Dynamic accurate control method for surrounding rock of roadway

Abstract

The invention discloses a roadway surrounding rock dynamic accurate control method, and relates to the technical field of underground roadway surrounding rock control. The technical problem that in the prior art, blindness exists in support design in roadway surrounding rock control is solved. The method comprises the steps that a data collection and analysis system is used for collecting and analyzing mine geological data and evaluating geomechanics key indexes; the stability influence factor analysis system evaluates the existing roadway support stability by classifying the roadway surrounding rock stability; a targeted supporting scheme is provided in combination with an existing supporting scheme, related standards are established, and continuous dynamic optimization and improvement are conducted on follow-up supporting design. According to the method, dynamic analysis and targeted design are carried out on the roadway, roadway deformation can be effectively controlled, the comprehensive cost of roadway supporting is reduced, the roadway tunneling efficiency is improved, the problem of coal mine excavation imbalance is solved, safety accidents caused by supporting design are avoided, and dynamic precise control over surrounding rock of the underground roadway is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of underground tunnel surrounding rock control, and in particular to a method for dynamic and precise control of tunnel surrounding rock. Background Art

[0002] During tunnel excavation and face mining, we often face risks brought by complex stress environments and geological uncertainties. Tunnel surrounding rock accidents are highly concealed, sudden, and have rapid dynamic evolution, which seriously threaten the safety of life and property. Traditional tunnel support methods often take a point-to-surface approach without considering the specific characteristics of different locations in the tunnel. The design of the support structure of the traditional support method lacks specificity in controlling the surrounding rock of the tunnel, and has poor adaptability under complex geological conditions, resulting in a high rate of support repairs, increasing the comprehensive cost of tunnel support, and delaying the construction period, causing a certain degree of mining imbalance, which directly or indirectly brings economic losses.

[0003] Research reports on the prior art include: CN 115726809 A discloses a comprehensive control method for three-dimensional mining area surrounding rock deformation under high stress and complex conditions, including step A, active support for deep mining area surrounding rock deformation control; step B, building a three-dimensional mining area dynamic pressure and deformation monitoring system based on LabVIEW and intelligent optical fiber sensors; step C, building a mining area dynamic pressure and deformation visualization and early warning system; step D, building a dynamic deformation intelligent monitoring and control system. This prior art is based on the selection of appropriate deep mining area surrounding rock deformation control active support, and establishes a three-dimensional mining area dynamic pressure and deformation monitoring system based on LabVIEW and intelligent optical fiber sensors, combined with remote real-time visualization monitoring and prediction of mining area dynamic pressure and deformation fracture. CN116306245A discloses a three-dimensional dynamic quantitative evaluation method for the stability of surrounding rock of deep hard rock tunnels, which relates to the field of deep tunnel surrounding rock stability assessment and intelligent construction technology. The method includes: dynamic determination of tunnel geology and surrounding rock parameters based on digital means and on-site in-situ testing means; rapid calculation of stress distribution in the damage zone based on the GZZ three-dimensional strength criterion and considering three-dimensional complex high ground stress; and rapid quantitative solution method for the distribution morphology of the damage zone based on artificial intelligence algorithm. This prior art takes stress precise control and refined analysis as the tunnel design concept, and on the basis of considering the surrounding rock joints, cracks, excavation disturbances and surrounding rock strength characteristics and mechanical mechanisms of deep tunnels, it uses the powerful global optimization ability of intelligent algorithms and the high-efficiency calculation characteristics of traditional analysis methods to obtain a programmed process for calculating the surrounding rock damage zone.

