Influence of Drainage Method on Improvement Effect of Dynamic Compaction for Saturated Silt
Saturated silt is a semi permeable soil between sand and clay.During dynamic compaction reinforcement,auxiliary drainage measures are usually needed to improve the treatment effect.There are mainly two drainage methods:plastic drainage boards and vacuum drainage.Therefore,it is necessary to pay attention to the impact of different drainage measures on the reinforcement effect of dynamic compaction.A certain project is located at a seaside aquaculture farm.The upper part of the original foundation is 3～5m thick saturated silt,with low bearing capacity and liquefiability.At the same time,the original ground level is high and low,and weathered mountain soil is used for backfilling.Therefore,the depth of foundation treatment includes the above two layers of soil,but the backfill soil has low moisture content and relatively better properties.The focus of foundation treatment is on the saturated silt layer.Different functional areas were tested by different units using the dynamic compaction method combined with vacuum drainage,plastic drainage board,and horizontal drainage cushion layer.The changes in drainage and dynamic compaction construction parameters,construction settlement,physical and mechanical indicators of the silt layer before and after reinforcement,and in-situ test indicators were compared through two methods.The results showed that the dynamic compaction combined with vacuum drainage method did not set a horizontal drainage cushion layer on the backfill soil,resulting in greater construction settlement and more significant improvement in the physical and mechanical indicators and in-situ test indicators of the silt;The method of dynamic compaction combined with plastic drainage board sets a horizontal drainage cushion layer on the backfill soil.The fine particle soil in the backfill soil is soaked and softened by the water discharged by the plastic drainage board,while increasing the water head height inside the plastic drainage board,which affects the drainage consolidation effect.
NETL
NSTL
万方数据
