Mining roadway key layer regulation and thick layer bearing collaborative adaptation supporting method and system

Abstract

The application provides a mining roadway key layer regulation and thick layer bearing cooperative adaptation supporting method and system, and belongs to the technical field of coal mine roadway surrounding rock control and supporting. The method comprises the following steps: drilling a hole in a roof key layer, implanting a time-varying enhanced grouting material and a stress triggering weakening device, and constructing an interventionable large structure regulation layer; constructing an ultra-long anchor rod penetrating a disturbance zone and deep into a stable rock layer, and combining grouting reinforcement to form a thick layer bearing body; based on real-time monitoring of a multi-source sensor, dynamically identifying a mining load stage through data fusion; a small structure is adaptively switched to a support state according to stress changes; a large structure is strengthened in a low stress period or weakened in a high stress period according to a stage identification result; and the cooperative performance of the large structure and the small structure is quantitatively evaluated. The system comprises multi-source intelligent sensing, large structure active regulation and execution, small structure thick layer bearing construction, cooperative stage identification and decision control. The application can realize dynamic adaptation and cooperative control of the whole process of mining influence.

Description

Technical Field

[0001] This invention belongs to the field of coal mine roadway surrounding rock control and support technology, specifically relating to a method and system for coordinated adaptive support of key layer regulation and thick layer bearing capacity in mining roadways. Background Technology

[0002] With the continuous increase in the depth and intensity of coal mining, the control of surrounding rock in mining-affected roadways faces severe challenges. Under the intense dynamic pressure of face mining, the stress and deformation of the surrounding rock exhibit complex and continuous staged characteristics. Specifically, it progresses from a relatively stable stage after roadway excavation to a stage of slow stress increase as the face approaches, then to a stage of accelerated deformation and rapid energy release under the intense influence of mining, and finally to a stage of post-mining deformation attenuation. During this process, the surrounding rock at different stages has dynamic and significantly different requirements for the stiffness of the support system. In the stable excavation period, the support system needs to have high stiffness to effectively maintain the roadway cross-section; in the mining-affected period, due to the need for large energy release, the support system needs to have excellent pressure-bearing capacity to effectively absorb energy; and in the post-mining stable period, high resistance is required to stabilize the deformation of the surrounding rock. However, traditional rigid support and static pressure relief support with fixed pressure relief parameters cannot dynamically adapt to this change throughout the entire process. This can easily lead to excessive deformation in the early stage due to insufficient resistance, and at the same time, it can cause uncontrolled pressure relief or insufficient energy absorption in the middle stage. Furthermore, it can cause a large waste of materials in the later stage due to excessive resistance, which can ultimately lead to instability of the roadway, high support costs, and even induce dynamic disasters such as rock bursts.

[0003] Currently, most research and practice in tunnel support focuses on optimizing the performance of support components (such as anchor bolts, anchor cables, and supports) or improving the pressure relief mechanism. These improvements primarily target small structures in the shallow surrounding rock, while the condition of key rock strata above the roof (such as the main roof structure), which plays a crucial role in tunnel stability, is often neglected or merely considered a source of passive load. Although some studies have recognized the dynamic changes in the mining stress environment, they often treat large structures as uncontrollable static boundary conditions. The few techniques available for grouting reinforcement or pressure relief are mostly one-time, pre-set static interventions, lacking the ability to dynamically adjust according to the mining stage. Existing technologies fail to design and control the active, time-varying control of the large structure's condition and the adaptive, phased adjustment of the small structure's stiffness as an organically coordinated and interconnected holistic system. The two are not only asynchronous in time but also mismatched in mechanics, thus failing to form an optimal collaborative bearing mechanism for the entire mining process. This may result in an overall stiffness of the support system that is too high, easily inducing impacts, or an overall stiffness that is too low, making it difficult to control deformation, thereby failing to meet reliable support requirements. In order to fundamentally solve the shortcomings of existing technologies, there is an urgent need to provide a method and system for collaborative adaptive support of key layer control and thick layer bearing capacity in mining roadways. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a method and system for the coordinated adaptive support of key layers and thick bearing capacity in mining roadways. This method can significantly improve the stability, adaptability, reliability, and intelligence level of roadway surrounding rock control under complex mining conditions, and can greatly reduce the risk of dynamic disasters. The system has a simple structure and low implementation cost. It can achieve dynamic adaptation and coordinated control of the entire mining impact process, which helps to improve the stability of roadway surrounding rock control.

[0005] To achieve the above objectives, the present invention provides a method for coordinated adaptive support of key layer control and thick layer bearing capacity in mining roadways, comprising the following steps:

[0006] S1: Preliminary survey, design, and simulation; design parameters for large-scale structural control schemes and small-scale thick-layer collaborative load-bearing bodies, and optimize them through simulation;

[0007] S2: Construct a large-scale active control layer; For the key layer above the roadway roof, construct vertical boreholes and implant control components with predetermined time-varying properties to form a large-scale active control layer with the ability to actively intervene in the key layer; Among them, the control components with predetermined time-varying properties include time-varying enhanced grouting materials and stress-triggered weakening devices.

[0008] S3: Construct a small-structure, thick-layer collaborative bearing body; construct ultra-long anchor bolts / cables around the tunnel, so that the anchoring section of the ultra-long anchor bolts / cables penetrates the disturbed area of ​​the surrounding rock and extends into the stable rock layer. Combined with full-length or end-grooving reinforcement, a small-structure, thick-layer collaborative bearing body is formed that is mechanically coupled with the deep rock mass and whose mechanical state can be autonomously switched according to the load it is subjected to.

[0009] S4: State perception and mining load stage identification; real-time monitoring of stress, deformation and micro-fracture signals, and dynamic identification of mining load stages through multi-source data fusion analysis;

[0010] S5: Collaborative response based on stage identification; based on the small-structure thick-layer collaborative bearing body, according to the change of surrounding rock stress, the small-structure thick-layer collaborative bearing body adaptively switches between elastic high-stiffness support state, damage yielding energy absorption support state, and overall high resistance stable support state; at the same time, based on the large-structure active control layer, according to the stage identification results of mining load, the performance time-varying process of the control components with predetermined time-varying performance is controlled remotely or automatically.

[0011] Furthermore, to ensure that the support system design accurately matches the needs of the entire mining process, the preliminary survey, design, and simulation process in S1 is as follows:

[0012] S11: Establish a large-scale structural file; detect and determine the layer location, thickness, and mechanical properties of key layers above the top slab, and design a large-scale structural control scheme;

[0013] S12: Design small-scale structural blueprints; assess the extent of surrounding rock failure; design parameters for the small-scale structural thick-layer co-supporting structure, including minimum design thickness. and final stable bearing capacity ;

[0014] S13: Digital twin simulation; establish a coupled numerical model of large-scale structural control and small-scale structural response, simulate and predict the mechanical response of roadways at different mining stages, and optimize control and bearing parameters;

[0015] S14: Monitoring and threshold scheme development; developing monitoring schemes and threshold criteria for responses at each stage.

