桩与土非线性耦合扭转振动特性分析.pdf

第22 卷 第5 期 中 国 公 路 学 报 V ol. 22 No. 5 2009 年9 月 China Journal of H ighway and T ransport Sept. 2009 : 1001 7372( 2009) 05 0041 07 尚守平, 任 慧, 曾裕林, 余 俊 ( , 410082) :在Novak 边界层模型基础上, 将 周土分为非线性粘弹性内域和线弹性外域, 采用随内域平 均应变减小的等效剪切模量和增长的等效材料阻尼比近似考虑 周土的非线性, 并采用等效线性 法对 与土层耦合扭转振动进行了研究, 得到了考虑 土动力相互作用的单 顶扭转角及其扭 转动力阻抗函数, 然后通过算例对 土体系进行了扭转振动特性的参数分析结果表明: 顶激 振扭转荷载的频率和幅值外域土与 的剪切波速比内域土非线性范围以及 长径比等因素对非 线性土中单 扭转动刚度和阻尼具有较大影响, 所得结论为进 一步研究 土桥梁结构非线性动 力相互作用机理提供了理论基础 : 桥梁工程; 土动力相互作用; 等效线性法; 耦合扭转振动; 动力阻抗函数; 非线性粘弹性 : U443. 15 : A Analysis of Dynamic Behaviors of Pile-soil Nonlinear Coupling Torsional Vibration SHAN G Shou ping, REN Hui, ZENG Yu lin, YU Jun ( School of Civil Engineering, Hunan University, Changsha 410082, Hunan, China) Abstract: Based on the boundary model presented by Novak, the soil around the single pile was divided into two regions: the inner zone on nonlinear viscoelastic field and the outer zone on linear viscoelastic region. The soil nonlinearity can be considered approximately by using a reduced equivalent shear modulus and an increased equivalent material damping ratio with decrease of the average strain in the inner zone. By means of equivalent linearization method, torsional angle and torsional dynamic impedance function of single pile head with consideration of pile soil interaction were deduced from studying pile soil coupling torsional vibration. Parameters of dynamic behaviors of pile soil system under torsional vibration were analyzed through an example. Results show that torsional dynami