非饱和冻土的强度分析

Analysis of Strength of Unsaturated Frozen Soil

冻土的强度是由土颗粒与冰的结合强度所决定 ,冰含量 (或初始含水量 )和干容重是非饱和冻土强度的主要影响因素 .干容重越大 ,土骨架能够承受荷载的有效面积越大 ,冻土的强度也越大 .同样干容重下的非饱和冻土 ,冰含量越多 ,冰与土颗粒的结合面积越大 ,承受的荷载能力增强 ,冻土的强度越大 .为此 ,提出冰饱和度的概念 ,建立了非饱和冻土强度与饱和冻土强度关系 ,它涵盖了干容重和冰含量的影响作用 ,揭示了非饱和冻土强度的机理 .通过试验验证 。

The strength of frozen soil depends on the join strength of soil particles and ice. Ice content or initial water content and dry density are the factors that control the strength of unsaturated frozen soil. The greater the dry density is, the greater the load bearing area of soil particles is, and the greater the strength of frozen soil will be. For a given dry density, the more the ice content is, the greater the strength of frozen soil is under unsaturated conditions. A new concept of the degree of ice saturation is suggested in the paper to explain the strength mechanism of unsaturated frozen soil. A strength prediction formula is put forward in this paper and verified by test data. The strength of unsaturated frozen soil is related with degree of ice saturated as shown in Eq. (10), which also can be expressed as a function of dry density and initial water content as shown in Eq. (11).