关键词: 爆炸挤淤, 结构性, 软土, 压缩变形, 软基处理

Abstract: The blasting-based squeezing and replacing method has been used to treat the soft clay in constructing the rockfill embankments in the reclamation projection in Xuanmen area, Zhejiang province. To obtain reliable soil parameters for the settlement prediction and stability analysis of embankments, in situ soils were sampled just before and after blasting operation in the range of foundations. Then oedometer consolidation and equipressure consolidation tests were performed. The compression and structural characteristics are preliminarily studied on the marine soft clays in the area. The results show that marine soft clays possess intrinsic structure, and behave differently from its disturbed counterpart. With introducing the concept of void index, the effect of soil structure is investigated, showing that the structure of soft clays is the intrinsic reason that the compression characteristics is very different between marine soft clay and its remolding counterpart; and the compression curves of undistributed soils and distributed soils merge into a single curve in the high pressure range. Blasting-based squeezing method can make marine soft clayey soils disturbed largely. And it influences significantly the physical and compression properties of clayey soils. Furthermore, the structural yielding stress and the structural strength are both reduced undergoing the disturbance effect. The defined structural destructive ratio can be used to quantify the degree of damage from blasting-based squeezing effect on the structure of the marine clayey soils. These results may be significant for developing the theoretical basis of blasting-based squeezing for treating the soft foundation of embankments.

Key words: squeezing silt by blasting, structure, soft soil, compression deformation, soft foundation treatment