摘要Expansive soils in cut slopes are prone to sliding for a period of time after excavation. They are commonly found during construction in expansive soil subgrade. Their sliding is not directly affected by the height and ratio of the slope. To understand the evolution of their deformation and the consequences of failure to implement effective engineering treatment, the finite difference procedure FLAC is used to analyze the regularity of the excavation process of expansive soil slopes and obtain the displacement, stress, and strain. The safety factor for slope cutting calculated by using the strength reduction method decreases as the slope depth increases, but is still stable after the complication of excavation. In addition, the thermodynamics module of the finite difference procedure FLAC is used to simulate the humidity field of the atmospheric effects for the expansive soil slope and to obtain the variability of the displacements, stresses, and strains of the cut slope after wetting and drying cycles. The numerical simulation results are basically in accordance with field observation results during and after the construction of cut slopes in the Sitang interchange ramp of the Bailong expressway in Guangxi Zhuang Autonomous Region, China. The four stages of evolution of expansive soil cutting slopes are summarized. It is proposed that flexible supporting structure technology should be used.
Abstract：Expansive soils in cut slopes are prone to sliding for a period of time after excavation. They are commonly found during construction in expansive soil subgrade. Their sliding is not directly affected by the height and ratio of the slope. To understand the evolution of their deformation and the consequences of failure to implement effective engineering treatment, the finite difference procedure FLAC is used to analyze the regularity of the excavation process of expansive soil slopes and obtain the displacement, stress, and strain. The safety factor for slope cutting calculated by using the strength reduction method decreases as the slope depth increases, but is still stable after the complication of excavation. In addition, the thermodynamics module of the finite difference procedure FLAC is used to simulate the humidity field of the atmospheric effects for the expansive soil slope and to obtain the variability of the displacements, stresses, and strains of the cut slope after wetting and drying cycles. The numerical simulation results are basically in accordance with field observation results during and after the construction of cut slopes in the Sitang interchange ramp of the Bailong expressway in Guangxi Zhuang Autonomous Region, China. The four stages of evolution of expansive soil cutting slopes are summarized. It is proposed that flexible supporting structure technology should be used.
基金资助:Supported by the National Natural Science Foundation of China (No.50978035);the Road and Transport R & D Project for Western Regions of China Commissioned by Ministry of Transport (No.2009353311060);and Guangxi Communications Science and Technology Projects (No.2011-20)
通讯作者:
YANG He-ping, cscuyang@163.com
E-mail: cscuyang@163.com
引用本文:
杨和平, 肖杰, 程斌, 赵文建. 开挖膨胀土边坡坍滑的演化规律[J]. Journal of Highway and Transportation Research and Development, 2014, 8(1): 13-20.
YANG He-ping, XIAO Jie, CHENG Bin, ZHAO Wen-jian. Landslide Evolution Rule of Cut Slopes in Expansive Soils. Journal of Highway and Transportation Research and Development, 2014, 8(1): 13-20.
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2014, Vol. 8 
