蠕变条件下吹填软土结构强度形成研究

A study of the formation of structure yield stress subject to creep of the soft dredger fill

土体的结构性对土的工程力学性质具有决定性的影响。本文以天津滨海吹填软土为土质材料,进行了蠕变作用下土体结构屈服应力形成试验及相应的微观结构分析。试验结果表明:蠕变对土体结构性的影响是一个综合作用的过程,其中排水条件最为关键,在此基础上,围压及偏压都对土体结构屈服应力的增长起作用,并随时间的增长而增长。反之,土体的结构屈服应力变化不大。微观结构分析表明,小偏应力蠕变作用下结构屈服应力的形成实质是其微观结构逐渐稳定的过程。

Soil structure has a significant influence on its engineering mechanics behavior.To investigate the form of structure yield stress of the soils,the creep tests and micro-structure are conducted on the soft dredger fill in the Tianjin Binhai New Area.The results indicate that the influence of the creep on the soil structure is a comprehensive process,among them,drainage is the most critical condition.Base on this,the structure yield stress are effected by the cell pressure and deviator pressure,increasing with time.Conversely,no obvious variations occur in the structure yield stress of the soils.Through micro-structure analysis,it is known that the essence of the form of structure yield stress by creep of small deviation stress is the gradual stability procession of micro-structure.