A method, system, equipment, and storage medium for underground engineering support design that fully utilizes the bearing capacity of deep surrounding rock.

Abstract

This invention provides a method, system, equipment, and storage medium for underground engineering support design that fully mobilizes the bearing capacity of deep surrounding rock. The method includes the following steps: S1, calculation of the surrounding rock stress envelope; S2, monitoring of the degree of surrounding rock fracture; S3, determination of the support strength envelope; S4, control of the optimal control range. By actively controlling the timing of support, the degree of damage and fracture of shallow surrounding rock can be controlled. Furthermore, by actively controlling the support length and strength, the bearing capacity of deep surrounding rock can be mobilized. The key to controlling the timing, length, and strength of support lies in a deep analysis and understanding of the coupling relationship between the stress adjustment process and the fracture evolution process of surrounding rock, which can be achieved through precise numerical calculations and real-time in-situ monitoring. The implementation of this invention can optimally maintain the stability of shallow surrounding rock, mobilize the bearing capacity of deep surrounding rock, save overall support costs, and ensure the safety and stability of the project.

Description

Technical Field

[0001] This invention belongs to the field of underground engineering, and specifically relates to an underground engineering support design method, system, equipment and storage medium that fully mobilizes the bearing capacity of deep surrounding rock. Background Technology

[0002] With the continuous development of the national economy, my country's rigid demands for energy, resources, water conservancy and hydropower, transportation, and the environment are increasing, prompting the construction of mining shafts, water conservancy tunnels, hydropower caverns, highways, and railway tunnels to continuously expand from the surface to underground spaces. Research on surrounding rock stability control is a primary issue for the safe construction of underground engineering projects. Surrounding rock instability reflects the inadequacy of the bearing potential and support strength of the surrounding rock mass to match the stress adjustment process. Therefore, proposing a support design method for underground engineering that fully mobilizes the bearing capacity of deep surrounding rock is imperative and of great significance for the safe and stable control of underground engineering projects.

[0003] Through long-term engineering practice, scholars and engineers both domestically and internationally have developed a series of relatively universal design methods for underground engineering, such as Protodyakonov's pressure arch theory, the mining method, the New Austrian Tunneling Method (NATM), the load-structure method, the convergence-constraint method, the innovative method, and the engineering analogy method. However, with the increasing depth of underground engineering and the growing influence of tectonic movements, the characteristics of high ground stress have become more prominent. Instability of the surrounding rock in underground engineering is increasingly caused by the fracturing of the internal rock mass due to high stress concentration. Previous underground engineering design methods emphasized timely support of the surrounding rock after excavation, stressing that excavation should cause minimal disturbance to the surrounding rock mass. Support measures were designed to minimize the degree and depth of rock fracturing to ensure the integrity and bearing capacity of the surrounding rock, thereby maximizing its self-supporting potential.

[0004] Engineering practice shows that cracking of shallow surrounding rock is inevitable after excavation of underground engineering. The most advantageous way to maximize the self-support potential of surrounding rock is to make reasonable use of stress concentration in the surrounding rock to limit the expansion of cracks within a controllable range and to fully mobilize the self-bearing capacity of the deep surrounding rock mass. Therefore, it is very necessary to develop an underground engineering support design method that fully mobilizes the bearing capacity of deep surrounding rock. Summary of the Invention

[0005] The first objective of this invention is to provide a method for underground engineering support design that fully utilizes the bearing capacity of deep surrounding rock, addressing the aforementioned problems.

[0006] Therefore, the above-mentioned objective of the present invention is achieved through the following technical solution: A method for underground engineering support design that fully utilizes the bearing capacity of deep surrounding rock. Based on the relationship between the degree of surrounding rock damage, the stress envelope of the surrounding rock, and the support strength envelope, the optimal support zone is determined. Within the optimal zone, targeted control points are selected according to the construction grade and control standards of the underground engineering project, thereby determining the support depth.l ), support strength ( p And the type of support, specifically including the following steps: S1, Calculation of the stress envelope of the surrounding rock; S2. Monitoring of the degree of surrounding rock fracture: The relationship between the stress envelope of the surrounding rock and the degree of surrounding rock failure is obtained based on the numerical calculation in step S1. However, in-situ monitoring is required to judge the degree of surrounding rock failure in real time on site. S3. Determination of support strength envelope: Verify the relationship between the support strength envelope and the fracture depth of the surrounding rock in the numerical calculation model in step S1. S4. Optimal control range: The specific timing, strength, and depth of support should be determined based on the engineering construction level and quality control level.

