Large-mining-height comprehensive mechanized dense filling mining working face roadway differentiation dynamic support design optimization method

Abstract

The invention discloses a large-mining-height comprehensive mechanized dense filling mining working face roadway differentiation dynamic support design optimization method which comprises the following steps: constructing a three-dimensional geomechanical model, and simulating surrounding rock mechanical response in a layered excavation process; a differentiated supporting strategy is implemented in the three-dimensional geomechanical model, supporting parameters of the upper layer are fixed, the row pitch of anchor rods of the lower layer is adjusted, and candidate optimized row pitches are screened through multi-scheme comparison; carrying out a staged test based on the candidate optimization array pitch, constructing a contrast type monitoring network comprising a test section and a normal support section, and obtaining multi-dimensional real-time mine pressure monitoring data; comparing the real-time mine pressure monitoring data with the simulation prediction data, and correcting the three-dimensional geomechanical model and adjusting a support scheme based on a comparison result; and based on all simulation, test and monitoring data, a layered support optimization scheme under standardization is formed. According to the method, differentiated, refined and dynamic supporting of the roadway is achieved.

Description

Technical Field

[0001] This invention relates to the field of coal mine roadway support technology, and in particular to a method for optimizing the design of differentiated dynamic support for roadways in high-extraction, fully mechanized, dense-filling mining faces. Background Technology

[0002] Integrated mechanized compaction backfilling is one of the important technologies for green mining in my country's coal mines. For working faces with large mining heights (such as 7-8 meters), a layered mining process is usually adopted. First, the upper layer (about 3.5-4 meters) is mined using a continuous miner, and permanent support is provided using threaded steel anchor bolts and steel strand anchor cables. Then, the lower layer (about 3.5-4 meters) is mined, and support is mostly provided using cutable materials such as fiberglass anchor bolts to facilitate subsequent backfilling.

[0003] Currently, the support design for this type of tunnel has significant shortcomings:

[0004] (1) Conservative design and lack of differentiation: Traditional designs usually use the same or similar support parameters (such as bolt spacing) for the upper and lower layers. This ignores the favorable conditions of the upper layer support forming a "bearing arch" effect and the lower layer roadway having a short exposure time (about 9-12 days from excavation to filling), resulting in over-support of the lower layer support and waste of support materials (bolts, anchor cables, explosive cartridges, etc.) and labor costs.

[0005] (2) The optimization methods are crude and lack scientific rigor: Existing parameter optimization methods mostly rely on engineering analogies and local empirical adjustments, lacking systematic theoretical guidance and data support. This "trial and error method" is not only inefficient, but may also lead to safety hazards due to inaccurate judgment of the mechanical behavior of the surrounding rock.

[0006] (3) The process is static and lacks dynamic feedback: Once the support scheme is determined, it usually remains unchanged throughout the entire working face mining process. It cannot be dynamically adjusted and optimized based on real-time mine pressure monitoring data, making it difficult to achieve truly refined support.

[0007] Therefore, there is an urgent need in this field for a support design optimization method that can achieve differentiation, refinement and dynamic optimization for the characteristics of large-extraction fully mechanized dense filling mining faces, so as to significantly reduce support costs while ensuring safety. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of the prior art and provide a differentiated dynamic support design optimization method for roadways in high-extraction fully mechanized dense filling mining faces. This method constructs a system engineering that integrates numerical simulation, industrial testing, multi-source information monitoring and closed-loop feedback to achieve safe and scientific optimization of the lower-level support parameters (especially the bolt spacing), thereby reducing support costs and workload.

[0009] To achieve the above objectives, this invention provides a method for optimizing the differentiated dynamic support design of roadways in fully mechanized dense filling mining faces with high extraction heights, comprising:

[0010] A three-dimensional geomechanical model was constructed to simulate the mechanical response of the surrounding rock during layered excavation.

[0011] Differential support strategies are implemented in the three-dimensional geomechanical model. The upper layer support parameters are fixed, the spacing of the lower layer anchor bolts is adjusted, and candidate optimized spacing is screened through comparison of multiple schemes.

[0012] Based on the candidate optimized row spacing, phased tests were carried out, and a comparative monitoring network including test sections and normal support sections was constructed to obtain multi-dimensional real-time mine pressure monitoring data.

[0013] The real-time mine pressure monitoring data is compared with the simulated prediction data, and the three-dimensional geomechanical model is corrected and the support scheme is adjusted based on the comparison results.

[0014] Based on all simulation, test and monitoring data, a standardized layered support optimization scheme was developed.

