论文部分内容阅读
冻土的抗压强度与抗剪强度是计算多年冻土区冻土地基的极限强度以及计算受外界荷载作用时冻土体稳定性的依据。为研究中国大兴安岭多年冻土区典型土样在负温条件下的力学性质,通过对大兴安岭多年冻土区典型土样在不同负温、不同含水率条件下进行抗压强度和抗剪强度试验,基于试验结果进行分析得到:冻结土体抗压强度随含水率的增加呈现出先增大后降低的变化规律,随着温度的下降而增大;冻结土体的粘聚力c和内摩擦角φ随着含水率的增加而减小,随着冻结温度的降低而增大;在相同负温条件下,大兴安岭多年冻土区低液限粉土的抗压强度与抗剪强度大于低液限粘土,低液限粉土单轴抗压强度在含水率为19%左右时达到最大,低液限粘土单轴抗压强度在含水率为22%左右时达到最大,且其二者的内摩擦角均小于25°。
The compressive strength and shear strength of frozen soil are the basis for calculating the ultimate strength of frozen soil foundation in permafrost region and calculating the stability of frozen soil under the action of external load. In order to study the mechanical properties of typical soil samples in the permafrost region of Daxing’an Mountains under negative temperature, the compressive strength and shear strength of typical soil samples in permafrost regions of Daxing’anling under different negative temperature and different moisture content were tested. Based on the experimental results, it is found that the compressive strength of frozen soil increases firstly and then decreases with the increase of water content, and increases with the decrease of temperature. The cohesion c and internal friction angle φ With the increase of moisture content, it decreases with the decrease of freezing temperature. Under the same negative temperature condition, the compressive strength and shear strength of low liquid limit silt in the permafrost region of Daxinganling are greater than those of low liquid limit clay , The uniaxial compressive strength of low liquid limit silt reached the maximum when the water content was about 19%, and the uniaxial compressive strength of low liquid limit clay reached the maximum when the water content was about 22%, and the internal friction angle Less than 25 °.