Ageing cooperative control method based on pre-peak and post-peak difference target spot selection of roadway surrounding rock

Abstract

The invention relates to the technical field of engineering rock mass, and particularly discloses an aging cooperative control method based on pre-peak and post-peak difference target spot selection of roadway surrounding rock, which is characterized in that pre-peak elastic deformation and post-peak tension-shear fracture inoculation-initiation-extension processes of surrounding rock after roadway excavation are obtained through simulation based on crustal stress conditions and coal rock mechanical parameters in combination with an FDEM method; predicting the development characteristics of a surrounding rock tension-shear fracture network in advance, and determining tension and shear control targets in a surrounding rock plastic zone range; through a two-stage control method of'pre-peak prediction 'targeting enhancement and'post-peak prediction + observation' targeting control, surrounding rock pre-peak and post-peak difference target spot aging cooperative control is realized. According to the method, through FDEM and drilling imaging, based on roadway tension-shear fracture network evolution characteristics, a tension control target, a shear control target and a grouting target in a surrounding rock tension-shear fracture network are recognized and distinguished on a microscale, an anchor rod (cable) structure and grouting parameters are specifically adjusted, and roadway whole life cycle surrounding rock targeted aging strengthening control is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of engineering rock mass, and in particular to a time-effective coordinated control method based on the selection of differential target points before and after a tunnel surrounding rock peak. Background Art

[0002] As the mesostructure of the underground tunnel excavation destruction zone (EDZ), the surrounding rock mesostructure tensile-shear fracture network has a significant incubation-initiation-extension process under the unloading of tunnel excavation. Affected by factors such as working face layout, lithology and ground stress direction, its development range and expansion direction have strong regularity and predictability. The existing support strategy based on elastic theory to control the macroscopic plastic zone of the tunnel is not very effective, and lacks consideration of the mesostructure and evolution law of the tunnel excavation destruction zone (EDZ). Existing surrounding rock control theories tend to focus on the suspension, combination and compression of macro-damage zones, or the improvement and interpretation of the macro-mechanical parameters of anchor bodies, without clearly discussing the fracture mechanism and micro-fracture network morphology in the excavation damage zone, and to a certain extent ignore the pre-peak inhibitory effect of anchor (cable) components on the initiation and development of potential fractures within the loosening damage zone. At present, the design of secondary support schemes for tunnel surrounding rock anchors (cables) under different geological conditions or mining states is mostly based on the macro-loosening circle of the surrounding rock. By increasing the number of anchors (cables) or changing the length of anchors (cables), the bearing capacity of post-peak fractured surrounding rock is enhanced. There is a lack of consideration of the synergistic effect of pre-peak control and post-peak regulation of surrounding rock in the entire life cycle of the tunnel, and the time-effective synergistic relationship between the pre-peak and post-peak control methods of surrounding rock and the control effect is not clear. Summary of the invention

