冻土旁压试验与单轴试验对比

为了认识冻土旁压试验结果与常规试验结果之间的关系,在室内分别开展了冻结重塑黏土的旁压试验和单轴压缩试验,并对试验结果进行了对比分析。结果表明,在各级荷载作用下旁压曲线一般都呈现应变速率衰减的趋势,而单轴曲线在冻土破坏时会出现渐进流动阶段。旁压试验的应力-应变曲线呈现应变硬化型,而且出现初始拟弹性阶段;而单轴试验的应力-应变曲线则属于应变软化型,并在轴向应变大约为10%时达到剪应力峰值。温度相同时,旁压试验的剪切强度以及初始弹性模量都要大于单轴试验,且温度越低差值越大。

Comparison Between Pressuremeter Test and Uniaxial Compression Test of Frozen Soil

In order to identify the relationship between pressuremeter tests and indoor tests , the pressuremeter tests and uniaxial tests were performed and the comparisons between the test results were analyzed .The results indicate that the pressuremeter creep curve presents a decaying form ;while a progressive flow stage appears in the uniaxial test once the frozen soil is broken .The stress‐strain curves of pressuremeter test manifest a strain‐hardening character with an initial quasi‐elastic stage ;while the uniaxial test shows a strain‐softening stress‐strain curve with peak strength at the axial strain of 10% . At the same temperature ,the shear strength as well as the initial deformation modulus of pressuremeter test are greater than those of uniaxial tests ; and the difference increases with the decreasing of temperature .