scholarly journals Research on the establishment of a mining subsidence prediction model under thick loose layer and its parameter inversion method

2021 ◽  
Vol 25 (2) ◽  
pp. 215-223
Author(s):  
Jingxian Li ◽  
Xuexiang Yu ◽  
Deshu Chen ◽  
Xinjian Fang

Most of the coal mining in China is underground, which will inevitably cause surface deformation and trigger a series of geological disasters. Therefore, it is essential to find a suitable method to forecast the ground sinking caused by underground mining. The most commonly used prediction model in China is the probability integral model (PIM). But when this model is used in the geological condition of mining under thick loose layers, the predicted edge of the sinking basin will converge faster than the actual measured sinking situation. A geometric model (GM) with a similar model shape as the PIM but with a larger boundary value was established in this paper to solve this problem. Then an improved cuckoo search algorithm (ICSA) was proposed in this paper to calculate the GM parameters. The stability and reliability of the ICSA were verified through a simulated working face. At last, the ICSA, in combination with the GM and the PIM, was used to fit 6 working faces with the geological mining condition of thick loose layers in the Huainan mining area. The results prove that GM can solve the above-mentioned PIM problem when it is used in geological mining conditions of thick loose layers. And it was obtained through comparative analysis that the GM and the PIM parameters can take the same value except for the main influence radius.

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Rongxing He ◽  
Jing Zhang ◽  
Yang Liu ◽  
Delin Song ◽  
Fengyu Ren

Continuous mining of metal deposits leads the overlying strata to move, deform, and collapse, which is particularly obvious when open-pit mining and underground mining are adjacent. Once the mining depth of the adjacent open-pit lags severely behind the underground, the ultimate underground mining depth needs to be studied before the surface deformation extends to the open-pit mining area. The numerical simulation and the mechanical model are applied to research the ultimate underground mining depth of the southeast mining area in the Gongchangling Iron mine. In the numerical simulation, the effect of granular rock is considered and the granular rock in the collapse pit is simplified as the degraded rock mass. The ultimate underground mining depth can be obtained by the values of the indicators of surface movement and deformation. In the mechanical model, the modified mechanical model for the progressive hanging wall caving is established based on Hoke’s conclusion, which considers the lateral pressure of the granular rock. Using the limiting equilibrium analysis, the relationship of the ultimate underground mining depth and the range of surface caving can be derived. The results show that the ultimate underground mining depth obtained by the numerical simulation is greater than the theoretical calculation of the modified mechanical model. The reason for this difference may be related to the assumption of the granular rock in the numerical simulation, which increases the resistance of granular rock to the deformation of rock mass. Therefore, the ultimate underground mining depth obtained by the theoretical calculation is suggested. Meanwhile, the surface displacement monitoring is implemented to verify the reasonability of the ultimate underground mining depth. Monitoring results show that the indicators of surface deformation are below the critical value of dangerous movement when the underground is mined to the ultimate mining depth. The practice proves that the determination of the ultimate underground mining depth in this work can ensure the safety of the open-pit and underground synergetic mining.


Author(s):  
Ling Zhang ◽  
Daqing Ge ◽  
Xiaofang Guo ◽  
Bin Liu ◽  
Man Li ◽  
...  

Abstract. Land subsidence can be caused by underground mining activities. Interferometric Synthetic Aperture Radar (InSAR) has became an economic, effective and accurate technique for land deformation survey and monitoring. In mining areas, there may be several factors to overcome for the succsessful application of InSAR, such as temporal decorrelation and detectable deformation gradient, that limit the ability of InSAR to monitoring rapid land subsidence. In this paper, images obtained by the Sentinel-1 satellite with 6 or 12 d revisiting time are used to improve the ability to detect a deformation gradient, and reduce the influence of temporal decorrelation. By combining Small Baseline Subsets (SBAS) and Interferometric Point Target Analysis (IPTA) methods, using the Nanhu mining area in Tangshan as an example, the spatial continuous results of land subsidence in this mining area are obtained with a 70 cm per year maximum rate, which clearly characterizes the deformation field and its deformation process. The results show that InSAR is a useful way to monitor land subsidence in a mining area and provides further data for environment mine restoration.


Author(s):  
Aleksander KOWALSKI ◽  
Krzysztof MACIEJAK

During mapping work carried out since October 2015 in the Nowy Kościół area in the Kaczawskie Foothills, Western Sudetes, a number of morphological forms were identified and catalogued. They indicate surface transformation due to ceased mining activity. Several depressions and grabens were recognized during the digital terrain model and satellite images analysis. The range of deformation has been determined, and their spatial parameters and the maximal depression of the ground level within the mining area have been estimated and described. Such ground level depressions have not been examined in detail before. The main aim of the studies was to determine the usefulness of geomorphometric methods based on LiDAR digital elevation models (DEM) for the purposes of high quality description of surface deformation caused by underground mining operations.


2021 ◽  
Vol 13 (1) ◽  
pp. 94-122
Author(s):  
Min Ren ◽  
Guanwen Cheng ◽  
Wancheng Zhu ◽  
Wen Nie ◽  
Kai Guan ◽  
...  

