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CN-121786397-B - Goaf earth surface subsidence prediction method and goaf earth surface subsidence prediction system

CN121786397BCN 121786397 BCN121786397 BCN 121786397BCN-121786397-B

Abstract

The invention discloses a method and a system for predicting ground subsidence of a goaf, and relates to the technical field of ground subsidence prediction, comprising the following steps of collecting unbalanced characteristics of residual stress distribution of the goaf, constructing a three-dimensional seismic wave propagation scene, and dividing an energy easy-gathering region according to a rock stratum compactness difference and an elasticity difference; according to the spatial distribution data of the energy easy-aggregation areas, grading stress release holes are distributed, a controllable stress buffer area is formed at the energy easy-aggregation sensitive positions by adopting a mode of combining directional pressure relief and deep grouting, and a stable residual stress background is established. According to the invention, the goaf energy amplification sensitive position is identified in advance, a controllable stress buffer zone is constructed, so that the ground surface subsidence is converted from post analysis to pre-sensing, a subsidence trend map is generated by combining dynamic stress and vibration time sequence, and the advanced identification and risk early warning of secondary subsidence are realized.

Inventors

  • LI YOUHONG
  • WANG CHONG
  • LIU DI

Assignees

  • 四川蜀能矿山开发技术咨询有限公司

Dates

Publication Date
20260505
Application Date
20260303

Claims (10)

