CN-122021011-A - Method and system for simulating stress distribution of roof-cutting roadway of retractive channel

CN122021011ACN 122021011 ACN122021011 ACN 122021011ACN-122021011-A

Abstract

The invention discloses a method and a system for simulating stress distribution of a roof-cutting roadway of a withdrawal channel, which particularly relates to the technical field of numerical simulation and is used for solving the problem that the mechanical behavior of the withdrawal channel which needs to be reused in a full life cycle cannot be continuously and truly simulated; the method comprises the steps of simulating a primary mining process, quantitatively analyzing a generated irreversible damage area and a residual stress field of surrounding rock, converting the quantized result into an initial mechanical state condition before a channel enters the next service stage, constructing a surrounding rock damage network based on the initial mechanical state condition, performing topological robustness analysis, identifying a potential instability key channel and risk parameters, performing high-fidelity numerical simulation of a secondary mining process based on the potential instability key channel and risk parameters, extracting a result for comprehensive evaluation of stress distribution and stability of a full life cycle, and realizing simulation of mechanical response of the roadway from primary lane formation to secondary multiplexing, thereby providing reliable analysis basis for long-period stability design and safety control of a withdrawal channel in coal pillar-free mining.

Inventors

WANG JIONG
WANG HAOSEN
YU GUANGYUAN
LIU PENG
CHEN JUN
ZHANG YONG
HE MANCHAO
JIANG JIAN
MA LEI
LIANG WENZHAO
CHANG YIWEN
WANG SHUAIJIE
Sang Biaowei
WU YONGWEI
SUN XIAOMING

Assignees

中国矿业大学(北京)

Dates

Publication Date: 20260512
Application Date: 20260126

Claims (10)

