In order to evaluate the seismic stability of reinforced soil walls against bearing capacity failure,the seismic safety factor of reinforced soil walls was determined by using pseudo-dynamic method,and calculated by c...In order to evaluate the seismic stability of reinforced soil walls against bearing capacity failure,the seismic safety factor of reinforced soil walls was determined by using pseudo-dynamic method,and calculated by considering different parameters,such as horizontal and vertical seismic acceleration coefficients,ratio of reinforcement length to wall height,back fill friction angle,foundation soil friction angle,soil reinforcement interface friction angle and surcharge.The parametric study shows that the seismic safety factor increases by 24-fold when the foundation soil friction angle varies from 25°to 45°,and increases by 2-fold when the soil reinforcement interface friction angle varies from 0 to 30°.That is to say,the bigger values the foundation soil and/or soil reinforcement interface friction angles have,the safer the reinforced soil walls become in the seismic design.The results were also compared with those obtained from pseudo-static method.It is found that there is a higher value of the safety factor by the present work.展开更多
A new method was presented to determine the safety factor of wall stability against overturning based on pseudo-dynamic approach. In this time-dependent method, the actual dynamic effect with variation of time and pro...A new method was presented to determine the safety factor of wall stability against overturning based on pseudo-dynamic approach. In this time-dependent method, the actual dynamic effect with variation of time and propagation of shear and primary wave velocities through the backfills was considered. Planar failure surface was considered behind the retaining wall. The results were compared with those obtained from Mononobe-Okabe theory. It is found that there is a higher value of safety factor by the present dynamic analysis. The effects of wall inclination, wall friction angle, soil friction angle and horizontal and vertical seismic coefficients on the overturning stability of retaining wall were investigated. The parametric study shows that both horizontal and vertical seismic accelerations have decreasing effect on the overturning stability of retaining wall.展开更多
A method combining the pseudo-dynamic approach and discretization technique is carried out for computing the active earth pressure.Instead of using a presupposed failure mechanism,discretization technique is introduce...A method combining the pseudo-dynamic approach and discretization technique is carried out for computing the active earth pressure.Instead of using a presupposed failure mechanism,discretization technique is introduced to generate the potential failure surface,which is applicable to the case that soil strength parameters have spatial variability.For the purpose of analyzing the effect of earthquake,pseudo-dynamic approach is adopted to introduce the seismic forces,which can take into account the dynamic properties of seismic acceleration.A new type of micro-element is used to calculate the rate of work of external forces and the rate of internal energy dissipation.The analytical expression of seismic active earth pressure coefficient is deduced in the light of upper bound theorem and the corresponding upper bound solutions are obtained through numerical optimization.The method is validated by comparing the results of this paper with those reported in literatures.The parametric analysis is finally presented to further expound the effect of diverse parameters on active earth pressure under non-uniform soil.展开更多
A formula was derived for the computation of seismic active earth pressure behind retaining wall using pseudo-dynamic method.This formula considered the actual dynamic effect with variation of time and propagation of ...A formula was derived for the computation of seismic active earth pressure behind retaining wall using pseudo-dynamic method.This formula considered the actual dynamic effect with variation of time and propagation of shear and primary wave velocities through the soil backfills.The influence of tension crack in the top portion of the backfill under seismic loading was investigated.The effects of wall friction angle,soil friction angle,horizontal and vertical seismic coefficients on the seismic active force were also explored.The parametric study shows that the total seismic active force increases as horizontal seismic coefficient increases,while it decreases with the increase in vertical seismic coefficient,internal friction angle and unit cohesion.The seismic active force calculated by the proposed method is larger than that calculated by previous theory.展开更多
文摘In order to evaluate the seismic stability of reinforced soil walls against bearing capacity failure,the seismic safety factor of reinforced soil walls was determined by using pseudo-dynamic method,and calculated by considering different parameters,such as horizontal and vertical seismic acceleration coefficients,ratio of reinforcement length to wall height,back fill friction angle,foundation soil friction angle,soil reinforcement interface friction angle and surcharge.The parametric study shows that the seismic safety factor increases by 24-fold when the foundation soil friction angle varies from 25°to 45°,and increases by 2-fold when the soil reinforcement interface friction angle varies from 0 to 30°.That is to say,the bigger values the foundation soil and/or soil reinforcement interface friction angles have,the safer the reinforced soil walls become in the seismic design.The results were also compared with those obtained from pseudo-static method.It is found that there is a higher value of the safety factor by the present work.
基金Project(50879077) supported by the National Natural Science Foundation of China
文摘A new method was presented to determine the safety factor of wall stability against overturning based on pseudo-dynamic approach. In this time-dependent method, the actual dynamic effect with variation of time and propagation of shear and primary wave velocities through the backfills was considered. Planar failure surface was considered behind the retaining wall. The results were compared with those obtained from Mononobe-Okabe theory. It is found that there is a higher value of safety factor by the present dynamic analysis. The effects of wall inclination, wall friction angle, soil friction angle and horizontal and vertical seismic coefficients on the overturning stability of retaining wall were investigated. The parametric study shows that both horizontal and vertical seismic accelerations have decreasing effect on the overturning stability of retaining wall.
基金Projects(51908557,51378510)supported by the National Natural Science Foundation of China。
文摘A method combining the pseudo-dynamic approach and discretization technique is carried out for computing the active earth pressure.Instead of using a presupposed failure mechanism,discretization technique is introduced to generate the potential failure surface,which is applicable to the case that soil strength parameters have spatial variability.For the purpose of analyzing the effect of earthquake,pseudo-dynamic approach is adopted to introduce the seismic forces,which can take into account the dynamic properties of seismic acceleration.A new type of micro-element is used to calculate the rate of work of external forces and the rate of internal energy dissipation.The analytical expression of seismic active earth pressure coefficient is deduced in the light of upper bound theorem and the corresponding upper bound solutions are obtained through numerical optimization.The method is validated by comparing the results of this paper with those reported in literatures.The parametric analysis is finally presented to further expound the effect of diverse parameters on active earth pressure under non-uniform soil.
基金Project(50879077)supported by the National Natural Science Foundation of China
文摘A formula was derived for the computation of seismic active earth pressure behind retaining wall using pseudo-dynamic method.This formula considered the actual dynamic effect with variation of time and propagation of shear and primary wave velocities through the soil backfills.The influence of tension crack in the top portion of the backfill under seismic loading was investigated.The effects of wall friction angle,soil friction angle,horizontal and vertical seismic coefficients on the seismic active force were also explored.The parametric study shows that the total seismic active force increases as horizontal seismic coefficient increases,while it decreases with the increase in vertical seismic coefficient,internal friction angle and unit cohesion.The seismic active force calculated by the proposed method is larger than that calculated by previous theory.
