0022] During the drilling and blasting excavation process, microseismic and / or acoustic emission monitoring systems are used to monitor the excavation damage of the surrounding rock of the drilling and blasting test tunnel;

[0023] The surrounding rock internal displacement monitoring system is used to continuously and dynamically measure the surrounding rock internal displacement parameters during the excavation process to obtain the time history curve of the surrounding rock internal displacement change during the whole process;

[0024] The disturbance stress monitoring system is used to monitor the stress changes during the entire process of drilling and blasting test tunnel excavation.

[0025] Optionally, the comparative analysis of the surrounding rock response characteristics and evolution laws of the TBM test tunnel and the drilling and blasting test tunnel, and guiding the TBM method and drilling and blasting method excavation processes according to the analysis results, specifically includes:

[0026] Compare and analyze the measurement range, accuracy and applicability of various excavation response monitoring methods, and build a technical system for monitoring excavation disturbances using the TBM method and drilling and blasting method;

[0027] Obtain the surrounding rock response characteristics and evolution law during the drilling and blasting excavation process, and compare them with the surrounding rock response characteristics and evolution law during the TBM excavation process to obtain the surrounding rock response comparison results;

[0028] Based on the excavation disturbance monitoring technology system of TBM and drilling and blasting methods and the surrounding rock response monitoring and comparison results, the subsequent TBM and drilling and blasting construction processes are guided.

[0029] Optionally, the TBM method and the drilling and blasting method surrounding rock excavation response comparison monitoring method further includes:

[0030] All pre-arranged boreholes are subjected to borehole wave velocity and borehole television tests before excavation to obtain the rock mass wave velocity and borehole fracture distribution characteristics.

[0031] Optionally, the TBM method and the drilling and blasting method surrounding rock excavation response comparison monitoring method further includes:

[0032] Open holes are arranged in parallel and vertical directions to the drilling and blasting test tunnels to carry out borehole television, single-hole wave velocity test, cross-hole wave velocity test, inter-well CT test and cross-hole permeability test.

[0033] Optionally, the TBM method and the drilling and blasting method surrounding rock excavation response comparison monitoring method further includes:

[0034] The hole wall coring was carried out before and after the TBM and drilling and blasting excavation, and a series of indoor tests were carried out indoors to study the changes in the physical and mechanical properties of the surrounding rock before and after excavation and to determine the damaged area of ​​the excavated surrounding rock.

[0035] Optionally, the TBM method and the drilling and blasting method surrounding rock excavation response comparison monitoring method further includes:

[0036] Small-pole-distance high-density electrical testing was performed on the TBM test tunnel and the drilling and blasting test tunnel to obtain the profile resistivity, which was used to evaluate the characteristics of a surface excavation damage area within the survey line range;

[0037] High-frequency ground penetrating radar detection was carried out on the TBM test tunnel and the drilling and blasting test tunnel to analyze the pore / crack structure of the rock mass in the damaged area and the undamaged rock mass.

[0038] Optionally, the TBM method and the drilling and blasting method surrounding rock excavation response comparison monitoring method further includes:

[0039] Conduct indoor tests on the excavated damaged area, including CT scans, fluorescence imaging tests and penetration tests;

[0040] The indoor test results were compared and analyzed with the in-situ test results of TBM and drilling and blasting excavation methods.

[0041] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0042] The present application provides a comparative monitoring method for surrounding rock excavation responses of TBM method and drilling and blasting method. With the help of the excavation process of underground engineering facilities, field tests of excavation disturbance monitoring of TBM method and drilling and blasting method are carried out. By pre-burying sensors around TBM test tunnels and drilling and blasting test tunnels, a variety of technical means are used to monitor the surrounding rock responses before, during and after TBM and drilling and blasting excavation, and obtain the excavation response characteristics and evolution laws of intact hard rock under low stress and cyclic blasting disturbance. It can quantitatively evaluate the chamber excavation characteristics of TBM method and blasting excavation, thereby providing a solid data foundation and scientific basis for guiding the subsequent TBM and drilling and blasting excavation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1 A flow chart of a method for comparative monitoring of surrounding rock excavation response using a TBM method and a drilling and blasting method is provided for this application;

