Temporary support optimization method, system and device based on stress diffusion model

Abstract

The present application relates to the technical field of mine exploitation and tunneling support, more particularly to a temporary support optimization method, system and device based on a stress diffusion model, the method comprising: establishing a temporary support stress diffusion model, and obtaining the distribution characteristics of the temporary support stress field in the unsupported area of the roadway surrounding rock based on the temporary support stress diffusion model; analyzing the characteristics of the stress field generated by the temporary support in the unsupported area of the roadway surrounding rock through numerical simulation experiments; verifying the temporary support stress diffusion model; obtaining factors affecting the stability of the surrounding rock in the unsupported area of the roadway surrounding rock; determining the linear relationship between the optimal temporary support force and the unsupported distance; and deducing the optimal temporary support force; determining the maximum unsupported distance based on the attenuation degree of the temporary support stress; and summing the length of the temporary support area and the unsupported distance, thereby designing and optimizing the cutting parameters and temporary support parameters; and the present application can achieve efficient development of coal resources.

Description

Technical Field

[0001] This invention relates to the field of mining and tunneling support technology, and more specifically to a temporary support optimization method, system and device based on a stress diffusion model. Background Technology

[0002] A key bottleneck in the efficient development of coal resources lies in the imbalance between tunneling and mining activities. The core problem hindering the slow progress of tunneling operations is the difficulty in implementing tunneling and permanent support operations in parallel, a limitation that significantly restricts production efficiency. Temporary support is considered a potential breakthrough in addressing this issue. However, the mechanism by which temporary support specifically affects the stability of the surrounding rock in unsupported areas is currently lacking a clear understanding. This technological gap not only hinders the effective guarantee of stability in unsupported areas but also makes the rational setting of unsupported spans a major challenge. Therefore, in-depth research into the mechanism of action of temporary support is crucial for improving tunneling efficiency and ensuring the overall safety of mining operations. Summary of the Invention

[0003] The purpose of this invention is to provide a temporary support optimization method based on a stress diffusion model, which provides a stress diffusion model for roadway excavation in fully mechanized coal mining faces. This model facilitates the analysis of the stress diffusion effect of temporary supports, determines their reasonable span and strength, thereby optimizing construction parameters, improving support design, and providing effective technical support for the rapid mining of coal resources.

[0004] To achieve the above objectives, the present invention is implemented through the following steps:

[0005] Step S1: Establish a temporary support stress diffusion model, and obtain the distribution characteristics of the temporary support stress field in the unsupported area of ​​the roadway surrounding rock based on the temporary support stress diffusion model;

[0006] Step S2: Analyze the characteristics of the stress field generated by the temporary support in the unsupported area of ​​the surrounding rock of the roadway through numerical simulation experiments, and verify the stress diffusion model of the temporary support.

[0007] Step S3: Based on the stress diffusion model of the temporary support and the characteristics of the stress field generated by the temporary support in the unsupported area of ​​the roadway, analyze the factors affecting the stability of the unsupported area of ​​the roadway. The factors include the magnitude of the temporary support force, the length of the temporary support area, and the unsupported distance.

[0008] Step S4: Based on the factors affecting the stability of the unsupported zone of the roadway, determine the linear relationship between the optimal temporary support force and the unsupported distance, and derive the optimal temporary support force required for the unsupported zone. Based on the attenuation degree of the temporary support stress, determine the maximum unsupported distance. Also, based on the roof stress, determine the sum of the length of the temporary support zone and the unsupported distance. Based on the temporary support stress diffusion model, design and optimize the cutting parameters and temporary support parameters, arrange equipment, and design and optimize the roadway excavation process.

[0009] As a preferred embodiment of the present invention, step S1, establishing a temporary support stress diffusion model includes:

[0010] Step S11: Divide the roadway into the area to be excavated, the unsupported roof area, the temporary support area and the permanent support area. Also, regard the surrounding rock of the roadway as an infinite beam and regard the effect of the temporary support force on the surrounding rock of the roadway as a uniform normal force acting on the plane of the infinite beam.

[0011] Step S12: Integrate the first radial stress over the temporary support area to obtain the second radial stress caused by the temporary support force at any given point. The first radial stress is represented by Formula 1, and the second radial stress is represented by Formula 2.

[0012]

[0013] Step S13: Integrate the second radial stress over the open roof area to obtain the diffused stress of the temporary support force in the roof space, expressed by Formula 3;

[0014]

[0015] Step S14: Obtain the diffusion law of the temporary support force in the surrounding rock of the roadway based on Formula 3;

[0016] Where F represents the temporary support force, σ1 represents any radial stress, σ2 represents the radial stress caused by the temporary support force F at any point, σ3 represents the stress of the temporary support force F in the unsupported roof area, x is the excavation direction along the roadway, z is the height direction along the roadway, L1 is the length of the unsupported roof area, L2 is the length of the temporary support area, ζ represents the micro-segment at x-axis ζ, and x1, x2, x3 are the coordinates on the x-axis.

