考虑含砂量影响的砂-黏混合土应力-应变关系特性研究

发布时间：2018-02-23 07:00

本文关键词： 砂-黏混合土初始切线模量应力-应变关系邓肯-张模型软化模型　出处：《工程地质学报》2014年06期 　论文类型：期刊论文

【摘要】：将砂与黏土按不同比例干重量均匀混合制成砂-黏混合土,进行不排水三轴剪切试验,研究了含砂量和试验围压对混合土初始切线模量和应力-应变关系的影响,并对其作用机理进行了分析。研究结果表明:含砂量小于50%时,可以认为混合土初始切线模量与含砂量无关。含砂量大于50%小于80%时,初始切线模量随含砂量增加呈线性趋势增长。通过把含砂量参数引入到初始切线模量中对Duncan-Chang模型进行修正,使修正后的模型能够描述含砂量小于80%时混合土的应力-应变关系。当含砂量超过80%,混合土呈应变软化型,随含砂量的增加,初始切线模量逐渐保持稳定,应力-应变曲线峰值应变左移,可应用软化模型对其应力-应变关系进行描述。围压对混合土应力-应变关系有很大影响,在双对数坐标中,随试验围压的增大,初始切线模量呈线性趋势增长。
[Abstract]:Sand-clay mixed soil was prepared by mixing sand and clay with different dry weight, and undrained triaxial shear tests were carried out. The effects of sand content and test confining pressure on initial tangent modulus and stress-strain relationship of mixed soil were studied. The results show that when the sand content is less than 50, the initial tangent modulus of mixed soil has nothing to do with the sand content, and when the sand content is greater than 50%, the sand content is less than 80%. The initial tangent modulus increases linearly with the increase of sand content. The Duncan-Chang model is modified by introducing the sand content parameters into the initial tangent modulus. The modified model can describe the stress-strain relationship of mixed soil when the sand content is less than 80. When the sand content exceeds 80, the mixed soil shows strain softening type, and the initial tangent modulus keeps stable gradually with the increase of sand content. The peak strain of the stress-strain curve shifts to the left, and the stress-strain relationship can be described by the softening model. The confining pressure has a great influence on the stress-strain relationship of mixed soil, and in the double logarithmic coordinate, with the increase of the experimental confining pressure, The initial tangent modulus increases linearly.
【作者单位】：天津城大岩土工程技术有限公司;天津城建大学天津市软土特性与工程环境重点实验室;
【基金】：国家自然科学基金项目(51179186 41372291)资助
【分类号】：TU43

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