含水率及应变速率对冻结粉质黏土强度特性影响-《郑州大学学报(工学版)》

文章信息/Info

Title:: Effect of Water Content and Strain Rate on the Strength Characteristics of Frozen Silty Clay

Author(s):: Zhang Yaqin 1; Yang Ping 1; Jiang Wangyang 1; Zhang Ting 1; Chen Liang 2; 1. School of Civil Engineering, Nanjing Forestry University; 2. Changzhou Rail Transit Co., Ltd.

Keywords:: Artificially frozen silty clay; moisture content; loading rate; strength properties; modulus of resilience

摘要:: 人工冻土单轴抗压强度和弹性模量是人工冻结法设计的关键参数，准确掌握其变化规律极为重要，为此开展了不同含水率及应变速率条件下,粉质黏土人工冻土单轴抗压强度试验研究。结果表明：大部分试样呈现腰鼓型破坏，随着含水率的增加，应力-应变曲线逐渐由应力软化型向应力硬化型转变。存在一达到强度峰值的最优含水率，对于南京典型粉质黏土该含水率为22%，接近饱和含水率；重塑粉质黏土的弹性模量随含水率的增长而增长，但增长率呈下降趋势；单轴抗压强度和弹性模量均随应变速率的增加而呈衰减性增大；回弹模量随加卸荷次数的增加逐渐增大，当加卸荷次数达7次后，回弹模量值基本稳定。

Abstract:: Artificial frozen soil uniaxial compressive strength and elastic modulus is the key parameters of artificial freezing method design, accurate understanding of the change rule is extremely important.So the experimental study on uniaxial compression strength of artificial frozen soil with silty clay was carried out under the conditions of different water content and strain rate. The results show that most samples showed drum type failure, with the increase of water content, the stress-strain curve gradually change from stress softening to stress hardening. There is an optimum moisture content to peak strength, for Nanjing typical silty clay the moisture content is 22%, close to saturation moisture content; elastic modulus of remolded silty clay increased with water content increasing, but the growth rate declined; the uniaxial compressive strength and elastic modulus decrease with increasing strain rate; The resilient modulus increases gradually with the increase of loading and unloading times, when loading and unloading times up to 7 times, the resilient modulus is basically stable. The stress - strain curve of the remolded soil specimen is more smooth than the original soil sample, and the compressive strength and modulus of elasticity are improved.