[0004] Although the above-mentioned prior art has studied the deformation of surrounding rocks, it is still unable to achieve dynamic and precise control of tunnel surrounding rocks. Summary of the invention

[0005] The purpose of the present invention is to provide a method for dynamic and precise control of tunnel surrounding rock, which solves the problem of blind support design in existing tunnel surrounding rock control. The method of the present invention dynamically analyzes the tunnel and designs targeted support schemes, thereby realizing dynamic and precise control of coal mine tunnel surrounding rock.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for dynamic and precise control of tunnel surrounding rock, comprising the following steps:

[0008] Step 1: Establish a dynamic and precise control system for tunnel surrounding rock, including a data collection and analysis system, a stability influencing factor analysis system, a surrounding rock control system and a continuous dynamic optimization system. The data collection and analysis system includes a mine basic data collection and analysis module and a field data acquisition module; the stability influencing factor analysis system includes a surrounding rock geomechanics evaluation module and a support system stability evaluation module; the surrounding rock control system includes a targeted support scheme design module; the continuous dynamic optimization system includes a mine pressure and support real-time monitoring module and a support update module;

[0009] Step 2: Obtain key indicators of mine geomechanics evaluation through the mine basic data collection and analysis module and the field data acquisition module. The key indicators of mine geomechanics evaluation mainly include: roof strength, roof integrity, roof rock distribution complexity, geological structure, rock layer occurrence and mining stress impact;

[0010] Step 3: Calculate the sum of the weights of the key indicators of mine geomechanics assessment through the surrounding rock geomechanics assessment module, as shown in formula (1):

[0011]

[0012] In formula (1): W t is the stability index; W i is the quantitative result of the i-th geological indicator; W imax is the maximum value of the quantitative result of the indicator; i is the key factor number; n is the total number of key factors;

[0013] The surrounding rock grade of the tunnel is classified according to the sum of all index weights. t When ≤0.2, it indicates that the tunnel surrounding rock stability level is level 1; when 0.2 <W t When ≤0.4, it indicates that the tunnel surrounding rock stability level is level 2; when 0.4 <W t When ≤0.6, it indicates that the tunnel surrounding rock stability level is level 3; when 0.6 <W t When W ≤0.8, it indicates that the tunnel surrounding rock stability level is level 4; tWhen >0.8, it indicates that the stability grade of the tunnel surrounding rock is Grade 5;

[0014] Step 4: Design a targeted support scheme based on the stability grade of the tunnel surrounding rock and in combination with the targeted support scheme design module;

[0015] Step 5: Use the mine pressure and support real-time monitoring module to observe the mine pressure and support stability in real time, and use the support update module to dynamically optimize and improve the current tunnel support design in combination with the tunnel surrounding rock stability grade.

[0016] In the above-mentioned method for dynamic and precise control of tunnel surrounding rock, in step one, the mine basic data collection and analysis module mainly collects and analyzes mine production and construction data, stratum and mineable coal seam occurrence data, geological structure data, and hydrogeological conditions data; the field data acquisition module mainly includes gas content data, impact tendency and spontaneous combustion.

[0017] In the above-mentioned method for dynamic and precise control of tunnel surrounding rock, in step three, the support system stability evaluation module evaluates the rationality of the tunnel anchor mesh support design, the matching of support products, the on-site construction quality, the stability of the existing support system and the construction process.

[0018] In the above-mentioned method for dynamic and precise control of tunnel surrounding rock, the key indicators evaluated by the support system stability evaluation module include the preload of the support body, the stress on the support body, the amount of tunnel movement, the range of loose damage or the expansion of cracks.

[0019] In the above-mentioned method for dynamic and precise control of tunnel surrounding rock, in step five, when monitoring the change of mine pressure, the data collection frequency is once an hour, and the monitored data is transmitted to the control center in real time via a wireless network to realize remote data monitoring and early warning.

[0020] In the above-mentioned method for dynamic and precise control of tunnel surrounding rock, the real-time support monitoring module predicts the future deformation trend of the tunnel by analyzing the data, and thus performs support design through a targeted support scheme design module.

[0021] In the above-mentioned method for dynamic and precise control of tunnel surrounding rock, in step five, the mine pressure and support stability are observed in real time through the mine pressure and support real-time monitoring module 100m before construction, and the corresponding monitoring frequency and duration are set for different construction stages and support types.

[0022] Compared with the prior art, the present invention brings the following beneficial technical effects:

[0023] The present invention forms a dynamic and precise control system for precise control of tunnel surrounding rocks by combining a data collection and analysis system, a stability influencing factor analysis system, a surrounding rock control system and a continuous dynamic optimization system.

