循环振动作用下残积土动力变形特性试验研究

发布时间：2018-04-27 20:50

本文选题：花岗岩残积土 + 循环荷载　；参考：《振动与冲击》2017年11期

【摘要】：为研究压实残积土在循环荷载作用下的变形特性,对不同含水率压实残积土进行改变围压及轴向动应力幅值条件的动三轴试验,得到了不同物理力学条件下土的动应力-应变关系滞回曲线、累积塑性应变发展规律曲线及骨干曲线,分析了动弹性模量随应变的衰变规律,探究了含水率、围压及动应力幅值等因素对试验结果的影响。结果表明:当累积塑性应变达到一定值时,压实残积土变形随动应力幅值σ_d的增大增幅明显,但最终表现为弹性安定行为,该特性随含水率的增加逐渐减弱;含水率增加不利于土样变形稳定,而提高围压可抑制该趋势。另外,增湿会加快模量的衰减,并降低残余模量,围压对衰变规律的影响随应变的增大逐渐减小。研究可为花岗岩残积土作为路基填料的施工过程及土体改良提供技术参考。
[Abstract]:In order to study the deformation characteristics of compacted residual soil under cyclic loading, dynamic triaxial tests were carried out to change the confining pressure and the amplitude condition of axial dynamic stress on the compacted residual soil with different moisture content. The hysteretic curve of dynamic stress-strain relation, the development law curve of cumulative plastic strain and the backbone curve of soil under different physical and mechanical conditions are obtained. The decay law of dynamic elastic modulus with strain is analyzed, and the moisture content is explored. The influence of confining pressure and dynamic stress amplitude on the test results. The results show that when the cumulative plastic strain reaches a certain value, the amplitude of the following stress 蟽 _ d of compacted residual soil increases obviously, but the ultimate behavior is elastic stability, which weakens gradually with the increase of water content. The increase of moisture content is not conducive to the stability of soil deformation, but the increase of confining pressure can restrain this trend. In addition, humidification will accelerate the attenuation of modulus and decrease the residual modulus. The effect of confining pressure on the decay law decreases with the increase of strain. The study can provide technical reference for the construction process of granite residual soil as subgrade filler and soil improvement.
【作者单位】：中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室;中原工学院建筑工程学院;天津市软土特性与工程环境重点实验室;
【基金】：国家自然科学基金(41372314;11672320) 中国科学院科技服务网络计划项目(KFJ-EW-STS-122)
【分类号】：U416.1

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