[0017] As a preferred technical solution of the present invention, in step S11, the area to be excavated refers to the area that has not yet been excavated, the empty roof area refers to the area that has been excavated but lacks temporary support, the temporary support area refers to the area directly supported by temporary support, and the permanent support area refers to the area where the anchoring work has been completed and the surrounding rock of the roadway has formed a stable area.

[0018] As a preferred embodiment of the present invention, in step S14, after obtaining the diffusion law of the temporary support force in the surrounding rock of the roadway:

[0019] Based on the diffusion law of the temporary support force in the surrounding rock of the roadway, when the distance of the temporary support force from the roof increases along the height direction of the roadway in the unsupported area, the stress diffusion of the temporary support force in the unsupported area first increases and then decreases, reaching a peak value at the first value.

[0020] The stress diffusion of the temporary support force in the unsupported area along the tunnel excavation direction is divided into three continuous regions: stress diffusion zone, stress attenuation zone, and no diffusion zone. The stress diffusion zone refers to the area where the temporary support force hardly attenuates, the stress attenuation zone refers to the area where the temporary support force attenuates relatively quickly, and the no diffusion zone refers to the area where the temporary support force is ineffective.

[0021] As a preferred embodiment of the present invention, step S1, obtaining the distribution characteristics of the temporary support stress field in the unsupported area of ​​the roadway surrounding rock, includes:

[0022] A mathematical model is performed on the surrounding rock of the tunnel. The temporary support is assumed to be subjected to a uniform normal force on a semi-infinite plane. The diffusion law of the temporary support stress along the tunnel height and the excavation direction in the surrounding rock is derived by integral derivation.

[0023] As a preferred embodiment of the present invention, analyzing the stress field generated by the temporary support in the unsupported zone includes:

[0024] Experiment A and Experiment B are set up. Experiment A simulates the situation where no temporary support is applied after the tunnel is excavated, and the stress distribution of the surrounding rock of the tunnel is recorded as the first distribution state. Experiment B simulates the situation where temporary support is applied after the tunnel is excavated, and the stress distribution of the surrounding rock of the tunnel is recorded as the second distribution state.

[0025] A tunnel model is established using numerical modeling software. The first parameters of Experiment A and Experiment B are input into the tunnel model. For Experiment B, the second parameters of Experiment B are also input into the tunnel model. The first parameters are parameters common to Experiment A and Experiment B, including tunnel dimensions and rock mechanics. The second parameters include the support force and support location of the temporary support.

[0026] Based on the tunnel model, Experiment A and Experiment B were run, and the stress and displacement changes of the surrounding rock in the tunnel were recorded as simulation results during the simulation of Experiment A and Experiment B.

[0027] By comparing the simulation results of Experiment A and Experiment B, the influence of temporary support on the stress field of the surrounding rock of the roadway is analyzed, and the stress concentration area and stress reduction area caused by temporary support are determined.

[0028] The stress difference between Experiment A and Experiment B at the same location is calculated, the stress variation values ​​at different heights are obtained, the stress distribution and variation values ​​along the tunneling direction are also obtained, and the stress diffusion zone, stress attenuation zone and stress-free diffusion zone are determined based on the stress distribution and variation values.

[0029] As a preferred embodiment of the present invention, step S3 further includes:

[0030] Based on Experiment A and Experiment B, it can be seen that as the temporary support force increases, the strain of the roadway roof in the unsupported area decreases and the stress increases. When the strain of the roadway roof in the unsupported area is equal to zero, the temporary support force is obtained and taken as the optimal temporary support force. At the same time, the linear relationship between the unsupported distance and the optimal temporary support force is obtained.

[0031] As a preferred embodiment of the present invention, step S4 further includes:

[0032] Based on the linear relationship between the unsupported distance and the optimal temporary support force, the unsupported distance is adjusted. Based on the length of the temporary support zone, the combined length of the temporary support zone and the unsupported zone is defined, and the combined length of the temporary support zone and the unsupported zone is less than a second value. Temporary support equipment is also designed, and the length of the temporary support equipment is less than a third value.

[0033] The present invention also provides a temporary support optimization system based on a stress diffusion model as described above, comprising the following modules:

[0034] The model building unit is used to build a temporary support stress diffusion model and obtain the distribution characteristics of the temporary support stress field in the unsupported area of ​​the roadway surrounding rock based on the temporary support stress diffusion model.

[0035] The model verification unit is used to analyze the characteristics of the stress field generated by the temporary support in the unsupported area of ​​the surrounding rock of the roadway through numerical simulation experiments, and to verify the stress diffusion model of the temporary support.

