Model test research on stress response of high and steep slopes with structural planes during excavation unloading
WANG Lehua1，2，HUANG Tianzhu1，2，LI Jianlin1，2，ZHOU Xin1，2，XU Xiaoliang1，2
(1. Key Laboratory of Geological Hazards on Three Gorges Reservoir Area，Ministry of Education，China Three Gorges University，Yichang，Hubei 443002，China；2. College of Civil Engineering and Architecture，China Three Gorges University，
Yichang，Hubei 443002，China)
Abstract：The failure of rock slopes is significantly affected by factors such as geological structures and human activities. In order to explore the influence of structural planes on the stress change of high-steep slopes during excavation unloading，the physical model test for excavation unloading of high and steep slopes with homogeneous and structural planes was carried out based on similarity theory. The initial stress field of the model and the internal stress response law of the excavated slope were studied，and the influence of the structural plane on the stress field and its mechanism are analyzed. The results show that：(1) During the loading process，the internal stress conduction of the model is closely related to the structural plane. The phenomenon of stress isolation and stress concentration will occur when the stress passes through the structural plane. The loading stress response of the model with structural planes shows three types of change: step-increasing，fluctuating-increasing and steady-increasing. The stress conduction process can be divided into three stages：stress loading，stress adjustment and stress stabilization. (2) After the loading is completed，there is a stress loss when the stress is transmitted from the boundary to the interior of the model. The stress loss rate per unit length(1 cm) in the homogeneous model is 0.91% to 1.17%，and the internal stress loss phenomenon is more significant in the model containing structural planes. (3) During the excavation process of the slope，the internal stress of the model presents the characteristics of relatively significant stress zone(original rock stress zone，stress reduction zone，stress increase zone and high stress zone)，and the stress zone is dynamically adjusted with the advance of excavation. After the excavation is completed，the magnitude of stress reduction gradually slows down from near the excavation face to the inside of the slope. (4) The stress zone of the slope is divided according to the stress change rate before and after excavation. The existence of structural planes expands the range of stress-reduced zone，stress-increased zone and high-stress zone. The stress distribution of the slope is closely related to the spatial position of structural plane and the excavation face.
王乐华1，2，黄天柱1，2，李建林1，2，周 鑫1，2，许晓亮1，2. 含结构面高陡边坡开挖卸荷应力响应物理模型试验研究[J]. 岩石力学与工程学报, 2023, 42(8): 1866-1877.
WANG Lehua1，2，HUANG Tianzhu1，2，LI Jianlin1，2，ZHOU Xin1，2，XU Xiaoliang1，2. Model test research on stress response of high and steep slopes with structural planes during excavation unloading. , 2023, 42(8): 1866-1877.
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2023, Vol. 42 
