Underground engineering support design method, system and equipment for fully transferring bearing capacity of deep surrounding rock and storage medium

Abstract

The invention provides an underground engineering support design method, system and device for fully transferring the bearing capacity of deep surrounding rock and a storage medium. The method comprises the following steps that S1, a surrounding rock stress envelope line is calculated; s2, monitoring the fracture degree of the surrounding rock; s3, determining a support strength envelope line; and S4, controlling the optimal regulation and control interval. The damage and fracture degree of the shallow surrounding rock is controlled by actively controlling the supporting opportunity, and then the purpose of transferring the bearing of the deep surrounding rock is achieved by actively controlling the supporting length and the supporting strength. The key of supporting opportunity, supporting length and supporting strength control lies in deep analysis and understanding of the coupling action relation between the surrounding rock stress adjustment process and the surrounding rock fracture evolution process, and the control can be achieved through fine numerical calculation and real-time in-situ monitoring. The implementation of the invention can optimally maintain the stability of the shallow surrounding rock, mobilize the bearing of the deep surrounding rock, save the overall support cost and ensure the safety and stability of the engineering.

Description

Technical Field

[0001] The present invention belongs to the field of underground engineering, and particularly relates to a design method, system, device and storage medium for underground engineering support that fully mobilizes the bearing capacity of deep surrounding rock. Background Art

[0002] With the continuous development of the national economy, the rigid demands of China for energy, resources, water conservancy and hydropower, transportation and environment are increasing day by day, which promotes the construction of projects such as mine roadways, water conservancy tunnels, hydropower chambers, highway and railway tunnels to continuously move from the surface to the underground space. The research on surrounding rock stability control is the primary issue for the safe construction of underground engineering. The instability of surrounding rock is a reflection that the bearing potential of the surrounding rock mass and the support strength are insufficient to match the process of surrounding rock stress adjustment. Therefore, it is imperative to propose a design method for underground engineering support that fully mobilizes the bearing capacity of deep surrounding rock, and it is of great significance for the safe and stable control of underground engineering.

[0003] Scholars and engineers at home and abroad have formed a series of relatively common design methods for underground engineering through long-term engineering practice, such as the Prandtl pressure arch theory, the mining method, the New Austrian Tunneling Method, the load-structure method, the convergence-confinement method, the new Italian method, the engineering analogy method, etc. However, with the increasing influence of the burial depth of underground engineering and tectonic movement, the characteristics of high in-situ stress are becoming more prominent, and the instability of the surrounding rock of underground engineering is more caused by the rupture of the rock mass inside the surrounding rock due to high stress concentration. The previous design methods for underground engineering emphasized timely support for the surrounding rock after excavation, highlighting the requirement that the excavation causes less disturbance to the surrounding rock mass, and the support measures should minimize the degree and depth of surrounding rock rupture to ensure the integrity and bearing capacity of the surrounding rock, so as to exert the self-supporting potential of the surrounding rock.

[0004] Engineering practice shows that the cracking of shallow surrounding rock after the excavation of underground engineering is inevitable. Reasonably using the stress concentration of the surrounding rock to limit the expansion of surrounding rock rupture within a controllable range and fully mobilizing the self-bearing capacity of the deep rock mass of the surrounding rock is the most favorable way to maximize the self-supporting potential of the surrounding rock. Therefore, it is very necessary to form a design method for underground engineering support that fully mobilizes the bearing capacity of deep surrounding rock. Summary of the Invention

[0005] The first object of the present invention is to provide a design method for underground engineering support that fully mobilizes the bearing capacity of deep surrounding rock in view of the above-mentioned problems.

[0006] To achieve the above object, the present invention adopts the following technical solutions: A design method for underground engineering support that fully mobilizes the bearing capacity of deep surrounding rock, determines the optimal area of support according to the relationship between the degree of surrounding rock failure, the surrounding rock stress envelope and the support strength envelope, and selects targeted control points within the optimal area, and then determines the support depth (l ), support strength ( p ), and support type. Specifically, it includes the following steps: S1. Calculation of the surrounding rock stress envelope; S2. Monitoring of the surrounding rock fracture degree: According to the relationship between the surrounding rock stress envelope and the surrounding rock fracture degree obtained by numerical calculation in step S1, on-site real-time judgment of the surrounding rock fracture degree needs to be achieved through in-situ monitoring; S3. Determination of the support strength envelope: Recheck and verify in the numerical calculation model of step S1, and finally obtain the relationship between the surrounding rock support strength envelope and the surrounding rock fracture depth; S4. Optimal control interval control: The specific support timing, support strength, and support depth need to be jointly determined according to the engineering construction level and quality control level.