Author(s):  
J. Zhang

Abstract. InSAR has developed a variety of methods, such as D-InSAR, PS-InSAR, MBAS, CT, SqueeSAR, POT, etc., which have been widely used in land subsidence monitoring. For open pit mining areas, there are usually mining activity, complex terrain features, low coherence, and local large deformation gradients, which makes it difficult for time series InSAR technology to obtain high-density surface deformation information in open pit mining areas. Traditional methods usually only monitor the linear deformation of the surface caused by the mining of a few working zone above the underground mining area, and the temporal and spatial resolution is lower. How to obtain high-precision, high-density, and time-sensitive deformation information is the main difficulty of InSAR monitoring in open pit mining areas. Make full use of the geosensor network monitoring system, optimize monitoring mode of collaborated satellite-to-ground based InSAR, further realize whole calculation and geographic information services, to achieve early identification and discovery of abnormal in large-area macro-monitoring, and accurate monitoring of local areas in real-time early warning, which is the development direction of ground deformation monitoring of mining areas. The study area is Pingshuo open pit mining area. we fully study the application mode and services of InSAR monitoring for geohazards in open-pit mining area, through the establishment of satellite InSAR technology system for large-scale macro-monitoring and forecasting, and GBSAR and GSN for local precision monitoring. The effective mode of InSAR monitoring of geohazard in open-pit mines is summarized. A combination of D-InSAR, POT (Pixel offset tracking), Time Series-InSAR and GB-SAR is used in a wide range, and high-resolution optical images are used to identify localized changes in subsidence areas and open-pit mining areas.


2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Yun Shi ◽  
Qianwen Li ◽  
Xin Meng ◽  
Tongkang Zhang ◽  
Jingjian Shi

Given the increasingly serious geological disasters caused by underground mining in the Hancheng mining area in China and the existing problems with mining subsidence prediction models, this article uses the small baseline subset interferometric synthetic aperture radar (SBAS-InSAR) technology to process 109 Sentinel-1A images of this mining area from December 2015 to February 2020. The results show that there are three subsidences: one in Donganshang, one in south of Zhuyuan village, and one in Shandizhaizi village. In the basin, the maximum annual average subsidence rate is 300 mm/a, and the maximum cumulative subsidence is 1000 mm. The SBAS-InSAR results are compared with Global Positioning System (GPS) observation results, and the correlation coefficient is 74%. Finally, a simulated annealing (SA) algorithm is used to estimate the optimal parameters of a support vector regression (SVR) prediction model, which is applied for mining subsidence prediction. The prediction results are compared with the results of SVR and the GM (1, 1). The minimum value of the coefficient of determination for prediction with SA-SVR model is 0.57, which is significantly better than that those of the other two prediction methods. The results indicate that the proposed prediction model offers high subsidence prediction accuracy and fully meets the requirements of engineering applications.


2018 ◽  
Vol 10 (9) ◽  
pp. 1392 ◽  
Author(s):  
Meinan Zheng ◽  
Kazhong Deng ◽  
Hongdong Fan ◽  
Sen Du

To determine the relationship between underground mining, groundwater storage change, and surface deformation, we first used two sets of ENVISAT data and one set of Sentinel-1A data to obtain surface deformation in eastern Xuzhou coalfield based on the temporarily coherent point interferometric synthetic aperture radar (TCPInSAR) technique. By comparison with underground mining activities, it indicated that the surface subsidence is mainly related to mine exploitation and residual subsidence in the goaf, while the surface uplift is mainly related to restoration of the groundwater level. The average groundwater storage change in the eastern Xuzhou coalfield from January 2005 to June 2017 was obtained through the Gravity Recovery and Climate Experiment (GRACE) data, and the results indicated that the groundwater storage changed nonlinearly with time. The reliability of the groundwater monitoring results was qualitatively validated by using measured well data from April 2009 to April 2010. Combining with time of mining and mine closing analysis, groundwater storage change within the research area had a strong correlation with drainage activity of underground mining. An analysis was finally conducted on the surface deformation and the groundwater storage change within the corresponding time. The results indicated that the groundwater storage variation in the research area has a great influence on the surface deformation after the mine closed.


2020 ◽  
Vol 39 (6) ◽  
pp. 8125-8137
Author(s):  
Jackson J Christy ◽  
D Rekha ◽  
V Vijayakumar ◽  
Glaucio H.S. Carvalho

Vehicular Adhoc Networks (VANET) are thought-about as a mainstay in Intelligent Transportation System (ITS). For an efficient vehicular Adhoc network, broadcasting i.e. sharing a safety related message across all vehicles and infrastructure throughout the network is pivotal. Hence an efficient TDMA based MAC protocol for VANETs would serve the purpose of broadcast scheduling. At the same time, high mobility, influential traffic density, and an altering network topology makes it strenuous to form an efficient broadcast schedule. In this paper an evolutionary approach has been chosen to solve the broadcast scheduling problem in VANETs. The paper focusses on identifying an optimal solution with minimal TDMA frames and increased transmissions. These two parameters are the converging factor for the evolutionary algorithms employed. The proposed approach uses an Adaptive Discrete Firefly Algorithm (ADFA) for solving the Broadcast Scheduling Problem (BSP). The results are compared with traditional evolutionary approaches such as Genetic Algorithm and Cuckoo search algorithm. A mathematical analysis to find the probability of achieving a time slot is done using Markov Chain analysis.


2019 ◽  
Vol 8 (4) ◽  
pp. 9465-9471

This paper presents a novel technique based on Cuckoo Search Algorithm (CSA) for enhancing the performance of multiline transmission network to reduce congestion in transmission line to huge level. Optimal location selection of IPFC is done using subtracting line utilization factor (SLUF) and CSA-based optimal tuning. The multi objective function consists of real power loss, security margin, bus voltage limit violation and capacity of installed IPFC. The multi objective function is tuned by CSA and the optimal location for minimizing transmission line congestion is obtained. The simulation is performed using MATLAB for IEEE 30-bus test system. The performance of CSA has been considered for various loading conditions. Results shows that the proposed CSA technique performs better by optimal location of IPFC while maintaining power system performance


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