Genetic Programming Approach for Predicting Surface Subsidence Induced by Mining

The surface subsidence induced by mining is a complex problem, which is related with many complex and uncertain factors. Genetic programming （GP） has a good ability to deal with complex and nonlinear problems, therefore genetic programming approach is propesed to predict mining induced surface subsidence in this article. First genetic programming technique is introduced, second, surface subsidence genetic programming model is set up by selecting its main affective factors and training relating to practical engineering data, and finally, predictions are made by the testing of data, whose results show that the relative error is approximately less than 10%, which can meet the engineering needs, and therefore, this proposed approach is valid and applicable in predicting mining induced surface subsidence. The model offers a novel method to predict surface subsidence in mining.

Control Mechanism of Surface Subsidence and Overburden Movement in Backfilling Mining based on Laminated Plate Theory

The backfilling mining technology is a type of high-efficiency coal mining technology that is used to address the environmental issues caused by the caving mining technology.In this paper,the mechanical model of symmetrical laminated plate representing the overburden movement caused by the backfilling mining technology is established,and the governing differential equation of the motion of the overburden is derived.The boundary conditions of the mechanical model are put forward,and the analytical solution of the overburden movement and surface subsidence is obtained.The numerical model of the overburden movement and surface subsidence,under mining with backfilling,is established by means of the FLAC3D numerical software,which aims to systematically study the influence of backfilling compactness,mining thickness,and mining depth on the overburden movement and surface subsidence in backfilling mining.When the compactnessηis less than 70%,the overburden movement and surface subsidence is greater,while whenηis greater than 70%,the overburden movement and surface subsidence is reduced significantly.On this basis,the control mechanism of surface subsidence and overburden movement in backfilling mining is obtained.The suitable backfilling compactness is the key to controlling surface subsidence and overburden movement in backfilling mining.

Time function of surface subsidence based on Harris model in mined-out area

The surface subsidence is a common environmental hazard in mined-out area. Based on careful analysis of the regularity of surface subsidence in mined-out area, we proposed a new time function based on Harris curve model in consideration of the shortage of current surface subsidence time functions. By analyzing the characteristics of the new time function, we found that it could meet the dynamic process, the velocity change process and the acceleration change process during surface subsidence. Then its rationality had been verified through project cases. The results show that the proposed time function model can give a good reflection of the regularity of surface subsidence in mined-out area and can accurately predict surface subsidence. And the prediction data of the model are a little greater than measured data on condition of proper measured data quantity, which is safety in the engineering. This model provides a new method for the analysis of surface subsidence in mined-out area and reference for future prediction, and it is valuable to engineering application.

Prediction of surface subsidence in Changchun City based on LSTM network

Monitoring and predicting of urban surface subsidence are important for urban disaster prevention and mitigation.In this paper,the Long Short-Term Memory(LSTM)network was used to predict the surface subsidence process of Changchun City from 2018 to 2020 based on PS-InSAR monitoring data.The results show that the prediction error of 57.89% of PS points in the LSTM network was less than 1mm with the average error of 1.8 mm and the standard deviation of 2.8 mm.The accuracy and reliability of the prediction were better than regression analysis,time series analysis and grey model.

Application of DEM overlaying technique in surface subsidence identification─a case study in Ruqigou coal mining area of Ningxia,China

Subsidence occurred in many parts of the world. particularly in densely populated deltaic regions, causing extremely expensive damage. It can be resulted from natural causes. man-made induced causes, or other mixed causes. For identifying surface subsidence, many techniques have been employed, for example, geodetic monitoring, airborne laser subsidence measurement system,differential S.A.R., interferometry DGPS, and satellite radar measurements. However. all these methods require large time span and a large amount of field work. With the development of GIS techniques, identification of surface subsidence is becoming a relative easy problem. Ruqigou coal mining area was selected as a case study to identify the surface subsidence with DEM (digital elevation model) overlaying techniques. The result shows that DEM overlaying technique is a very useful method on surface subsidence identification. The accuracy of the results are largely dependent on the precision of the data-input.

