水平多向荷载下桩-土相互作用初探

利用香港科技大学离心机双向振动台,进行了群桩基础模型的水平单向和双向振动试验;振动过程中的桩身弯矩响应表明,群桩基础在单向振动中表现出的对称性在双向振动下不复存在;并进行了桩-土相互作用的颗粒流数值模拟,初步探寻了试验观测到的"垂向加载效应"的产生机制;同时通过简单的推导,指出了当前桩-土相互作用分析方法的局限性.在试验、数值和理论分析方面对水平多向荷载下的桩-土相互作用进行了初步研究,为今后的进一步研究提供了重要参考.

Preliminary study on soil-pile interaction under multidirectional horizontal loading

A pair of dynamic tests was performed on pile-group foundation models under both uniaxial and biaxial shakings, by use of the biaxial shaking table at the HKUST centrifuge. By comparing the bending moments developed on the piles, it is found that the symmetric property of pile-group foundation response observed under the uniaxial shaking does not exist any more when under the biaxial shaking. The results of numerical tests using PFC2D provide some explanation to the phenomenon of orthogonal loading effect. At the same time, the limitation of currently used analysis methods for soil-pile interaction is pointed out based on some derivation. The paper presents the preliminary study on soil-pile interaction under multidirectional horizontal loading, so as to provide basis and reference for further study along this line.