[0045] Figure 2 This is a schematic diagram of the location of the main structure of the underground laboratory and the various tunnels at the -280m auxiliary test level;

[0046] Figure 3 This is a schematic diagram of the cross-section structure of the drilling and blasting test tunnel;

[0047] Figure 4 This is a schematic diagram of the numerical model of the excavation area;

[0048] Figure 5 This is a schematic diagram of the relative positions of the drilling and blasting test tunnel and the connecting tunnel;

[0049] Figure 6 This is a schematic diagram of the overall architecture of the field test technical solution;

[0050] Figure 7 This is a schematic diagram of drilling and sensor installation;

[0051] Figure 8 Schematic diagram of the analysis process of crack evolution law during drilling and blasting construction. DETAILED DESCRIPTION

[0052] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0053] The purpose of this application is to provide a comparative monitoring method for surrounding rock excavation responses of TBM and drilling and blasting methods, and to provide a scientific basis for guiding the excavation process of TBM and drilling and blasting methods through comprehensive interpretation and comparative verification of multiple excavation response monitoring methods.

[0054] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0055] This example is based on an underground laboratory project. The rock mass conditions of the underground project are high-integrity, high-strength granite; the cores with RQD>90 account for 86% of the total length; the average uniaxial compressive strength of the rock is above 170MPa, and the highest uniaxial compressive strength is 235MPa or higher; the ground stress is low, and the maximum principal stress at a depth of -280m is less than 12MPa. The main structure and rock mass conditions of the underground project provide a good basis for comparative monitoring of surrounding rock excavation responses using the TBM method and the drilling and blasting method.

[0056] See also Figure 1 The present application provides a comparative monitoring method for surrounding rock excavation response using a TBM method and a drilling and blasting method, comprising the following steps 1 to 5.

[0057] Step 1: Determine the location and cross-sectional dimensions of the TBM test tunnel, dedicated monitoring tunnel, and drilling and blasting test tunnel based on the main structure of the underground project.

[0058] After excavation by TBM and drilling and blasting, stress redistribution and excavation construction will cause rock deformation and damage. On the one hand, timely monitoring and analysis and prediction of surrounding rock deformation can ensure construction safety, prevent accidents and determine the appropriate support time. On the other hand, determine the scope of the surrounding rock damage zone, understand the formation and evolution process and distribution characteristics of excavation damage, establish a comparative relationship between the low-loss and low-disturbance excavation characteristics of the drilling and blasting method and the TBM, and analyze the impact of different excavation methods on the long-term safety of the repository. Combined with detailed geological cataloging and borehole cataloging information of the excavation section tunnel, a fine three-dimensional fracture network model is established, which can also provide a rare experimental verification example for the research on numerical analysis technology of underground laboratory engineering. Therefore, this application determines the location and cross-sectional dimensions of the TBM test tunnel, special monitoring tunnel and drilling and blasting test tunnel based on the main structure of the underground laboratory, and conducts multi-surrounding rock parameter monitoring by pre-burying sensors to achieve full-process monitoring of rock excavation response. The step 1 specifically includes:

[0059] Step 1.1: Determine the location of the TBM test tunnel based on the excavation progress of the main structure of the underground project.

[0060] like Figure 2 As shown, the present application method is mainly used in the excavation process of the underground laboratory. The main structure of the underground laboratory adopts a ramp + shaft + horizontal tunnel scheme. Among them, the ramp is connected to the two-layer horizontal tunnels of -280m and -560m. Part of the -280m horizontal tunnel has been excavated by drilling and blasting. The ramp part is excavated by TBM and is about to reach the -280m horizontal tunnel area. The present application method requires three parallel tunnels, one is a TBM excavation tunnel, called a TBM test tunnel; one is a monitoring tunnel excavated before the TBM test tunnel, called a dedicated monitoring tunnel; and one is a drilling and blasting tunnel, called a drilling and blasting test tunnel. In view of the fact that there are tunnels in the excavated tunnels in the -280m horizontal tunnel area that are parallel to the ramp section to be excavated at a depth of -280m, the ramp section to be excavated at a depth of -280m can be selected as the TBM test tunnel.