[0003] The purpose of the present invention is to provide a time-effective coordinated control method based on the selection of target points before and after the peak of surrounding rock in the tunnel to solve the above-mentioned technical problems. In order to solve the above-mentioned technical problems, the present invention adopts the following technical solutions: A time-effective collaborative control method based on target selection of differences before and after the peak of surrounding rock in tunnels involves the following stages and steps: Pre-peak stage: (1) Based on the mine geological data and mining data, determine the location of the pre-excavation tunnel, the excavation direction and the surrounding ground stress distribution state, and clarify the type and mechanical parameters of the coal and rock mass near the tunnel; (2) Based on the mining status, ground stress parameters and coal rock mechanical parameters near the pre-excavated tunnel, a FDEM tunnel excavation numerical model is constructed. The evolution process of the tensile-shear fracture network of the surrounding rock after tunnel excavation is obtained through numerical calculation. Combined with the mining data of the mine, the surrounding rock stress transfer process, deformation and failure law, and the extension range and development direction of the tensile-shear fracture network are predicted; (3) The anchoring target points in the anchoring range of the bolt and cable are classified according to the development characteristics of the tensile shear fracture network predicted by FDEM simulation; the locations where tensile cracks in the shallow surrounding rock are widely developed within the anchoring range of the bolt and cable are taken as the tensile control targets, and the intersection areas of the shear strain zones in the deep surrounding rock within the anchoring range of the bolt and cable are taken as the shear control targets; (4) Based on the distribution of tension-shear control target points within the anchoring range of the anchor rods and cables, adjust the material, structure and layout parameters of the anchor rods and cables in the initial support plan; for the distribution area of ​​tension control target points within the anchoring range, change the material to increase the tensile strength of the anchor rod and cable body or increase the installation preload; for the shear control target points within the anchoring range, increase the radius of the anchor rod and cable at the corresponding position, install a shear device or increase the anchoring force; (5) Use the modified specific anchor bolts and cables to carry out primary support for the surrounding rock, adjust the length and angle of the anchor bolts and cables, make the length of the anchor bolts and cables greater than the plastic zone radius of the surrounding rock in that direction, and make the anchor bolts and cables perpendicular to the predicted tensile shear fracture; Post-peak stage: (6) Real-time monitoring of the excavated tunnels, monitoring the deformation of the surrounding rock through the GWL300 intrinsically safe displacement sensor, and full-section drilling imaging through the ZLJ350 tunnel drilling rig and the ZKXG100 mining intrinsically safe borehole peep detector for locations where the tunnel has undergone significant deformation or severe surrounding rock crushing during the service period; (7) Compare the borehole imaging with the FDEM numerical simulation results of the corresponding section of the tunnel to determine the development state of the surrounding rock tensile-shear fracture network of the corresponding section of the tunnel, and judge the development range of the surrounding rock tensile-shear fracture network, the development depth of tensile fracture, and the development location of the shear strain band; (8) Based on the observation and simulation comparison results, the target point identification criteria in step (4) are used to determine the location of the surrounding rock tension and shear control target points, and specific transformation of the reinforcement anchor bolts and cables is carried out. At the same time, the anchor bolt length, layout direction, layout density and layout position are adjusted according to the development range of the fracture network, and the secondary support plan for the large deformation area of ​​the tunnel is determined; (9) Based on the borehole imaging and simulation comparison results, the grouting control targets in the surrounding rock are divided into shallow grouting control targets and deep grouting control targets. The shallow grouting control targets are mainly composed of the locations where tensile fractures or tensile-shear mixed fractures of the surrounding rock are developed. The borehole imaging results are characterized by shallow target locations, short fracture intervals, and high degree of surrounding rock fragmentation. A targeted round of grouting is used to bond the broken rock mass into a whole to construct the shallow pressure-bearing shell of the tunnel, thereby controlling the crushing and expansion deformation of the post-peak fracture surrounding rock. (10) The control target of deep grouting is mainly the slip position of the shear strain zone of the surrounding rock. The main features of the borehole imaging results are the deep target position, long fracture interval and intact surrounding rock. A second round of targeted grouting is carried out to build a deep pressure shell by increasing the grouting pressure and grouting range to control the slip deformation of the post-peak fracture surrounding rock. (11) Targeted reinforcement control of the surrounding rock in the large deformation area of ​​the tunnel is carried out through local specific anchor bolt and cable reinforcement and targeted grouting reinforcement; (12) Through FDEM numerical simulation and borehole imaging observation methods, the evolution characteristics of the tensile-shear fracture network of the tunnel are predicted before and observed after the peak. Combined with the identification of the target points of the tensile-shear fracture network of the tunnel surrounding rock at the microscopic scale, the anchor material, structure, and layout parameters are modified in a targeted manner, and the surrounding rock grouting parameters are specifically adjusted to strengthen the targeted timeliness of controlling the surrounding rock throughout the life cycle of the tunnel.

[0004] Furthermore, the distribution state of the ground stress includes the direction of the principal stress 、 、 and size , , ; Furthermore, the mechanical parameters include the elastic modulus E d ,tensile strength , compressive strength , cohesion C , internal friction angle Φ , Poisson's ratio v .