[0036] The factor analysis unit is used to analyze the factors affecting the stability of the unsupported area of ​​the roadway surrounding rock based on the stress diffusion model of the temporary support and the characteristics of the stress field generated by the temporary support in the unsupported area of ​​the roadway surrounding rock. The factors include the magnitude of the temporary support force, the length of the temporary support area and the unsupported distance.

[0037] The parameter optimization unit is used to determine the linear relationship between the optimal temporary support force and the unsupported distance based on the factors affecting the stability of the unsupported zone of the roadway, and to derive the optimal temporary support force required for the unsupported zone. Based on the attenuation degree of the temporary support stress, it determines the maximum unsupported distance. Based on the roof stress, it also determines the sum of the length of the temporary support zone and the unsupported distance. Based on the temporary support stress diffusion model, it designs and optimizes the cutting parameters and temporary support parameters, arranges equipment, and designs and optimizes the roadway excavation process.

[0038] The present invention also provides a computing device, the device comprising:

[0039] Memory, used to store computer programs;

[0040] A processor is used to implement the aforementioned temporary support optimization method based on the stress diffusion model when executing the computer program.

[0041] Compared with the prior art, the beneficial effects of the present invention are at least as follows:

[0042] The technical solution of this invention establishes a temporary support stress diffusion model to obtain the distribution law of temporary support force in the surrounding rock. Based on the stress difference in the unsupported area with and without temporary support, the stress distribution characteristics of temporary support in the unsupported area are obtained, and these characteristics are similar to the law of the temporary support stress diffusion model, demonstrating the correctness of the model. The effects of temporary support force, temporary support length, and unsupported distance on the stress and strain of the roof in the unsupported area are also determined. The distribution of temporary support in the surrounding rock of the unsupported area is along the height direction of the roadway; with increasing height, the stress first increases and then decreases, reaching its maximum at a height of 3m from the roof. Along the roadway excavation direction, the stress remains almost constant within 3m, then decreases sharply beyond 3m. Thus, an optimized scheme for temporary support parameters is obtained, enabling efficient development of coal resources. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0044] Figure 1 This is a flowchart illustrating the steps of the temporary support optimization method based on the stress diffusion model in this invention.

[0045] Figure 2 This is a structural diagram of the temporary support optimization system based on the stress diffusion model in this invention;

[0046] Figure 3 This is a schematic diagram of the underground support area in a coal mine according to the present invention;

[0047] Figure 4 This refers to curve one in this invention;

[0048] Figure 5 This is curve two in this invention. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0050] It is understood that the terms "first," "second," etc., used in this application may be used herein to describe various elements, but unless otherwise specified, these elements are not limited by these terms. These terms are used only to distinguish one element from another. For example, without departing from the scope of this application, a first script may be referred to as a second script, and similarly, a second script may be referred to as a first script.

[0051] A key bottleneck in the efficient development of coal resources lies in the imbalance between tunneling and mining activities, namely, the difficulty in carrying out tunneling and permanent support operations in parallel, which significantly restricts production efficiency.

[0052] To address the aforementioned technical problems, the present invention proposes the following... Figure 1 The temporary support optimization method based on the stress diffusion model shown includes the following steps:

[0053] Step S1: Establish a temporary support stress diffusion model, and obtain the distribution characteristics of the temporary support stress field in the unsupported area of ​​the roadway surrounding rock based on the temporary support stress diffusion model.

[0054] Specifically, a stress diffusion model for temporary support is first established. This model assumes that a uniform normal force is applied to the temporary support on a semi-infinite plane, and the diffusion law of the temporary support force along the roadway height and excavation direction is derived through two integrations. The model treats the surrounding rock of the roadway as an infinite beam to conform to the assumption of stress diffusion.

[0055] Step S2: Analyze the characteristics of the stress field generated by temporary support in the unsupported area of ​​the roadway surrounding rock through numerical simulation experiments, and verify the stress diffusion model of temporary support.

[0056] Specifically, numerical simulation experiments were conducted to compare the stress field with and without temporary support. Two sets of simulation experiments (Experiment A and Experiment B) were performed using FLAC3D software. Experiment A simulated the situation without temporary support, while Experiment B simulated the situation with temporary support. By comparing the stress differences between the two sets of experiments, the stress diffusion model of temporary support was verified, and the distribution characteristics of temporary support stress in the unsupported area were determined.

[0057] Step S3: Based on the validated temporary support stress diffusion model and the characteristics of the stress field generated by temporary support in the unsupported area of ​​the roadway, obtain the factors affecting the stability of the unsupported area of ​​the roadway. These factors include the magnitude of the temporary support force, the length of the temporary support area, and the unsupported distance.

[0058] Specifically, the effects of temporary support force, the length of the temporary support zone, and the unsupported distance on the stability of the surrounding rock in the unsupported zone were analyzed. Experimental data showed that as the temporary support force increased, the roof strain decreased, indicating an increase in stress in the unsupported zone. Furthermore, it was found that the maximum unsupported distance should not exceed 3 meters, and the length of the temporary support zone should not exceed 17 meters from the working face of the roadway. A reasonable roof-to-roof distance can reduce the frequency of equipment relocation and improve operational efficiency. Determining the optimal temporary support force and maximum unsupported distance in the unsupported zone can ensure the stability of the surrounding rock and reduce the risk of roadway collapse and rockfall.

