循环荷载下冻土桩基力学特性分析

ANALYSIS ON MECHANICAL CHARACTERISTICS OF FROZEN SOIL PILE FOUNDATION UNDER CYCLIC LOADING

近几年,我国重大基础设施工程建设向寒冷地区转移趋势尽显。作为寒冷区域工程的基础承载体,冻土桩基在不同类别环境、运营条件下的力学特性得到了工程建设者的极大关注。因此,为了给冻土桩基施工提供一些参考,利用冻土低温循环三轴试验方法,研究了冻土桩基在往复循环荷载下的力学特性及变化规律。结果表明,作为特殊岩土材料,在低温循环荷载下,桩侧冻结应力呈现出先增加后减小趋势,在桩深10.0 cm位置出现较大值;而桩身应变、桩身轴力均随着荷载幅度的增加而增加,随着温度的下降而减少。

In recent years,China’s major infrastructure projects have shifted to cold regions.As the foundation bearing body for cold area projects,the mechanical properties of frozen soil pile foundations under different types of environments and operating conditions have attracted great attention from engineering builders.Therefore,in order to provide some references for the construction of pile foundations in frozen soil,the mechanical properties and changing laws of pile foundations in frozen soil under cyclic loading are studied by using the lowtemperature cyclic triaxial test method of frozen soil.The results show that,as a special rock-soil material,under low-temperature cyclic loading,the freezing stress on the side of the pile increases first and then decreases,with a larger value at the pile depth of 10.0 cm;while the strain of the pile and the axial force of the pile both increase when load amplitude increases,and decrease with decreasing temperature.