在室内试验的基础上,对不同含水量和干密度的粘性土试样进行了不同环境温度下的直剪试验,获得了南京地区非饱和下蜀土重塑土抗剪强度与温度的关系。试验结果表明:温度对粘性土的抗剪强度有比较复杂的影响。当含水量大于约18%时,土的抗剪强度随着温度的升高而降低,表现出强度的热软化现象;而当含水量等于或低于18%时,土的抗剪强度在干密度等于1.67g·cm^-3时,几乎不受温度影响,而当干密度小于1.67g·cm^-3时,土的抗剪强度随着温度的升高而增加,呈现出强度的热固结现象。与此同时,还对土的热固结和热软化现象的机理进行了分析。
In order to assess the urban heat island effect on the engineering properties of clayey soil, some laboratory tests have been done on moisture contents and dry densities of the clayey soil under different environmental temperatures, and some thermodynamic characteristics of clayey soil are revealed. The research results indicate that the temperature has complicated influence on the shear strength of clayey soil. When the moisture content of soil is more than 18 %, the shear strength of soil decreases with the increasing temperature, showing the thermal softening on strength; When the moisture content is less than 18 % and dry density is 1.67 g·cm^-3, the temperature hardly affects the soil strength; However when the dry density is less than 1.67 g·cm^-3, the soil strength increases with the temperature rising, showing the thermal hardening on strength. Finally, the mechanisms of the thermal softening and hardening of soil are analyzed.