[0059] Step S4: Based on the factors affecting the stability of the unsupported zone of the roadway, determine the linear relationship between the optimal temporary support force and the unsupported distance, and derive the optimal temporary support force required for the unsupported zone. Based on the attenuation degree of the temporary support stress, determine the maximum unsupported distance. Also, based on the roof stress of the roadway surrounding rock, determine the sum of the length of the temporary support zone and the unsupported distance. Based on the maximum unsupported distance, the length of the temporary support zone, and the unsupported distance, design and optimize the cutting parameters and temporary support parameters.

[0060] Specifically, based on experimental data, the linear relationship between the optimal temporary support force and the unsupported distance was determined. For example, for unsupported distances ranging from 1 meter to 5 meters, the optimal support forces were 13 MPa, 17 MPa, 20 MPa, 23 MPa, and 26 MPa, respectively, showing a strong linear relationship. Based on this relationship, the optimal temporary support force required for the unsupported zone was derived, and the cutting parameters and temporary support parameters were designed and optimized to improve tunneling efficiency.

[0061] Through the coordination of the above steps, tunnel excavation can achieve efficient development of coal resources while ensuring safety and efficiency.

[0062] Furthermore, in step S1 above, establishing the stress diffusion model for temporary support includes:

[0063] Step S11: Divide the roadway into the area to be excavated, the unsupported roof area, the temporary support area and the permanent support area. Also, regard the surrounding rock of the roadway as an infinite beam and regard the effect of the temporary support force on the surrounding rock of the roadway as a uniform normal force acting on the plane of the infinite beam.

[0064] Step S12: Integrate the first radial stress over the temporary support zone to obtain the second radial stress caused by the temporary support force at any given point. The first radial stress is expressed by Formula 1, and the second radial stress is expressed by Formula 2.

[0065]

[0066] Step S13: Integrate the second radial stress in the open roof area to obtain the diffused stress of the temporary support force in the roof space, expressed by Formula 3;

[0067]

[0068] Step S14: Obtain the diffusion law of temporary support force in the surrounding rock of the roadway based on Formula 3;

[0069] Where F represents the temporary support force, σ1 represents any radial stress, σ2 represents the radial stress caused by the temporary support force F at any point, σ3 represents the stress of the temporary support force F in the unsupported area, x is the direction of tunneling along the roadway, z is the direction of tunneling height, L1 is the length of the unsupported area, L2 is the length of the temporary support area, ζ represents the micro-segment at x-axis ζ, and x1, x2, x3 are the coordinates on the x-axis.

[0070] Specifically, the diffusion law of temporary support force can be derived from mathematical model formula 3. The diffusion of temporary support force F in the unsupported area (i.e., the open roof area) can be divided into three different stages. For example... Figure 4 As shown, Zone I is the stress diffusion zone, where the temporary support force shows almost no attenuation; Zone II is the stress attenuation zone, where the temporary support force attenuates relatively quickly; Zone III is the non-diffusion zone, where the temporary support force has no effect. Figure 5 As can be seen, the temporary support force first increases and then decreases along the z-axis distance from the roof, reaching a peak at 3 meters. Stress diffusion along the tunneling direction (x-axis) is divided into three continuous regions: the stress diffusion zone, the stress attenuation zone, and the stress-free diffusion zone. During tunneling, it is essential to ensure that the unsupported zone remains within the stress diffusion zone at all times; this is the foundation and prerequisite for safe tunneling operations.

[0071] Furthermore, in step S11 above, the area to be excavated refers to the area that has not yet been excavated, the empty roof area refers to the area that has been excavated but lacks temporary support, the temporary support area refers to the area directly supported by temporary support, and the permanent support area refers to the stable area where the anchoring work has been completed and the surrounding rock of the roadway has been formed.

[0072] Specifically, the rapid tunneling robot system based on a tunnel boring machine (TBM) consists of a cutting system, a temporary support system, a permanent support system, a ventilation and dust removal system, and an electro-hydraulic control platform. Based on the spatial relationship between the equipment and the surrounding rock, the tunnel is divided into four zones: the area to be excavated, the unsupported roof area, the temporary support area, and the permanent support area. Figure 3 As shown in the diagram. The area to be excavated refers to the area that has not yet been excavated; the unsupported roof area refers to the area that has been excavated but lacks temporary support, essentially the unsupported area in the surrounding rock of the roadway; the temporarily supported area is the area directly supported by temporary supports; and the permanently supported area refers to the area where anchoring and other work have been completed and the surrounding rock has stabilized. Due to the presence of temporary supports, excavation and permanent support can be carried out in parallel, significantly improving excavation efficiency. A reasonable unsupported roof distance can effectively reduce the frequency of equipment movement, further improving efficiency. While ensuring the stability of the surrounding rock, a larger unsupported roof distance can achieve a longer excavation section, reducing the frequency of equipment movement. Furthermore, the unsupported roof distance also affects the temporary support force and the length of the temporary supported area, which will be described in detail below. The unsupported roof distance, also known as the unsupported roof area length or unsupported distance, refers to the length of the area that has been excavated but has not yet been temporarily supported during the excavation of coal mine roadways or tunnels.