1. A method for simulating stress distribution of a retractable channel roof-cutting lane is characterized by comprising the following steps: S1, an initial three-dimensional geomechanical model is established, numerical simulation of a first mining process is carried out, and mechanical response data of roadway surrounding rocks are obtained; S2, quantitatively analyzing an irreversible damage area and a residual stress field generated by first mining based on mechanical response data to generate surrounding rock damage quantitative data; S3, converting an irreversible damage area and a residual stress field represented by surrounding rock damage quantitative data into initial mechanical state conditions before the surrounding rock of the roadway enters the next service stage; S4, based on initial mechanical state conditions, constructing a surrounding rock damage network by taking an irreversible damage area as a node and according to a preset mechanical association rule, and identifying a key path and risk parameters which cause the overall instability of the surrounding rock by analyzing the topological robustness evolution of the surrounding rock damage network under secondary mining to generate damage evolution tendency prediction data; s5, carrying out numerical simulation on the secondary mining process based on the initial mechanical state condition and the damage evolution tendency prediction data; S6, extracting and outputting mechanical response data of the roadway surrounding rock in the numerical simulation of the secondary mining process as stress distribution and stability evaluation basis of the roadway in the whole life cycle.
2. The method for simulating the stress distribution of a pull-back channel roof-cutting roadway according to claim 1, wherein S1 comprises: Constructing an initial three-dimensional geomechanical model comprising a roadway entity, a coal face, a roof stratum, a floor stratum and a key mark layer based on mine geological survey data and roadway design parameters; setting a joint cutting position and an angle according to a roof cutting pressure relief design parameter in an initial three-dimensional geomechanical model, and endowing rock mass materials with corresponding mechanical constitutive relation and parameters; and simulating the complete mining process from the working surface to the passage of the retracement on the initial three-dimensional geomechanical model, and calculating to obtain the stress distribution data, the displacement deformation data and the plastic region distribution data of the surrounding rock of the roadway as the mechanical response data of the surrounding rock of the roadway.
3. The method for simulating the stress distribution of a pull-back channel roof-cutting roadway according to claim 1, wherein S2 comprises: According to a preset damage criterion, comprehensively analyzing stress distribution data, displacement deformation data and plastic region distribution data in mechanical response data, and identifying and defining a spatial range and a distribution form of an irreversible damage region formed after first mining; Extracting a residual stress field existing in the roadway surrounding rock after mining disturbance is stable from stress distribution data in the mechanical response data; And integrating the spatial range and distribution form data and the residual stress field data of the irreversible damage area to generate structured surrounding rock damage quantification data.
4. The method for simulating the stress distribution of a pull-back channel roof-cutting roadway according to claim 1, wherein S3 comprises: Based on the spatial range and distribution form data of irreversible damage areas in surrounding rock damage quantification data, giving mechanical parameters representing material degradation to corresponding geometric areas in an initial three-dimensional geomechanical model so as to define the mechanical state of the damage areas; Based on residual stress field data in surrounding rock damage quantized data, corresponding stress distribution is given to the whole roadway surrounding rock in an initial three-dimensional geomechanical model so as to define an initial stress state of the surrounding rock; And combining the mechanical state of the defined damaged area with the initial stress state of the whole surrounding rock to jointly form the initial mechanical state condition of the surrounding rock of the roadway before entering the next service stage.
5. The method for simulating the stress distribution of a pull-back channel roof-cutting roadway according to claim 1, wherein S4 comprises: Calculating the mechanical association strength between any two irreversible damaged areas based on the mechanical state of the damaged area defined in the initial mechanical state condition and the initial stress state of the whole surrounding rock, and establishing a connecting edge between the two damaged areas with the mechanical association strength exceeding a preset strength threshold in a surrounding rock damaged network; Simulating a failure process of a network node or a connecting edge under the action of a secondary mining load on the basis of a surrounding rock damage network comprising the connecting edge, and quantitatively calculating the attenuation degree of a topological performance index representing the overall connectivity of the surrounding rock damage network in the failure process; According to the corresponding relation between the attenuation degree of the topological performance index and the failure process, identifying a node and a connecting edge sequence which first causes sudden drop or continuous accelerated attenuation of the topological performance index in the failure process as a key path for causing the integral instability of surrounding rock, and extracting a failure load threshold value corresponding to the key path as a risk parameter; and integrating and recording the identified key paths and risk parameters as predicted data of the evolution tendency of the damage.
6. The method for simulating the stress distribution of the roof-cutting roadway forming of the retractive channel according to claim 5, wherein the preset mechanical association rule is that based on an initial mechanical state condition, when the minimum spatial distance between two irreversible damage areas is smaller than a preset distance threshold or the main stress direction between the two irreversible damage areas is continuous and the stress difference exceeds a preset range, the mechanical association between the corresponding two irreversible damage areas is judged, and a connecting edge is established in a surrounding rock damage network.
7. The method for simulating the stress distribution of the pull-back channel roof-cutting lane according to claim 5, wherein the topology performance index comprises network global efficiency, network connected component scale and node betweenness centrality distribution entropy, and the attenuation degree of the topology performance index is quantitatively judged by reducing the topology performance index in the simulation process relative to the initial state of the network below a preset critical value.
8. The method for simulating the stress distribution of a pull-back channel roof-cutting roadway according to claim 1, wherein S5 comprises: the mechanical state of the damaged area defined in the initial mechanical state condition and the initial stress state of the whole surrounding rock are endowed to a three-dimensional numerical model for secondary simulation to be used as an initial mechanical field; In a three-dimensional numerical model for secondary simulation, according to key path identification in damage evolution tendency prediction data, mechanical state monitoring points are set at corresponding spatial positions; And simulating a secondary mining process of pushing adjacent continuous working faces in the direction of a retracting channel on a three-dimensional numerical model which is formed by completing the initial mechanical field giving and mechanical state monitoring point setting, setting a load applying path according to risk parameters in damage evolution tendency prediction data in the simulation process, and simultaneously recording the data change of the mechanical state monitoring point.
9. The method for simulating the stress distribution of a pull-back channel roof-cutting roadway according to claim 1, wherein S6 comprises: Extracting data change of mechanical state monitoring points in the whole simulation process from the numerical simulation of the secondary mining process, and acquiring stress distribution data and displacement deformation data of the whole roadway surrounding rock after the secondary mining is completed; Comparing and integrating analysis is carried out on the extracted secondary mining process data and the mechanical response data of the roadway surrounding rock obtained through numerical simulation of the primary mining process, and the damage evolution degree of a key passage area and the migration rule of the whole stress field of the surrounding rock are evaluated; Based on the integrated analysis result, a comprehensive evaluation report containing the stress distribution, damage evolution and stability change of the roadway surrounding rock in the whole process of the primary mining and the secondary mining is generated and is used as the stress distribution and stability evaluation basis of the roadway in the whole life cycle.
10. A system for simulating the roof-cutting lane-forming stress distribution of a retracting channel, which is used for realizing the method for simulating the roof-cutting lane-forming stress distribution of the retracting channel according to any one of claims 1 to 9, and is characterized by comprising the following modules: The data acquisition module is used for establishing an initial three-dimensional geomechanical model, carrying out numerical simulation of the first mining process and acquiring mechanical response data of the surrounding rock of the roadway; the data quantization module is used for quantitatively analyzing an irreversible damage area and a residual stress field generated by first mining based on the mechanical response data to generate surrounding rock damage quantized data; the condition conversion module is used for converting an irreversible damage area and a residual stress field which are represented by surrounding rock damage quantitative data into initial mechanical state conditions before the surrounding rock of the roadway enters the next service stage; The data prediction module is used for constructing a surrounding rock damage network by taking an irreversible damage area as a node based on an initial mechanical state condition and according to a preset mechanical association rule, and generating damage evolution tendency prediction data by analyzing topological robustness evolution of the surrounding rock damage network under secondary mining to identify a key path and risk parameters which cause the overall instability of the surrounding rock; The secondary simulation module is used for carrying out numerical simulation on the secondary mining process based on the initial mechanical state condition and the damage evolution tendency prediction data; the data extraction module is used for extracting and outputting mechanical response data of the roadway surrounding rock in the numerical simulation of the secondary mining process as stress distribution and stability evaluation basis of the roadway in the whole life cycle.