[0007] While adopting the above technical solutions, the present invention may also adopt or combine the following technical solutions: As a preferred technical solution of the present invention: the underground project is in a three-dimensional geostress field environment. After the tunnel is excavated, an excavation fracture zone, an excavation damage zone, an excavation disturbance zone and a stress concentration zone will be formed around the tunnel.

[0008] As a preferred embodiment of the present invention, step S1 further includes the following sub-steps: S11. Construct a three-dimensional numerical calculation model for underground engineering based on the three-dimensional geostress state, rock mechanics parameters, and tunnel design parameters. S12. Calculate the relative changes between the surrounding rock excavation fracture zone and the stress concentration zone during tunnel excavation; S13. Set stress monitoring lines radially along the tunnel wall, extract the stress change curves of the surrounding rock corresponding to different calculation steps, and connect their peak values ​​to form the stress envelope of the surrounding rock.

[0009] As a preferred technical solution of the present invention: in step S2, the monitoring methods include contact monitoring and non-contact monitoring. The contact monitoring includes borehole acoustic waves and borehole television, and the non-contact monitoring includes acoustic emission and micro-vibration.

[0010] As a preferred technical solution of the present invention: in step S3, the support strength p The determination of the envelope is crucial for the overall stiffness of the support structure. K radial displacement of tunnel support u r Volume of the fracture zone during surrounding rock excavation V f Average density of surrounding rock ρ Safety factor S Maximum value of stress concentration zone in surrounding rock σ maxThe factors were jointly determined and verified in the numerical calculation model in step S1, and the relationship between the surrounding rock support strength envelope and the surrounding rock fracture depth was finally obtained.

[0011] As a preferred technical solution of the present invention: in step S4, the optimal control range is near the minimum value of the support strength envelope, which corresponds to the area near the maximum value of the surrounding rock stress envelope.

[0012] The second objective of this invention is to provide an underground engineering support design system that fully mobilizes the bearing capacity of deep surrounding rock, comprising the following modules: A surrounding rock stress envelope calculation module, which is used to calculate the surrounding rock stress envelope; A surrounding rock fracture degree monitoring module, which is used to determine the degree of surrounding rock fracture in real time; A support strength envelope determination module, wherein the support strength envelope determination module is used to determine the support strength envelope; An optimal control interval control module is used to determine the optimal control interval.

[0013] A third objective of this invention is to provide an electronic device comprising a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other via the communication bus. The memory is used to store computer programs; A processor is configured to execute a computer program stored in a memory to implement the underground engineering support design method steps described above for fully mobilizing the bearing capacity of deep surrounding rock.

[0014] Another objective of this invention is to provide a non-volatile storage medium storing an executable program, which, when executed by a processor, implements the steps of the underground engineering support design method for fully mobilizing the bearing capacity of deep surrounding rock as described above.

[0015] Compared with the prior art, the present invention has the following beneficial effects: This invention employs four steps: calculating the surrounding rock stress envelope, monitoring the degree of surrounding rock fracture, determining the support strength envelope, and controlling the optimal control range. By actively controlling the timing of support, the degree of damage and fracture in shallow surrounding rock can be controlled. Furthermore, by actively controlling the support length and strength, the load-bearing capacity of deep surrounding rock can be mobilized. The key to controlling the timing, length, and strength of support lies in a thorough analysis and understanding of the coupling relationship between the surrounding rock stress adjustment process and the surrounding rock fracture evolution process, which can be achieved through precise numerical calculations and real-time in-situ monitoring. The implementation of this invention can optimally maintain the stability of shallow surrounding rock, mobilize the load-bearing capacity of deep surrounding rock, save overall support costs, and ensure the safety and stability of the project. Attached Figure Description

[0016] Figure 1 The design curve diagram of underground engineering support that fully mobilizes the bearing capacity of deep surrounding rock provided by the present invention.

[0017] Figure 2 This is a schematic diagram after the tunnel has been excavated.

[0018] Figure 3 This is a diagram showing the relationship between the fracture depth of the surrounding rock and the stress distribution in the surrounding rock.

[0019] Figure 4 This diagram shows the relationship between the degree of surrounding rock fracture at different support times. Detailed Implementation