[0073] Furthermore, in step S14 above, after obtaining the diffusion law of temporary support force in the surrounding rock of the roadway:

[0074] Based on the diffusion law of temporary support force in the surrounding rock of the roadway, when the distance of temporary support force from the roof increases along the height direction of the roadway in the unsupported area, the stress diffusion of temporary support force in the unsupported area first increases and then decreases, reaching a peak at the first value.

[0075] The stress diffusion of temporary support force in the unsupported area along the tunnel excavation direction is divided into three continuous regions: stress diffusion zone, stress attenuation zone, and no diffusion zone. The stress diffusion zone refers to the area where the temporary support force hardly attenuates, the stress attenuation zone refers to the area where the temporary support force attenuates relatively quickly, and the no diffusion zone refers to the area where the temporary support force is ineffective.

[0076] Specifically, at this time, the first value is the same as or close to the value corresponding to the distance of the unsupported zone with the largest value in the stress diffusion zone, which is the largest unsupported distance, i.e., the safe and stable range.

[0077] Furthermore, the stress field generated by temporary supports in the unsupported zone is analyzed, including:

[0078] Experiment A and Experiment B were set up. Experiment A simulated the situation where no temporary support was applied after the tunnel was excavated, and the stress distribution of the surrounding rock of the tunnel was recorded as the first distribution state. Experiment B simulated the situation where temporary support was applied after the tunnel was excavated, and the stress distribution of the surrounding rock of the tunnel was recorded as the second distribution state.

[0079] A tunnel model was built using numerical modeling software. The first parameters of Experiment A and Experiment B were input into the tunnel model. For Experiment B, the second parameters of Experiment B were also input into the tunnel model. The first parameters are common to Experiment A and Experiment B, including tunnel dimensions and rock mechanics. The second parameters include the support force and support location of the temporary support.

[0080] Based on the tunnel model, Experiment A and Experiment B were run, and the stress and displacement changes of the surrounding rock in the tunnel were recorded as simulation results during the simulation of Experiment A and Experiment B.

[0081] By comparing the simulation results of Experiment A and Experiment B, the influence of temporary support on the stress field of the surrounding rock of the roadway is analyzed, and the stress concentration area and stress reduction area caused by temporary support are determined.

[0082] The stress difference between Experiment A and Experiment B at the same location was calculated, the stress variation values ​​at different heights were obtained, and the stress distribution and variation values ​​along the tunneling direction were also obtained. Based on the stress distribution and variation values, the stress diffusion zone, stress attenuation zone and stress-free diffusion zone were determined.

[0083] Specifically, different forms of support induce different stress fields in the surrounding rock. As a slender rod-shaped element, the stress field induced by the anchor bolt in the surrounding rock far exceeds its own size. To study the impact of temporary support on the unsupported zone, it is first necessary to analyze the stress field generated by the temporary support in this area. However, FLAC3D software cannot directly calculate the stress field of temporary support diffused into the unsupported zone. Therefore, two sets of simulation experiments, A and B, were conducted to simulate the excavation and support of the same roadway. Experiment A represents the case without temporary support after excavation, and Experiment B represents the case with temporary support after excavation. By analyzing the stress differences between these two sets of experiments, the distribution characteristics of the temporary support stress in the unsupported zone can be determined. The investigation of the stress field distribution characteristics of the surrounding rock in the unsupported zone shows that although the temporary support does not directly support the unsupported zone, it still generates a significant stress field in this area. The appearance of these stress fields in the unsupported zone can be attributed to the diffusion of the temporary support force. By studying the variation law of the temporary support stress field at different height planes, it was observed that the stress first increases and then decreases with increasing height. This change may be related to the difference in the diffusion capacity of temporary support forces at different heights. This pattern of change is consistent with the rules obtained from our mathematical model, the stress diffusion model, and verifies the accuracy of the mathematical model. Furthermore, there is a significant difference between the maximum stress at 3 meters and the stress at other heights, which will increase the risk of roof (i.e., the roof of the tunnel) separation at 3 meters. Therefore, caution should be exercised when using temporary supports at the location of layered roofs (the roof of the tunnel). In addition, the stress field of bolted supports first decreases and then increases with increasing height. Therefore, temporary supports can effectively supplement bolted supports and improve the stability of the surrounding rock before permanent support.