[0005] The present invention has significant technical effects due to the adoption of the above technical solutions: (1) This method fully combines the microscopic evolution characteristics of the tensile shear fracture network of the tunnel surrounding rock through FDEM numerical simulation and borehole imaging technology. Based on the microscopic distinction of the surrounding rock fracture type, development range, and expansion law, the method realizes the differentiated selection and targeted control of the tensile control target, shear control target, and grouting target of the tunnel surrounding rock, and improves the refined strategy selection of the surrounding rock control scheme. (2) This method fully considers the evolution characteristics of the tensile shear fracture network structure of the tunnel surrounding rock, and combines the advanced inhibition of the initiation and development of potential fractures in the loosening damage zone by the anchor (cable) component, so as to realize the discrimination of differentiated targets for tunnel surrounding rock control, pre-peak prediction and prevention, and post-peak coordinated control. (3) Based on the evolution law of the tensile shear fracture network of the tunnel surrounding rock, the method differentiates the effectiveness mechanisms of different surrounding rock control means, selects the surrounding rock control target, and establishes a pre-peak and post-peak coordinated control system for surrounding rock, which significantly reduces the cost of tunnel stability control and realizes the targeted and time-effective strengthening control of the surrounding rock throughout the life cycle of the tunnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 It is a technical roadmap of the time-effective collaborative control method based on the selection of target points before and after the peak of surrounding rock in the tunnel in the present invention; Figure 2 It is a schematic diagram of target selection based on the microscopic tensile-shear fracture network of tunnel surrounding rock in the present invention. DETAILED DESCRIPTION