[0061] Step 1.2: Based on the location of the TBM test tunnel, determine one of the excavated tunnels as a dedicated monitoring tunnel, and ensure that the drilling and blasting test tunnel and the TBM test tunnel are symmetrically arranged with respect to the dedicated monitoring tunnel.

[0062] In the embodiment of the present application, the public area tunnel 1 is selected from the excavated tunnels as a dedicated monitoring tunnel. Figure 2In the illustrated embodiment, the distance between the public area tunnel 1 and the excavated TBM test tunnel is 22.75 m. Therefore, when the drilling and blasting test tunnel is excavated, its distance from the public area tunnel 1 is also set to 22.75 m, and the excavation length is approximately 39 m.

[0063] Step 1.3: Based on the cross-sectional dimensions of the TBM test tunnel, the cross-sectional dimensions of the drilling and blasting test tunnel are designed as a rectangular straight wall + horseshoe, circular, semicircular or three-center arch vault structure and the corresponding cross-sectional dimensions are determined.

[0064] In the embodiment of the present application, the cross section of the drilling and blasting test tunnel is designed as Figure 3 The rectangular straight wall + three-center arch vault structure shown has an overall cross-section width of 6m and a height of 6.5m. The straight wall is 4.5m high and the three-center arch part is 2m high.

[0065] Step 1.4: Determine the relative position of the drilling and blasting test tunnel and the connecting tunnel based on the cross-sectional dimensions of the drilling and blasting test tunnel, the cross-sectional dimensions of the connecting tunnel between the dedicated monitoring tunnel and the drilling and blasting test tunnel, and the layout of the key monitoring boreholes.

[0066] like Figure 4 As shown, a numerical model of the excavation area is established for numerical analysis. The model is 105×125×50m in length, width and height. The grid sizes of the communication tunnel, sensor layout tunnel (public area tunnel 1) and external surrounding rock are set as 0.5m, 0.1m and 5m. Density: 2.67g / cm 3 , elastic modulus: 61.63GPa, cohesion: 0.24. The direction y of the connecting tunnel is the direction of the maximum principal stress, the vertical stress z is the direction of the intermediate principal stress, and the TBM excavation direction x is the direction of the minimum principal stress. Number of grids: 813w; number of nodes: 1092w; grid accuracy: 0.2m. Numerical analysis shows that the maximum principal stress is 34MPa, located at the bottom of the drilling and blasting tunnel, the maximum stress of the arch is 21MPa; the maximum displacement is 1mm, located on the right side of the drilling and blasting tunnel, and the maximum displacement on the left side is 0.86mm. Therefore, it is necessary to focus on stress monitoring of the upper part of the drilling and blasting test tunnel and displacement monitoring of the side of the tunnel.

[0067] The relative position of the drilling and blasting test tunnel and the connecting tunnel is as follows: Figure 5 As shown in the figure, in order to meet the monitoring requirements of arranging boreholes at the spandrel position of the drilling and blasting test tunnel, the top of the drilling and blasting test tunnel needs to be flush with the connecting tunnel. According to the cross-sectional dimensions of the drilling and blasting test tunnel and the connecting tunnel, it is determined that the bottom of the drilling and blasting test tunnel is 2m lower than that of the connecting tunnel.

[0068] Step 2: Use dedicated monitoring tunnels to deploy multiple excavation response monitoring systems in advance, including microseismic and / or acoustic emission monitoring systems, surrounding rock internal displacement monitoring systems, and disturbance stress monitoring systems.

[0069] The overall structure of the field test technical solution of this application is as follows Figure 6 As shown, the underground laboratory excavation process is determined according to the engineering geological conditions, hydrogeological conditions, main structure design and current construction conditions, and the -280m drilling and blasting excavation disturbance monitoring and EDZ (Excavation Damaged Zone) characterization test are carried out during the excavation process. The main on-site monitoring methods of surrounding rock used in the excavation of underground engineering facilities in this application are shown in Table 1.