[0020] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0021] like Figure 1 As shown, an underground engineering support design method that fully mobilizes the bearing capacity of deep surrounding rock determines the optimal support zone based on the relationship between the degree of surrounding rock damage, the stress envelope of the surrounding rock, and the support strength envelope. Figure 1 In the blue zone, the shallow surrounding rock has a moderate degree of fracturing and will not collapse. The stress concentration zone shifts to the deeper part of the surrounding rock, the support length and support force are moderate, and the bearing capacity of the surrounding rock is optimal. Within the optimal zone, targeted control points are selected according to the underground engineering construction level and control standards to determine the support depth. l ), support strength ( p The support types are mainly anchor-sprayed support (anchor bolts + wire mesh + shotcrete) and reinforced concrete lining (35 cm thick). Anchor bolt types can be further divided into mortar anchor bolts (corresponding to Class I, II, and III surrounding rock) and prestressed anchor bolts (Class IV and V surrounding rock). For Class IV surrounding rock large-section caverns (diameter greater than 6 m) and Class V surrounding rock, additional steel arch frames and advanced small guide pipe support measures are required. Specifically, the following steps are included: S1, Calculation of the stress envelope of the surrounding rock; like Figure 2 As shown, underground engineering is in a three-dimensional geostress field environment. After the tunnel is excavated, excavation fracture zone, excavation damage zone, excavation disturbance zone and stress concentration zone will be formed around the tunnel.

[0022] like Figure 3 As shown, based on the three-dimensional geostress state, rock mechanics parameters, and tunnel design parameters of underground engineering, a three-dimensional numerical calculation model for underground engineering is constructed to calculate the relative changes in the excavation fracture zone and stress concentration zone of the surrounding rock during tunnel excavation. The surrounding rock stress variation curve represents the stress values ​​at different locations along the surrounding rock stress monitoring line, which runs radially from the tunnel wall through the stress concentration zone. As the tunnel continues to advance, the excavation fracture zone at the current analysis section continuously develops (i.e., the fracture depth increases), and the stress concentration zone continuously shifts deeper into the surrounding rock (i.e., the maximum stress value shifts deeper). Connecting the peak values ​​of the surrounding rock stress variation curves corresponding to different calculation steps yields the surrounding rock stress envelope, as shown below. Figure 1 As shown.

[0023] S2. Monitoring of the degree of fracture in the surrounding rock; The relationship between the stress envelope of the surrounding rock and the degree of damage to the surrounding rock is obtained by numerical calculation in step S1, while the real-time judgment of the degree of damage to the surrounding rock needs to be achieved through in-situ monitoring.

[0024] Monitoring methods include contact monitoring and non-contact monitoring. Contact monitoring includes borehole acoustic monitoring and borehole television monitoring. Borehole acoustic monitoring and borehole television monitoring require drilling at the location of the surrounding rock stress monitoring line in step S1. Subsequently, as the tunnel is excavated, the acoustic instruments and television cameras are used to continuously test and determine the depth of the surrounding rock fracture. Non-contact monitoring includes acoustic emission and microseismic monitoring. Acoustic emission and microseismic monitoring can achieve long-distance non-contact testing. Acoustic emission and microseismic matrices are set up at a distance of no more than twice the tunnel diameter from the monitoring section, and then acoustic emission and microseismic signals are collected and tested in real time as the tunnel is excavated.

[0025] S3. Determination of the support strength envelope; Support strength p The determination of the envelope is crucial for the overall stiffness of the support structure. K radial displacement of tunnel support u r Volume of the fracture zone during surrounding rock excavation V f Average density of surrounding rock ρ Safety factor S Maximum value of stress concentration zone in surrounding rock σ max The relationship between the surrounding rock support strength envelope and the surrounding rock fracture depth is determined by a combination of factors and verified in the numerical calculation model in step S1. Figure 1 As shown.

[0026] The support strength envelope shows a trend of first decreasing and then increasing with the increase of the surrounding rock fracture depth. The initial decreasing trend is because the shallow surrounding rock fracture consumes energy, the stress concentration of the surrounding rock decreases, and the external force that the support needs to resist decreases. The subsequent increasing trend is because the shallow surrounding rock fracture is too large, forming a disaster of overall collapse of the surrounding rock. The support not only needs to resist concentrated stress, but also needs to resist the gravity and impact of the collapsed body.

[0027] S4, Optimal control range.

[0028] like Figure 1 As shown, the optimal control range is near the minimum value of the support strength envelope, corresponding to the area near the maximum value of the surrounding rock stress envelope. The specific timing, strength, and depth of support should be determined jointly based on the engineering construction level and quality control level.

[0029] like Figure 4 As shown, compared to the optimal control range: The left side of the optimal control range corresponds to the area of ​​excessive support. At this time, the support is provided early, the support strength is high, the support depth is small, the stress concentration of the surrounding rock is high, the damage and fracture zone of the surrounding rock is small, the internal stress and energy accumulation of the surrounding rock are high, and the risk of dynamic disasters is high.

[0030] The right side of the optimal control range corresponds to the post-support area. At this time, the support timing is late, the support strength is high, the support depth is large, the stress concentration of the surrounding rock is low, but the damage and fracture zone of the surrounding rock is large, and the risk of overall collapse of the surrounding rock is high.