[0007] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0008] In the description of the present invention, it should be noted that the terms "vertical", "upper", "lower", "horizontal", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, "first", "second", "third", and "fourth" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0009] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection, it can be a mechanical connection, it can be an electrical connection, it can be a direct connection, it can be connected through an intermediate medium, and it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0010] like Figure 1-2 As shown, a time-effective collaborative control method based on the selection of target points before and after the peak of surrounding rock in the tunnel in the present invention involves the following stages and steps: Pre-peak stage: (1) Based on the mine geological data and mining data, determine the location of the pre-excavation tunnel, the excavation direction and the surrounding ground stress distribution state, and clarify the type and mechanical parameters of the coal and rock mass near the tunnel; (2) Based on the mining status, ground stress parameters and coal rock mechanical parameters near the pre-excavated tunnel, a FDEM tunnel excavation numerical model was constructed. The evolution process of the tensile-shear fracture network of the surrounding rock after tunnel excavation was obtained through numerical calculation. Combined with the mining data of the mine, the surrounding rock stress transfer process, deformation and failure law, and the extension range and development direction of the tensile-shear fracture network were predicted; (3) The anchoring targets within the anchoring range of the bolt (cable) are classified according to the development characteristics of the tensile shear fracture network predicted by FDEM simulation. The locations where tensile cracks in the shallow surrounding rock within the anchoring range of the bolt (cable) are widely developed are taken as the tension control targets (the anchor in this area is mainly characterized by tension along the axial direction of the bolt), and the intersection areas of the deep surrounding rock shear strain zones within the anchoring range of the bolt (cable) are taken as the shear control targets (the anchor in this area is mainly characterized by shear along the sliding direction of the shear strain zone). (4) Based on the distribution of tension-shear control target points within the anchoring range of the anchor rod (cable), adjust the material, structure and layout parameters of the anchor rod (cable) in the initial support plan. In the distribution area of ​​tension control target points within the anchoring range, by changing the material to increase the tensile strength of the rod (cable) body or increasing the installation preload, the anchoring force of the anchor rod (cable) is further improved to inhibit the development of tension cracks in the shallow surrounding rock; for the shear control target points within the anchoring range, by increasing the radius of the anchor rod (cable) at the corresponding position, installing a shear device or increasing the anchoring force (normal stress), the shear strength of the anchor rod (cable) and the overall shear resistance of the rock are specifically improved to control the sliding and dislocation of the surrounding rock; (5) Use the modified specific anchor rods (cables) to carry out primary support for the surrounding rock. Adjust the length and angle of the anchor rods (cables) so that the length of the anchor rods (cables) is greater than the plastic zone radius of the surrounding rock in that direction. At the same time, the rod (cable) body is perpendicular to the predicted tensile shear fracture, so as to achieve targeted strengthening of the surrounding rock in the pre-peak stage during the primary support process. Post-peak stage: (6) Real-time monitoring of the excavated tunnels, monitoring the deformation of the surrounding rock through the GWL300 intrinsically safe displacement sensor, and full-section drilling imaging through the ZLJ350 tunnel drilling rig and the ZKXG100 mining intrinsically safe borehole peep detector for locations where the tunnel has undergone significant deformation or severe surrounding rock crushing during the service period; (7) Compare the borehole imaging with the FDEM numerical simulation results of the corresponding section of the tunnel to determine the development state of the surrounding rock tensile-shear fracture network of the corresponding section of the tunnel, and judge the development range of the surrounding rock tensile-shear fracture network, the development depth of tensile fracture, and the development location of the shear strain band; (8) Based on the observation and simulation comparison results, the target point identification criteria in step (4) are used to determine the position of the surrounding rock tension and shear control target points, and specific transformation of the reinforcement anchors (cables) is carried out. At the same time, the anchor (cable) length, layout direction, layout density and layout position are adjusted according to the development range of the fracture network, and the secondary support scheme for the large deformation area of ​​the tunnel is determined; (9) According to the borehole imaging and simulation comparison results, along the borehole direction, based on the regionality of the development of tension and shear fractures in the surrounding rock, it is stipulated that the relative position of the development of tension and shear fractures close to the free surface of the tunnel excavation is shallow, and the relative position of the development of tension and shear fractures far from the free surface of the tunnel excavation is deep. The grouting control targets in the surrounding rock are divided into shallow grouting control targets and deep grouting control targets. The shallow grouting control targets are mainly composed of the development positions of tension fractures or tension-shear mixed fractures in the surrounding rock. The borehole imaging results are characterized by shallow target positions (close to the free surface of the tunnel excavation), short fracture intervals, and high degree of surrounding rock fragmentation. A low-pressure targeted one-round grouting is used to bond the broken rock mass into a whole to construct a shallow pressure-bearing shell, thereby improving the crushing and expansion deformation of the shallow surrounding rock. (10) The control target of deep grouting is mainly the sliding position of the shear strain zone of the surrounding rock. The main features of the borehole imaging results are the deep position of the target (far away from the free surface of the tunnel excavation), the long fracture interval distance, and the integrity of the core block. The targeted second round of grouting is carried out to build a deep pressure shell by increasing the grouting pressure and grouting range to control the sliding deformation of the surrounding rock after the peak fracture. (11) Through local specific anchor (cable) reinforcement and targeted grouting reinforcement of the surrounding rock, targeted reinforcement control is carried out on the surrounding rock in the large deformation area of ​​the tunnel, so as to inhibit the continuous occurrence of post-peak surrounding rock structural instability and shear slip deformation, and achieve targeted reinforcement of the tunnel surrounding rock; (12) Through FDEM numerical simulation and borehole imaging observation methods, the pre-peak prediction and post-peak observation of the evolution characteristics of the tensile-shear fracture network of the tunnel were realized. Combined with the identification of the target points of the tensile-shear fracture network of the tunnel surrounding rock at the microscopic scale, the targeted time-effective strengthening control of the surrounding rock of the tunnel throughout its life cycle was achieved by targeted modification of the anchor (cable) material, structure, and layout parameters and specific adjustment of the surrounding rock grouting parameters.