[0016] Furthermore, in order to ensure that the load-bearing structure can completely cover the failure zone and form a reliable mechanical coupling with the deep stable rock mass, in S12, the minimum design thickness of the small-structure thick-layer cooperative load-bearing body is determined according to formula (1). Meanwhile, in order to scientifically quantify the final bearing capacity of the overall high-resistance stable stage and ensure that the small structure has a high reliability bearing capacity during the stress decay stabilization period, the final stable bearing capacity of the overall high-resistance stable support stage is calculated according to formula (2). ;

[0017] (1);

[0018] In the formula, This refers to the depth of the plastic zone in the surrounding rock of the tunnel. This refers to the minimum length of the anchoring section that extends into the stable rock mass outside the plastic zone.

[0019] (2);

[0020] In the formula, The effective number of anchor bolts / cables; For a single anchor bolt / cable, the yield or breaking resistance is considered. The angle between the average installation angle of the anchor bolt / anchor cable and the horizontal plane; This represents the average arch stress formed within the load-bearing structure. This refers to the effective bearing area of ​​the load-bearing structure.

[0021] Furthermore, in order to achieve precise and on-demand reinforcement of key rock strata within a predetermined time window, and to provide a reliable technical means for differentiated control strategies for reinforcement of large structures during low stress periods, in S2, the time-varying enhanced grouting material is a two-component chemical grout based on modified epoxy resin or polyurethane. By adjusting the catalyst ratio or utilizing ambient temperature triggering, its gelation time and strength growth curve are controlled, enabling it to achieve the desired results. Material strength at time Within the preset intensity growth time window From initial setting value to final design strength of the material , where the growth law of gel strength satisfies formula (3);

[0022] (3);

[0023] In the formula, ; This is the initial offset coefficient for intensity growth; is the intensity growth time constant.

[0024] Furthermore, in order to achieve real-time automatic triggering when high stress accumulation reaches a dangerous threshold, and to accurately form a controllable fracture network in the key layer for active pressure relief, thereby transforming potential strong rockburst events into controllable weak energy release, in S2, the stress-triggered weakening device is modularly integrated from inert blasting material, a miniature detonator, and an encapsulated stress sensor; the stress-triggered weakening device is pre-embedded in the high stress accumulation area of ​​the key layer; when the encapsulated stress sensor monitors the surrounding rock stress in real time... Reaching the preset impact danger threshold When, trigger signal As shown in formula (4), the micro detonator is automatically triggered to start the blasting operation, instantly generating a controllable fracture network to weaken the local rock mass and form a pressure relief zone.

[0025] (4).

[0026] Furthermore, in order to achieve dynamic optimization and matching of mining stress from the load source, and to effectively balance the bearing capacity and safety stability of the critical layer throughout the mining process, in S5, based on the mining load stage identification results, the performance time-varying process of the control component with predetermined time-varying performance is adjusted remotely or automatically, as follows:

[0027] S51: When the mining load stage is in the low stress slow increase period, time-varying enhanced grouting material is used to proactively reinforce the key layer, improve its ability to resist the impact of subsequent violent mining, and delay high stress concentration.

[0028] S52: During the high stress and severe impact period of the mining load stage, the stress-triggered weakening device is automatically activated to implement local and precise pressure relief, transforming possible strong impact events into controllable weak energy release and avoiding dynamic disasters.

[0029] S53: During the stress decay and stabilization period of the mining load stage, continuous monitoring shall be carried out.

[0030] This invention aims to address the fundamental problem in existing mining-induced roadway support technologies: the lack of coordination and dynamic, proactive control capabilities between the critical roof strata (large structure) and the roadway surrounding rock support system (small structure). To this end, this invention provides a collaborative adaptive support method capable of simultaneously adjusting the mechanical state of the large structure and the bearing stiffness of the small structure, thereby achieving stable roadway support.

[0031] First, the preliminary survey, design, and simulation can provide a reliable design basis and accurate criteria for subsequent adaptive support, ensuring the effectiveness of subsequent collaborative support.

[0032] Secondly, the implantation of control components with predetermined time-varying performance in the critical layer facilitates the implementation of different proactive intervention measures at the load source of the roadway during different mining load stages. This process moves the intervention node forward to the critical layer at the load source, overcoming the limitations of traditional support methods that only focus on the surrounding rock of the roadway. By actively controlling the mechanical state of the large structure, the load characteristics transmitted to the small structure can be optimized from the root. Simultaneously, the implantation of both reinforcing and weakening control components gives the system bidirectional adjustment capabilities. It can strengthen the critical layer to significantly improve bearing capacity, or weaken local high-stress areas to achieve effective pressure relief. Furthermore, it allows for flexible and differentiated combinations based on the critical layer conditions and risk levels of different sections of the same roadway, making the control process more flexible and engineering adaptable. This provides a basis for adjusting differentiated control strategies of strengthening during low-stress periods and weakening during high-stress periods.

[0033] Furthermore, by constructing an ultra-long anchoring system and grouting reinforcement, a thick-layer collaborative load-bearing body with a mechanical state that can autonomously switch according to the load is constructed. This allows the small-structure thick-layer collaborative load-bearing body to adaptively adapt to different mining load conditions, fundamentally ensuring the anchoring reliability and overall stability of the load-bearing structure.

[0034] Subsequently, the deployed multi-source sensors can comprehensively acquire multi-source monitoring data, avoiding the one-sidedness of information from single-parameter monitoring. Simultaneously, through multi-source data fusion analysis, the changing stages of mining loads can be accurately perceived during dynamic identification, thus providing accurate information for subsequent coordinated response and ensuring that the active control process precisely matches the actual dynamics of the mining load.

[0035] Finally, based on predetermined mechanical criteria and the changes in surrounding rock stress, the small structure adaptively switches between three support states: elastic high-stiffness support, damage-induced pressure absorption, and overall high-resistance stability. This achieves dynamic matching between load-bearing stiffness and surrounding rock deformation requirements. In the initial stage, high stiffness suppresses deformation; in the middle stage, controllable damage absorbs energy; and in the later stage, a stable structure is formed to ensure long-term stability. This autonomous conversion mechanism based on mechanical response reflects the inherent intelligent characteristics of the structure and achieves a unity of efficient energy absorption and long-term stable load-bearing. Simultaneously, based on the stage identification results, a dual-mode control method is implemented—actively strengthening during the low-stress risk period and weakening during the high-stress danger period—through remote or automatic triggering. This strengthens key layers during the low-stress period to delay high-stress concentration and weakens local rock masses during the high-stress period to implement precise pressure relief. Therefore, by actively regulating the source load of the large structure and dynamically matching the bearing requirements of the small structure, both respond collaboratively based on the same stage of judgment results, a two-layer linkage mechanism of load source optimization and bearing dynamic matching is formed, enabling the support system to adaptively cope with the entire process of mining impact. This invention actively regulates the mechanical state of key rock strata above the roadway roof and simultaneously constructs a thick collaborative bearing body for the roadway surrounding rock, forming a two-layer architecture of a large structure active regulation layer and a small structure thick collaborative bearing body. This enables the roadway support system to achieve collaborative variable stiffness behavior of large structure load source optimization and small structure bearing dynamic matching under the influence of mining, realizing the optimal matching and dynamic coupling of large structure active regulation and small structure adaptive bearing in time and space, and fundamentally changing the support of mining roadways from passive resistance to active intervention.

[0036] This method is simple to implement, has low implementation costs, and is highly applicable to engineering. It significantly improves the stability, adaptability, reliability, and intelligence of roadway surrounding rock control under complex mining conditions, greatly reduces the risk of dynamic disasters, and helps to improve the economy of support schemes while ensuring safety.