[0007] While adopting the above technical solution, the present invention can 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 in-situ stress field environment. After the tunnel excavation, 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 technical solution of the present invention: Step S1 further includes the following sub-steps: S11. Construct a three-dimensional numerical calculation model of the underground project based on the three-dimensional in-situ stress state of the underground project, rock mass mechanical parameters, and tunnel design parameters; S12. Calculate the relative change relationship between the surrounding rock excavation fracture zone and the stress concentration zone during the tunnel excavation process; S13. Set stress monitoring lines along the radial direction of the tunnel wall, extract the surrounding rock stress change curves corresponding to different calculation steps, and connect their peaks to form the surrounding rock stress envelope.

[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 wave and borehole television, and the non-contact monitoring includes acoustic emission and microseismic.

[0010] As a preferred technical solution of the present invention: In step S3, the determination of the support strength p envelope is a comprehensive consideration of the support structure stiffness K , the radial displacement of the tunnel support u r , the volume of the surrounding rock excavation fracture zone V f , the average density of the surrounding rock ρ , the safety factor S , the maximum value of the surrounding rock stress concentration zone σ maxIt is jointly determined by various factors and verified in the numerical calculation model in step S1. Finally, the relationship between the surrounding rock support strength envelope and the surrounding rock fracture depth is obtained.

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

[0012] The second object of the present invention is to provide an underground engineering support design system that fully mobilizes the bearing capacity of deep surrounding rock, including 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 judge the surrounding rock fracture degree in real time; A support strength envelope determination module, which is used to determine the support strength envelope; An optimal regulation interval control module, which is used to determine the optimal regulation interval.

[0013] The third object of the present invention is to provide an electronic device, which includes a processor, a communication interface, a memory, and a communication bus. The processor, communication interface, and memory complete mutual communication through the communication bus. A memory, which is used to store a computer program; A processor, which is used to execute the computer program stored on the memory to implement the steps of the underground engineering support design method for fully mobilizing the bearing capacity of deep surrounding rock as described above.

[0014] Another object of the present invention is to provide a non-volatile storage medium, in which an executable program is stored. When the executable program is executed by a processor, it realizes 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: Through four steps: calculating the surrounding rock stress envelope, monitoring the degree of surrounding rock fracture, determining the support strength envelope, and controlling the optimal regulation interval, by actively controlling the support timing, the control of the damage and fracture degree of the shallow surrounding rock is achieved. Furthermore, by actively controlling the support length and support strength, the purpose of mobilizing the bearing capacity of the deep surrounding rock is achieved. The key to controlling the support timing, support length, and support strength lies in deeply analyzing and understanding the coupling relationship between the surrounding rock stress adjustment process and the surrounding rock fracture evolution process, which can be realized through fine numerical calculations and real-time in-situ monitoring. The implementation of the present invention can optimally maintain the stability of the shallow surrounding rock, mobilize the bearing capacity of the deep surrounding rock, save the overall support cost, and ensure the safety and stability of the project. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0017] Figure 2 It is a schematic diagram after the tunnel excavation.

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

[0019] Figure 4 It is a diagram showing the relationship between the degree of surrounding rock fracture corresponding to different support timings. DETAILED DESCRIPTION OF THE EMBODIMENTS