[0011] The ground stress distribution state includes the principal stress direction 、 、 and size , , ; The mechanical parameters include elastic modulus E d ,tensile strength , compressive strength , cohesion C , internal friction angle Φ , Poisson's ratio v ; The patent of this invention discloses a method for coordinated control of pre-peak and post-peak differential target time effects based on the evolution of tunnel mesoscopic tensile-shear fracture network. As the mesoscopic structure of underground tunnel excavation destruction zone (EDZ), the surrounding rock mesoscopic tensile-shear fracture network has a significant incubation-germination-extension process under the unloading action of tunnel excavation. Affected by factors such as working face layout, lithology and ground stress direction, its development range and expansion direction have strong regularity and predictability. Based on the in-situ stress conditions and coal rock mechanical parameters of the pre-excavated tunnel obtained from field investigations and laboratory tests, combined with the FDEM numerical simulation method, the process of incubation-initiation-extension of the pre-peak elastic deformation of the surrounding rock and the post-peak tensile-shear fracture after tunnel excavation can be obtained through numerical calculation and simulation, and the development range and expansion direction of the post-peak tensile-shear fracture network of the surrounding rock can be predicted in advance, and the tension and shear control targets within the plastic zone of the surrounding rock of the pre-excavated tunnel can be determined; according to the predicted target type and target generation location, the corresponding section material and structure of the anchor (cable) are modified, and the layout direction of the anchor (cable) is adjusted, so as to achieve targeted strengthening of the surrounding rock in the pre-peak stage during the primary support process; for the primary support under the initial support, the development range and expansion direction of the post-peak tensile-shear fracture network of the surrounding rock can be predicted in advance, and the tension and shear control targets within the plastic zone of the surrounding rock of the pre-excavated tunnel can be determined; according to the predicted target type and target generation location, the corresponding section material and structure of the anchor (cable) are modified, and the layout direction of the anchor (cable) is adjusted, so as to achieve targeted strengthening of the surrounding rock in the pre-peak stage during the primary support process; for the post-peak tensile-shear fracture network under the initial support, the development range and expansion direction of the post-peak tensile-shear fracture network of the surrounding rock can be predicted in advance, and the tension and shear control targets within the plastic zone of the surrounding rock of the pre-excavated tunnel can be determined; for the post-peak tensile-shear fracture network under the initial support, the development range and expansion direction of the post-peak tensile-shear fracture network can be predicted in advance, and the tension and shear control targets within the plastic zone of the surrounding rock of the pre-excavated tunnel can be determined; for the post-peak tensile-shear fracture network under the initial support, the development range and expansion direction of the post-peak tensile- At the location of the tunnel with significant large deformation, the borehole imaging technology is used to observe the evolution characteristics of the fracture in the surrounding rock, and the FDEM simulation results are compared to determine the scope of the tensile fracture zone and the development location of the shear strain band in the surrounding rock; the location of the tensile fracture and shear strain band development within the grouting hole is taken as the grouting target, and the grouting parameters such as the grouting position, grouting radius and slurry material are adjusted, while the layout parameters of the secondary support anchor (cable) of the tunnel are adjusted to achieve targeted reinforcement of the surrounding rock in the large deformation area of ​​the tunnel in the post-peak stage; through the two-stage control method of "pre-peak prediction" targeted reinforcement of the tunnel surrounding rock and "post-peak prediction + observation" targeted control, the coordinated control of the pre-peak and post-peak difference targets of the tunnel surrounding rock is achieved. This method uses FDEM numerical simulation and borehole imaging methods. Based on the evolution characteristics of the tunnel tensile-shear fracture network, the tunnel surrounding rock tensile-shear fracture network is divided into tension control targets, shear control targets and grouting targets on a microscopic scale. By targeted modification of the anchor (cable) structure and specific adjustment of the surrounding rock grouting parameters, targeted time-effective strengthening control of the tunnel surrounding rock throughout its life cycle is achieved, thereby improving the stability of the surrounding rock during the tunnel service period.

[0012] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0013] The above-described embodiments only express the implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention of the present invention. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