[0037] This invention also provides a key layer control and thick layer bearing capacity collaborative adaptive support system for mining roadways, which is used to realize a method for key layer control and thick layer bearing capacity collaborative adaptive support for mining roadways, including a multi-source intelligent sensing subsystem, a large structure active control execution subsystem, a small structure thick layer bearing capacity construction subsystem, and a collaborative stage identification and decision control subsystem;

[0038] The multi-source intelligent sensing subsystem is used to collect multi-source monitoring data related to the stability of the surrounding rock;

[0039] The large-structure active control execution subsystem includes a time-varying enhanced grouting unit, a stress-triggered weakening unit, and a drilling and sealing unit. The time-varying enhanced grouting unit includes a two-component chemical grout and a proportional mixing pumping system for pumping the two-component chemical grout. The stress-triggered weakening unit is a stress-triggered weakening device, which includes inert blasting material, a micro detonator, and a sealed stress sensor. It is used to automatically trigger blasting operations when the surrounding rock stress reaches the impact danger threshold to perform pressure relief. The drilling and sealing unit includes a directional drilling rig and an in-hole sealing casing for drilling holes perpendicular to the bedding plane and for providing a delivery channel for the two-component chemical grout to ensure that the two-component chemical grout is accurately injected into the set layer.

[0040] The small-structure thick-layer load-bearing subsystem includes ultra-long anchor bolts / cables, an ultra-long anchoring construction unit, and a grouting reinforcement unit. The ultra-long anchoring construction unit includes an ultra-long anchor bolt / cable drilling rig and an automatic pushing device, used to construct anchoring boreholes that penetrate the disturbed surrounding rock zone and reach the stable rock strata through the ultra-long anchor bolt / cable drilling rig, and simultaneously used to push the ultra-long anchor bolts / cables into the boreholes through the automatic pushing device. The grouting reinforcement unit includes a grout mixing system and a full-length / end grouting pump, used to prepare the reinforcement grout through the grout mixing system, and simultaneously used to perform full-length / end grouting operations on the anchoring boreholes through the full-length / end grouting pump, to form a composite load-bearing structure of rock mass, grout, and anchor bolts.

[0041] The collaborative stage identification and decision control subsystem includes a data preprocessing and fusion unit, a collaborative stage identification unit, and a decision control unit. The data preprocessing and fusion unit is used to preprocess multi-source monitoring data and fuse the preprocessed multi-source monitoring data. The collaborative stage identification unit is used to identify the mining load stage based on the fused data and historical case library. The decision control unit is used to output grouting start command or weakening device start command to the large structure active control execution subsystem according to the identification result of the mining load stage.

[0042] As a preferred embodiment, the multi-source intelligent sensing subsystem includes a stress monitoring unit, a displacement monitoring unit, a micro-fracture monitoring unit, a strain monitoring unit, and a data acquisition and transmission unit. The stress monitoring unit is located inside the large-structure active control layer and the small-structure thick-layer collaborative support structure to monitor surrounding rock stress. The displacement monitoring unit is located at the top and bottom plates and sidewalls of the roadway to monitor the closure of the top and bottom plates and the convergence of the sidewalls. The micro-fracture monitoring unit is located in the key monitoring area of ​​the small-structure thick-layer collaborative support structure to monitor acoustic emission energy rate. The strain monitoring unit is located inside the small-structure thick-layer collaborative support structure to monitor volumetric strain. The data acquisition and transmission unit is located in an explosion-proof enclosure underground to simultaneously acquire multi-source monitoring data through multiple channels.

[0043] In this invention, the multi-source intelligent sensing subsystem facilitates the simultaneous acquisition of multi-dimensional monitoring data such as stress, displacement, and micro-fractures, providing a rich and reliable data foundation for subsequent accurate identification and decision-making. For the large-structure active control execution subsystem, its internal time-varying enhanced grouting unit achieves precise proportioning and timed injection of two-component chemical grout through a proportional mixing pumping system, thereby actively strengthening key rock strata within a preset time window. Simultaneously, its internal stress-triggered weakening unit integrates stress sensing and micro-blasting technology, automatically triggering pressure relief when the surrounding rock stress reaches a dangerous threshold, converting potential strong impacts into controllable energy release. Furthermore, its internal drilling and sealing unit utilizes directional drilling rigs and in-hole sealing casings to ensure precise injection of control materials into target strata, avoiding ineffective diffusion and environmental pollution. For the small-structure thick-layer load-bearing subsystem, it can utilize ultra-long anchoring construction units to drill deep holes penetrating the disturbance zone in the surrounding rock, and use an automatic pushing device to complete the installation of ultra-long anchor bolts or cables. Then, through grouting reinforcement units, full-length or end grouting is performed, ultimately forming a thick-layer load-bearing structure composed of rock mass, grout, and anchor bolts. This thick-layer load-bearing structure can sequentially exhibit three progressive states according to the deformation requirements of the surrounding rock: elastic high-stiffness support, damage-induced pressure absorption, and overall high-resistance stability, achieving dynamic matching between load-bearing stiffness and surrounding rock deformation requirements. For the collaborative stage identification and decision control subsystem, it can clean and fuse multi-source sensing data through data preprocessing and fusion units to extract high-value feature information. Subsequently, the collaborative stage identification unit accurately identifies the current mining load stage based on the fused data and historical case library. Finally, the decision control unit automatically outputs corresponding grouting or weakening start commands to the large-structure control execution subsystem based on the identification results. The synergistic performance evaluation and parameter optimization subsystem can quantitatively evaluate the synergistic performance of large-structure control and small-structure bearing capacity based on the long-term stability effect of the surrounding rock of the tunnel, and feed the evaluation results back to the early design stage to optimize subsequent control schemes and bearing parameters, so that the entire system can continuously improve itself in practice.

[0044] The system has a simple structure and low implementation cost. It can achieve dynamic adaptation and coordinated control of the entire mining process, which helps to improve the stability of roadway surrounding rock control. Attached Figure Description

[0045] Figure 1 This is a flowchart of the support method in this invention;

[0046] Figure 2 This is a schematic diagram of the support system in this invention. Detailed Implementation

[0047] The invention will now be further described with reference to the accompanying drawings.

[0048] like Figure 1 As shown, this invention provides a method for coordinated adaptive support of key layer control and thick layer bearing capacity in mining roadways, comprising the following steps:

[0049] S1: Preliminary survey, design, and simulation; design parameters for large-scale structural control schemes and small-scale thick-layer collaborative load-bearing bodies, and optimize them through simulation;

[0050] Based on actual engineering needs, key strata and mechanical properties are determined through geological exploration, and large-scale structural control schemes are designed. The extent of surrounding rock failure is assessed, and small-scale structural bearing parameters are designed. Coupled numerical models are established for simulation and prediction to optimize control and bearing parameters. At the same time, monitoring schemes and response thresholds are formulated, and digital twin pre-simulation is completed to provide design basis and criteria for subsequent adaptive support.