  1. 1. The prediction method for goaf earth surface subsidence is characterized by comprising the following steps: firstly, collecting unbalanced characteristics of goaf residual stress distribution, constructing a three-dimensional seismic wave propagation scene, and dividing an energy easy-gathering region according to a rock stratum compactness difference and an elasticity difference; Step two, according to the space distribution data of the easy-to-gather energy area, arranging grading stress release holes, forming a controllable stress buffer area at the easy-to-gather energy sensitive position by adopting a mode of combining directional pressure relief and deep grouting, and establishing a stable residual stress background; step three, embedding a multi-frequency vibration detection device in a stable state of the stress buffer region, dynamically comparing the input frequency of the earthquake waves with the natural vibration frequency of the rock stratum, identifying a resonance approaching signal according to the comparison result, and adjusting the pressure relief rhythm of the stress release hole; Step four, based on resonance approaching signals obtained by vibration detection comparison, implementing seismic wave energy regulation and control, and reducing local energy peaks in a mode of reverse seismic source intervention and phase dislocation interference; And fifthly, carrying out earth surface settlement response monitoring by combining stress change information in an energy regulation stage, correspondingly analyzing a dynamic stress sequence and a seismic wave vibration time sequence, generating an earth surface settlement trend updating map, identifying a secondary settlement triggering area, and outputting an earth surface settlement risk forward-moving early warning result.
  2. 2. The method for predicting goaf surface subsidence according to claim 1, wherein the steps of collecting imbalance characteristics of goaf residual stress distribution, constructing a three-dimensional seismic wave propagation scene, and dividing an energy-prone region comprise: Comprehensively acquiring geological structures and residual stress states of a goaf and surrounding areas thereof, arranging multi-layer stress measuring points on an overburden rock layer, lateral surrounding rock and a bottom plate rock body, and acquiring stress parameters with different depths and directions by using a drilling stress meter, an acoustic emission probe and a core cleavage analysis method to form a residual stress space distribution diagram; Constructing a three-dimensional seismic wave propagation scene according to the residual stress space distribution data, reconstructing three-dimensional structures of a goaf and an overlying rock stratum in a space coordinate system, mapping the residual stress data into a model, setting a seismic wave propagation path, and establishing a wave reflection boundary and an energy dissipation area; dividing an energy easy-gathering region according to the compactness difference and the elasticity difference of a rock stratum in a three-dimensional seismic wave propagation scene, carrying out space partition on a wave impedance abrupt change interface, and endowing an energy response coefficient and a communication attribute; and determining the potential energy amplification sensitive position according to the energy transmission path of the energy easy-gathering area to form the energy easy-gathering area space distribution data comprising the energy response intensity and the residual stress state.
  3. 3. The method for predicting goaf surface subsidence according to claim 2, wherein the steps of arranging the hierarchical stress relief holes according to the spatial distribution data of the energy-concentrated region, performing directional pressure relief and deep grouting, and establishing a stable residual stress background comprise: according to the spatial distribution data of the energy easy-gathering area, carrying out hole distribution design on the stress sensitive area in the goaf and the overlying strata, dividing the energy easy-gathering area into a main control area, a secondary control area and an auxiliary area according to the energy response intensity, and determining the spatial range, the hole pitch, the hole depth and the hole diameter of the stress release holes to form a multilayer stress dredging network covering the energy easy-gathering area; Implementing directional pressure relief operation, forming a controllable microcrack zone in a deep drilling burst mode, a mechanical reaming mode or a hydraulic splitting mode in a primary stress relief hole, releasing local energy in a secondary and tertiary stress relief hole in a hydraulic pulse or mechanical vibration mode, and constructing a space pressure relief gradient region; deep grouting is carried out by taking the graded stress release holes as channels, pressurizing or medium-low pressure injection is carried out on different hole sites by adopting inorganic slurry, a continuous reinforcing band covering key nodes of an energy easy-aggregation area is formed, and a controllable stress buffer area is formed at an energy easy-aggregation sensitive position; And (3) carrying out stress balance adjustment on the stress buffer area by combining the spatial distribution data of the energy easy-aggregation area, and establishing a stable residual stress background by means of micro secondary grouting, ventilation, water pumping and surface backfill.
  4. 4. A method for predicting goaf surface subsidence according to claim 3, wherein the steps of embedding a multi-frequency vibration detecting device in a stable state of the stress buffer region, performing frequency comparison, recognizing a resonance approaching signal, and adjusting a stress relief hole relief rhythm comprise: Under the condition that a stable state is formed in the stress buffer area, according to the hierarchical distribution of stress release holes and the space form of an energy easy-aggregation area, a multi-frequency vibration detection device is embedded into a rock stratum structure in a partitioned mode, main control detection points are distributed around the primary stress release holes, and secondary and auxiliary detection points are distributed in the secondary and tertiary stress release hole areas, so that a monitoring network decreasing from the center outwards is formed; Implementing dynamic comparison of the input frequency of the earthquake wave and the natural vibration frequency of the rock stratum, carrying out time sequence correlation on vibration amplitude values, period changes and waveform characteristics of different monitoring points according to frequency signals acquired by the multi-frequency vibration detection device, identifying resonance approaching signals and determining a spatial distribution range; adjusting the pressure relief rhythm of the stress relief holes according to the comparison result, taking the primary stress relief holes as control centers, and adjusting the residual stress relief speed by controlling the pressure relief interval and sequence; On the basis of finishing the adjustment of the pressure relief rhythm, the whole stress state of the stress buffer area is coordinated, and the gas pressure, the hydraulic transmission rate and the grouting diffusion direction of the stress release hole are controlled to form a stress distribution gradient decreasing from inside to outside.
