Current Science

Open Access Open Access  Restricted Access Subscription Access

Geometric Characteristics of Slope Toppling Failure and its Interpretation


Affiliations
1 Key Laboratory of Shale Gas and Geoengineering, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
2 University of Chinese Academy ofSciences, Beijing 100049, China
 

Several studies have simulated and studied the phenomenon of toppling failure caused by open-pit excavation. However, these studies do not involve or neglect the interpretation of some special geometric characteristics and laws of this deformation. Only by understanding the subtle geometric characteristics and geometric laws of slope toppling failure, can we understand the conditions, processes and mechanisms of such deformation. In this study, a soft material, small model, deformable element method is successfully used to simulate the phenomenon of the bending each layer element from the lower part of the slope to the upper, with the dislocation distance (scraps on the slope) being bigger. This method overcomes the short-coming of the rigid body element that traditional methods cannot simulate. Finally, the conditions and mechanism of this phenomenon are further analysed and explained by structural unit of inclined composite cantilever and elastic theory. Under the action of the body force component fx which is parallel to the longitudinal direction of the cantilever, the geometric characteristics of the single cantilever in the composite cantilever are changed such that the upper part of it is narrowed and the lower part of it is widened. Under the action of the body force component fy which is perpendicular to the longitudinal direction of the cantilever, the cantilever is bent. Under the action of these two body force components, the composite cantilever is bent as a whole after open-pit excavation. Because of the change in the geometric shape of the cantilever, any single cantilever has a larger deflection than the other single cantilever below it; that is, greater the deflection of each cantilever along the slope upwards, greater is the curvature of the corresponding point. Finally from the lower part of the slope to the upper, the scraps on the slope are bigger.

Keywords

Cantilever Beam, Elastic Theory, Geometric Characteristics, Rigid Body Element, Soft Material Small Model, Toppling Failure.
User
Notifications
Font Size

  • Sun, Y., Chinese Open Pit Mine Slope Stability Analysis, Beijing, China Science and Technology Press, 1999 (in Chinese).

  • Lu, S., The red flag range open pit mine slope toppling-displaced characteristic. In The Chinese Typical Landslides, Beijing, Science Press, 1988 (in Chinese).

  • Li, G., Deformation features and controlling of destabilization of western wall side-slope in Buzhaoba opencast. Opencast Coal Min. Technol., 2000, (2), 11–13 (in Chinese).

  • Goodman, R. and Bray, J. W., Toppling of rock slopes. In Proceedings of the ASCE Specialty Conference on Rock Engineering for Foundations and Slopes. Boulder, CO, August 1977, pp. 201– 234.

  • Amini, M., Majdi, A. and Veshadi, M. A., Stability analysis of rock slopes against block-flexure toppling failure. Rock Mech.Rock. Eng., 2012, 45, 519–532.

  • Nonomura, A. and Hasegawa, S., Regional extraction of flexural-toppled slopes in epicentral regions of subduction earthquakes along the Nankai Trough using DEM. Environ. Earth Sci., 2013, 68, 139–149.

  • Mehdi Amini, Abbas Majdi and Mohammad Amin Veshadi, Stability analysis of rock slopes against block-flexure toppling failure. Rock Mech. Rock Eng., 2012, 45, 519–532.

  • Pinheiro, A. L., Lana, M. S. and Sobreira, F. G., Use of the distinct element method to study flexural toppling at the Pico Mine, Brazil. Bull. EngGeol. Environ., 2015, 74, 1177–1186.

  • Adhikary, D. P., Dyskin, A. V., Jewell, R. J. and Stewart, D. P., A study of the mechanism of flexural toppling failure of rock slopes. Rock Mech. Rock Eng., 1997, 30(2), 75–93.

  • Zhang, J., Chen, Z. and Wang, X., Centrifuge modeling of rock-slopes susceptible to block toppling. Rock Mech. Rock Eng., 2007, 40(4), 363–382.

  • Huang, R., Wang, Z. and Xu, Q., A Research of the Deformation and the Failure of Anti-dip Rock Slope, Southwest Jiaotong University Press, Chengdu, 1994, pp. 62–73.

  • Pritchard, M. A. and Savigny, K. W., Numerical modeling of toppling. Can. Geotech J., 1990, 27, 824–834.

  • Cheng, D. X., Liu, D. A. and Ding, E. B., Analysis on influential factors and toppling conditions of toppling rockslope. Chinese J. GeotechEng., 2005, 27(11), 127–131.


Abstract Views: 398

PDF Views: 145




  • Geometric Characteristics of Slope Toppling Failure and its Interpretation

Abstract Views: 398  |  PDF Views: 145

Authors

Jiayuan Cao
Key Laboratory of Shale Gas and Geoengineering, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
Fengshan Ma
Key Laboratory of Shale Gas and Geoengineering, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
Jiamo Xu
Key Laboratory of Shale Gas and Geoengineering, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
Jie Guo
Key Laboratory of Shale Gas and Geoengineering, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
Rong Lu
University of Chinese Academy ofSciences, Beijing 100049, China

Abstract


Several studies have simulated and studied the phenomenon of toppling failure caused by open-pit excavation. However, these studies do not involve or neglect the interpretation of some special geometric characteristics and laws of this deformation. Only by understanding the subtle geometric characteristics and geometric laws of slope toppling failure, can we understand the conditions, processes and mechanisms of such deformation. In this study, a soft material, small model, deformable element method is successfully used to simulate the phenomenon of the bending each layer element from the lower part of the slope to the upper, with the dislocation distance (scraps on the slope) being bigger. This method overcomes the short-coming of the rigid body element that traditional methods cannot simulate. Finally, the conditions and mechanism of this phenomenon are further analysed and explained by structural unit of inclined composite cantilever and elastic theory. Under the action of the body force component fx which is parallel to the longitudinal direction of the cantilever, the geometric characteristics of the single cantilever in the composite cantilever are changed such that the upper part of it is narrowed and the lower part of it is widened. Under the action of the body force component fy which is perpendicular to the longitudinal direction of the cantilever, the cantilever is bent. Under the action of these two body force components, the composite cantilever is bent as a whole after open-pit excavation. Because of the change in the geometric shape of the cantilever, any single cantilever has a larger deflection than the other single cantilever below it; that is, greater the deflection of each cantilever along the slope upwards, greater is the curvature of the corresponding point. Finally from the lower part of the slope to the upper, the scraps on the slope are bigger.

Keywords


Cantilever Beam, Elastic Theory, Geometric Characteristics, Rigid Body Element, Soft Material Small Model, Toppling Failure.

References





DOI: https://doi.org/10.18520/cs%2Fv118%2Fi10%2F1569-1574