[0051] In one specific embodiment of the present invention, the process of preliminary surveying, design, and simulation is as follows:

[0052] S11: Establish a large-scale structural file; detect and determine the layer position, thickness and mechanical properties of the key layer above the top plate, and design a large-scale structural control scheme; the large-scale structural control scheme includes the location, timing and material parameters of strengthening / weakening, and complete the establishment of the large-scale structural file;

[0053] S12: Design small-scale structural blueprints; assess the extent of surrounding rock failure; design parameters for the small-scale structural thick-layer co-supporting structure, including minimum design thickness. and final stable bearing capacity ;

[0054] To ensure that the load-bearing structure can completely cover the failure zone and form a reliable mechanical coupling with the deep stable rock mass, the minimum design thickness of the small-structure thick-layer cooperative load-bearing body can be determined according to formula (1). This ensures that it can both cover the main damaged area and form an effective load-bearing structure, while also working in conjunction with the deep surrounding rock.

[0055] (1);

[0056] In the formula, This refers to the depth of the plastic zone in the surrounding rock of the roadway, which can be obtained through calculation or actual measurement, under typical moderately stable roof conditions. Based on theoretical calculations or actual measurements from drilling, the depth is typically 2.5~4.5m; The minimum length of the anchorage section extending into the stable rock mass outside the plastic zone is defined as 2.0~2.5m. Limiting the length to a minimum of 2.0 meters effectively ensures anchorage reliability. Ultimately, The typical value range is 4.5~7.0m.

[0057] After the small-structure, thick-layer collaborative bearing structure enters a state of overall high-resistance stable support, it signifies that the support system has entered the final stabilization stage; the final stable bearing capacity of the small-structure, thick-layer collaborative bearing structure... The load is mainly provided by the enhanced group anchoring effect of ultra-long anchor bolts / cables and the self-organized stress arch formed inside the thick-layer bearing body of the small structure. As a preferred option, ultra-long anchor bolts / cables are grouting anchor bolts / cables with increased resistance and pressure relief. In engineering practice, in order to scientifically quantify the final bearing capacity of the overall high resistance stable stage and ensure that the small structure has a high reliability bearing capacity during the stress decay stable period, the final stable bearing capacity of the overall high resistance stable support stage can be calculated according to formula (2). ;

[0058] (2);

[0059] In the formula, The effective number of anchor bolts / cables is determined based on the cross-sectional dimensions of the roadway. For a rectangular roadway with a net width of 5.0m, 6 to 8 anchor cables can be arranged on the roof to form a reliable group anchoring effect. The yield or breaking resistance of a single anchor bolt / cable is 400–600 kN. The angle between the average installation angle of the anchor bolt / anchor cable and the horizontal plane, with a value ranging from 75° to 85°. The average arch stress formed inside the load-bearing structure, as determined by numerical inversion analysis, can reach 0.8–1.5 MPa in the steady-state stage. This refers to the effective bearing area of ​​the load-bearing structure.

[0060] S13: Digital twin pre-simulation; Establish a coupled numerical model of large-structure control and small-structure response, simulate and predict the mechanical response of roadways at different mining stages, optimize control and bearing parameters, and realize digital twin pre-simulation;

[0061] S14: Monitoring and threshold scheme development; develop monitoring schemes and threshold criteria for responses at each stage to facilitate accurate monitoring, identification, regulation, and load control processes in the future.

[0062] In this process, the preliminary survey, design and simulation can provide a reliable design basis and accurate criteria for subsequent adaptive support, ensuring the effectiveness of subsequent collaborative support.

[0063] S2: Construct a large-scale active control layer;

[0064] For the critical layer above the tunnel roof, boreholes are drilled perpendicular to the layer, and control components with predetermined time-varying properties are implanted to form a large-scale active control layer with the ability to actively intervene in the critical layer. The critical layer above the tunnel roof includes, but is not limited to, the main load-bearing rock strata such as the immediate roof and the old roof. The control components with predetermined time-varying properties include time-varying enhanced grouting materials and stress-triggered weakening devices. Thus, in engineering practice, the material parameters and embedding locations can be determined based on the large-scale control scheme.

[0065] The time-varying enhanced grouting material is used to proactively and periodically strengthen the integrity and load-bearing stiffness of key layers before the impact of mining intensifies, based on system instructions. This time-varying enhanced grouting material is a two-component chemical grout based on modified epoxy resin or polyurethane. Its gelation time and strength growth curve are controlled by adjusting the catalyst ratio or utilizing ambient temperature triggering, allowing it to... Material strength at time Within the preset intensity growth time window From initial setting value to final design strength of the material The growth law of gel strength satisfies formula (3); thus, key rock layers can be precisely strengthened within a predetermined time window according to actual needs, thereby providing a reliable technical means for the differentiated control strategy of strengthening large structures during low stress periods.

[0066] (3);

[0067] In the formula, ; The initial offset coefficient for strength growth is determined by the formulation design, and its value ranges from 0.8 to 1.2 depending on the actual engineering conditions. This is the strength growth time constant, used to control the rate of strength growth of materials. Its value ranges from 12 to 48 hours depending on the actual engineering situation.

[0068] When the working face advances at a relatively high speed (≥6m / d), select A fast-setting formula for hours; when the propulsion speed is slow (≤3m / d), select... The slow-setting formula is used for hours to ensure that the reinforcement of the key layer is completed just before the mining stress increases significantly.

[0069] The stress-triggered weakening device is modularly integrated from inert blasting material, a miniature detonator, and an encapsulated stress sensor. This device is pre-embedded precisely in the high-stress accumulation zone of the critical layer. When the encapsulated stress sensor monitors the surrounding rock stress in real time... Reaching the preset impact danger threshold When, trigger signal As shown in formula (4), the micro detonator is automatically triggered to start the blasting operation, instantly generating a controllable fracture network to weaken the local rock mass and form a pressure relief zone. Thus, it can be automatically triggered in real time when the high stress accumulation reaches the danger threshold, thereby forming a controllable fracture network in the key layer and realizing active pressure relief operation, and then transforming potential strong rockburst events into controllable weak energy release.

[0070] (4).

[0071] By embedding control components with predetermined time-varying properties into the critical layer, it is beneficial to implement different active intervention measures at the load source of the roadway during different mining load stages. This process moves the intervention node forward to the critical layer at the load source, breaking through the limitation of traditional support methods that only focus on the surrounding rock of the roadway. By actively controlling the mechanical state of the large structure, the load characteristics transmitted to the small structure can be optimized from the root. At the same time, the embedding of two types of control components, namely strengthening and weakening, gives the system a two-way adjustment capability. It can strengthen the critical layer to significantly improve the bearing capacity, and weaken local high-stress areas to achieve effective pressure relief. In addition, it can be flexibly and differentially combined and applied according to the critical layer conditions and risk levels of different sections of the same roadway, making the control process more flexible and more engineering adaptable. This provides a basis for adjusting the differentiated control strategy of strengthening during low-stress periods and weakening during high-stress periods.

[0072] S3: Construct a small-structure, thick-layer collaborative load-bearing structure;

[0073] By constructing ultra-long anchor bolts / cables around the tunnel, the anchoring section of the ultra-long anchor bolts / cables penetrates the disturbed surrounding rock zone and extends into the stable rock layer. Combined with full-length or end-grooving reinforcement, an intelligent variable stiffness small-structure thick-layer collaborative load-bearing body is formed, which is coupled with the mechanics of the deep rock mass and whose mechanical state can autonomously switch according to the load. Thus, in engineering practice, various parameters can be determined based on the small structure's load-bearing parameters.

[0074] Among them, the small-structure thick-layer collaborative load-bearing body has three progressive support states, namely, elastic high-stiffness support state, damage-induced pressure-absorbing energy support state, and overall high-resistance stable support state.