[0024] In the present invention, the data collection and analysis system is used to collect and analyze mine geological data and evaluate key geomechanical indicators; the stability influencing factor analysis system classifies the stability of the tunnel surrounding rock and evaluates the stability of the existing tunnel support; combined with the existing support scheme, a targeted support scheme is proposed, relevant standards are established, and subsequent support designs are continuously and dynamically optimized and improved.

[0025] The present invention performs dynamic analysis and targeted design of tunnels, can effectively control tunnel deformation, reduce the comprehensive cost of tunnel support, improve tunnel excavation efficiency, solve the problem of coal mining imbalance, avoid safety accidents caused by support design, and realize dynamic and precise control of surrounding rock of underground tunnels. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 , Figure 2 This is a flow chart of the dynamic and precise control method of tunnel surrounding rock of the present invention.

[0027] Figure 3 It is a schematic diagram of the dynamic and precise control system of tunnel surrounding rock of the present invention. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0029] like Figure 3 As shown, the present invention establishes a dynamic and precise control system for tunnel surrounding rock, including a data collection and analysis system, a stability influencing factor analysis system, a surrounding rock control system and a continuous dynamic optimization system.

[0030] The above-mentioned data collection and analysis system includes a mine basic data collection and analysis module and a field data acquisition module; the mine basic data collection and analysis module and the field data acquisition module are both for collecting and analyzing the mine geomechanical indicators, among which the main factors in the mine basic data collection and analysis module are: collecting and analyzing the mine production and construction situation, the occurrence of strata and mineable coal seams, geological structure, hydrogeological conditions and other geological conditions. Among them, the mine production and construction situation includes the mining situation of surrounding mines, the mine production system, and the future mining plan of the mine; the occurrence of strata and mineable coal seams includes regional stratum distribution, coal-bearing stratum distribution characteristics, basic occurrence of coal seams, and basic conditions of coal seam roof and floor; geological structure includes regional geological structure characteristics and coal mine geological structure distribution characteristics; hydrogeological conditions include; other geological conditions include gas, rock burst, spontaneous combustion, etc. The field data acquisition module is to conduct field tests to supplement the mine basic data collection and analysis module.

[0031] The key indicators of mine geomechanical evaluation mainly include: exposed rock layer thickness, exposed rock layer inclination, parameters related to the range of twice the tunnel height, geological structure, hydrogeological conditions, tunnel burial depth, original rock stress magnitude and direction, maximum horizontal stress and angle in the axial direction of the tunnel, tunnel shape and geometric dimensions, tunnel excavation method, coal rock pillar width, mining stress and bonding strength; specifically, the exposed rock layer thickness is obtained through drilling to help understand the mechanical properties of the rock mass and guide support design; the number of rock layers, thickness of each layer and spacing of each joint and fissure in the range of twice the tunnel height are obtained through drilling; the physical and mechanical parameters of each layer are measured in the laboratory through on-site coring; the geological structure is obtained through geological exploration drilling, geophysical detection and geological mapping; the hydrogeological conditions are obtained through hydrogeological drilling and advance water exploration and release at the working face; the original rock stress magnitude and direction are obtained through comprehensive analysis of drilling stress relief method or hydraulic fracturing method and laboratory numerical simulation.

[0032] The stability influencing factor analysis system includes a surrounding rock geomechanics assessment module and a support system stability evaluation module; the surrounding rock control system includes a targeted support scheme design module; the continuous dynamic optimization system includes a mine pressure and support real-time monitoring module and a support update module.

[0033] As the main technical concept of the present invention, the present invention realizes dynamic and precise control of surrounding rock of coal mine tunnels by dynamically analyzing the tunnels and designing targeted support schemes.

[0034] Combination Figure 1 and Figure 2 As shown, the present invention provides a method for dynamic and precise control of tunnel surrounding rock, which specifically includes the following steps:

[0035] Step 1: Establish the above-mentioned tunnel surrounding rock dynamic precision control system, collect mine geological data, and obtain key indicators of geomechanical evaluation for mine production and construction conditions, strata and mineable coal seam occurrence conditions, geological structures, hydrogeological conditions and other geological conditions;

[0036] Step 2: Obtain key indicators of mine geomechanics evaluation through the mine basic information collection and analysis module and the field data acquisition module. The key indicators of mine geomechanics evaluation mainly include: roof strength, roof integrity, complexity of roof rock distribution, geological structure, rock layer occurrence, and mining stress impact.