[0084] Furthermore, step S3 above also includes:

[0085] Based on Experiment A and Experiment B, it can be seen that as the temporary support force increases, the roof strain of the unsupported area decreases and the stress increases. When the roof strain of the unsupported area is equal to zero, the temporary support force is obtained and taken as the optimal temporary support force. At the same time, the linear relationship between the unsupported distance and the optimal temporary support force is obtained.

[0086] Furthermore, step S4 above also includes:

[0087] Based on the linear relationship between the unsupported distance and the optimal temporary support force, the unsupported distance is adjusted. Based on the length of the temporary support zone, the combined length of the temporary support zone and the unsupported zone is defined, and the combined length of the temporary support zone and the unsupported zone is less than the second value. Temporary support equipment is also designed, and the length of the temporary support equipment is less than the third value.

[0088] Specifically, the key to safe and efficient excavation lies in ensuring the stability of the surrounding rock in the unsupported zone. Changes in temporary support parameters lead to changes in the stress-strain characteristics of the surrounding rock in the unsupported zone. The main parameters of temporary support include the length of the temporary support zone, the length of the unsupported zone (distance between unsupported zones), and the magnitude of the temporary support force. The length of the support zone determines the equipment requirements, the temporary support force plays a crucial role in controlling the surrounding rock, and the unsupported distance determines the maximum spacing between excavation rows. First, the relationship between the temporary support force in the unsupported zone and the roof (roadtop) strain was studied. It was observed that as the temporary support force increases, the roof (roadtop) strain decreases, indicating a corresponding increase in stress in the unsupported zone. This is similar to the behavior of permanent support (rock bolt support), where higher support forces enhance stress diffusion. The optimal temporary support force is defined as the force required when the roof (roadtop) strain approaches zero. The investigation revealed that the optimal support forces for unsupported distances ranging from 1 meter to 5 meters were 13 MPa, 17 MPa, 20 MPa, 23 MPa, and 26 MPa, respectively. A strong linear relationship was found between the unsupported distance and the optimal temporary support force. This relationship can accurately predict the temporary support force required in unsupported areas, providing valuable guidance for the setting of temporary support forces on site.

[0089] Secondly, analysis of the roof (roadway roof) strain in the temporarily supported and unsupported zones at different unsupported distances shows that the roof (roadway roof) strain in the temporarily supported zone decreases with increasing unsupported distance. This decrease can be attributed to stress diffusion from the unexcavated area to the temporarily supported zone. Furthermore, when the unsupported distance is less than 3 meters, the roof (roadway roof) strain in the unsupported zone is lower than that in the temporarily supported zone. When the unsupported distance is less than 3 meters, the roof (roadway roof) strain in the unsupported zone does not increase significantly. Compared to the maximum opening distance of 2 meters with permanent support, the maximum opening distance using temporary support can reach 3 meters, approximately 33% higher. This increase effectively improves tunneling efficiency.

[0090] Third, the study on the strain evolution of the roof (tunnel roof) in unsupported zones focuses on the length of the temporary support zone. An inflection point was observed in the strain change within the unsupported zone relative to the length of the temporary support. Specifically, before this inflection point, increasing the length of the temporary support had no significant effect on the roof (tunnel roof) strain. However, after reaching this inflection point, the roof (tunnel roof) strain increased significantly with further extension of the temporary support. The inflection points corresponding to unsupported distances of 1 to 5 meters occurred at temporary support zone lengths of 16, 15, 14, 13, and 12 meters, respectively. The sum of the inflection point lengths corresponding to the length of the temporary support zone and the unsupported distance is 17 meters, indicating that the combined length of the temporary and unsupported zones should not exceed 17 meters. Furthermore, based on the above conclusions, it can be inferred that the maximum permissible length of the temporary support zone should not exceed 14 meters. Existing temporary support equipment is less than 14 meters long.

[0091] The present invention also provides, for example Figure 2 The temporary support optimization system based on the stress diffusion model shown includes the following modules:

[0092] The model building unit is used to build a temporary support stress diffusion model and obtain the distribution characteristics of the temporary support stress field in the unsupported area of ​​the roadway surrounding rock based on the temporary support stress diffusion model.

[0093] The model verification unit is used to analyze the characteristics of the stress field generated by the temporary support in the unsupported area of ​​the surrounding rock of the roadway through numerical simulation experiments, and to verify the stress diffusion model of the temporary support.

[0094] The factor analysis unit is used to analyze the factors affecting the stability of the unsupported area of ​​the roadway surrounding rock based on the stress diffusion model of the temporary support and the characteristics of the stress field generated by the temporary support in the unsupported area of ​​the roadway surrounding rock. The factors include the magnitude of the temporary support force, the length of the temporary support area and the unsupported distance.

