非线性土中单桩竖向动力特性分析

在Novak边界层模型基础上,将桩周土分为非线性粘弹性内域和线性粘弹性外域,采用随内域平均应变减小的剪切模量和增长的材料迟滞阻尼比近似考虑内域的非线性粘弹性,采用等效线性方法对端承桩与三维土层的竖向耦合振动进行了研究,得到了非线性土中单桩竖向动力阻抗函数。对动力特性进行算例分析,讨论了内域土非线性、桩长细比、桩-土刚度关系和密度比、材料阻尼、激振荷载幅值等因素对非线性土中单桩竖向动刚度和阻尼的影响,对进一步研究桩-土-结构动力相互作用机理具有理论价值和实践意义。

DYNAMIC BEHAVIOR ANALYSIS OF SINGLE PILES EMBEDDED IN NONLINEAR SOILS UNDER VERTICAL VIBRATION

Based on the boundary model presented by Novak, the soil around the single pile is divided into two regions: the inner nonlinear viscoelastic region and the outer linear viscoelastic region. Soil nonlinearity can be accounted for approximately by using a reduced shear modulus and an increased material damping ratio. The shear modulus and material damping ratio are in nonlinear relationship with the average strain in the inner zone. By means of equivalent linearization method, the three dimensional soil coup...