[0037] The surrounding rock geomechanical evaluation module assigns values ​​to the key indicators of mine geomechanical evaluation obtained by the data collection and analysis system, as shown in Table 1.

[0038] Table 1 Quantitative table of geomechanical evaluation indicators

[0039]

[0040] The above key indicators of mine geomechanics evaluation are quantified, and the sum of the weights of the key indicators of mine geomechanics evaluation is calculated through the surrounding rock geomechanics evaluation module, as shown in formula (1):

[0041]

[0042] In formula (1): W t is the stability index; W i is the quantitative result of the i-th geological indicator; W imax is the maximum value of the quantitative result of the indicator; i is the key factor number; n is the total number of key factors.

[0043] The surrounding rock grade of the tunnel is classified according to the sum of all index weights. t When ≤0.2, it indicates that the tunnel surrounding rock stability level is level 1; when 0.2 <W t When ≤0.4, it indicates that the tunnel surrounding rock stability level is level 2; when 0.4 <W t When ≤0.6, it indicates that the tunnel surrounding rock stability level is level 3; when 0.6 <W t When W ≤0.8, it indicates that the tunnel surrounding rock stability level is level 4; t When >0.8, it indicates that the stability grade of the tunnel surrounding rock is level five.

[0044] The tunnel surrounding rock grade is classified, and the specific classification standards are shown in Table 2.

[0045] Table 2 Classification of tunnel surrounding rock stability

[0046] Stability grade of tunnel surrounding rock steady state Stability Index Ⅰ Very stable <![CDATA[W t ≤0.2]]> Ⅱ Stablize <![CDATA[0.2<W t ≤0.4]]> Ⅲ Moderately stable <![CDATA[0.4<W t ≤0.6]]> Ⅳ Unstable <![CDATA[0.6<W t ≤0.8]]> Ⅴ Very unstable <![CDATA[W t >0.8]]>

[0047] The stability of existing supports is evaluated based on the stability influencing factor analysis system, specifically:

[0048] First, based on the support stability evaluation module, the support stability is comprehensively judged through the rationality of the tunnel anchor wire support design, the matching of the support equipment, the quality of on-site construction, the stability of the existing support system, and the construction process. Second, the rationality of the tunnel anchor wire support design includes the rationality of the support parameters, the pertinence of the support design, the temporary support strength, and the advance support strength. Third, for the matching of support products, the rationality of anchor rods, anchor cables and configurations is tested in the laboratory; the rationality test of anchor rods and accessories is analyzed in the underground torque conversion, and the rationality of surface support, long-term anchoring effect and strength matching relationship of each accessory are verified through pull-out test; Fourth, for the quality of on-site construction, whether the installation stress corresponds to the installation torque is tested on-site to evaluate the rationality of the preload; according to the requirements of national standards, the rationality of the anchor length and anchoring force requirements is evaluated; Fifth, the initial support efficiency, long-term support efficiency, tunnel movement, and loose damage range are analyzed together; Sixth, using the acoustic wave method, an ultrasonic transmitter is used to emit sound waves to the anchor rod, and the time or speed of the sound wave propagation in the anchor rod is recorded. The preload is calculated based on the relationship between the change in sound wave propagation and the tension of the anchor rod; Seventh, a dynamometer is installed between the free section of the anchor rod or the nut and the support plate to measure the force borne by the anchor rod. The force borne by the anchor rod should be 60% to 90% of the yield strength; Eighth, the distance between two points in the tunnel is measured by a laser rangefinder to calculate the surface movement. Select a measurement point on the tunnel surface to ensure that the position is fixed; use a laser rangefinder to measure the initial distance between the two points; regularly use a laser rangefinder to measure the current distance; calculate the amount of movement: surface movement = initial distance - current distance. The tunnel surface movement should be less than 80% of the critical shrinkage; ninth, arrange sound wave transmitters and receivers on both sides of the tunnel or on the top and bottom plates to ensure that the measurement area is covered; emit sound waves and record the arrival time of the sound waves at the receiving end; calculate the wave velocity distribution based on the sound wave propagation distance and time, and determine the damage range in combination with the wave velocity distribution diagram.

