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寒区工程建筑物的设计有时需要冻土抗拉强度指标。但是,十分遗憾,至今人们对冻土抗拉强度的研究做得不多。Haynes等(1975)用阿拉斯加费尔班克斯重塑粉砂研究了在-9.4℃下应变速度对容重较大的冻结试样抗拉强度的影响,发现在应变速度ε=10~(-2)s~(-1)时发生塑性—脆性破坏过渡。 本研究的目的旨在研究应变速度、温度及容重(或含水量)对饱和冻土抗拉强度的影响。为此,试验按如下三个系列进行:(1)试样容重和温度不变,改变变形速度(采用由5.9×10~(-5)—5.9×10~2cm/min 8种速度);(2)容重和变形速度不变,改变试验温度(采用-1、-2、-3、-5、-7及-10℃6种温度);(3)温度和变形速度不变,改变试样容重,即采用1.36—1.41(较高)、1.20—1.26(中等)及1.08—1.12g/cm~3(较低)三种容重范围。
Cold-area engineering building designs sometimes require frozen soil tensile strength indicators. However, it is very regrettable that so far people have done little research on the tensile strength of frozen soil. Haynes et al. (1975) used Alaska’s Fairbanks remodeling silt to study the effect of strain rate on the tensile strength of frozen specimens with larger bulk density at -9.4°C and found that the strain rate is ε=10~(-2). ) The plastic-brittle failure transition occurs at s~(-1). The purpose of this study was to investigate the effect of strain rate, temperature and bulk density (or water content) on the tensile strength of saturated frozen soil. To this end, the test is carried out in the following three series: (1) The bulk density and temperature of the sample are constant, and the deformation rate is changed (adopting 8 kinds of speed from 5.9×10 -5 -5.9×10 -2 cm/min); ( 2) The bulk density and deformation speed are unchanged, and the test temperature is changed (6 temperatures of -1, -2, -3, -5, -7, and -10 degrees Celsius are used); (3) The temperature and the deformation speed are unchanged, and the sample is changed. Bulk density, that is, using 1.36-1.41 (higher), 1.20-1.26 (medium) and 1.08-1.12g/cm~3 (lower) three kinds of bulk density range.