[0075] In the state of elastic high stiffness support, the small structure thick layer cooperative bearing body is in the elastic working stage, resisting the deformation of the surrounding rock with high stiffness;

[0076] In the state of damage-induced compressive energy absorption support, the small-structure thick-layer collaborative load-bearing body enters a controllable plastic deformation stage, absorbing energy through distributed damage.

[0077] Under the overall high resistance and stable support state, the small structure and thick layer cooperative load-bearing body form a stable load-bearing structure and enter the final stable state;

[0078] By constructing an ultra-long anchoring system and grouting reinforcement, a thick-layer collaborative load-bearing body with a mechanical state that can autonomously switch according to the load is constructed. This allows the small-structure thick-layer collaborative load-bearing body to adaptively adapt to different mining load conditions, fundamentally ensuring the anchoring reliability and overall stability of the load-bearing structure.

[0079] S4: State perception and mining load stage identification;

[0080] Based on multi-source sensors (such as stress gauges and displacement gauges) deployed in the active control layer of the large structure and the thick-layer collaborative bearing body of the small structure, stress, deformation and micro-fracture signals are monitored in real time. Based on the response threshold, through multi-source data fusion analysis, the stage of mining load is dynamically identified as a low stress slow increase period, a high stress severe influence period or a stress decay and stabilization period. The identification results are sent to the control module used to control the active control layer of the large structure to provide a decision basis for subsequent adaptive response.

[0081] The specific identification process is as follows:

[0082] A. Pre-install surrounding rock stress gauges or encapsulated stress sensors in boreholes at key strata of the large-structure active control layer, and use these gauges or sensors to collect real-time surrounding rock stress values ​​at key strata. Simultaneously, fiber optic strain sensors and multi-point displacement gauges are pre-installed at the ends and middle of the ultra-long anchor bolts / cables of the small-structure, thick-layer collaborative bearing structure. Acoustic emission sensors are pre-positioned on the surface of the small-structure, thick-layer collaborative bearing structure and in the deep surrounding rock. The volumetric strain of the bearing structure is calculated in real time based on the strain and displacement signals collected by the fiber optic strain sensors and multi-point displacement gauges. Simultaneously, based on acoustic emission sensors, micro-fracture events are continuously monitored and recorded, and the acoustic emission energy rate per unit time is calculated in real time.

[0083] B. Based on preset threshold criteria, dynamically divide the mining load stage:

[0084] 2.1 When all of the following triggering conditions are met simultaneously, it is determined that the current period is a low stress gradual increase period;

[0085] (1) The monitored value of the surrounding rock stress is less than the lower limit of the warning, that is ,in, As a safety factor, its value ranges from 0.6 to 0.8. To determine the impact hazard threshold, based on the uniaxial compressive strength of the key rock strata... The stress concentration factor was determined comprehensively and set as follows: ;

[0086] (2) Volumetric strain It increases slowly and approximately linearly over time, and the current value is much smaller than the damage threshold. ;

[0087] (3) The acoustic emission energy rate is at the background noise level and there is no obvious abnormal jump. The criterion for abnormal jump in acoustic emission energy rate is defined as follows: if the average energy rate in the current 10 minutes exceeds 3 to 5 times the average value in the previous hour and the duration exceeds 5 minutes, it is judged as an abnormal jump.

[0088] 2.2. When any of the following triggering conditions are met, it is determined that the current period is one of intense high stress.

[0089] (1) Damage criterion for small structures; volumetric strain of the thick-layered co-supporting structure of small structures was monitored. Reaching or exceeding the preset damage threshold Alternatively, a stepwise increase in acoustic emission energy rate may be detected, indicating that microfractures within the surrounding rock have rapidly expanded. Therefore, it can be determined that the small-structure, thick-layered collaborative load-bearing structure has switched from an elastic, high-stiffness support state to a damage-yielding, pressure-absorbing support state.

[0090] (2) Major structural hazard criteria; real-time monitoring values ​​of surrounding rock stress gauges or encapsulated stress sensors deployed within the active control layer of the major structure. Reaching the preset impact danger threshold When, trigger signal =1;

[0091] 2.3 When the following conditions are met simultaneously, it is determined that the stress decay stabilization period has begun;

[0092] (1) Surrounding rock stress value After reaching its peak, it showed a significant decline, and the rate of change of stress approached zero;

[0093] (2) Volumetric strain The growth rate ceases to be significant, and the deformation rate of the surrounding rock converges to within the permissible range.

[0094] (3) The acoustic emission energy rate drops back to the preset low level range, indicating that the surrounding rock fracturing activity has basically stopped.

[0095] The deployment of multi-source sensors enables comprehensive acquisition of multi-source monitoring data, avoiding the limitations of single-parameter monitoring information. Furthermore, by using multi-source data fusion analysis, the changing stages of mining loads can be accurately detected during dynamic identification, providing accurate information for subsequent coordinated responses and ensuring that the proactive control process precisely matches the actual dynamics of the mining load.

[0096] S5: Collaborative response based on stage identification;

[0097] Based on the small-structure thick-layer collaborative bearing body, according to the change of surrounding rock stress, the small-structure thick-layer collaborative bearing body can automatically switch between elastic high-stiffness support state, damage yielding pressure energy absorption support state and overall high resistance stability support state, so as to achieve dynamic matching between the bearing stiffness of the small-structure thick-layer collaborative bearing body and the deformation requirements of the surrounding rock.

[0098] Among them, the damage-induced pressure-absorbing energy support state mainly absorbs energy through the controllable distributed plastic deformation and micro-fracture propagation of the rock mass and reinforcing materials inside the bearing body, thereby achieving a smooth pressure-absorbing process.

[0099] To ensure timely energy absorption through controlled damage during periods of high stress and severe impact, thereby effectively preventing structural failure and enhancing the impact resistance of the surrounding rock, multi-source sensors deployed within a thick-layered, small-structure co-supporting body can be used in practical engineering to collect volumetric strain data. Harmony acoustic emission energy rate, when volume strain Reaching the set critical value When the acoustic emission energy rate undergoes a step change, it is determined that the small-structure thick-layer collaborative load-bearing body changes from an elastic high-stiffness support state to a damage-yielding pressure-absorbing energy support state.

[0100] Meanwhile, based on the active control layer of the large structure, according to the identification results of the mining load stage, the performance time-varying process of the control components with predetermined time-varying performance is controlled by remote or automatic triggering, so as to match the expected mining load changes through the active control of the large structure, to actively strengthen the mechanical properties of the key layer during the low stress risk period or weaken the mechanical properties during the high stress danger period, thereby achieving the purpose of optimizing the load size and dynamic characteristics transmitted to the small structure thick layer collaborative bearing body.

[0101] When implementing proactive control measures for large structures, the core logic of prevention first and control combined is followed. Specifically, proactive strengthening is carried out during low-stress periods and proactive weakening is carried out during high-stress periods. This enables dynamic optimization and matching of mining stress from the load source, thereby effectively balancing the bearing capacity and safety stability of key layers throughout the mining process. In specific engineering practice, based on the mining load stage identification results, the performance time-varying process of control components with predetermined time-varying properties can be adjusted remotely or automatically. The process is as follows:

[0102] S51: When the mining load is in a low stress slow increase period, time-varying enhanced grouting material is used to proactively reinforce the key layer, improve its ability to resist the impact of subsequent violent mining, and effectively delay the high stress concentration condition.