[0049] Step 3: Design a targeted support scheme based on the stability grade of the tunnel surrounding rock and combine it with the targeted support scheme design module, and establish relevant standards.

[0050] Specifically, based on the targeted support scheme design module, the tunnel design is carried out in accordance with the concepts of active support, "three highs and one low" (high strength, high stiffness, high reliability and low density), targeted design, targeted special design for special locations, targeted special design for special geology, adaptation of support materials to site conditions, continuous dynamic optimization and improvement, and stability throughout the life cycle.

[0051] The "three highs and one low" plan is: use high-strength anchor rods to ensure the support system's ability to control the surrounding rock; increase the preload of the anchor rods, increase the support stiffness, effectively control the initial deformation and harmful delamination of the surrounding rock within the anchor support range, improve the integrity of the reinforced surrounding rock, and ensure the initial support efficiency of the anchor support system; the anchor position of anchor rods and anchor cables should be in stable rock formations to ensure their long-term anchoring performance.

[0052] The targeted design concept is: the support design should be based on the tunnel's own surrounding rock structure, the distribution law of the roof surrounding rock, the mechanical parameters of the roof surrounding rock, the changes in the stress environment of the tunnel throughout its life cycle, the anchorage of each rock layer and other parameters to conduct a geomechanical evaluation of the tunnel, and then divide the difficulty of the tunnel support into different levels, and propose targeted support scheme designs for different factors that affect the stability of the tunnel support.

[0053] The concept of targeted special design for special locations is: for special locations with large changes in roof structure, focus on the coupled support design of anchor cable support system and anchor rod support system to control the delamination deformation of weakly cemented surrounding rock and improve the safety factor of tunnel support.

[0054] The concept of targeted special design for special geological conditions is: targeted special design is carried out for special geological conditions such as geological structural zones, broken roofs, abnormal stress areas, and roof water dripping. For areas where the stability of anchor net cable support is difficult to ensure, anchor net cable + scaffolding combined support can be adopted; advance grouting reinforcement measures are taken in loose and broken areas of the roof near the fault.

[0055] The principle of adapting support materials to site conditions is as follows: surface support must have certain strength, toughness and protected surface area; when selecting metal mesh, focus on adapting it to the service life of the tunnel and the integrity of the surface surrounding rock; anchor rods and anchor cable accessories should be adapted to the strength of the rod or cable body.

[0056] The concept of continuous dynamic optimization and improvement principle is: after the support scheme design is proposed, systematic monitoring and mine pressure monitoring are carried out 100m before construction, the scheme design is fed back according to the test and monitoring results, and the tunnel support stability evaluation is carried out, and then continuous optimization design is carried out.

[0057] The concept of the whole life cycle stability principle is: the tunnel support design needs to consider the support stability at different stress environment change stages during the whole life cycle (the preparation of tunnels in the mining area shall consider the impact of mining in nearby working faces, and the stability of the drift shall consider the action of advance support pressure).

[0058] Step 4: Use the mine pressure and support real-time monitoring module to observe the mine pressure and support stability in real time, and use the support update module to dynamically optimize and improve the current tunnel support design in combination with the tunnel surrounding rock stability grade.

[0059] Specifically, based on the real-time monitoring module of mine pressure and support, systematic monitoring and mine pressure monitoring are carried out at least 100m in front of the working surface. According to different construction stages and support types, the corresponding monitoring frequency and duration are set, such as monthly monitoring after tunnel support, and long-term monitoring data are used as the basis for safety assessment; further, data analysis and processing should be based on the monitoring data, analyze the deformation and stress changes of the tunnel, and issue timely warnings and formulate emergency treatment plans; safety assessment standards should evaluate the support stability based on the monitoring results, set danger thresholds, and ensure that remedial measures can be taken in time when problems are found.

[0060] Based on the support update module, combined with the surrounding rock stability level of the current tunnel location and the existing support system stability evaluation, the current tunnel support design is dynamically optimized and improved.

[0061] Parts not described in the present invention can be implemented by referring to the existing technology.