Description

Method and system for simulating stress distribution of roof-cutting roadway of retractive channel Technical Field The invention relates to the technical field of numerical simulation, in particular to a method and a system for simulating stress distribution of a roof-cutting lane of a withdrawal channel. Background In the field of coal mining, particularly in mines adopting roof-cutting pressure relief self-forming technology, the advanced stability analysis and design of a withdrawal channel are key engineering links. At present, engineering practice generally relies on a numerical simulation method, such as finite difference or finite element software, to simulate and calculate stress distribution, displacement deformation and plastic region range of surrounding rock of a withdrawal channel under preset roof-cutting pressure relief parameters, so as to provide quantitative basis for determining reasonable roof-cutting positions, angles and roadway support parameters, wherein a standard flow is to establish a three-dimensional geomechanical model comprising a roadway, a working surface and a key stratum, and to evaluate whether mechanical response of the roadway in the specific mining stage meets safety requirements by simulating one complete mining activity. However, the simulation method limits the service period of the retraced channel artificially during the stoping of a single working surface, the simulation target only aims at confirming the stability of the channel at the stage, neglecting the core engineering requirement that the channel is designed to be reserved and multiplexed into a roadway of an adjacent continuous working surface in a non-coal pillar mining technology system, because the initial mining, including roof cutting pressure relief and roadway forming processes, inevitably causes irreversible damage and disturbance to surrounding rocks of the roadway and forms a specific residual stress field, and the initial states are just the basis of the channel entering the next service stage, and the simulation assumption of single-stage and zero initial damage adopted in the prior art cannot accept and reflect the real mechanical history, so that the analysis result and the actual mechanical behavior of the roadway in the whole life cycle are seriously disjointed, and any effective guidance cannot be provided for the long-term stability assessment and the prospective design of the multiplexing stage. Disclosure of Invention In order to overcome the above-mentioned drawbacks of the prior art, the present invention provides a method and a system for simulating the stress distribution of a pull-back channel roof-cutting lane, which solve the above-mentioned problems in the prior art. In order to achieve the above purpose, the present invention provides the following technical solutions: a method for simulating stress distribution of a pull-back channel roof-cutting lane comprises the following steps: S1, an initial three-dimensional geomechanical model is established, numerical simulation of a first mining process is carried out, and mechanical response data of roadway surrounding rocks are obtained; S2, quantitatively analyzing an irreversible damage area and a residual stress field generated by first mining based on mechanical response data to generate surrounding rock damage quantitative data; S3, converting an irreversible damage area and a residual stress field represented by surrounding rock damage quantitative data into initial mechanical state conditions before the surrounding rock of the roadway enters the next service stage; S4, based on initial mechanical state conditions, constructing a surrounding rock damage network by taking an irreversible damage area as a node and according to a preset mechanical association rule, and identifying a key path and risk parameters which cause the overall instability of the surrounding rock by analyzing the topological robustness evolution of the surrounding rock damage network under secondary mining to generate damage evolution tendency prediction data; s5, carrying out numerical simulation on the secondary mining process based on the initial mechanical state condition and the damage evolution tendency prediction data; S6, extracting and outputting mechanical response data of the roadway surrounding rock in the numerical simulation of the secondary mining process as stress distribution and stability evaluation basis of the roadway in the whole life cycle. Further, S1 includes: Constructing an initial three-dimensional geomechanical model comprising a roadway entity, a coal face, a roof stratum, a floor stratum and a key mark layer based on mine geological survey data and roadway design parameters; setting a joint cutting position and an angle according to a roof cutting pressure relief design parameter in an initial three-dimensional geomechanical model, and endowing rock mass materials with corresponding mechanical constitutive relation and parame