围压对冻结粉土动力特性的影响

The Salt Heave of Sulphate Salty Soil Under Different Cooling Rates

通过恒应变速率控制下等应变幅三轴动强度试验，对不同围压下的冻结粉土的应力－应变关系、动强度、破坏时间和破坏振次以及退荷回弹动弹模的讨论，认为围压效应有增强效应（提高动强度）和减强效应（降低动强度）两部分合成。在低围压时，围压效应中增强效应占主导，动强度随围压增加而提高；围压达到一定值之后，减强效应起主导作用，动强度随围压增加而下降。导致这一特点的主要机理是，围压作用下冰点下降引起冻土的未冻水含量增大和基本强度下降及两者交互作用的结果。强度偏离摩尔－库仑直线的差值恰与未冻水含量增值、基本强度降值两者之乘积成正比。

The cooling rate has a great effect on the salt heave of sulphate salty soils, with decrease of cooling rate, the salt heave increase in the following power series form, η= AV T -B In the tested range A and B increase with increase of salt content and decrease with increase of density