[0070] Table 1 On-site monitoring methods for surrounding rock used in excavation of underground engineering facilities

[0071]

[0072] The overall research goal of this application is to embed sensors around the tunnels constructed by TBM and drilling and blasting methods, use a variety of technical means to monitor the surrounding rock response before and after excavation, obtain the excavation response characteristics and evolution laws of intact hard rock under low stress and multiple blasting cycle disturbances, quantitatively evaluate the excavation characteristics of chambers under different blasting parameters, establish an underground laboratory drilling and blasting excavation disturbance monitoring technology system, and accumulate implementation experience, experimental technology and data interpretation methods for large-scale comprehensive excavation technology experiments.

[0073] The step 2 uses a dedicated monitoring tunnel to pre-arrange multiple excavation response monitoring systems, specifically including:

[0074] Step 2.1: Drill holes from the dedicated monitoring tunnel toward the drilling and blasting test tunnel and the TBM test tunnel, and install microseismic sensors and / or acoustic emission sensors in the holes to form a microseismic and / or acoustic emission monitoring system. Figure 7 As shown, boreholes are drilled from the public area tunnel 1 (i.e., the dedicated monitoring tunnel in the embodiment of the present application) toward the drilling and blasting test tunnel and the TBM test tunnel (each borehole is represented by a straight line), and corresponding sensors are installed in the boreholes (different types of sensors are represented by dots of different colors).

[0075] Among them, microseismic and / or acoustic emission monitoring utilizes a dedicated monitoring tunnel (public area tunnel 1), and pre-arranges the on-site microseismic and / or acoustic emission monitoring system to finely characterize the spatiotemporal evolution characteristics of microfractures during the drilling and blasting section excavation process, locate the surrounding rock excavation damage area, and provide support for evaluating TBM / drilling and blasting excavation disturbance and damage.

[0076] Step 2.2: One or more of a multi-point displacement meter, a fiber Bragg grating (FRP) smart reinforcement and a sliding micrometer are buried in the borehole to form a surrounding rock internal displacement monitoring system.

[0077] The monitoring of the internal displacement of the surrounding rock is to use a dedicated monitoring tunnel (public area tunnel 1) to advance the burial of multi-point displacement meters, sliding micrometers, fiber Bragg grating FRP smart bars and other displacement monitoring sensors in the direction of the TBM section / drilling and blasting section test tunnel. During the drilling and blasting excavation process, the internal displacement parameters of the surrounding rock are continuously and dynamically measured to obtain the time history curve of the whole process of the internal displacement of the surrounding rock and the proportion of loss displacement, revealing the evolution characteristics and spatial effects of the internal displacement. At the same time, the three monitoring methods of multi-point displacement meters, sliding micrometers and fiber Bragg grating FRP smart bars are compared and verified with each other.

[0078] Step 2.3: Install multiple stress gauges in the borehole to form a disturbance stress monitoring system.

[0079] Disturbance stress monitoring uses sensors such as strain gauge multi-point stress gauges and optical fiber multi-point stress gauges to monitor the changes in ground stress and disturbance stress during the entire process of TBM / drilling and blasting excavation.

[0080] In field tests, excavation response monitoring methods can also include cave wall rock cutting detection methods, EDZ on-site rapid non-destructive detection methods, and borehole wave velocity and borehole television testing methods.

[0081] Among them, the method of fine characterization of rock block cutting and excavation damage in the cave wall refers to carrying out rock block cutting in the cave wall at the junction of the test section, carrying out crack staining and block cutting after obtaining large-sized rock blocks, and conducting fine cataloging of macro cracks in the rock body, and conducting rock microscopic characteristics and permeability tests to complete the three-dimensional reconstruction of cracks in the damaged area and fine damage characterization.

[0082] The EDZ on-site rapid non-destructive detection method refers to arranging survey lines on the bottom plate and side walls of the tunnel, carrying out small-pole-spacing high-density electrical detection and high-frequency geological radar detection at each drilling and blasting test cycle position, and accurately measuring the conductivity response and radar response characteristics of the surrounding rock damage zone.