  5. 5. The method for predicting the subsidence of the earth's surface in the goaf according to claim 4, wherein when the overall stress state of the stress buffer is coordinated, the first-stage stress relief holes are controlled to adopt an intermittent pressure relief mode, the second-stage stress relief holes are controlled to adopt a low-speed pressure relief mode, and the third-stage stress relief holes are controlled to release the periodic small-amplitude stress.
  6. 6. The method for predicting goaf surface subsidence according to claim 4, wherein the step of performing seismic wave energy control based on the resonance proximity signal obtained by the vibration detection comparison comprises: After a resonance approaching signal obtained by vibration detection comparison is obtained, determining a target area for regulating and controlling the earthquake wave energy according to the space range of a stress buffer area, extracting a time window and a space position of the resonance approaching signal, and establishing a space mapping relation between the propagation direction of earthquake waves and energy gradients; Performing reverse seismic source intervention on the basis of determining a target area, arranging reverse seismic source points below a rock stratum corresponding to a resonance approaching area, controlling the release intensity, detonation time and wave direction of seismic source energy, reducing the peak value of seismic wave energy through reverse wave interference, and balancing energy distribution; implementing phase dislocation interference, arranging a phase dislocation interference source on an energy propagation path, and weakening a main wave energy peak value and uniformly distributing energy density by adjusting the phase of an interference wave and forming half-period difference with a main seismic wave; On the basis of completing reverse seismic source intervention and phase dislocation intervention, the dynamic stress distribution of an overlying strata and the response of a stress buffer area are coordinated, and the stress system is kept in dynamic balance by adjusting the reverse seismic source release interval and the interference wave phase difference.
  7. 7. The method for predicting goaf earth surface subsidence according to claim 6, wherein in the cooperative implementation process of reverse seismic source intervention and phase dislocation interference, reverse seismic source points are arranged on an energy transmission reflection band at the lower part of the stress buffer area, interference sources are arranged on an energy reflection band intersection area at the periphery of the stress buffer area, the two are started in sequence in time, and reverse seismic source release interval and interference wave phase difference are dynamically adjusted according to the seismic wave energy peak value change.
  8. 8. The method for predicting surface subsidence in a goaf according to claim 6, wherein the step of developing surface subsidence response monitoring in combination with stress variation information in the energy regulation stage and outputting a surface subsidence risk forward warning result comprises: On the basis of ending the energy regulation stage, stress change information formed in the seismic wave energy regulation process is collected, and stress change amplitude, direction and speed are recorded through a multipoint stress induction device arranged in a stress buffer zone, at a rock stratum interface and on the earth surface, so that a dynamic stress sequence with time sequence is formed; Performing earth surface settlement response monitoring according to the dynamic stress sequence, arranging a multi-layer displacement monitoring array above the goaf, collecting earth surface vertical and horizontal displacement changes in real time, and correspondingly analyzing earth surface deformation and stress sequences of a stress buffer zone; Correspondingly analyzing the dynamic stress sequence and the seismic wave vibration time sequence, and generating an earth surface subsidence trend updating map according to the three-dimensional association relation of time, stress and subsidence formed by superposition of earth surface displacement monitoring data and stress change information; And identifying a secondary sedimentation triggering area according to the surface sedimentation trend updating map, establishing a surface sedimentation risk forward-movement early-warning index by combining the residual stress distribution of the stress buffer area and the surface sedimentation rate change result, and outputting the surface sedimentation risk forward-movement early-warning result.
  9. 9. The method for predicting the subsidence of the earth surface in the goaf according to claim 8, wherein in the generation process of the earth surface subsidence trend update map, according to the synchronous relation between the vibration time sequence of the earthquake waves and the stress release rate of the stress buffer area, the earth surface displacement increment is analyzed in a time sequence, the change of the subsidence speed is represented in the map by a color gradient, and the secondary subsidence trigger area is determined by identifying a high displacement gradient zone, so that the dynamic update and the risk forward identification of the earth surface subsidence trend are realized.
  10. 10. The prediction system for goaf earth surface subsidence is used for realizing the prediction method for goaf earth surface subsidence according to any one of the claims 1-9, and is characterized by comprising an energy distribution identification module, a stress buffer construction module, a vibration frequency comparison module, a seismic energy regulation module and a subsidence monitoring and early warning module; the energy distribution identification module is used for collecting unbalanced characteristics of goaf residual stress distribution, constructing a three-dimensional seismic wave propagation scene and dividing an energy easy-gathering area according to a rock stratum compactness difference and an elasticity difference; The stress buffering construction module is used for arranging grading stress release holes according to the space distribution data of the energy easy-aggregation area, forming a controllable stress buffer area at the energy easy-aggregation sensitive position by adopting a mode of combining directional pressure relief and deep grouting, and establishing a stable residual stress background; The vibration frequency comparison module is embedded with the multi-frequency vibration detection device under the stable state of the stress buffer area, dynamically compares the input frequency of the earthquake waves with the natural vibration frequency of the rock stratum, recognizes a resonance approaching signal according to the comparison result, and adjusts the pressure relief rhythm of the stress relief hole; the earthquake energy regulation and control module is used for regulating and controlling earthquake wave energy based on resonance approaching signals obtained by vibration detection comparison, and reducing local energy peaks in a mode of reverse earthquake focus intervention and phase dislocation interference; And the settlement monitoring and early warning module is used for carrying out earth surface settlement response monitoring by combining stress change information in an energy regulation stage, carrying out corresponding analysis on a dynamic stress sequence and a seismic wave vibration time sequence, generating an earth surface settlement trend updating map, identifying a secondary settlement triggering area and outputting an earth surface settlement risk forward movement early warning result.

