考虑水化状态影响的膨胀土强度特性

Strength characteristics of expansive soil considering effect of hydrous state

从膨胀土水化作用时间和温度两个影响因素出发,在室内研究了膨胀土的膨胀变形特性与强度特性。结果表明,膨胀土饱和后还会经历相当长的膨胀过程,这就使得土体的饱和强度随水化作用时间的延长而逐渐降低;膨胀土在膨胀过程中,温度越高,土体的膨胀速率越大,土体最终的膨胀率也越大,土体的饱和强度随水化作用温度的升高而逐渐降低。饱和膨胀土的抗剪强度指标宜考虑水化作用时间和温度的影响,采用变动强度公式更为合适。

Considering two effects of hydration time and temperature, the swelling deformation and strength characteristics of expansive soil are studied through the laboratory test. The results show that the swelling process of expansive soil after saturation could even still continue for quite a long time, which makes the strength of saturated soil gradually reduced with the extended hydration time. Moreover, during the swelling process of expansive soil, the higher the hydration temperature is, the greater the swelling rate and ultimate swelling ratio are, which results in the strength of saturated soil gradually decreasing with the increasing of hydration temperature. Therefore, the shear strength parameters of saturated expansive soil should consider the effects of hydration time and temperature; and a more suitable formula for expressing the variable shear strength is proposed.