Bulletin of Engineering Geology and the Environment,2009,68:195-200

Significance of outward dipping strata in argillaceous limestones in the area of the Three Gorges reservoir, China　

Qi SW (Qi, Shengwen), Yue ZQ (Yue, Zhong Qi), Liu CL (Liu, Chunling), Zhou YD (Zhou, Yuande) 

Abstract 

Re-location of the town of Fengjie due to the impounding of the Three Gorges reservoir involved some significant excavations into the valley slopes. It was noted that the mainly calcareous strata in gullies had a northerly dip while in the excavation the dips were sub-horizontal and even southerly, towards the Yangtze River. The paper discusses the process which leads to this change in dip in the superficial strata. This is particularly significant where orthogonal sub-vertical discontinuities are present such that gravitational effects result in blocks toppling out of the free face.