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

[0021] As Figure 1 shown, a design method for underground engineering support that fully mobilizes the bearing capacity of the deep surrounding rock determines the optimal area of support ( Figure 1 blue interval. In this interval, the degree of fracture of the shallow surrounding rock is moderate, the surrounding rock will not collapse, the stress concentration area transfers towards the deep part of the surrounding rock, the support length and support force are moderate, and the surrounding rock bearing circle is optimal) according to the relationship between the degree of surrounding rock failure, the surrounding rock stress envelope, and the support strength envelope. Within the optimal area, according to the construction grade and control standards of the underground project, targeted control points are selected, and then the support depth ( l ), support strength ( p ), and support type are determined. The support type is mainly shotcrete with bolts (bolt + wire mesh + shotcrete) and reinforced concrete lining (35 cm thick). The bolt types can be specifically divided into mortar bolts (corresponding to Class I, Class II, and Class III surrounding rocks) and prestressed bolts (Class IV and Class V surrounding rocks). For large-section caverns (diameter greater than 6 m) in Class IV surrounding rocks and Class V surrounding rocks, steel arch frames and advanced small pipe support measures are also required. Specifically, it includes the following steps: S1. Calculating the surrounding rock stress envelope; AsFigure 2 As shown in the figure, the underground project is in a three-dimensional in-situ stress field environment. After the tunnel excavation, an excavation failure zone, an excavation damage zone, an excavation disturbance zone, and a stress concentration zone will be formed around the tunnel.

[0022] As Figure 3 shown, based on the three-dimensional in-situ stress state of the underground project, rock mass mechanical parameters, tunnel design parameters, etc., a three-dimensional numerical calculation model of the underground project is constructed to calculate the relative change relationship between the excavation failure zone and the stress concentration zone of the surrounding rock during the tunnel tunneling process. Among them, the surrounding rock stress change curve is the stress value corresponding to different positions of the surrounding rock stress monitoring line, and the surrounding rock stress monitoring line passes through the stress concentration zone along the tunnel radial direction from the tunnel wall. As the tunnel continues to advance forward, the excavation failure zone of the surrounding rock at the current analysis section position continues to develop (i.e., the surrounding rock failure depth increases), and the stress concentration zone of the surrounding rock continuously transfers towards the deep part of the surrounding rock (i.e., the maximum value of the surrounding rock stress continuously transfers towards the deep part of the surrounding rock). Connecting the peaks of the surrounding rock stress change curves corresponding to different calculation steps can obtain the surrounding rock stress envelope, as Figure 1 shown.

[0023] S2. Monitoring of the surrounding rock failure degree; According to the relationship between the surrounding rock stress envelope and the surrounding rock failure degree obtained from the numerical calculation in step S1, the on-site real-time judgment of the surrounding rock failure degree needs to be realized through in-situ monitoring.

[0024] The monitoring methods include contact monitoring and non-contact monitoring. Contact monitoring includes borehole acoustic wave and borehole television. Borehole acoustic wave and borehole television need to drill holes at the position of the surrounding rock stress monitoring line in step S1, and then continuously test through acoustic wave instruments and television cameras during the tunnel tunneling process to determine the surrounding rock failure depth; Non-contact monitoring includes acoustic emission and microseismic. Acoustic emission and microseismic can realize long-distance non-contact testing. At a position no more than 2 times the tunnel diameter away from the monitoring section, an acoustic emission and microseismic matrix is arranged, and then acoustic emission and microseismic signals are collected and tested in real time during the tunnel tunneling process.

[0025] S3. Determination of the support strength envelope; The support strength p envelope is determined by comprehensively considering factors such as the stiffness of the support structure K , the radial displacement of the tunnel support u r , the volume of the excavation failure zone of the surrounding rock V f , the average density of the surrounding rock ρ , the safety factor S , the maximum value of the stress concentration zone of the surrounding rock σ max etc., and is verified in the numerical calculation model in step S1. The relationship between the finally obtained surrounding rock support strength envelope and the surrounding rock failure depth is asFigure 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 trend of first decreasing is because the fracture of shallow surrounding rock consumes energy, the stress concentration degree of the surrounding rock decreases, and the external force that the support needs to resist decreases; the trend of subsequent increase is because the fracture degree of shallow surrounding rock is too large, and a disaster of overall collapse of the surrounding rock has occurred. The support not only needs to resist the concentrated stress, but also needs to resist the gravity and impact force of the collapsed body.

[0027] S4. Optimal regulation interval control.

[0028] such as Figure 1 as shown, the optimal regulation interval is near the minimum value of the support strength envelope, corresponding to the area near the rear of the maximum value of the surrounding rock stress envelope. The specific support timing, support strength and support depth need to be jointly determined according to the engineering construction grade and quality control grade.

