The Action Law of Geometry and Structure Characteristic Parameters of Anti-Dumping Layered Rock Slope Toppling Deformation

Huang, Shaoping (China University of Geosciences) | Yan, Echuan (China University of Geosciences) | Li, Xingming (China University of Geosciences) | Liu, Xuyao (China University of Geosciences) | Chen, Qian (China University of Geosciences) | Yang, Kai (China University of Geosciences)

OnePetro 

ABSTRACT: The anti-dumping layered rock slope is a common type of slope with various deformation and failure modes, complicated mechanics mechanism and many influencing factors. Through utilizing 3DEC to research on deformation and failure of toppling rock slope in 3D, ”curved book dumping” mode under the condition of two free faces was proposed, and based on ”Cantilever Theory”, a mechanical model was established for stress analysis. The action law of Geometry and structure characteristic parameters can be concluded from the research: deformation displacement of slope increases as slope height, slope angle and joint inclination increase; the displacement decreases as the included angle between the joint surface and the free face decreases; the largest deformation displacement of the slope appears either when the angle between the two free faces is 90°or when the joint spacing is 1.5m. The sensitivity sorting is concluded through orthogonal test on numerical simulation results: joint inclination angle > slope height > cut slope angle > angle of two free surface > angle between slope surfaces > layer thickness > included angle between the joint surface and the free face.

1. INTRODUCTION

The anti-tilted slope refers to the slope that the strike of the rock strata is close to the trend of the slope, and the inclination of the slope is opposite to the slope. The dumping deformation is a typical failure form of rock slope. A method to analyze the stability of slopes based on the principle of limit equilibrium was proposed (Goodman et al, 1976). Many scholars have further developed and studied on the basis of Goodman's theory (ZANBAK C, 1983; AYDAN O et al, 1989; KLICHE CA, 1999; LIU C H et al, 2009; LIU C H et al, 2008; Hai Feng LU et al, 2012). A large number of scholars have conducted detailed studies on formation mechanism, criterion of instability, influencing factors and possible instability modes of anti-incline rock slopes by means of geological analysis, numerical simulation, physical simulation and modern scientific theory(Dong Xing CHENG et al, 2005; Xi Jie YIN et al, 2007; Bao Cheng ZUO et al, 2005). However, at present, the study is conducted under the condition of one free surface to research on the formation mechanism of anti-dip slope from a two-dimensional perspective (Bei Chuan HAN et al, 1999; Nichol S L,Hungr O and Evans S G, 2002; Ji Liang ZHU et al, 2001; Fa Quan WU et al,1997). Only a few scholars have studied the deformation and failure of anti-dip slope under the condition of two free surfaces (YOON W S et al, 2002: Liang Qing WANG et al, 2011: Jun QIU et al, 2016). In practical engineering, there may exist multiple free surfaces for the anti-dumping rock slope, and the slope is a spatial geometry. So the study should be conducted on the anti-incline rock slope in three-dimensional space, in this paper, 3DEC is used to study the genetic mechanism of the anti-tilting layered rock slope with different faces. The dumping deformation of the anti-inclined bedded rock slope is affected by many factors, a large number of scholars have studied the relationship between the stability of anti-dip slope and factors such as slope angle, rock dip, slope height, rock thickness and other factors (Dong Xing CHENG et al, 2005: Bei Chuan HAN et al. 1999: Jun QIU et al. 2016).