[0015] Preferably, the three-dimensional geomechanical model is constructed to simulate the mechanical response of the surrounding rock during layered excavation, including:

[0016] Based on the rock strata columnar section, physical and mechanical parameters, and tunnel design dimensions of the target working face, a three-dimensional numerical simulation software was used to simulate the dynamic excavation process of the tunnel in layers by setting the boundary conditions as bottom fixed, surrounding normal displacement constraint, and applying an equivalent overlying rock load to the upper part.

[0017] Preferably, simulating the dynamic excavation process of the tunnel in layers includes:

[0018] At least two rounds of layered excavation are conducted, with the first round simulating the upper layer excavation and support, and subsequent rounds simulating the lower layer excavation and support.

[0019] Preferably, the differentiated support strategy is as follows:

[0020] The spacing between the upper-layer anchor bolts and anchor cables remains constant, serving as a stable load-bearing structure.

[0021] Several sets of comparative schemes were set according to an increasing gradient for the spacing of the lower-level anchor bolts. The mechanical response index of each scheme was obtained through simulation calculation, and candidate optimized spacing that balances safety and economy was selected.

[0022] Preferably, the mechanical response indicators include at least two of the following: roof subsidence, sidewall convergence, axial stress of anchor bolts or cables, range of plastic zone of surrounding rock, and stress distribution.

[0023] Preferably, the phased experiment includes:

[0024] First approach: Select a local section in the roadway, adjust the spacing of the lower layer anchor bolts to the candidate optimized spacing for testing, and after verifying safety and stability, gradually expand the application scope;

[0025] Second approach: Based on the success of the first approach, select a larger row spacing value for exploratory testing.

[0026] Preferably, the multi-dimensional real-time mine pressure monitoring data includes roadway surface displacement, roof delamination, support stress, and internal damage development of the surrounding rock.

[0027] Preferably, modifying the three-dimensional geomechanical model includes:

[0028] Based on the revised model and measured data, the long-term stability of the current experimental row spacing is evaluated, and a decision is made based on the evaluation results on whether to expand the application of the current row spacing, explore larger row spacings, or carry out reinforcement support.

[0029] Preferably, the standardized layered support optimization scheme includes:

[0030] By integrating numerical simulation data, industrial test data, mine pressure monitoring data, and expert evaluation conclusions, the recommended spacing range and construction process requirements for layered anchor bolts under different geological conditions are clarified.

[0031] Compared with the prior art, the present invention has the following advantages and technical effects:

[0032] (1) This invention pioneered a differentiated support technology path for high mining height integrated mechanized dense filling: for the first time, it systematically proposed and practiced the core idea of ​​"constant strong support in the upper layer and optimized weak support in the lower layer", accurately utilizing the mechanical properties and spatiotemporal effects of the surrounding rock in the lower layer, and realizing a fundamental and refined transformation of support design.

[0033] (2) This invention constructs a scientific and reliable “digital twin” optimization closed loop: through the cycle of “numerical simulation-industrial test-monitoring feedback-model correction”, virtual simulation is closely coupled with the physical world, so that each parameter optimization is based on sufficient theoretical calculation and empirical data, which greatly improves the scientificity, predictability and safety of the optimization process and eliminates blind adjustment.

[0034] (3) The present invention achieves significant economic benefits: by safely increasing the spacing of the lower layer anchor bolts, the amount of support materials such as anchor bolts, anchor cables, and resin cartridges and the corresponding installation time are directly reduced. It is estimated that the cost of lower layer support can be effectively reduced by 10%-20%, while improving tunneling efficiency.

[0035] (4) Risk management is moved forward and is controllable throughout the process: The gradual implementation strategy of “local test → data verification → scope expansion” is adopted, and the monitoring network is deployed in advance to realize the early identification and active control of potential risks. Any abnormal mine pressure manifestation can be detected and dealt with in a timely manner, ensuring the safety of the test and subsequent application. Attached Figure Description

[0036] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0037] Figure 1 This is a flowchart illustrating a method for optimizing the design of differentiated dynamic support for roadways in a fully mechanized dense filling mining face according to an embodiment of the present invention.

[0038] Figure 2 This is a schematic diagram of the layout of mine pressure monitoring stations in a comparative field test section and normal section according to an embodiment of the present invention. Detailed Implementation

[0039] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0040] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0041] This embodiment proposes a differentiated dynamic support design optimization method for roadways in fully mechanized dense filling mining faces with high extraction heights, including:

[0042] A three-dimensional geomechanical model was constructed to simulate the mechanical response of the surrounding rock during layered excavation.