[0095] The parameter optimization unit is used to determine the linear relationship between the optimal temporary support force and the unsupported distance based on the factors affecting the stability of the unsupported zone of the roadway, and to derive the optimal temporary support force required for the unsupported zone. Based on the attenuation degree of the temporary support stress, it determines the maximum unsupported distance. Based on the roof stress, it also determines the sum of the length of the temporary support zone and the unsupported distance. Based on the temporary support stress diffusion model, it designs and optimizes the cutting parameters and temporary support parameters, arranges equipment, and designs and optimizes the roadway excavation process.

[0096] The present invention also provides a computing device, comprising:

[0097] Memory, used to store computer programs;

[0098] The processor is used to implement the aforementioned temporary support optimization method based on the stress diffusion model when executing computer programs.

[0099] In summary, by establishing a stress diffusion model for temporary support, the distribution law of temporary support force within the surrounding rock was obtained. Based on the stress difference in the unsupported area with and without temporary support, the stress distribution characteristics of temporary support within the unsupported area were obtained, and these characteristics are similar to those of the stress diffusion model, demonstrating the correctness of the model. The effects of temporary support force, temporary support length, and unsupported distance on the stress and strain of the roof in the unsupported area were also determined. The distribution of temporary support force within the surrounding rock in the unsupported area follows the roadway height direction; with increasing height, the stress first increases and then decreases, reaching its maximum at a height of 3m from the roof. Along the roadway excavation direction, the stress remains almost constant within 3m, then decreases sharply beyond 3m. This allows for the acquisition of optimized temporary support parameters, enabling efficient development of coal resources.

[0100] It should be understood that although the steps in the flowcharts of the various embodiments of the present invention are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the various embodiments may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least a portion of the sub-steps or stages of other steps.

[0101] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and RAMbus dynamic RAM (RDRAM), etc.

[0102] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above 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.

[0103] The above-described embodiments are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

[0104] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for optimizing temporary support based on a stress diffusion model, characterized in that, The method comprises: Step S1: establishing a temporary support stress diffusion model, and obtaining distribution characteristics of a stress field of a temporary support area of a roadway surrounding rock based on the temporary support stress diffusion model; Step S2: analyzing characteristics of a stress field generated by the temporary support in the temporary support area of the roadway surrounding rock through numerical simulation experiments, and verifying the temporary support stress diffusion model; Step S3: based on the temporary support stress diffusion model and the characteristics of the stress field generated by the temporary support in the temporary support area of the roadway surrounding rock, analyzing factors affecting the stability of the surrounding rock of the temporary support area of the roadway, the factors including a temporary support force, a length of the temporary support area, and a distance without support; Step S4: based on the factors affecting the stability of the surrounding rock of the temporary support area of the roadway, determining a linear relationship between an optimal temporary support force and a distance without support, and deducing an optimal temporary support force required by the temporary support area, determining a maximum distance without support based on a degree of attenuation of the temporary support stress, determining a sum of the length of the temporary support area and the distance without support based on a roof stress, and designing and optimizing cutting parameters and temporary support parameters based on the temporary support stress diffusion model, arranging equipment, and designing and optimizing a roadway tunneling process; Wherein, the establishment of the temporary support stress diffusion model comprises: Step S11: dividing the roadway into a to-be-tunneling area, a roof removal area, a temporary support area, and a permanent support area, regarding the roadway surrounding rock as an infinite beam, and regarding the effect of the temporary support force on the roadway surrounding rock as a uniform normal force acting on the plane of the infinite beam; Step S12: integrating a first radial stress on the temporary support area to obtain a second radial stress caused by the temporary support force at any given point, the first radial stress being represented by formula 1, and the second radial stress being represented by formula 2: (Formula 1) (Formula 2) Step S13: integrating the second radial stress on the roof removal area to obtain a diffusion stress of the temporary support force in the roof space, which is represented by formula 3; (Formula 3) Step S14: obtaining a diffusion law of the temporary support force in the roadway surrounding rock based on the formula 3; Wherein, F represents the temporary support force, σ1 represents an arbitrary radial stress, σ2 represents a radial stress caused by the temporary support force F at any point, σ3 represents a stress of the temporary support force F in the roof removal area, x is in the tunneling direction of the roadway, z is in the height direction of the roadway, L1 is the length of the roof removal area, L2 is the length of the temporary support area, ζ represents a micro-section at the x-axis ζ, x1, x2, x3 are coordinates on the x-axis.

2. The method of claim 1, wherein, In the step S11, the to-be-tunneling area refers to an area that has not been tunneled, the roof removal area refers to an area that has been tunneled but lacks temporary support, the temporary support area refers to an area directly supported by temporary support, and the permanent support area refers to a stable area formed by the roadway surrounding rock after anchoring work is completed.