Description

Goaf earth surface subsidence prediction method and goaf earth surface subsidence prediction system Technical Field The invention relates to the technical field of ground subsidence prediction, in particular to a goaf ground subsidence prediction method and system. Background Goaf refers to an underground cavity or loose area formed after mining ore bodies in the mining process, and the areas are damaged due to the original rock mass support, so that overlying strata are moved, deformed and collapsed, and an area with loose underground space structure and redistributed stress is formed. The prediction of the subsidence of the ground surface of the goaf is to establish the corresponding relation between the deformation of the ground surface and the underground goaf based on factors such as the mining depth, thickness, dip angle, geologic structure characteristics, overlying strata mechanical parameters and the like, and predict the subsidence quantity, the subsidence range and the deformation rate generated by the change of the ground surface above the goaf along with time through a physical mechanical model, a numerical simulation or a data driving method. The prediction aims at identifying possible geological disaster risks such as surface subsidence, building deformation, ground crack expansion and the like in advance, and providing scientific basis for safe production of mining areas and ground building protection. The prior art has the following defects: In the goaf earth surface subsidence prediction process, after far-field seismic waves are transmitted into a residual stress area, local amplification is easy to occur due to wave impedance difference and energy reflection effect, so that stress redistribution is generated on rock stratum which is originally in a stable equilibrium state. When the frequency of the earthquake wave is close to the natural frequency of the residual stress area, an energy superposition effect is formed, so that micro cracks in the rock stratum are further expanded and even penetrated, and the original stress balance structure is damaged. The phenomenon is easy to trigger secondary sedimentation of the earth surface, and sudden deformation behaviors such as local collapse or slow sinking occur, so that the earth surface deformation process has delay and nonlinear characteristics, and a larger error risk is brought to a traditional sedimentation prediction model. The above information disclosed in the background section is only for enhancement of understanding of the background of the disclosure and therefore it may include information that does not form the prior art that is already known to a person of ordinary skill in the art. Disclosure of Invention The invention aims to provide a prediction method and a prediction system for goaf earth surface subsidence, which are used for solving the problems in the background technology. In order to achieve the purpose, the invention provides the following technical scheme that the goaf earth surface subsidence prediction method comprises the following steps: firstly, collecting unbalanced characteristics of residual stress distribution of a goaf, constructing a three-dimensional seismic wave propagation scene, dividing an energy easy-gathering region according to a rock stratum compactness difference and an elasticity difference, and determining a potential energy amplification sensitive position before earthquake vibration action to obtain space distribution data of the energy easy-gathering region; Step two, according to the space distribution data of the easy-to-gather energy area, arranging grading stress release holes, forming a controllable stress buffer area at the easy-to-gather energy sensitive position by adopting a mode of combining directional pressure relief and deep grouting, establishing a stable residual stress background, and providing a stable response basis for subsequent vibration detection; Step three, embedding a multi-frequency vibration detection device in a stable state of the stress buffer region, dynamically comparing the input frequency of the earthquake waves with the natural vibration frequency of the rock stratum, identifying a resonance approaching signal according to the comparison result, and adjusting the pressure relief rhythm of the stress relief hole to enable the stress state of the buffer region to be coordinated with the input frequency of the earthquake waves; Step four, based on resonance approaching signals obtained by vibration detection comparison, implementing seismic wave energy regulation and control, reducing local energy peak values in a mode of reverse seismic source intervention and phase dislocation interference, and ensuring that dynamic stress distribution of an overlying strata is kept synchronous with stress buffer area response; And fifthly, carrying out earth surface settlement response monitoring by combining stress change information in an energy regulation stage, corres