摘要: Earthquake shakes the soil and induces modulus softening and liquefaction of non-cohesive soil, which causes instability of the slope. A practical numerical method is proposed for predicting large deformation and horizontal displacement of submarine gentle slope due to earthquake. The new method take normal wave loads as pseudo-static steady pressure and initial excess pore water pressure. Using 2-D nonlinear effective stress finite element method, dynamic response and liquefaction analysis are conducted with an infinite submarine slope model. Regarding the seismic motion of soil skeleton as process of softening gradually, softened soil modulus is attained during earthquake. Deformation analysis is performed with the modulus of liquefied and softened soil and the process of lateral movement is obtained. Compared with other related researches, the proposed method shows that gives reasonable results for the conditions indicated. The influences of non-liquefied surface layer, liquefied layer thickness and slope angle on horizontal displacement are studied by series of cases.

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作者: Fan Chao Meng, Xiao Ming Yuan, Hui Xue

摘要: The shaking table test on liquefied soil - structure interaction was desighed. In the test, the building model and the soil were evenly arranged, after being put horizontal sine wave acceleration time history, building symmetrical basal dynamic stress, pore water pressure and earthquake-induced settlement time history were obtained. The results are: (1) symmetrical basal vertical dynamic stress, pore water pressure, earthquake-induced settlement reaction time history appeared antisymmetric distribution; (2) basal dynamic stress is controlled by the input waveform, the basal vertical dynamic stress plays a decisive role in the increase of the pore water pressure, while difference of pore water pressure decides difference of earthquake-induced settlement, which causes the building tilts toward the direction of higher pore water pressure; (3) a correlation exists among input wave, basal vertical dynamic stress, pore water pressure and structural earthquake-induced settlement. The mechanism of earthquake-induced settlement is: acceleration waveform form of both sides basal dynamic stress cumulative form of both sides basal pore pressure form of earthquake-induced settlement.

352

作者: Chun Jing Lai, Yan Peng Zhu, Chun Qing Wang, Tian Zhong Ma

摘要: Based on analysis of characteristics of earthquake-induced landslides and summary of main factors of controlling earthquake-induced landslides, three main factors which are seismic parameters, topography and landforms features and engineering properties of soil are considered the main factor affecting on earthquake-induced landslides. These factors should be focused on to meet the similitude ratio design of the dynamics of landslide in Shaking table test design. Based on study of dynamic similitude law of landslide, the method of changing model soil specifications is used to prepare the model soil which is in accordance with the maximum shear modulus of prototype soil. Also, the engineering properties similitude of model soil is checked by the method of shear wave velocity similitude. By taking the theory of vibration behavior theory of similarity and dynamic failure similar, the formula of dynamic parameters similitude ratio was got. This formula provides calculating methods using shaking table test to simulate earthquake induced landslide.

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