[0083] The borehole wave velocity and borehole television testing method is to conduct borehole wave velocity and borehole television tests on all pre-arranged boreholes before excavation, and to conduct borehole acoustic wave and borehole television tests on bare holes before and after excavation; at the same time, the borehole wave velocity and borehole television tests are carried out using 8 boreholes arranged by rock block cutting to obtain the rock mass wave velocity and borehole fracture distribution characteristics before cutting the rock block.

[0084] Field tests need to comply with the following principles: 1) Systematic principle: monitoring items are organically combined to form a whole; make full use of drilling holes and multi-parameter coupling; 2) Reliability principle: ensure high-precision data; appropriate sensor selection, layout, installation / grouting; 3) Principle of integration with the construction site: take into account the monitoring of the excavation response of the original fracture according to the on-site conditions; 4) Timely feedback principle: monitoring data is timely and accurate, and feedback is fast; 5) Economic rationality principle: improve work efficiency and reduce costs.

[0085] Through comprehensive interpretation and comparative verification of the above-mentioned monitoring methods, and comparative analysis of the measurement range, accuracy and applicability of various monitoring methods, we can build an underground laboratory TBM / drilling and blasting excavation disturbance monitoring technology system and provide the most suitable monitoring method for the current excavation area within the target measurement range and accuracy.

[0086] Step 3: During the drilling and blasting excavation process, a variety of excavation response monitoring systems are used to monitor the surrounding rock response of the drilling and blasting test tunnel.

[0087] During the drilling and blasting excavation process, a variety of excavation response monitoring systems are used to monitor the surrounding rock response of the drilling and blasting test tunnel, including:

[0088] Step 3.1: During the drilling and blasting excavation process, a microseismic and / or acoustic emission monitoring system is used to monitor the excavation damage of the surrounding rock of the drilling and blasting test tunnel.

[0089] During the excavation of surrounding rock, the changes in the mechanical properties of granite under long-term load can be studied by monitoring microseismic and / or acoustic emission (AE) technology. During the excavation process, the number of AE impacts usually has the following changes: 1) Initial stage: When the specimen is in a low stress state, the number of AE impacts is small, which is mainly related to the release of random defects and micro cracks inside the material; 2) Creep stage: With the passage of time and the continuous application of external stress, the number of AE impacts will gradually increase, indicating that more significant deformation and micro-destruction processes have occurred inside the material; 3) Acceleration stage: When the material is close to failure, the number of AE impacts rises sharply, because crack extension and merging lead to more AE events; 4) Destruction stage: At the final destruction, the number of AE impacts reaches a peak, and then drops rapidly (or disappears completely), indicating the failure of the material.

[0090] The relationship between the number of acoustic emission impacts N and time t can be described by the following formula:

[0091] N(t)=N0+β(1-e αt )(1)

[0092] Where N(t) represents the number of acoustic emission impacts at time t. N0 represents the constant of the initial acoustic emission activity, representing the AE activity benchmark of the material in the initial stage. α is the time factor, which represents the rate at which the number of AE impacts increases rapidly with the increase of time during the creep process of the material. β is the basic constant affected by the acoustic emission activity, which represents the basic level of AE activity under the influence of a certain acoustic emission activity. By fitting the field monitoring data of the microseismic and / or acoustic emission monitoring system, the specific parameter values ​​suitable for a specific type of granite material can be further refined. The initial creep process of rock is a rock viscous elastic damage process, and the acoustic emission activity is a direct manifestation of the damage process. The viscoelastic damage process of rock during the creep process can be well characterized according to the acoustic emission activity.

[0093] Step 3.2: Use the surrounding rock internal displacement monitoring system to continuously and dynamically measure the surrounding rock internal displacement parameters during the excavation process to obtain the time history curve of the surrounding rock internal displacement change during the entire process.

[0094] Draw the time history curve of the whole process of displacement change of surrounding rock obtained by various monitoring methods, and analyze the displacement size at different monitoring positions. Draw the LDP curve reflecting the rock stress state, surrounding rock characteristics and the influence of excavation disturbance, and analyze the spatial effect of surrounding rock excavation.