[0103] S52: During the high stress and severe impact period of the mining load stage, the stress-triggered weakening device is automatically activated to implement local and precise pressure relief, thereby converting possible strong impact events into controllable weak energy for release and avoiding dynamic disasters.

[0104] S53: During the stress decay and stabilization period of the mining load stage, continuous monitoring shall be carried out.

[0105] Based on predetermined mechanical criteria and the changes in surrounding rock stress, the small structure adaptively switches between three support states: elastic high-stiffness support, damage-induced pressure absorption, and overall high-resistance stability. This achieves dynamic matching between load-bearing stiffness and surrounding rock deformation requirements. Initially, high stiffness suppresses deformation; in the middle stage, controllable damage absorbs energy; and in the later stage, a stable structure is formed to ensure long-term stability. This autonomous conversion mechanism based on mechanical response reflects the structure's inherent intelligent characteristics and achieves a unity of efficient energy absorption and long-term stable load-bearing. Simultaneously, based on the stage identification results, a dual-mode control method is implemented—actively strengthening during low-stress risk periods and weakening during high-stress danger periods—through remote or automatic triggering. This strengthens key layers during low-stress periods to delay high-stress concentration and weakens local rock masses during high-stress periods to implement precise pressure relief. Therefore, by actively regulating the source load of the large structure and dynamically matching the bearing requirements of the small structure, both respond collaboratively based on the same stage of judgment results, a two-layer linkage mechanism of load source optimization and bearing dynamic matching is formed, enabling the support system to adaptively cope with the entire process of mining impact. This invention actively regulates the mechanical state of key rock strata above the roadway roof and simultaneously constructs a thick collaborative bearing body for the roadway surrounding rock, forming a two-layer architecture of a large structure active regulation layer and a small structure thick collaborative bearing body. This enables the roadway support system to achieve collaborative variable stiffness behavior of large structure load source optimization and small structure bearing dynamic matching under the influence of mining, realizing the optimal matching and dynamic coupling of large structure active regulation and small structure adaptive bearing in time and space, and fundamentally changing the support of mining roadways from passive resistance to active intervention.

[0106] In another specific embodiment of the present invention, in order to have the ability to continuously optimize, in addition to S1 to S5, S6 is also included: system performance evaluation and optimization.

[0107] Based on the long-term stability effect of the surrounding rock of the tunnel, the synergistic effect of the large structure active control layer and the small structure thick layer synergistic bearing body is quantitatively evaluated, and the synergistic effect evaluation results are used to optimize the control and design of subsequent cycles.

[0108] Based on the long-term stability of the surrounding rock in the tunnel, the inherent synergistic effectiveness of the large and small structures is quantitatively assessed, providing an objective and quantifiable evaluation standard for system performance. The synergistic effectiveness assessment results can be fed back to optimize the control and design parameters for subsequent cycles, enabling the system to be continuously improved and optimized based on actual service performance. Through multiple cycles of evaluation and optimization, the system can better adapt to specific geological conditions and mining operations, and possess the ability to continuously evolve and optimize over time.

[0109] In order to achieve a scientific quantification of the overall effect of load source optimization and dynamic load matching, the synergistic efficiency can be obtained according to formula (5). ; Synergistic efficiency The closer it is to 1, the higher the synergistic effect between the large and small structures;

[0110] (5);

[0111] In the formula, , The absolute difference between the measured peak stress in the roadway after active control of the large structure and the predicted peak stress before control. The peak stress predicted under uncontrolled conditions; , This represents the maximum measured closure of the tunnel roof and floor slabs. To design allowable closure.

[0112] Example 1:

[0113] Taking a mining roadway at a depth of 650m in a certain mine as the engineering background, the roadway has a rectangular cross-section, 5.2m wide and 3.8m high. The immediate roof is 4.5m thick sandy mudstone, and the main roof is 12.0m thick medium-grained sandstone. The method of this invention is used for support design and mining response control.

[0114] 1. Parameter design;

[0115] Based on preliminary exploration, the depth of the plastic zone... =3.8, take =2.2m, then the minimum design thickness =6.0m. The top slab is equipped with 7 prestressed anchor cables, each Φ21.8m long and 8.0m in diameter, with a single cable breaking strength of... =550kN, installation angle 80°. Time-varying enhanced grouting material setting. =30h, =1.0, and it is expected to reach 90% of the design strength 48 hours after grouting. The critical value of volumetric strain is set as follows. =0.45%.

[0116] 2. Stage Identification and Response Process;

[0117] Low stress gradual increase period: When the working face is 80m away from the monitoring section, the surrounding rock stress is 8.2MPa (less than 0.7MPa). The volumetric strain was 0.12%, and the acoustic emission energy rate remained stable. This triggered the activation of the time-varying reinforced grouting material.

[0118] High-stress period: When the working face advanced to a distance of 15m, the volumetric strain suddenly increased to 0.51% (exceeding the critical value of 0.45%), and the acoustic emission energy rate jumped to 4.8 times the background value. The system identified that it had entered the high-stress period, and the small structure automatically entered the damage relief state; at the same time, the local stress monitoring value of the roof reached 32.5MPa (exceeding the 30MPa threshold), and the stress-triggered weakening device was automatically activated to generate a controllable crack zone.

[0119] Stress attenuation stabilization period: After the working face has been pushed 60m, the stress drops back to 12.4MPa and tends to stabilize, the volumetric strain stabilizes at 0.68%, and the deformation rate is less than 0.1mm / d. Continuous monitoring is carried out.

[0120] 3. Results data;

[0121] After adopting this invention, compared with the adjacent 205 working surface that does not adopt this invention:

[0122] The maximum approach distance of the roadway roof and floor was reduced from 420mm to 215mm, a decrease of 48.8%;

[0123] The measured peak stress decreased from the predicted 36.5 MPa to 28.3 MPa. ;

[0124] Allowable closing quantity =250mm, actual measurement =215mm, ;

[0125] System synergy efficiency .

[0126] This invention aims to address the fundamental problem in existing mining roadway support technologies: the lack of coordination and dynamic, proactive control capabilities between the critical roof strata (large structure) and the roadway surrounding rock support system (small structure). Traditional methods only optimize the performance of support components (small structure) or perform static, one-time reinforcement / decompression on critical strata, failing to design the two as a unified system dynamically controlled and mutually feedback-driven during the mining process. This results in fixed or slow-changing stiffness of the support system, failing to meet the differentiated and temporal requirements for high support, pressure absorption, and high resistance stability at different stages of mining (low stress gradual increase period, high stress severe impact period, and stress decay stabilization period). This easily leads to a series of problems such as early deformation, mid-term impact risk accumulation, and excessive residual deformation in the later stage affecting reuse. To address this, the present invention provides a collaborative adaptive support method capable of real-time sensing of the mining phase and, accordingly, adjusting the mechanical state of the large structure and the bearing stiffness of the small structure. The core technology of this method is the construction of a spatiotemporal collaborative system for active control of the large structure and adaptive bearing of the small structure. By sensing the mining impact phase in real time, grouting or weakening materials with time-varying properties are implanted into key rock strata above the roof, enabling on-demand, timed active strengthening or weakening of the key rock strata's strength. This optimizes the load magnitude and dynamic characteristics transmitted to the roadway from the load source, transforming strong impact risks into a controllable energy release process. Simultaneously, an integrated thick-layer collaborative bearing body is constructed, formed by ultra-long anchor bolts / cables and grouting reinforcement, capable of co-deformation with deep stable rock mass. This allows the macroscopic mechanical state to adaptively undergo three macroscopic mechanical stages—elastic high-stiffness support, damage-induced pressure absorption, and overall high-resistance stability—according to the load and internal damage state, achieving adaptive and phased changes in bearing stiffness. This invention precisely matches the active control of the large structure with the adaptive bearing response of the small structure in time and space, enabling the macroscopic stiffness of the support system to match the differentiated needs of the surrounding rock at different mining stages in real time. This solves the defects of traditional support methods, which have fixed stiffness and cannot dynamically adapt to the contradiction of different stiffness requirements throughout the mining process. It effectively improves the overall stability of the roadway and provides a scientific, complete and engineering-implementable adaptive support solution for the entire mining roadway process, which is used to effectively control the deformation of the surrounding rock in deep, strongly mined roadways and actively prevent rockbursts.