GF-3 InSAR Achieves Sub-centimeter Level Surface Subsidence Monitoring

The GF-3 satellite was launched on August 10,2016 from the Taiyuan Satellite Launch Center and was put into operation at the end of January,2017.It has acquired nearly 100 thousand C-band multi-polarization ocean and land SAR images,providing data support for many departments covering resource survey,typhoon early warning,disaster assessment,crop yield estimation and polar investigation.Recently,the team led by ZHANG Qingjun from

Detecting Surface Subsidence in Coal Mining Area Based on DInSAR Technique

Coal is the primary energy resource in China. Thousands of underground coal mines are operating in China and cause severe land subsidence, leading to many environmental and engineering problems. Huainan （淮南） coal mine is the largest coal mining area in East China. Surface subsidence associated with Huainan coal mining activities has been monitoring by DInSAR （differential synthetic aperture radar） techniques in this study. Four ASAR （advanced SAR） pairs from 2009 to 2010 are selected to perform 2-pass DInSAR processing with spatial and temporal baselines suitable for subsidence monitoring. The subsidence maps generated from these pairs show that the extension of subsidence is consistent with the field observation. Quantitative measurements indicated that the magnitudes of subsidence are increased with the development of underground coal mining exploitation. This study demonstrates that DInSAR technique is effective for surface subsidence monitoring in coal mining area. Limitations and recommendations both in the adopted method and auxiliary data are also discussed.

Research on the Surface Subsidence Monitoring Technology Based on Fiber Bragg Grating Sensing

In order to monitor the process of surface subsidence caused by mining in real time, we reported two types of fiber Bragg grating （FBG） based sensors. The principles of the FBG-based displacement sensor and the FBG-based micro-seismic sensor were described. The surface subsidence monitoring system based on the FBG sensing technology was designed. Some factual application of using these FBG-based sensors for subsidence monitoring in iron mines was presented.

A novel ground surface subsidence prediction model for sub-critical mining in the geological condition of a thick alluvium layer

A substantial number of the coal mines in China are in the geological condition of thick alluvium layer. Under these circumstances, it does not make sense to predict ground surface subsidence and other deformations by using conventional prediction models. This paper presents a novel ground surface subsidence prediction model for sub-critical mining in the geological condition of thick alluvium layer. The geological composition and mechanical properties of thick alluvium is regarded as a random medium, as are the uniformly distributed loads on rock mass; however, the overburden of the rock mass in the bending zone is looked upon as a hard stratum controlling the ground surface subsidence. The different subsidence and displacement mechanisms for the rock mass and the thick alluvium layer are respectively considered and described in this model, which indicates satisfactory performances in a practical prediction case.

Mechanical responses of underground carriageway structures due to construction of metro tunnels beneath the existing structure:A case study

To understand the mechanical response pattern of the existing structure and ground due to the construction of metro tunnels underneath,the finite difference method is adopted to study the torsional deformation and stress variation of the existing structure and the effect of underground carriageway structures on the surface subsidence.The curves of the maximum differential subsidence,torsion angle,and distortion of the cross-section of the existing structure show two peaks in succession during traversing of two metro tunnels beneath it.The torsion angle of the existing structure changes when the two tunnels traverse beneath it in opposite directions.The first traversing of the shield tunnel mainly induces the magnitude variation in torsional deformation of the existing structure,but the second traversing of the subsurface tunnel may cause a dynamic change in the magnitude and form of torsional deformation in the existing structure.The shielding effect can reduce the surface subsidence caused by metro tunnel excavation to a certain extent,and the development trend of subsidence becomes slower as the excavation continues.

Study on the Safety and Prevention Technology of Coal Mining under the River in Xingyuan Coal Mine

Coal mining-induced surface subsidence poses significant ecological and infrastructural challenges, necessitating a comprehensive study to ensure safe mining practices, particularly in underwater conditions. This project aims to address the extensive impact of coal mining on the environment, infrastructure, and overall safety, focusing on the Shigong River area above the working face. The study employs qualitative and quantitative analyses, along with on-site engineering measurements, to gather data on crucial parameters such as coal seam characteristics, roof rock lithology, thickness, water resistance, and structural damage degree. The research encompasses a multidisciplinary approach, involving mining, geology, hydrogeology, geophysical exploration, rock mechanics, mine surveying, and computational mathematics. The importance of effective safety measures and prevention techniques is emphasized, laying the foundation for research focused on the Xingyun coal mine. The brief concludes by highlighting the potential economic and social benefits of this project and its contribution to valuable experience for future subsea coal mining.