[0095] Step 3.3: Use the disturbance stress monitoring system to monitor the stress variation during the entire excavation process of the drilling and blasting test tunnel.

[0096] Step 3.4: Conduct borehole velocity and borehole television tests on all pre-arranged boreholes before excavation to obtain rock mass velocity and borehole fracture distribution characteristics.

[0097] Step 3.5: Open holes are arranged in parallel and vertical directions to the drilling and blasting test tunnels to conduct borehole television, single-hole wave velocity test, cross-hole wave velocity test, inter-well CT test and cross-hole permeability test.

[0098] Step 3.6: Take coring samples from the tunnel wall before and after the drilling and blasting excavation, and conduct a series of indoor tests to study the changes in the physical and mechanical properties of the surrounding rock before and after excavation and determine the damaged area of ​​the excavated surrounding rock.

[0099] Step 3.7: Conduct small-pole-spacing high-density electrical testing on the drill-and-blast test tunnel to obtain the profile resistivity, which is used to evaluate the characteristics of a face excavation damage zone within the survey line range.

[0100] Step 3.8: Conduct high-frequency ground penetrating radar detection on the drilling and blasting test tunnel to analyze the pore / crack structure of the rock mass in the damaged area and the undamaged rock mass.

[0101] Step 3.9: Conduct indoor tests on the damaged excavation area, including CT scanning, fluorescence imaging test, and penetration test; compare and analyze the indoor test results with the in-situ test results of the drilling and blasting excavation.

[0102] Step 4: During the TBM excavation process, a variety of excavation response monitoring systems are used to monitor the surrounding rock response of the TBM test tunnel.

[0103] The monitoring methods during TBM excavation are similar to those for drilling and blasting and will not be elaborated here.

[0104] Step 5: Compare and analyze the surrounding rock response characteristics and evolution laws of the TBM test tunnel and the drilling and blasting test tunnel, and guide the TBM and drilling and blasting excavation processes based on the analysis results.

[0105] Step 5.1: By comparing and analyzing the measurement range, accuracy and applicability of various excavation response monitoring methods, a technical system for monitoring excavation disturbances using the TBM and drilling and blasting methods can be constructed.

[0106] The interpretation results of the surrounding rock internal displacement include the monitoring data of multi-point displacement meter, sliding micrometer, and fiber Bragg grating FRP intelligent reinforcement. The interpretation results of stress, displacement and damage include the monitoring data of multi-point stress meter, multi-point displacement meter and acoustic emission, as well as the interpretation results of acoustic emission monitoring sensor and microseismic monitoring sensor data. The acoustic emission and microseismic monitoring, stress and internal displacement results are verified by combining the borehole TV and cave wall coring test results to evaluate the applicability of various test methods. In this way, a set of surrounding rock disturbance monitoring technology and solutions suitable for hard rock drilling and blasting excavation can be integrated.

[0107] Step 5.2: Obtain the surrounding rock response characteristics and evolution law during the drilling and blasting excavation process, and compare them with the surrounding rock response characteristics and evolution law during the TBM excavation process to obtain the surrounding rock response comparison results. Figure 8 As shown, it includes: obtaining test data, obtaining borehole TV / sonic test measurement results and core logging results before, during and after drilling and blasting; analyzing the structural characteristics of the original fractures in the test chamber; comparing the fracture occurrence before and after each round of drilling and blasting; and obtaining the fracture evolution characteristics during drilling and blasting. The combined use of multiple EDZ characterization methods can finely characterize the EDZ range under different blasting parameters / TBM excavation parameters, thereby evaluating the adaptability of different EDZ characterization methods under current conditions.

[0108] Step 5.3: Based on the excavation disturbance monitoring technology system of TBM method and drilling and blasting method and the surrounding rock response monitoring and comparison results, guide the subsequent TBM method and drilling and blasting method construction process.

