A simplified approach is presented to analyze the single pile settlement in multilayered soil. First, a fictitious soil-pile model is employed to consider the effect of layered soil beneath pile toe on pile settlement...A simplified approach is presented to analyze the single pile settlement in multilayered soil. First, a fictitious soil-pile model is employed to consider the effect of layered soil beneath pile toe on pile settlement behavior. Two approximation methods are proposed to simplify the nonlinear load transfer function and simulate the nonlinear compression of fictitious soil-pile, respectively. On this basis, an efficient program is developed. The procedures for determining the main parameters of mathematical model are discussed. Comparisons with two well-documented field experimental pile loading tests are conducted to verify the rationality of the present method. Further studies are also made to evaluate the practicability of the proposed approach when a soft substratum exists, and the results suggest that the proposed method can provide a constructive means for assessing the settlement of a single pile for use in engineering design.展开更多
为了探究不同含冰率下的有砟道床在列车循环荷载作用下的沉降特性,采用平行黏结模型模拟道砟-冰和冰-冰的黏结作用,建立了不同含冰率下的冰冻有砟道床细观仿真模型,基于离散元法(Discrete Element Method,DEM)与多体动力学(Multi-Body D...为了探究不同含冰率下的有砟道床在列车循环荷载作用下的沉降特性,采用平行黏结模型模拟道砟-冰和冰-冰的黏结作用,建立了不同含冰率下的冰冻有砟道床细观仿真模型,基于离散元法(Discrete Element Method,DEM)与多体动力学(Multi-Body Dynamics,MBD)双向耦合(DEM-MBD)数值模拟,对冰冻道床施加了500次列车循环荷载,对道床宏观上的累积沉降,微观上的冰结键状态,颗粒运动,道砟颗粒力链传递及分布进行了分析。结果表明,高含冰率能显著抑制有砟道床沉降,并呈现“快速沉降-基本稳定”两阶段特征;同时,随着含冰率增加,冰冻作用使道床内部的传力体系从“均匀颗粒力链”向“黏结块状体力链”演变,但也应注意含冰率超过20%时,冰冻有砟道床开始凸显“脆性”。本研究成果丰富了列车循环荷载下冰冻有砟道床沉降特性的研究,并对指导寒区铁路有砟道床运维养护具有参考价值。展开更多
基金Project(51378464) supported by the National Natural Science Foundation of China
文摘A simplified approach is presented to analyze the single pile settlement in multilayered soil. First, a fictitious soil-pile model is employed to consider the effect of layered soil beneath pile toe on pile settlement behavior. Two approximation methods are proposed to simplify the nonlinear load transfer function and simulate the nonlinear compression of fictitious soil-pile, respectively. On this basis, an efficient program is developed. The procedures for determining the main parameters of mathematical model are discussed. Comparisons with two well-documented field experimental pile loading tests are conducted to verify the rationality of the present method. Further studies are also made to evaluate the practicability of the proposed approach when a soft substratum exists, and the results suggest that the proposed method can provide a constructive means for assessing the settlement of a single pile for use in engineering design.
文摘为了探究不同含冰率下的有砟道床在列车循环荷载作用下的沉降特性,采用平行黏结模型模拟道砟-冰和冰-冰的黏结作用,建立了不同含冰率下的冰冻有砟道床细观仿真模型,基于离散元法(Discrete Element Method,DEM)与多体动力学(Multi-Body Dynamics,MBD)双向耦合(DEM-MBD)数值模拟,对冰冻道床施加了500次列车循环荷载,对道床宏观上的累积沉降,微观上的冰结键状态,颗粒运动,道砟颗粒力链传递及分布进行了分析。结果表明,高含冰率能显著抑制有砟道床沉降,并呈现“快速沉降-基本稳定”两阶段特征;同时,随着含冰率增加,冰冻作用使道床内部的传力体系从“均匀颗粒力链”向“黏结块状体力链”演变,但也应注意含冰率超过20%时,冰冻有砟道床开始凸显“脆性”。本研究成果丰富了列车循环荷载下冰冻有砟道床沉降特性的研究,并对指导寒区铁路有砟道床运维养护具有参考价值。
