Simulation of earthquake‐induced slope deformation using SPH method

This paper presents the development, calibration, and validation of a smoothed particle hydrodynamics (SPH) model for the simulation of seismically induced slope deformation under undrained condition. A constitutive model that combines the isotropic strain softening viscoplasticity and the modified Kondner and Zelasko rule is developed and implemented into SPH formulations. The developed SPH model accounts for the effects of wave propagation in the sliding mass, cyclic nonlinear behavior of soil, and progressive reduction in shear strength during sliding, which are not explicitly considered in various Newmark‐type analyses widely used in the current research and practice in geotechnical earthquake engineering. Soil parameters needed for the developed model can be calibrated using typical laboratory shear strength tests, and experimental or empirical shear modulus reduction curve and damping curve. The strain‐rate effects on soil strength are considered. The developed SPH model is validated against a readily available and well‐documented model slope test on a shaking table. The model simulated slope failure mode, acceleration response spectra, and slope deformations are in excellent agreement with the experimental data. It is thus suggested that the developed SPH model may be utilized to reliably simulate earthquake‐induced slope deformations. This paper also indicates that if implemented with appropriate constitutive models, SPH method can be used to model large‐deformation problems with high fidelity. Copyright © 2013 John Wiley & Sons, Ltd.     

Viscoplastic Torsional Buckling of Cylindrical Shell

- The Bodner-Partom constitutive equation is used to study the viscoplastic torsional bucklingof perfect cylindrical shell. By treating the viscoplastic shell as an orthotropic shell at each moment and neglecting the inertia term, the critical torque is determined from a set of homogeneous linear equations. The strain rate sensitivity is mainly discussed in the present paper.     

水泥土桩加固海洋土的渐进变形破坏试验与数值分析

应用一个高度非线性的三维各向异性粘弹塑性(EVP)模型及有限元法,对一水泥土桩(CDM)加固海洋土的复合地基进行数值模拟。海洋软粘土的渐进变形采用粘弹塑性模型来模拟,水泥土桩破坏前后的应力-应变关系采用一个双曲线模型来模拟,提出了一个简单且非常实用的数值分析方法来解决水泥土桩碎裂软化的数值模拟问题。将数值模拟结果与实测数据进行了比较,二者吻合较好。