[0109] Aiming at the problem of mechanical deformation and damage of granite during TBM and drilling and blasting excavation, this application conducts field tests on TBM and drilling and blasting excavation disturbance monitoring on the -280m test platform with the help of underground laboratory excavation process. By pre-burying sensors around the tunnels for TBM and drilling and blasting excavation, and using a variety of technical means to monitor the surrounding rock response before, during and after TBM and drilling and blasting excavation, the excavation response characteristics and evolution laws of intact hard rock under low stress and cyclic blasting disturbance can be obtained, which can quantitatively evaluate the chamber excavation characteristics of TBM and blasting excavation, thereby providing a solid data foundation for guiding the subsequent TBM and drilling and blasting excavation process. Establish a comparative relationship between the low-loss, low-disturbance excavation characteristics of TBM and excavation by drilling and blasting; establish a technical system for monitoring disturbances during TBM excavation and drilling and blasting excavation in underground laboratories, and accumulate implementation experience, experimental technology and data interpretation methods for subsequent large-scale comprehensive excavation technology experiments; after the excavation is completed, carry out wall cutting, detailed cataloging of cracks and micro-damage characteristic testing in the surrounding rock of the tunnel excavated with different driving parameters, and finely excavate the damage characteristics of the surrounding rock, and carry out in-situ testing such as wave velocity, borehole television, high-density electrical method and geological radar to obtain the detection response characteristics of the surrounding rock in the damaged area, and combine the crack-pore distribution characteristics in the damaged area to reveal the inherent mechanism of the geophysical detection response in the damaged area, providing a solid theoretical basis for underground engineering excavation.

[0110] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A method for monitoring the excavation response comparison of surrounding rock using TBM and drilling and blasting methods, characterized in that: include: Determine the location and cross-sectional dimensions of the TBM test tunnel, dedicated monitoring tunnel, and drilling and blasting test tunnel based on the main structure of the underground project; Use special monitoring tunnels to deploy multiple excavation response monitoring systems in advance, including microseismic and / or acoustic emission monitoring systems, surrounding rock internal displacement monitoring systems, and disturbance stress monitoring systems; During the drilling and blasting excavation process, various excavation response monitoring systems are used to monitor the surrounding rock response of the drilling and blasting test tunnel; During the TBM excavation process, various excavation response monitoring systems are used to monitor the surrounding rock response of the TBM test tunnel; The surrounding rock response characteristics and evolution laws of the TBM test tunnel and the drilling and blasting test tunnel were compared and analyzed, and the TBM and drilling and blasting excavation processes were guided according to the analysis results.

2. The method for comparative monitoring of surrounding rock excavation response using TBM and drilling and blasting methods according to claim 1 is characterized in that: The location and cross-sectional dimensions of the TBM test tunnel, the dedicated monitoring tunnel and the drilling and blasting test tunnel are determined based on the main structure of the underground project, specifically including: Determine the location of the TBM test tunnel based on the excavation progress of the main structure of the underground project; Based on the location of the TBM test tunnel, one tunnel is selected from the excavated tunnels as a dedicated monitoring tunnel, and the drilling and blasting test tunnel and the TBM test tunnel are arranged symmetrically with respect to the dedicated monitoring tunnel. Based on the cross-sectional dimensions of the TBM test tunnel, the cross-sectional dimensions of the drilling and blasting test tunnel are designed as a rectangular straight wall + horseshoe, circular, semicircular or three-center arch vault structure and the corresponding cross-sectional dimensions are determined; The relative position of the drilling and blasting test tunnel and the connecting tunnel is determined based on the cross-sectional dimensions of the drilling and blasting test tunnel, the cross-sectional dimensions of the connecting tunnel between the dedicated monitoring tunnel and the drilling and blasting test tunnel, and the layout positions of the key monitoring boreholes.

