基于动态强度折减DDA法的边坡多滑面稳定性分析
|
摘要
为解决岩体结构面损伤的程度不一性问题及边坡多滑面分析中数值模型的选取问题,借鉴DDA计算位移的优势,考虑块体间相对位移,提出动态强度折减DDA法(Dynamic Strength Reduction Discontinuous Deformation Analysis,简称DSR-DDA)的边坡多滑面搜索,通过对不同破坏程度下岩体结构面动态折减不同的强度及动态变化边坡多滑面分析中的数值模型,以解决数值分析中岩体结构面损伤的程度不一性问题及边坡多滑面分析中数值模型的选取问题。利用倾斜平面滑块经典案例测试位移阈值,验证方法的可行性及计算精度,并将其应用到抚顺西露天矿岩质高边坡多滑面稳定性分析中,且与自主研发的GeoSMA-3D系统进行耦合。研究结果表明:在设定位移阈值为1 mm时,DSR-DDA与理论解误差在0.5%以内,满足计算要求。后续得到了抚顺西露天矿边坡最危险滑落面(对应安全系数为1. 136),与分析现场监测位移得出的潜在滑落位置基本一致,并在首次滑坡后的数值边坡模型基础上,得到了次级滑落面位置(对应安全系数为1.189),与常规分析得出的结果大相径庭,佐证了边坡多滑面稳定性分析中数值模型需动态变化的必要性。DSRDDA法与GeoSMA-3D系统识别出的关键块体耦合效果良好,从块体理论角度印证了DSR-DDA法的实用性。抚顺西露天矿边坡破坏模式为牵引式滑动破坏,中下部油母页岩对边坡稳定性起关键作用,故不可继续开采剩余油母页岩,以免引起边坡上部大面积滑坡及矿坑-城市边界滑坡。
This research aims to solve the problem of the different degrees of damage in rock mass structural surface and the numerical model selection problem in slope multi-slip surface analysis. With the advantage of the DDA displacement calculation, considering the relative displacement between blocks, the slope multi-slip surface search by dynamic strength reduction-discontinuous deformation analysis method( hereinafter referred to as DSR-DDA) is proposed. Through dynamically reducing different strengths of rock mass structural planes under different degrees of damage and dynamically changing the slope multi-slip surface analysis numerical model, the problem of the different degrees of damage in rock mass structural surface and the numerical model selection problem in slope multi-slip surface analysis can be solved. The tilting plane slider classic case is used to test displacement threshold, and also applied to the stability analysis of multi-slip surface of rock high slope in Fushun Western Open-pit Mine,coupled with the selfdeveloped GeoSMA-3 D system. The results show that when the displacement threshold is set to 1 mm, the error between DSR-DDA and the theoretical solution is within 0. 5%, which satisfies the calculation requirements. The most dangerous slip surface(corresponding to a safety factor of 1. 136) of the Fushun West Open Pit Slope is obtained,and it is basically consistent with the potential slip position obtained by analyzing the displacement of the on-site monitoring. Based on the numerical slope model after the first landslide, the position of the secondary slip surface( corresponding to a safety factor of 1. 189) is obtained. The results are quite different from the con-ventional analysis,which proves the necessity of the dynamic change of the numerical model in the slope stability analysis. The DSR-DDA method has a good coupling effect with the key blocks identified by the GeoSMA-3 D system. It proves the practicability of the DSR-DDA method from the perspective of block theory. The failure mode is traction sliding failure,and the middle and lower oil shale plays a key role in slope stability. Therefore, to avoid causing large-scale landslides at the upper part of the slope and landslides at the pit-city boundary, it is not possible to continue the mining of remaining oil shale.