[0062] Those skilled in the art should recognize that the above implementation modes are only used to illustrate the present application, and are not used as limitations on the present application. As long as they are within the essential spirit of the present application, appropriate changes and modifications made to the above embodiments should fall within the scope of protection of the claims of the present application.

Claims

1. A method for dynamic and precise control of tunnel surrounding rock, characterized in that: The following steps are involved: Step 1: Establish a dynamic and precise control system for tunnel surrounding rock, including a data collection and analysis system, a stability influencing factor analysis system, a surrounding rock control system and a continuous dynamic optimization system. The data collection and analysis system includes a mine basic data collection and analysis module and a field data acquisition module; the stability influencing factor analysis system includes a surrounding rock geomechanics evaluation module and a support system stability evaluation module; the surrounding rock control system includes a targeted support scheme design module; the continuous dynamic optimization system includes a mine pressure and support real-time monitoring module and a support update module; Step 2: Obtain key indicators of mine geomechanics evaluation through the mine basic data collection and analysis module and the field data acquisition module. The key indicators of mine geomechanics evaluation mainly include: roof strength, roof integrity, roof rock distribution complexity, geological structure, rock layer occurrence and mining stress impact; Step 3: Calculate the sum of the weights of the key indicators of mine geomechanics assessment through the surrounding rock geomechanics assessment module, as shown in formula (1): In formula (1): W t is the stability index; W i is the quantitative result of the i-th geological indicator; W imax is the maximum value of the quantitative result of the indicator; i is the key factor number; n is the total number of key factors; The surrounding rock grade of the tunnel is classified according to the sum of all index weights. t When ≤0.2, it indicates that the tunnel surrounding rock stability level is level 1; when 0.2 <W t When ≤0.4, it indicates that the tunnel surrounding rock stability level is level 2; when 0.4 <W t When ≤0.6, it indicates that the tunnel surrounding rock stability level is level 3; when 0.6 <W t When W ≤0.8, it indicates that the tunnel surrounding rock stability level is level 4; t When >0.8, it indicates that the stability grade of the tunnel surrounding rock is Grade 5; Step 4: Design a targeted support scheme based on the stability grade of the tunnel surrounding rock and in combination with the targeted support scheme design module; Step 5: Use the mine pressure and support real-time monitoring module to observe the mine pressure and support stability in real time, and use the support update module to dynamically optimize and improve the current tunnel support design in combination with the tunnel surrounding rock stability grade.

2. A method for dynamic and precise control of tunnel surrounding rock according to claim 1, characterized in that: In step one, the mine basic data collection and analysis module mainly collects and analyzes mine production and construction data, stratum and mineable coal seam occurrence data, geological structure data, and hydrogeological conditions data; the field data acquisition module mainly includes gas content data, impact tendency and spontaneous combustion.

3. A method for dynamic and precise control of tunnel surrounding rock according to claim 1, characterized in that: In step three, the support system stability evaluation module evaluates the rationality of the tunnel anchor mesh support design, the matching of support products, the on-site construction quality, the stability of the existing support system and the construction process.

4. A method for dynamic and precise control of tunnel surrounding rock according to claim 3, characterized in that: The key indicators evaluated by the support system stability evaluation module include the pre-tightening force of the support body, the stress on the support body, the amount of tunnel movement, the scope of loose damage or the expansion of cracks.

5. The method for dynamic and precise control of tunnel surrounding rock according to claim 1, characterized in that: In step five, when monitoring the change of mine pressure, the data collection frequency is once an hour, and the monitored data is transmitted to the control center in real time via a wireless network to realize remote data monitoring and early warning.

6. A method for dynamic and precise control of tunnel surrounding rock according to claim 1, characterized in that: The support real-time monitoring module predicts the future deformation trend of the tunnel by analyzing the data, and then performs support design through the targeted support scheme design module.

7. The method for dynamic and precise control of surrounding rock in a tunnel according to claim 1, characterized in that: In step five, 100 m before construction, the mine pressure and support stability are observed in real time through the mine pressure and support real-time monitoring module, and the corresponding monitoring frequency and duration are set for different construction stages and support types.

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