Innovative backfilling longwall panel layout for better subsidence control effect-separating adjacent subcritical panels with pillars

In recent years,field trials of non-pillar longwall mining using complete backfill have been implemented successively in the Chinese coal mining industry.The objective of this paper is to get a scientific understanding of surface subsidence control effect using such techniques.It begins with a brief overview on complete backfill methods primarily used in China,followed by an analysis of collected subsidence factors under mining with complete backfill.It is concluded that non-pillar longwall panel layout cannot protect surface structures against damages at a relatively large mining height,even though complete backfill is conducted.In such cases,separated longwall panel layout should be applied,i.e.,panel width should be subcritical and stable coal pillars should be left between the adjacent panels.The proposed method takes the principles of subcritical extraction and partial extraction;in conjunction with gob backfilling,surface subsidence can be effectively mitigated,thus protecting surface buildings against mining-induced damage.A general design principle and method of separated panel layout have also been proposed.

Strata consolidation subsidence induced by metro tunneling in saturated soft clay strata

To choose the optimum construction method of metro tunneling, we conducted research with numerical simulation on strata consolidation subsidence by dewatering, dynamic dewatering, and non-dewatering construction method, taking the integrated effects of fluid-solid coupling and tunneling mechanics into account. We obtained the curved surfaces of ground surface subsidence and strata consolidation subsidence. The results show that the quantity of ground surface subsidence is 31 mm for the non-dewatering method, 39 mm for the dynamic dewatering method, and 105 mm for the dewatering method. Their ratio is 1：1.3：3.4; and the percentages of strata consolidation subsidence to whole ground surface subsidence of each construction method is 27% （no-dewatering）, 50% （dynamic dewatering）, and 79% （dewatering）. It is obvious that the non-dewatering construction method is the most effective method to control the strata consolidation subsidence induced by metro tunneling in saturated soft clay strata, and it has been successfully applied to the construction of the Shenzben metro line 1.

Twenty years of coal mining-induced subsidence in the Upper Silesia in Poland identified using InSAR

The paper presents the results of terrain subsidence monitoring in Poland's Upper Silesian Coal Basin(USCB)mining area using Differential Interferometry Synthetic Aperture Radar(DInSAR)and Persistent Scatterer Interferometry(PSI).The study area accounts for almost three million inhabitants where mining which started in the 19th century,has produced severe damage to buildings and urban infrastructures in past years.The analysis aimed to combine eight different datasets,processed in two techniques,coming from various sensors and covering different periods.As a result,a map of areas that have been exposed to subsidence within 3045 square kilometers was obtained.The map covers a period of twenty years of intensive mining activities,i.e.1992-2012.A total of 81 interferograms were used in the study.The interferograms allowed not only to determine subsidence troughs(basins)formed from 1992 to 2012 but also to observe subsidence development over time.The work also included five sets of PSI processing,covering different temporal and spatial ranges,which were used to determine zones of residual subsidence.Based on InSAR datasets,an area of 521 square kilometers under the influence of mining activities were determined.Within the subsiding zones,an area of 312.5 square kilometers of the rapid increase in subsidence was identified on the interferograms.The study of combined different InSAR datasets provided large-area and long-term information on the impact of mining activities in the Upper Silesia Coal Basin.

Geodetic Monitoring of the Surface within the Trial Operation of the Room and Pillar Mining Method in the Ostrava-Karvina Coal District

Mine Plant 2 is a part of the Ostrava-Karvina Coal District (OKD) that is located in the Czech part of the Upper Silesian Basin. The first coal was exhausted from Mine Plant 2 in 1968. The most used method of mining so far in this area has been strike longwall mining with controlled caving. Due to extensive changes in the surface, which occur as a consequence of deep mining by the method of longwall mining with controlled caving, it is not possible to use this method in densely populated areas. At the present time, therefore, the trial operation of a new mining method called room and pillar is carried out. The method was chosen with the aim to minimize subsidence and deformations of the surface. The room and pillar mining method has never been used before in the conditions of the OKR, therefore it is necessary to prove the real effect of mining by this method on the surface. For this purpose, a surface observation station was designed, consisting of 36 surface points. The position and height of all points of the observation station is determined in stages three times a year.