This research aims to solve the problem of the different degrees of damage in rock mass structural surface and the numerical model selection problem in slope multi-slip surface analysis. With the advantage of the DDA displacement calculation, considering the relative displacement between blocks, the slope multi-slip surface search by dynamic strength reduction-discontinuous deformation analysis method( hereinafter referred to as DSR-DDA) is proposed. Through dynamically reducing different strengths of rock mass structural planes under different degrees of damage and dynamically changing the slope multi-slip surface analysis numerical model, the problem of the different degrees of damage in rock mass structural surface and the numerical model selection problem in slope multi-slip surface analysis can be solved. The tilting plane slider classic case is used to test displacement threshold, and also applied to the stability analysis of multi-slip surface of rock high slope in Fushun Western Open-pit Mine,coupled with the selfdeveloped GeoSMA-3 D system. The results show that when the displacement threshold is set to 1 mm, the error between DSR-DDA and the theoretical solution is within 0. 5%, which satisfies the calculation requirements. The most dangerous slip surface(corresponding to a safety factor of 1. 136) of the Fushun West Open Pit Slope is obtained,and it is basically consistent with the potential slip position obtained by analyzing the displacement of the on-site monitoring. Based on the numerical slope model after the first landslide, the position of the secondary slip surface( corresponding to a safety factor of 1. 189) is obtained. The results are quite different from the con-ventional analysis,which proves the necessity of the dynamic change of the numerical model in the slope stability analysis. The DSR-DDA method has a good coupling effect with the key blocks identified by the GeoSMA-3 D system. It proves the practicability of the DSR-DDA method from the perspective of block theory. The failure mode is traction sliding failure,and the middle and lower oil shale plays a key role in slope stability. Therefore, to avoid causing large-scale landslides at the upper part of the slope and landslides at the pit-city boundary, it is not possible to continue the mining of remaining oil shale.
引文
[1]WANG S H,NI P P. Application of block theory modeling on spatial block topological identification to rock slope stability analysis[J].International Journal of Computational Methods,2014,11(1):903-914.
[2]王家臣,陈冲.露天矿节理岩质边坡稳定性分析[J].煤炭学报,2017,42(7):1643-1649.WANG Jiachen, CHEN Chong. Stability analysis for jointed rock slope in an open iron ore mine[J]. Journal of China Coal Society,2017,42(7):1643-1649.
[3]王旭春,管晓明,杜明庆,等.安太堡露天矿边坡蠕滑区滑动机理与稳定性分析[J].煤炭学报,2013,38(S2):312-318.WANG Xuchun, GUAN Xiaoming, DU Mingqing,et al. Analysis of sliding mechanism and stability of creep area of Antaibao OpenPit Mine slope[J]. Journal of China Coal Society,2013,38(S2):312-318.
[4] MORGENSTERN N R, PRICE V E. The analysis of the stability of general slip surfaces[J]. Geotechnique, 1965,15(1):79-93.
[5] ZEINKIEWICZ O,HUMPHESON C,LEWIS R. Associated and nonassociated visco-plasticity in soils mechanics[J]. Geotechnique,1975,25(4):671-689.
[6] DUNCAN J M. State of the art:Limit equilibrium and finite element analysis of slopes[J]. Journal of the Geotechnical Engineering(ASCE),1996,122(7):577-596.
[7] CALA M,FLISIAK J,TAJDUS A. Slope stability analysis with modified shear strength reduction technique[A]. Proceedings of the Ninth International Symposium on Landslides:Evaluation and Stabilization[C]. Rio de Janeiro, Brazil:[s. n.]. 2004.
[8]李小春,袁维,白冰,等.基于局部强度折减法的边坡多滑面分析方法及应用研究[J].岩土力学,2014,35(3):847-854.LI Xiaochun, YUAN Wei, BAI Bing, et al. Analytic approach of slope multi-slip surfaces based on local strength reduction method and its application[J]. Rock and Soil Mechanics, 2014,35(3):847-854.
[9] SHI G H,GOODMAN R E. Two dimensional discontinuous deformation analysis[J]. International Journal for Numerical and Analytical Methods in Geomechanics, 1985,9:541-556.
[10] MACLAUGHLIN M,SITAR N,DOOLIN D,et al. Investigation of slope-stability kinematics using discontinuous deformation analysis[J]. International Journal of Rock Mechanics and Mining Science,2001,38(5):753-762.
[11] FU X D,SHEN Q,ZHANG Y H,et al. Computation of the safety factor for slope stability using discontinuous deformation analysis and the vector sum method[J]. Computers and Geotechnics,2017,92:68-76.
[12] SHI G H. Discontinuous deformation analysis:A new numerical model for the statics and dynamics of block systems[D]. Berkeley:University of California, 1988.
[13] NOLAN Timothy A, KECOJEVIC Vladislav. Selection of overburden surface mining method in West Virginia by analytical hierarchy process[J]. International Journal of Coal Science&Technology,2014,1(3):306-314.
[14] LONG Nguyen Quoc,BUCZEK Michal M,HIEN La Phu,et al. Accuracy assessment of mine walls'surface models derived from terrestrial laser scanning[J]. International Journal of Coal Science&Technology,2018,5(3):328-338.