3. The method for comparative monitoring of surrounding rock excavation response using TBM and drilling and blasting methods according to claim 2 is characterized in that: The use of a dedicated monitoring tunnel to pre-arrange a variety of excavation response monitoring systems specifically includes: Drill holes from the dedicated monitoring tunnel toward the drilling and blasting test tunnel and the TBM test tunnel, and install microseismic sensors and / or acoustic emission sensors in the holes to form a microseismic and / or acoustic emission monitoring system; One or more of a multi-point displacement meter, a fiber Bragg grating (FRP) intelligent reinforcement and a sliding micrometer are buried in the borehole to form a surrounding rock internal displacement monitoring system; Install multiple stress gauges in the borehole to form a disturbance stress monitoring system.

4. The method for comparative monitoring of surrounding rock excavation response using TBM and drilling and blasting methods according to claim 3 is characterized in that: During the drilling and blasting excavation process, a variety of excavation response monitoring systems are used to monitor the surrounding rock response of the drilling and blasting test tunnel, specifically including: During the drilling and blasting excavation process, microseismic and / or acoustic emission monitoring systems are used to monitor the excavation damage of the surrounding rock of the drilling and blasting test tunnel; The surrounding rock internal displacement monitoring system is used to continuously and dynamically measure the surrounding rock internal displacement parameters during the excavation process to obtain the time history curve of the surrounding rock internal displacement change during the whole process; The disturbance stress monitoring system is used to monitor the stress changes during the entire process of drilling and blasting test tunnel excavation.

5. The method for comparative monitoring of surrounding rock excavation response using TBM and drilling and blasting methods according to claim 4 is characterized in that: The comparative analysis of the surrounding rock response characteristics and evolution laws of the TBM test tunnel and the drilling and blasting test tunnel, and the guidance of the TBM method and drilling and blasting method excavation process according to the analysis results, specifically include: Compare and analyze the measurement range, accuracy and applicability of various excavation response monitoring methods, and build a technical system for monitoring excavation disturbances using the TBM method and drilling and blasting method; Obtain the surrounding rock response characteristics and evolution law during the drilling and blasting excavation process, and compare them with the surrounding rock response characteristics and evolution law during the TBM excavation process to obtain the surrounding rock response comparison results; Based on the excavation disturbance monitoring technology system of TBM and drilling and blasting methods and the surrounding rock response monitoring and comparison results, the subsequent TBM and drilling and blasting construction processes are guided.

6. The method for comparative monitoring of surrounding rock excavation response using TBM and drilling and blasting methods according to claim 3, characterized in that: Also includes: All pre-arranged boreholes are subjected to borehole wave velocity and borehole television tests before excavation to obtain the rock mass wave velocity and borehole fracture distribution characteristics.

7. The method for comparative monitoring of surrounding rock excavation response using TBM and drilling and blasting methods according to claim 2, characterized in that: Also includes: Open holes are arranged in parallel and vertical directions to the drilling and blasting test tunnels to carry out borehole television, single-hole wave velocity test, cross-hole wave velocity test, inter-well CT test and cross-hole permeability test.

8. The method for comparative monitoring of surrounding rock excavation response using TBM and drilling and blasting methods according to claim 1, characterized in that: Also includes: The hole wall coring was carried out before and after the TBM and drilling and blasting excavation, and a series of indoor tests were carried out indoors to study the changes in the physical and mechanical properties of the surrounding rock before and after excavation and to determine the damaged area of ​​the excavated surrounding rock.

9. The method for comparative monitoring of surrounding rock excavation response using TBM and drilling and blasting methods according to claim 1, characterized in that: Also includes: Small-pole-distance high-density electrical testing was performed on the TBM test tunnel and the drilling and blasting test tunnel to obtain the profile resistivity, which was used to evaluate the characteristics of a surface excavation damage area within the survey line range; High-frequency ground penetrating radar detection was carried out on the TBM test tunnel and the drilling and blasting test tunnel to analyze the pore / crack structure of the rock mass in the damaged area and the undamaged rock mass.

10. The method for comparative monitoring of surrounding rock excavation response using TBM and drilling and blasting methods according to claim 1, characterized in that: Also includes: Conduct indoor tests on the excavated damaged area, including CT scans, fluorescence imaging tests and penetration tests; The indoor test results were compared and analyzed with the in-situ test results of TBM and drilling and blasting excavation methods.

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