[0029] such as Figure 4 as shown, compared with the optimal regulation interval: The left side of the optimal regulation interval corresponds to the over-strong support area. At this time, the support timing is early, the support strength is large, the support depth is small, the stress concentration degree of the surrounding rock is high, and the surrounding rock damage and fracture area is small. At this time, the internal stress and energy accumulation degree of the surrounding rock is high, and the risk of dynamic disasters is high.

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

[0031] The present invention also provides an underground engineering support design system that fully mobilizes the bearing capacity of deep surrounding rock, including the following modules: A surrounding rock stress envelope calculation module for calculating the surrounding rock stress envelope; A surrounding rock fracture degree monitoring module for real-time judgment of the surrounding rock fracture degree; A support strength envelope determination module for determining the support strength envelope; An optimal regulation interval control module for determining the optimal regulation interval.

[0032] The present invention also provides an electronic device. The electronic device includes a processor, a communication interface, a memory, and a communication bus. The processor, the communication interface, and the memory complete mutual communication through the communication bus. The memory is used to store a computer program; The processor is used to execute the computer program stored on the memory to implement the steps of the underground engineering support design method for fully mobilizing the bearing capacity of deep surrounding rock as described above.

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

[0034] So far, the technical solution of the present invention has been described in combination with the specific experimental process shown in the drawings. However, the protection scope of the present invention is not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A method for designing underground engineering support that fully mobilizes the bearing capacity of deep surrounding rock, characterized by: According to the relationship between the surrounding rock damage degree, surrounding rock stress envelope, and support strength envelope, the optimal support area is determined. In the optimal area, according to the underground engineering construction level and control standards, targeted control points are selected to determine the support depth, support strength, and support type. Specifically, the following steps are included: S1. Calculation of surrounding rock stress envelope; S2. Monitoring of surrounding rock fracture degree: obtaining the relationship between the surrounding rock stress envelope and the surrounding rock damage degree according to the numerical calculation in step S1; S3, support strength envelope determination: verify in the numerical calculation model of step S1, the relationship between the surrounding rock support strength envelope and the surrounding rock fracture depth finally obtained; S4. Optimal control interval control: The specific support timing, support strength and support depth must be determined based on the engineering construction level and quality control level.

2. The method according to claim 1, characterized in that: Underground projects are in a three-dimensional geostress field environment. After tunnel excavation, excavation rupture zones, excavation damage zones, excavation disturbance zones and stress concentration zones 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 of underground engineering based on the three-dimensional ground stress state, rock mass mechanical parameters and tunnel design parameters of underground engineering; S12. Calculate the relative change relationship between the surrounding rock excavation fracture zone and the stress concentration zone during tunnel excavation; S13. Set stress monitoring lines along the radial direction of the tunnel wall, extract the surrounding rock stress change curves corresponding to different calculation steps, and connect their peak values ​​to form the surrounding rock stress envelope.

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 drilling sound waves and drilling television, and the non-contact monitoring includes acoustic emission and microseismic.

5. The method according to claim 1 or 4, characterized in that: In step S3, the support strength p The determination of the envelope is the stiffness of the comprehensive support structure. K , radial displacement of tunnel support u r , Volume of surrounding rock excavation fracture zone V f , average density of surrounding rock ρ , Safety factor S , the maximum value of surrounding rock stress concentration zone σ max factors are jointly determined.

6. The method according to claim 1, characterized in that: In step S4, the optimal control interval is near the minimum value of the support strength envelope, corresponding to the area near the rear of the maximum value of the surrounding rock stress envelope.

7. An underground engineering support design system that fully mobilizes the bearing capacity of deep surrounding rock, characterized in that: Includes the following modules: A surrounding rock stress envelope calculation module, wherein the surrounding rock stress envelope calculation module is used to calculate the surrounding rock stress envelope; A surrounding rock fracture degree monitoring module, which is used to determine the surrounding rock fracture degree in real time; A support strength envelope determination module, wherein the support strength envelope determination module is used to determine the support strength envelope; The optimal control interval control module is used to determine the optimal control interval.

8. 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: A memory, the memory being used to store a computer program; A processor, wherein the processor is used to execute a computer program stored in a memory to implement the steps of an underground engineering support design method for fully mobilizing the bearing capacity of deep surrounding rock as described in any one of claims 1 to 6.

9. A non-volatile storage medium, characterized in that: The non-volatile storage medium stores an executable program, and when the executable program is executed by the processor, 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 1-6 are implemented.

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