3. The method of claim 1, wherein, In the step S14, after obtaining the diffusion law of the temporary support force in the roadway surrounding rock: Based on the diffusion law of the temporary support force in the surrounding rock of the roadway, the stress diffusion of the temporary support force in the open roof area increases first and then decreases along the height direction of the roadway, and reaches a peak at a first value; The stress diffusion of the temporary support force in the open roof area along the driving direction of the roadway is divided into three continuous regions: a stress diffusion region, a stress attenuation region and a non-diffusion region. The stress diffusion region refers to a region in which the temporary support force hardly attenuates, the stress attenuation region refers to a region in which the temporary support force attenuates rapidly, and the non-diffusion region refers to a region in which the temporary support force does not work.

4. The method of claim 1, wherein, In step S1, the distribution characteristics of the temporary support stress field in the unsupported area of the surrounding rock of the roadway are obtained, including: The surrounding rock of the roadway is mathematically modeled, a uniform normal force is applied to the temporary support on a semi-infinite plane, and the diffusion law of the temporary support stress in the surrounding rock of the roadway along the height and driving direction of the roadway is derived by integration.

5. The method of claim 1, wherein, The stress field generated by the temporary support in the unsupported area is analyzed, including: An experiment A and an experiment B are set up. The experiment A simulates the case where no temporary support is applied after the roadway is driven, and the stress distribution state of the surrounding rock of the roadway is recorded as a first distribution state. The experiment B simulates the case where a temporary support is applied after the roadway is driven, and the stress distribution state of the surrounding rock of the roadway is recorded as a second distribution state. A numerical model software is used to establish a roadway model, and the first parameters of the experiment A and the experiment B are input into the roadway model. For the experiment B, the second parameters of the experiment B are also input into the roadway model. The first parameters belong to the parameters common to the experiment A and the experiment B, including the size of the roadway and rock mechanics. The second parameters include the support force and the support position of the temporary support. Based on the roadway model, the experiment A and the experiment B are run, and the stress and displacement change data of the surrounding rock of the roadway during the simulation process of the experiment A and the experiment B are recorded as simulation results. The simulation results of the experiment A and the experiment B are compared to analyze the influence of the temporary support on the stress field of the surrounding rock of the roadway, and to determine the stress concentration area and the stress reduction area caused by the temporary support. The stress difference of the experiment A and the experiment B at the same position is calculated to obtain the change value of the stress at different heights, and the distribution and change value of the stress along the driving direction are also obtained. Based on the distribution and change value of the stress, the stress diffusion region, the stress attenuation region and the non-stress diffusion region are determined.

6. The method of claim 2, wherein, The step S3 further includes: Based on the experiment A and the experiment B, it can be known that with the increase of the temporary support force, the roof strain of the unsupported area of the roadway decreases and the stress increases. When the roof strain of the unsupported area of the roadway is equal to zero, the temporary support force is obtained as the optimal temporary support force, and the linear relationship between the unsupported distance and the optimal temporary support force is obtained.

7. The method of claim 2, wherein, The step S4 further includes: Based on the linear relationship between the unsupported distance and the optimal temporary support force, the unsupported distance is adjusted, the combined length of the temporary support zone and the unsupported zone is defined based on the length of the temporary support zone, and the combined length of the temporary support zone and the unsupported zone is less than a second value, and a temporary support device is also designed, and the length of the temporary support device is less than a third value.

8. A stress-diffusion model based temporary support optimization system for implementing the stress-diffusion model based temporary support optimization method of any one of claims 1-7, characterized in that, The system comprises the following modules: a model establishing unit, configured to establish a temporary support stress diffusion model, and acquire distribution characteristics of a stress field of a temporary support zone of a roadway surrounding rock based on the temporary support stress diffusion model; a model verifying unit, configured to analyze characteristics of a stress field generated by the temporary support in the temporary support zone of the roadway surrounding rock through numerical simulation experiments, and verify the temporary support stress diffusion model; a factor analyzing unit, configured to analyze factors affecting stability of the surrounding rock of the temporary support zone of the roadway surrounding rock based on the temporary support stress diffusion model and the characteristics of the stress field generated by the temporary support in the temporary support zone of the roadway surrounding rock, the factors including a size of a temporary support force, a length of a temporary support zone, and an unsupported distance; a parameter optimizing unit, configured to determine a linear relationship between an optimal temporary support force and an unsupported distance based on the factors affecting the stability of the surrounding rock of the temporary support zone of the roadway surrounding rock, and derive an optimal temporary support force required by the unsupported zone, determine a maximum unsupported distance based on a degree of attenuation of a temporary support stress, determine a sum of the length of the temporary support zone and the unsupported distance based on a roof stress, and design and optimize cutting parameters and temporary support parameters based on the temporary support stress diffusion model, arrange devices, and design and optimize a roadway tunneling process.

9. An arithmetic device, characterized by comprising: The device comprises a memory and a processor: the memory, configured to store a computer program; the processor, configured to implement the temporary support optimization method based on the stress diffusion model in any one of claims 1-7 when the computer program is executed.

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