Law of surface movement for multi-coal seam strip mining

It is an important part of green mining to control the disasters of coal mining which have caused irreversible damages to buildings and ecological environment. Strip mining is one of the efficient measures to control surface subsidence and mining damage. However, the research on the laws of the surface subsidence are still deficient in multi-coal seam strip mining at present. Based on the Fast Lagrangian Analysis of Continua(short for FLAC3D) numerical simulation software, the laws of the surface subsidence and horizontal movement were systematically studied for different depths, different mining widths, different distances between seams, different mining thickness, different parameters between seams and the special relations of the upper pillar and the lower pillar in the vertical direction in multi-seam strip mining. The function relation between the maximum subsidence and the maximum horizontal movement with the depth, the mining width, the seam distance, mining thickness, different parameters between seams and the partial offset are summarized respectively. Finally the formula integrating the surface maximum subsidence value and the maximum horizontal movement was deduced. The results can be used for reference theory and measure in forecasting the surface displacement in multi-coal seam strip mining.

Study on Deep Well Dewatering Optimization Design in Deep Foundation Pit and Engineering Application

Based on analyses of the theories of groundwater unsteady flow in deep well dewatering in the deep foundation pit, Theis equations are chosen to calculate and analyze the relationship between water level drawdown of confined aquifer and dewatering duration. In order to reduce engineering cost and diminish detrimental effect on ambient surrounding, optimization design target function based on the control of confined water drawdown and four restriction requisitions based on the control of safe water level, resistance to throwing up from the bottom of foundation pit, avoiding excessively great subsidence and unequal surface subsidence are proposed. A deep well dewatering project in the deep foundation pit is optimally designed. The calculated results including confined water level drawdown and surface subsidence are in close agreement with the measured results, and the optimization design can effectively control both surface subsidence outside foundation pit and unequal subsidence as a result of dewatering.

对哈萨克斯坦浙斯卡扎干矿区地面塌落的地震监测(英文)

Catastrophic sesmic events, such as a sudden collapse of open pits and underground excavations,as well as a vast surface subsidence induced by mining activities, present serious dangers to the modem infrastructure . In fact these "sudden" events are the result of long-term preparatory processes, which are occurring in mine pillars and ambient rock.The kinetic approach was proposed for the descripiton of the preparatory process.The process presents a stochastic accumulation of defects in rock caused by a long-term redistribution of stress-strain in an ambient rock massif. Case studies related to mining activities at Zhezkazgan copper mines, Rep. kazakhstan, were coni\sidered.As was shown the seismic monitoring is a good method for forecasting catastrophic caving and surface subsidence.

Measurement of subsidence in the Yangbajing geothermal fields,Tibet,from TerraSAR-X InSAR time series analysis

Yangbajain contains the largest geothermal energy power station in China.Geothermal explorations in Yangbajain first started in 1976,and two plants were subsequently built in 1981 and 1986.A large amount of geothermal fluids have been extracted since then,leading to considerable surface subsidence around the geothermal fields.In this paper,InSAR time series analysis is applied to map the subsidence of the Yangbajain geothermal fields during the period from December 2011 to November 2012 using 16 senses of TerraSAR-X stripmap SAR images.In the case of the TerraSAR-X data,most orbital fringes were removed using precise orbits during the interferometric processing.However,residual orbital ramps remain in some interferograms due to the uncertainties in the TerraSAR-X orbits.To remove the residual orbital ramps,we estimated a best-fit‘twisted plane’for each epoch interferogram using quadratic polynomial models based on a network approach.This method removes most of the long-wavelength signals,including orbit ramps and atmospheric effects.The vertically stratified component(Topography Correlated Atmospheric Delay,TCAD)was also removed using a network approach.If the influence of seasonal frozen ground(SFG)is not taken into consideration,our results show that the subsidence rate around power plant I(the south plant)is approximately 20 mm/yr with a peak of 30 mm/yr.The subsidence rate around power plant II(the north plant)is approximately 10 mm/yr,when accounting for the influence of SFG on the power plant and its surrounding ground surface.Our results show that ground motion is caused by seasonal frozen ground and is strongly related to the temperature change.