• 标题：Experimental study on the dynamic characteristics of low-angle loess slope under the influence of long- and short-term effects of rainfall before
• 关键词：Low-angle loess slope,Long- and short-term effects,
• 作者：Jinchang Chen, Lanmin Wang, Xiaowu Pu, Fuxiu Li, Tonglin Li

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Landslides on low-angle slopes can be caused under the coupled effffect of rainfall and earthquake. In order to investigate the inflfluence of duration of time between rainfall and earthquake on the scale and failure mode of landslides, a low-angle loess slope at Lanzhou New Area was adopted as a prototype, and a large-scale shaking table test was performed. By using self-designed artifificial rainfall equipment, 30 mm of rainfall 12 h before shaking and 20 mm rainfall immediately before shaking were exerted on the slope model to investigate the responses and determine the difffferences in the failure mode of the low-angle slope under difffferent rainfall cases. To measure the dynamic response of the test model at each working condition, 18 acceleration sensors, 7 soilpressure sensors, 10 pore water-pressure sensors, and optical measurement techniques were used. The results show that the acceleration amplifification effffect increased with increasing intensity and the soil pressure increased with decreasing elevation under the long-term effffects of rainfall before earthquake, but the value on the slope surface decreased under the short-term effffects of rainfall before earthquake. The dynamic pore pressure value varied considerably between positive and negative and the maximum displacements at slope surface increased about 69.7% under the short-term effffects of rainfall before earthquake. Large displacements and deep cracks occurred on the surface of the slope, mainly caused by the loess losing its strength and the large inertial force on the surface owing to the long-term effffect of rainfall before the earthquake. The damage to the low-angle slope was mainly caused by liquefaction and the loss of loess strength under the inflfluence of short-term rainfall before the earthquake. The failure of the slope was soil flflow, which was similar to the sliding process of the Yongguang village landslides. Finally, we note that the effffect of coupled effffect on the low-angle slope should be evaluated in future work from two aspects: the intensity of rainfall and earthquake and the time when rainfall occurred before the earthquake.