冻土原位旁压蠕变试验粘弹性模型分析  

Viscoelastic Model Analysis of In-situ Pressuremter Creep Test in Permafrost

作　　者：张虎[1] 张建明[1] 苏凯[1] 刘世伟[1] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所,兰州730000

出　　处：《土木建筑与环境工程》2013年第6期22-27,39,共7页Journal of Civil,Architectural & Environment Engineering

基　　金：国家自然科学基金(40971045);冻土工程国家重点实验室自主研究课题(SKLFSE-ZY-02-6)

摘　　要：研究高温高含冰量冻土的蠕变特性,采用Menard旁压仪在青藏高原多年冻土区开展了大量的旁压蠕变试验,利用Merchant粘弹性模型对蠕变曲线进行回归分析并得到模型参数。结果表明,温度对高温冻土力学性质的影响要大于含水量。随着压力的增加,每级压力下冻土的瞬时应变在总应变中所占的比例逐渐减小。回归分析发现,瞬时剪切模量与负温的绝对值呈线性关系,而延迟剪切模量和粘滞系数与负温的绝对值之间为幂函数关系;当冻土的含水量达到46%时,各参数均出现峰值,而后缓慢减小,此结果与低温冻土有所差别。In order to investigate the creep behavior of warm and ice-rich frozen soils, a number of pressuremeter tests were carried out in permafrost regions on the Qinghai-Tibetan Plateau with Menard pressuremeter. Then, the regression analysis results of the creep curves generated by Merchant model and relevant parameters were obtained. The test results indicate that the temperature plays a more important role than the water content in affecting the mechanical behavior of warm frozen soils. As pressure increases, the proportion of instantaneous strain in the total strain under each pressure decreases gradually. The regression results show that the instantaneous shear modulus increases linearly with decreasing temperature, but the delayed shear modulus as well as the viscous coefficient present a power function trend. Their peak values appear at the water content of 46%, which is rather different from the test result on lower temperature frozen soils.

关 键 词：青藏高原 高温-高含冰量冻土 旁压仪 粘弹性 

分 类 号：TU413.3[建筑科学—岩土工程]