Claims

1. A time-effective collaborative control method based on the selection of target points before and after the peak of surrounding rock in tunnels, characterized in that: The following stages and steps are involved: Pre-peak stage: (1) Based on the mine geological data and mining data, determine the location of the pre-excavation tunnel, the excavation direction and the surrounding ground stress distribution state, and clarify the type and mechanical parameters of the coal and rock mass near the tunnel; (2) Based on the mining status, ground stress parameters and coal rock mechanical parameters near the pre-excavated tunnel, a FDEM tunnel excavation numerical model is constructed. The evolution process of the tensile-shear fracture network of the surrounding rock after tunnel excavation is obtained through numerical calculation. Combined with the mining data of the mine, the surrounding rock stress transfer process, deformation and failure law, and the extension range and development direction of the tensile-shear fracture network are predicted; (3) The anchoring target points in the anchoring range of the bolt and cable are classified according to the development characteristics of the tensile shear fracture network predicted by FDEM simulation; the locations where tensile cracks in the shallow surrounding rock are widely developed within the anchoring range of the bolt and cable are taken as the tensile control targets, and the intersection areas of the shear strain zones in the deep surrounding rock within the anchoring range of the bolt and cable are taken as the shear control targets; (4) Based on the distribution of tension-shear control target points within the anchoring range of the anchor rods and cables, adjust the material, structure and layout parameters of the anchor rods and cables in the initial support plan; for the distribution area of ​​tension control target points within the anchoring range, change the material to increase the tensile strength of the anchor rod and cable body or increase the installation preload; for the shear control target points within the anchoring range, increase the radius of the anchor rod and cable at the corresponding position, install a shear device or increase the anchoring force; (5) Use the modified specific anchor bolts and cables to carry out primary support for the surrounding rock, adjust the length and angle of the anchor bolts and cables, make the length of the anchor bolts and cables greater than the plastic zone radius of the surrounding rock in that direction, and make the anchor bolts and cables perpendicular to the predicted tensile shear fracture; Post-peak stage: (6) Real-time monitoring of the excavated tunnels, monitoring the deformation of the surrounding rock through the GWL300 intrinsically safe displacement sensor, and full-section drilling imaging through the ZLJ350 tunnel drilling rig and the ZKXG100 mining intrinsically safe borehole peep detector for locations where the tunnel has undergone significant deformation or severe surrounding rock crushing during the service period; (7) Compare the borehole imaging with the FDEM numerical simulation results of the corresponding section of the tunnel to determine the development state of the surrounding rock tensile-shear fracture network of the corresponding section of the tunnel, and judge the development range of the surrounding rock tensile-shear fracture network, the development depth of tensile fracture, and the development location of the shear strain band; (8) Based on the observation and simulation comparison results, the target point identification criteria in step (4) are used to determine the location of the surrounding rock tension and shear control target points, and specific transformation of the reinforcement anchor bolts and cables is carried out. At the same time, the anchor bolt length, layout direction, layout density and layout position are adjusted according to the development range of the fracture network, and the secondary support plan for the large deformation area of ​​the tunnel is determined; (9) Based on the borehole imaging and simulation comparison results, the grouting control targets in the surrounding rock are divided into shallow grouting control targets and deep grouting control targets. The shallow grouting control targets are mainly composed of the locations where tensile fractures or tensile-shear mixed fractures of the surrounding rock are developed. The borehole imaging results are characterized by shallow target locations, short fracture intervals, and high degree of surrounding rock fragmentation. A targeted round of grouting is used to bond the broken rock mass into a whole to construct a shallow pressure-bearing shell, thereby controlling the crushing and expansion deformation of the post-peak fracture surrounding rock. (10) The control target of deep grouting is mainly the slip position of the shear strain zone of the surrounding rock. The main features of the borehole imaging results are the deep target position, long fracture interval and intact surrounding rock. A second round of targeted grouting is carried out to build a deep pressure shell by increasing the grouting pressure and grouting range to control the slip deformation of the post-peak fracture surrounding rock. (11) Targeted reinforcement control of the surrounding rock in the large deformation area of ​​the tunnel is carried out through local specific anchor bolt and cable reinforcement and targeted grouting reinforcement; (12) Through FDEM numerical simulation and borehole imaging observation methods, the evolution characteristics of the tensile-shear fracture network of the tunnel are predicted before and observed after the peak. Combined with the identification of the target points of the tensile-shear fracture network of the tunnel surrounding rock at the microscopic scale, the anchor material, structure, and layout parameters are modified in a targeted manner, and the surrounding rock grouting parameters are specifically adjusted to strengthen the targeted timeliness of controlling the surrounding rock throughout the life cycle of the tunnel.

2. The time-effective collaborative control method based on the selection of target points before and after the peak of surrounding rock in tunnel according to claim 1 is characterized by: The ground stress distribution state includes the principal stress direction 、 、 and size , , .

3. The time-effective collaborative control method based on the selection of target points before and after the peak of surrounding rock in tunnel according to claim 1 is characterized by: The mechanical parameters include the elastic modulus E d ,tensile strength , compressive strength , cohesion C , internal friction angle Φ , Poisson's ratio v .

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