[0127] like Figure 2 As shown, the present invention also provides a key layer control and thick layer bearing capacity collaborative adaptive support system for mining roadways, which is used to realize a method for key layer control and thick layer bearing capacity collaborative adaptive support for mining roadways, including a multi-source intelligent sensing subsystem, a large structure active control execution subsystem, a small structure thick layer bearing capacity construction subsystem, and a collaborative stage identification and decision control subsystem;

[0128] The multi-source intelligent sensing subsystem is used to collect multi-source monitoring data related to the stability of the surrounding rock. In this way, by integrating multiple sensors such as stress, displacement, and micro-fracture to collect monitoring signals from multiple dimensions, comprehensive and real-time monitoring of the surrounding rock condition can be achieved, providing a rich and reliable data foundation for subsequent accurate identification and decision-making.

[0129] The large-structure active control execution subsystem includes a time-varying enhanced grouting unit, a stress-triggered weakening unit, and a drilling and sealing unit. The time-varying enhanced grouting unit includes a two-component chemical grout and a proportional mixing pumping system for pumping the two-component chemical grout. Thus, the time-varying enhanced grouting unit can achieve precise proportioning and timed injection of the two-component chemical grout through the proportional mixing pumping system, thereby actively strengthening key rock strata within a preset time window. The stress-triggered weakening unit is a stress-triggered weakening device, which includes inert blasting material, a micro-detonator, and an encapsulated stress sensor. It is used to automatically trigger blasting operations to perform pressure relief when the surrounding rock stress reaches the impact danger threshold. Thus, by integrating stress sensing and micro-blasting technology, pressure relief can be automatically triggered when the surrounding rock stress reaches the danger threshold, converting potential strong impacts into controllable energy release. The drilling and sealing unit includes a directional drilling rig and an in-hole sealing casing, used for drilling holes perpendicular to the bedding plane and for providing a delivery channel for the two-component chemical slurry to ensure that the two-component chemical slurry is accurately injected into the set layer. Thus, it is convenient to use the directional drilling rig and the in-hole sealing casing to ensure that the control material can be accurately injected into the target layer, avoiding ineffective diffusion and environmental pollution.

[0130] The small-structure thick-layer load-bearing subsystem includes ultra-long anchor bolts / cables, an ultra-long anchoring construction unit, and a grouting reinforcement unit. The ultra-long anchoring construction unit includes an ultra-long anchor bolt / cable drilling rig and an automatic pushing device, used to construct anchoring boreholes penetrating the disturbed surrounding rock zone and reaching deep into stable rock strata via the ultra-long anchor bolt / cable drilling rig, and simultaneously used to push the ultra-long anchor bolts / cables into the borehole via the automatic pushing device. The grouting reinforcement unit includes a grout mixing system and a full-length / end-length grouting pump, used to... A grout mixing system is used to prepare the reinforcing grout. Simultaneously, it is used for full-length / end-length grouting of the anchoring boreholes via full-length / end-length grouting pumps, forming a composite load-bearing structure of rock mass, grout, and anchor bolts. This facilitates the drilling of deep holes penetrating the disturbed zone in the surrounding rock using ultra-long anchoring construction units, and the installation of ultra-long anchor bolts or cables using an automatic pushing device. Full-length or end-length grouting is then performed by the grouting reinforcement unit, ultimately forming a thick-layered load-bearing structure composed of rock mass, grout, and anchor bolts. This thick-layered load-bearing structure is configured to exhibit three progressive states according to the deformation requirements of the surrounding rock: elastic high-stiffness support, damage-induced pressure absorption, and overall high-resistance stability, achieving a dynamic match between load-bearing stiffness and the deformation requirements of the surrounding rock.

[0131] The collaborative stage identification and decision control subsystem includes a data preprocessing and fusion unit, a collaborative stage identification unit, and a decision control unit. The data preprocessing and fusion unit preprocesses multi-source monitoring data and fuses the preprocessed multi-source monitoring data. The collaborative stage identification unit identifies the mining load stage based on the fused data and a historical case library. The decision control unit outputs grouting start commands or weakening device start commands to the large structure active control execution subsystem based on the mining load stage identification results. In this way, the data preprocessing and fusion unit can clean and fuse multi-source sensing data to extract high-value feature information. Furthermore, the collaborative stage identification unit can accurately identify the current mining load stage based on the fused data and the historical case library, and finally, the decision control unit automatically outputs the corresponding grouting or weakening start commands to the large structure control execution subsystem based on the identification results.

[0132] As another specific embodiment of the present invention, it also includes a synergistic effectiveness evaluation and parameter optimization subsystem. This subsystem is used to quantitatively evaluate the synergistic effectiveness of the large-structure active control layer and the small-structure thick-layer synergistic bearing capacity based on the long-term stability effect of the surrounding rock of the roadway, and to feed back and optimize subsequent design parameters. This facilitates the quantitative evaluation of the synergistic effectiveness of the large-structure control and small-structure bearing capacity based on the long-term stability effect of the surrounding rock of the roadway, and feeds the evaluation results back to the early design stage to optimize subsequent control schemes and bearing parameters, enabling the entire system to continuously improve itself in practice.

[0133] As a preferred embodiment, the multi-source intelligent sensing subsystem includes a stress monitoring unit, a displacement monitoring unit, a micro-fracture monitoring unit, a strain monitoring unit, and a data acquisition and transmission unit. The stress monitoring unit is located inside the large-structure active control layer and the small-structure thick-layer collaborative support structure to monitor surrounding rock stress. The displacement monitoring unit is located at the top and bottom plates and sidewalls of the roadway to monitor the closure of the top and bottom plates and the convergence of the sidewalls. The micro-fracture monitoring unit is located in the key monitoring area of ​​the small-structure thick-layer collaborative support structure to monitor acoustic emission energy rate. The strain monitoring unit is located inside the small-structure thick-layer collaborative support structure to monitor volumetric strain. The data acquisition and transmission unit is located in an explosion-proof enclosure underground to simultaneously acquire multi-source monitoring data through multiple channels.

[0134] The system has a simple structure and low implementation cost. It can achieve dynamic adaptation and coordinated control of the entire mining process, which helps to improve the stability of roadway surrounding rock control.