[0043] Differential support strategies are implemented in the three-dimensional geomechanical model. The upper layer support parameters are fixed, the spacing of the lower layer anchor bolts is adjusted, and candidate optimized spacing is screened through comparison of multiple schemes.

[0044] Based on the candidate optimized row spacing, phased tests were carried out, and a comparative monitoring network including test sections and normal support sections was constructed to obtain multi-dimensional real-time mine pressure monitoring data.

[0045] The real-time mine pressure monitoring data is compared with the simulated prediction data, and the three-dimensional geomechanical model is corrected and the support scheme is adjusted based on the comparison results.

[0046] Based on all simulation, test and monitoring data, a standardized layered support optimization scheme was developed.

[0047] Furthermore, the three-dimensional geomechanical model is constructed to simulate the mechanical response of the surrounding rock during layered excavation, including:

[0048] Based on the rock strata columnar section, physical and mechanical parameters, and tunnel design dimensions of the target working face, a three-dimensional numerical simulation software was used to simulate the dynamic excavation process of the tunnel in layers by setting the boundary conditions as bottom fixed, surrounding normal displacement constraint, and applying an equivalent overlying rock load to the upper part.

[0049] Specifically, based on the rock strata columnar section, physical and mechanical parameters, and tunnel design dimensions of the target working face, a three-dimensional geomechanical model is constructed that can accurately reflect the characteristics of high mining height and layered excavation.

[0050] Using numerical simulation software such as FLAC3D, reasonable boundary conditions were set (bottom fixed, normal displacement restricted around the perimeter, and equivalent overlying rock load applied to the top) to simulate the dynamic excavation process of the tunnel in stages and layers.

[0051] Furthermore, the simulation of the dynamic layered excavation process of the tunnel includes:

[0052] At least two rounds of layered excavation are conducted, with the first round simulating the upper layer excavation and support, and subsequent rounds simulating the lower layer excavation and support.

[0053] The differentiated support strategy is as follows:

[0054] The spacing between the upper-layer anchor bolts and anchor cables remains constant, serving as a stable load-bearing structure.

[0055] Several sets of comparative schemes were set according to an increasing gradient for the spacing of the lower-level anchor bolts. The mechanical response index of each scheme was obtained through simulation calculation, and candidate optimized spacing that balances safety and economy was selected.

[0056] Specifically, in the three-dimensional geomechanical model, a core differentiated support strategy is implemented: the spacing of the upper-layer anchor bolts and cables remains unchanged as a stable top load-bearing structure; only the spacing of the lower-layer anchor bolts is systematically adjusted to form a set of incrementally increasing comparative schemes (e.g., 1.2m, 1.25m, 1.3m, 1.35m, etc.). Through simulation calculations, multiple mechanical response indicators under different schemes are obtained. Through comparative analysis of these indicators, one or two candidate optimized spacings with sufficient safety margin and significant economic benefits are theoretically selected.

[0057] Table 1 shows the setting table for differentiated support parameters in numerical simulation.

[0058] Table 1

[0059]

[0060] Furthermore, the mechanical response indicators include at least two of the following: roof subsidence, sidewall convergence, axial stress of anchor bolts or cables, range of plastic zone of surrounding rock, and stress distribution.

[0061] Furthermore, the aforementioned phased trials will be conducted, such as... Figure 2 ,include:

[0062] First approach: Select a local section in the roadway, adjust the spacing of the lower layer anchor bolts to the candidate optimized spacing for testing, and after verifying safety and stability, gradually expand the application scope;

[0063] Second approach: Based on the success of the first approach, select a larger row spacing value for exploratory testing.

[0064] Specifically, based on the simulation optimization results, phased industrial trials will be conducted on-site, following the principles of gradual expansion from specific points to broader areas, from small to large scale, and with a focus on safety.

[0065] (1) Path 1 (Verification and promotion of optimized spacing): First, select a local section (e.g., 50-60m) in the middle of the roadway and adjust the spacing of the lower layer anchor bolts to the candidate optimized value (e.g., 1.3m) for testing; after the mine pressure monitoring data verifies its safety and stability, gradually expand the application range of this spacing (e.g., 100-110m or even the entire branch roadway).

[0066] (2) Path 2 (exploration of large row spacing): Based on the success of Path 1, select an appropriate time (such as 50 meters before the end of the bottoming process) to launch an exploratory test to a larger row spacing (such as 1.5m or 2.0m) to further explore the potential for cost reduction.

[0067] Throughout the experiment, a comparative monitoring network was constructed, in which identical monitoring systems were simultaneously deployed in the experimental section and the normal support section (control group).