[15] WANG F L,WANG S H,MUHAMMAD Z H,et al. The characterization of rock slope stability using key blocks within the framework of GeoSMA-3D[J]. Bulletin of Engineering Geology and the Environment,2018,77:1405-1420.
[16] WANG S H, NI P P, GUO M D. Spatial characterization of joint planes and stability analysis of tunnel blocks[J]. Tunnelling and Underground Space Technology,2013,38:357-367.
[17] NI P P,WANG S H,ZHANG Simiao,et al. Response of heterogeneous slopes to increased surcharge load[J]. Computers and Geotechnics, 2016,78,99-109.
[2]王家臣,陈冲.露天矿节理岩质边坡稳定性分析[J].煤炭学报,2017,42(7):1643-1649.WANG Jiachen, CHEN Chong. Stability analysis for jointed rock slope in an open iron ore mine[J]. Journal of China Coal Society,2017,42(7):1643-1649.
[3]王旭春,管晓明,杜明庆,等.安太堡露天矿边坡蠕滑区滑动机理与稳定性分析[J].煤炭学报,2013,38(S2):312-318.WANG Xuchun, GUAN Xiaoming, DU Mingqing,et al. Analysis of sliding mechanism and stability of creep area of Antaibao OpenPit Mine slope[J]. Journal of China Coal Society,2013,38(S2):312-318.
[4] MORGENSTERN N R, PRICE V E. The analysis of the stability of general slip surfaces[J]. Geotechnique, 1965,15(1):79-93.
[5] ZEINKIEWICZ O,HUMPHESON C,LEWIS R. Associated and nonassociated visco-plasticity in soils mechanics[J]. Geotechnique,1975,25(4):671-689.
[6] DUNCAN J M. State of the art:Limit equilibrium and finite element analysis of slopes[J]. Journal of the Geotechnical Engineering(ASCE),1996,122(7):577-596.
[7] CALA M,FLISIAK J,TAJDUS A. Slope stability analysis with modified shear strength reduction technique[A]. Proceedings of the Ninth International Symposium on Landslides:Evaluation and Stabilization[C]. Rio de Janeiro, Brazil:[s. n.]. 2004.
[8]李小春,袁维,白冰,等.基于局部强度折减法的边坡多滑面分析方法及应用研究[J].岩土力学,2014,35(3):847-854.LI Xiaochun, YUAN Wei, BAI Bing, et al. Analytic approach of slope multi-slip surfaces based on local strength reduction method and its application[J]. Rock and Soil Mechanics, 2014,35(3):847-854.
[9] SHI G H,GOODMAN R E. Two dimensional discontinuous deformation analysis[J]. International Journal for Numerical and Analytical Methods in Geomechanics, 1985,9:541-556.
[10] MACLAUGHLIN M,SITAR N,DOOLIN D,et al. Investigation of slope-stability kinematics using discontinuous deformation analysis[J]. International Journal of Rock Mechanics and Mining Science,2001,38(5):753-762.
[11] FU X D,SHEN Q,ZHANG Y H,et al. Computation of the safety factor for slope stability using discontinuous deformation analysis and the vector sum method[J]. Computers and Geotechnics,2017,92:68-76.
[12] SHI G H. Discontinuous deformation analysis:A new numerical model for the statics and dynamics of block systems[D]. Berkeley:University of California, 1988.
[13] NOLAN Timothy A, KECOJEVIC Vladislav. Selection of overburden surface mining method in West Virginia by analytical hierarchy process[J]. International Journal of Coal Science&Technology,2014,1(3):306-314.
[14] LONG Nguyen Quoc,BUCZEK Michal M,HIEN La Phu,et al. Accuracy assessment of mine walls'surface models derived from terrestrial laser scanning[J]. International Journal of Coal Science&Technology,2018,5(3):328-338.
[15] WANG F L,WANG S H,MUHAMMAD Z H,et al. The characterization of rock slope stability using key blocks within the framework of GeoSMA-3D[J]. Bulletin of Engineering Geology and the Environment,2018,77:1405-1420.
[16] WANG S H, NI P P, GUO M D. Spatial characterization of joint planes and stability analysis of tunnel blocks[J]. Tunnelling and Underground Space Technology,2013,38:357-367.
[17] NI P P,WANG S H,ZHANG Simiao,et al. Response of heterogeneous slopes to increased surcharge load[J]. Computers and Geotechnics, 2016,78,99-109.