Claims

1. A method for coordinated adaptive support of key layer control and thick layer bearing capacity in mining roadways, characterized in that, Includes the following steps: S1: Preliminary survey, design, and simulation; The parameters of the large-structure control scheme and the small-structure thick-layer collaborative load-bearing body were designed and optimized through simulation; The preliminary survey, design, and simulation process is as follows: S11: Establish a large-scale structural file; detect and determine the layer location, thickness, and mechanical properties of key layers above the top slab, and design a large-scale structural control scheme; S12: Design small-scale structural blueprint; Assess the extent of surrounding rock failure and design parameters for a small-structure, thick-layered, collaborative load-bearing structure, including the minimum design thickness. and final stable bearing capacity ; The minimum design thickness of the small-structure thick-layer cooperative bearing body is determined according to formula (1). The final stable bearing capacity of the overall high-drag stable support stage is calculated according to formula (2). ; （1）； In the formula, This refers to the depth of the plastic zone in the surrounding rock of the tunnel. The minimum length of the anchorage section extending into stable rock mass outside the plastic zone; （2）； In the formula, The effective number of anchor bolts / cables; For a single anchor bolt / cable, the yield or breaking resistance is considered. The angle between the average installation angle of the anchor bolt / anchor cable and the horizontal plane; This represents the average arch stress formed within the load-bearing structure. The effective bearing area of ​​the load-bearing structure; S13: Digital Twin Preview; Establish a coupled numerical model of large-scale structural control and small-scale structural response, simulate and predict the mechanical response of roadways at different mining stages, and optimize control and bearing parameters; S14: Monitoring and threshold scheme development; developing monitoring schemes and threshold criteria for response at each stage; S2: Construct a large-scale active control layer; For the key layer above the roadway roof, construct vertical boreholes and implant control components with predetermined time-varying properties to form a large-scale active control layer with the ability to actively intervene in the key layer; The control components with predetermined time-varying properties include time-varying enhanced grouting materials and stress-triggered weakening devices. S3: Construct a small-structure, thick-layer collaborative load-bearing body; construct ultra-long anchor bolts / cables around the tunnel, so that their anchoring sections penetrate the disturbed surrounding rock zone and extend into the stable rock layer. Combined with full-length or end-mounted grouting reinforcement, a small-structure, thick-layer collaborative load-bearing body with a mechanical state that can be autonomously switched according to the load is formed. S4: State perception and mining load stage identification; real-time monitoring of stress, deformation and micro-fracture signals, and dynamic identification of mining load stages based on multi-source data fusion analysis; S5: Collaborative response based on stage identification; according to the changes in surrounding rock stress, the small-structure thick-layer collaborative bearing body automatically switches between elastic high-stiffness support state, damage-induced pressure-absorbing energy support state, and overall high-resistance stable support state; at the same time, based on the stage identification results of mining load, the performance time-varying process of the control components with predetermined time-varying performance is controlled remotely or automatically.

2. The method for coordinated adaptive support of key layer control and thick layer bearing capacity in mining roadways according to claim 1, characterized in that, In S2, the time-varying reinforced grouting material is a two-component chemical grout based on modified epoxy resin or polyurethane. Its gelation time and strength growth curve are controlled by adjusting the catalyst ratio or by utilizing ambient temperature triggering, thus enabling it to... Material strength at time Within the preset intensity growth time window From initial setting value to final design strength of the material The growth law of gel strength satisfies formula (3); （3）； In the formula, ; This is the initial offset coefficient for intensity growth; is the intensity growth time constant.

3. The method for coordinated adaptive support of key layer control and thick layer bearing capacity in a mining roadway according to claim 1, characterized in that, In S2, the stress-triggered weakening device is modularly integrated from inert explosive material, a miniature detonator, and an encapsulated stress sensor; the stress-triggered weakening device is pre-embedded in the high stress accumulation area of ​​the critical layer; When the encapsulated stress sensor monitors the surrounding rock stress in real time Reaching the preset impact danger threshold When, trigger signal As shown in formula (4), the micro detonator is automatically triggered to start the blasting operation, instantly generating a controllable fracture network to weaken the local rock mass and form a pressure relief zone. （4）。 4. The method for coordinated adaptive support of key layer control and thick layer bearing capacity in mining roadways according to claim 1, characterized in that, In S5, based on the results of the load stage identification, the process of adjusting the performance of the control component with predetermined time-varying properties through remote or automatic triggering is as follows: S51: When the mining load stage is in a period of low stress and slow increase, time-varying enhanced grouting material is used to proactively reinforce the key layer. S52: When the mining load stage is in a period of high stress and severe influence, the stress-triggered weakening device is automatically activated to implement local pressure relief. S53: During the stress decay and stabilization period of the mining load stage, continuous monitoring shall be carried out.

5. A collaborative adaptive support system for key layer control and thick layer bearing capacity in mining roadways, used to implement the collaborative adaptive support method for key layer control and thick layer bearing capacity in mining roadways as described in any one of claims 1 to 4, characterized in that, include: A multi-source intelligent sensing subsystem is used to collect multi-source monitoring data related to surrounding rock stability; The large structure active control execution subsystem includes a time-varying enhanced grouting unit, a stress-triggered weakening unit, and a drilling and sealing unit; The time-varying enhanced grouting unit is used to pump two-component chemical grout through a proportional mixing pumping system. The stress-triggered weakening unit is a stress-triggered weakening device used to automatically trigger blasting operations when the surrounding rock stress reaches the impact danger threshold; the drilling and sealing unit is used to drill holes perpendicular to the bedding plane and to provide a delivery channel for the two-component chemical slurry. The small-structure thick-layer load-bearing subsystem includes ultra-long anchor bolts / cables, ultra-long anchoring construction units, and grouting reinforcement units. The ultra-long anchoring construction units are used to construct anchoring boreholes that penetrate the disturbed surrounding rock zone and reach the stable rock strata using ultra-long anchor bolt / cable drilling rigs. Simultaneously, they are used to push the ultra-long anchor bolts / cables into the boreholes using an automatic pushing device. The grouting reinforcement unit is used to prepare the reinforcement grout using a grout mixing system. Simultaneously, it is used to perform full-length / end-length grouting operations on the anchoring boreholes using full-length / end-length grouting pumps. The collaborative stage identification and decision control subsystem includes a data preprocessing and fusion unit, a collaborative stage identification unit, and a decision control unit; the data preprocessing and fusion unit is used to preprocess multi-source monitoring data and fuse the preprocessed multi-source monitoring data. The collaborative stage identification unit is used to identify the sampling load stage based on fused data and historical case library; The decision control unit is used to output grouting start command or weakening device start command to the active control execution subsystem of the large structure based on the identification results of the mining load stage.

6. The key layer control and thick layer bearing capacity adaptive support system for mining roadways according to claim 5, characterized in that, The multi-source intelligent sensing subsystem includes: The stress monitoring unit is installed inside the active control layer of the large structure and the thick-layer collaborative bearing body of the small structure to monitor the stress of the surrounding rock. The displacement monitoring unit is installed at the top and bottom plates and the two sides of the roadway to monitor the closure of the top and bottom plates and the convergence of the two sides. The micro-fracture monitoring unit is set in the key monitoring area of ​​the small-structure thick-layer collaborative load-bearing body to monitor the acoustic emission energy rate; The strain monitoring unit is installed inside the small-structure, thick-layer collaborative support structure to monitor volumetric strain. The data acquisition and transmission unit is installed in an explosion-proof box underground and is used to acquire multi-source monitoring data synchronously through multiple channels.

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