[0068] Furthermore, the multi-dimensional real-time mine pressure monitoring data includes roadway surface displacement, roof delamination, support stress, and internal damage development of the surrounding rock.

[0069] Specifically, the monitoring content must be multi-dimensional:

[0070] (1) Surface displacement of the roadway: The convergence of the two sides is monitored by a laser rangefinder.

[0071] (2) Delamination of top plate: The delamination of deep and shallow base points is monitored by an electronic delamination meter.

[0072] (3) Stress on the support structure: The stress changes of the top slab anchor bolts / cables and the side anchor bolts / cables are monitored using a force gauge.

[0073] (4) Internal damage to the surrounding rock: The development range and morphology of the plastic zone of the surrounding rock were observed using a borehole inspection instrument.

[0074] Furthermore, the three-dimensional geomechanical model is modified, including:

[0075] Based on the revised model and measured data, the long-term stability of the current experimental row spacing is evaluated, and a decision is made based on the evaluation results on whether to expand the application of the current row spacing, explore larger row spacings, or carry out reinforcement support.

[0076] Specifically, the acquired real-time monitoring data is compared with numerical simulation prediction data to form a scientific closed loop:

[0077] (1) Model correction: If there is a systematic deviation between the monitoring data and the simulation prediction, the rock mass parameters of the numerical model are corrected by inverting the measured data to improve the calculation accuracy and prediction reliability of the model.

[0078] (2) Scheme evaluation and optimization: Based on the revised model and measured data, the long-term stability of the current experimental row spacing is evaluated. If the evaluation is successful, it will provide a design basis for the next stage (expanding the application or increasing the row spacing); if risks are found, the scheme will be adjusted or the support will be strengthened in a timely manner.

[0079] (3) The closed-loop process is represented as: numerical simulation → design optimization → industrial test → mine pressure monitoring → data feedback → model correction / scheme iteration.

[0080] Furthermore, the standardized layered support optimization scheme is formed, including:

[0081] By integrating numerical simulation data, industrial test data, mine pressure monitoring data, and expert evaluation conclusions, the recommended spacing range and construction process requirements for layered anchor bolts under different geological conditions are clarified.

[0082] Specifically, by summarizing all numerical simulation data, multi-stage industrial test data, full-process mine pressure monitoring data, and analysis conclusions, and after multiple rounds of expert review, a final optimized scheme for layered differentiated support in high-extraction, fully mechanized, dense-filling working faces was developed. This scheme clearly provides the recommended optimized spacing range, applicable conditions, and corresponding construction process requirements for lower-layer anchor bolts under different geological conditions and engineering backgrounds, providing standardized technical guidance for the large-scale application in subsequent working faces.

[0083] To more clearly illustrate the technical solution of the present invention, specific embodiments are provided below for description:

[0084] This technical solution is explained in detail using the No. 1 backfilling working face (phase II) of a certain mine as an example. The working face has a mining height of 8m and is mined in two layers, each 4m high. Figure 1 Specifically, it includes:

[0085] S1: Construct a detailed numerical model with dimensions of 300m×210m×80m. The rock strata sequence from top to bottom includes limestone, siltstone, sandy mudstone, etc., to simulate the dynamic excavation process of four layers.

[0086] S2: The spacing of the upper layer anchor bolts (cables) is set to a constant 1.2m. Four models are set for the lower layer, with spacings of 1.2m (original design), 1.25m, 1.3m, and 1.35m respectively. Simulation results show that when the spacing of the lower layer is increased to 1.3m, all mechanical properties (such as top slab settlement <200mm) are within the safe range, and the material consumption is reduced by about 8% compared to the 1.2m scheme.

[0087] S3:

[0088] (1) First, select 60 meters as the test section in the second branch roadway and adjust the anchor bolt spacing to 1.3m.

[0089] (2) A comprehensive monitoring system was simultaneously deployed in the test section and the adjacent normal section (1.2m row spacing). The monitoring results showed that the maximum convergence of the surrounding rock in the test section was 180mm, and the anchor bolt force and the delamination value of the top plate tended to stabilize within 3 days after filling. There was no significant difference compared with the normal section, and both were better than the safety threshold of numerical simulation.

[0090] S4:

[0091] (1) Monitoring data successfully verified the feasibility of a 1.3m row spacing. Based on this, the next round of numerical simulation and scheme design for transitioning to a 1.5m row spacing was initiated.

[0092] (2) Feed back the initial monitoring data to the numerical model and fine-tune the mudstone layer parameters to make the model prediction more realistic and provide a more accurate theoretical safety assessment for the 1.5m row spacing test.