[0031] This invention also provides an underground engineering support design system that fully mobilizes the bearing capacity of deep surrounding rock, comprising the following modules: The surrounding rock stress envelope calculation module is used to calculate the surrounding rock stress envelope. The surrounding rock fracture degree monitoring module is used to determine the degree of surrounding rock fracture in real time; The support strength envelope determination module is used to determine the support strength envelope; The optimal control range module is used to determine the optimal control range.

[0032] The present invention also provides an electronic device, which includes a processor, a communication interface, a memory, and a communication bus. The processor, the communication interface, and the memory communicate with each other via the communication bus. Memory, used to store computer programs; The processor executes computer programs stored in memory to implement the underground engineering support design method steps that fully mobilize the bearing capacity of deep surrounding rock, as described above.

[0033] The present invention also provides a non-volatile storage medium containing an executable program. When the executable program is executed by a processor, it implements the steps of the underground engineering support design method for fully mobilizing the bearing capacity of deep surrounding rock as described above.

[0034] The technical solution of the present invention has been described in conjunction with the specific experimental procedures shown in the accompanying drawings. However, the scope of protection of the present invention is not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions resulting from such changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A method for designing underground engineering support that fully utilizes the bearing capacity of deep surrounding rock, characterized in that: Based on the relationship between the degree of surrounding rock damage, the stress envelope of the surrounding rock, and the support strength envelope, the optimal support zone is determined. Within the optimal zone, targeted control points are selected according to the underground engineering construction grade and control standards, thereby determining the support depth, support strength, and support type. Specifically, this includes the following steps: S1, Calculation of the stress envelope of the surrounding rock; S2. Monitoring of the degree of surrounding rock fracture: The relationship between the stress envelope of the surrounding rock and the degree of surrounding rock failure is obtained based on the numerical calculation in step S1. S3. Determination of support strength envelope: Verify the relationship between the support strength envelope and the fracture depth of the surrounding rock in the numerical calculation model in step S1. S4. Optimal control range: The specific timing, strength, and depth of support should be determined jointly based on the engineering construction level and quality control level. In step S3, the support strength p The determination of the envelope is crucial for the overall stiffness of the support structure. K radial displacement of tunnel support u r Volume of the fracture zone during surrounding rock excavation V f Average density of surrounding rock ρ Safety factor S Maximum value of stress concentration zone in surrounding rock σ max The factors are determined together.

2. The method according to claim 1, characterized in that: Underground engineering projects are located in a three-dimensional geostress field environment. After the tunnel is excavated, excavation fracture zone, excavation damage zone, excavation disturbance zone and stress concentration zone will be formed around the tunnel.

3. The method according to claim 1, characterized in that: Step S1 also includes the following sub-steps: S11. Construct a three-dimensional numerical calculation model for underground engineering based on the three-dimensional geostress state, rock mechanics parameters, and tunnel design parameters. S12. Calculate the relative changes between the surrounding rock excavation fracture zone and the stress concentration zone during tunnel excavation; S13. Set stress monitoring lines radially along the tunnel wall, extract the stress change curves of the surrounding rock corresponding to different calculation steps, and connect their peak values ​​to form the stress envelope of the surrounding rock.

4. The method according to claim 1, characterized in that: In step S2, the monitoring methods include contact monitoring and non-contact monitoring. The contact monitoring includes borehole acoustic waves and borehole television, and the non-contact monitoring includes acoustic emission and microvibration.

5. The method according to claim 1, characterized in that: In step S4, the optimal control range is near the minimum value of the support strength envelope, which corresponds to the area near the maximum value of the surrounding rock stress envelope.

6. An underground engineering support design system that fully utilizes the bearing capacity of deep surrounding rock, characterized in that, The system is based on the underground engineering support design method for fully mobilizing the bearing capacity of deep surrounding rock as described in claim 1, and includes the following modules: A surrounding rock stress envelope calculation module, which is used to calculate the surrounding rock stress envelope; A surrounding rock fracture degree monitoring module, which is used to determine the degree of surrounding rock fracture in real time; A support strength envelope determination module, wherein the support strength envelope determination module is used to determine the support strength envelope; An optimal control interval control module is used to determine the optimal control interval.

7. An electronic device, comprising a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other via the communication bus, characterized in that: The memory is used to store computer programs; A processor for executing a computer program stored in a memory to implement the steps of the underground engineering support design method for fully mobilizing the bearing capacity of deep surrounding rock as described in any one of claims 1-5.

8. A non-volatile storage medium, characterized in that: The non-volatile storage medium stores an executable program, which, when executed by a processor, implements the steps of the underground engineering support design method for fully mobilizing the bearing capacity of deep surrounding rock as described in any one of claims 1-5.

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