[0093] S5: Based on all data and successful experience, an optimized solution was finally formulated: Under similar geological conditions in this mine, the spacing of the layered anchor bolts under the No. 1 filling working face can be safely optimized to 1.3m, and the application of a spacing of 1.5m will be explored in subsequent working faces. This solution has become the new standard for mine support technology.

[0094] The implementation of this technical solution has successfully achieved refined optimization of the layered support under the fully mechanized dense filling mining face with high mining height, resulting in significant safety and economic benefits.

[0095] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for optimizing the design of differentiated dynamic support for roadways in a high-extraction, fully mechanized, dense-filling mining face, characterized in that... include: A three-dimensional geomechanical model was constructed to simulate the mechanical response of the surrounding rock during layered excavation. Differential support strategies are implemented in the three-dimensional geomechanical model. The upper layer support parameters are fixed, the spacing of the lower layer anchor bolts is adjusted, and candidate optimized spacing is screened through comparison of multiple schemes. Based on the candidate optimized row spacing, phased tests were carried out, and a comparative monitoring network including test sections and normal support sections was constructed to obtain multi-dimensional real-time mine pressure monitoring data. The real-time mine pressure monitoring data is compared with the simulated prediction data, and the three-dimensional geomechanical model is corrected and the support scheme is adjusted based on the comparison results. Based on all simulation, test and monitoring data, a standardized layered support optimization scheme was developed.

2. The method for optimizing the differentiated dynamic support design of roadways in a fully mechanized dense filling mining face according to claim 1, characterized in that, The three-dimensional geomechanical model is constructed to simulate the mechanical response of the surrounding rock during layered excavation, including: Based on the rock strata columnar section, physical and mechanical parameters, and tunnel design dimensions of the target working face, a three-dimensional numerical simulation software was used to simulate the dynamic excavation process of the tunnel in layers by setting the boundary conditions as bottom fixed, surrounding normal displacement constraint, and applying an equivalent overlying rock load to the upper part.

3. The method for optimizing the differentiated dynamic support design of roadways in a fully mechanized dense filling mining face according to claim 2, characterized in that, Simulates the dynamic layered excavation process of a tunnel, including: At least two rounds of layered excavation are conducted, with the first round simulating the upper layer excavation and support, and subsequent rounds simulating the lower layer excavation and support.

4. The method for optimizing the differentiated dynamic support design of roadways in a fully mechanized dense filling mining face according to claim 1, characterized in that, The differentiated support strategy is as follows: The spacing between the upper-layer anchor bolts and anchor cables remains constant, serving as a stable load-bearing structure. Several sets of comparative schemes were set according to an increasing gradient for the spacing of the lower-level anchor bolts. The mechanical response index of each scheme was obtained through simulation calculation, and candidate optimized spacing that balances safety and economy was selected.

5. The method for optimizing the differentiated dynamic support design of roadways in a fully mechanized dense filling mining face according to claim 4, characterized in that, The mechanical response indicators include at least two of the following: roof subsidence, sidewall convergence, axial stress of anchor bolts or cables, range of plastic zone of surrounding rock, and stress distribution.

6. The method for optimizing the differentiated dynamic support design of roadways in a fully mechanized dense filling mining face according to claim 1, characterized in that, The phased trials include: First approach: Select a local section in the roadway, adjust the spacing of the lower layer anchor bolts to the candidate optimized spacing for testing, and after verifying safety and stability, gradually expand the application scope; Second approach: Based on the success of the first approach, select a larger row spacing value for exploratory testing.

7. The method for optimizing the differentiated dynamic support design of roadways in a fully mechanized dense filling mining face according to claim 6, characterized in that, The multi-dimensional real-time mine pressure monitoring data includes roadway surface displacement, roof delamination, support stress, and internal damage development of the surrounding rock.

8. The method for optimizing the differentiated dynamic support design of roadways in a fully mechanized dense filling mining face according to claim 1, characterized in that, The correction of the three-dimensional geomechanical model includes: Based on the revised model and measured data, the long-term stability of the current experimental row spacing is evaluated, and a decision is made based on the evaluation results on whether to expand the application of the current row spacing, explore larger row spacings, or carry out reinforcement support.

9. The method for optimizing the differentiated dynamic support design of roadways in a fully mechanized dense filling mining face according to claim 1, characterized in that, The standardized layered support optimization scheme includes: By integrating numerical simulation data, industrial test data, mine pressure monitoring data, and expert evaluation conclusions, the recommended spacing range and construction process requirements for layered anchor bolts under different geological conditions are clarified.

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