Soft Soil Improvement by Vertical Sand piles

点击翻译按钮获取中文摘要

Sand Drains(1)The range of soil permeability which yields the variation of partial drain behavior was found10^<-7>cm/sec k 10^<-4>cm/secwhen a clay deposit of about 25 meters thick is considered.(2)When soil permeability lies on this particular range the bigger the load intensity, the more the partial drain effect should be expected.(3)The efficiency of sand drains is to be observed in a limited range of soil permeability and under a particular magnitude of load intensity.2. Sand Compaction Piles(1)The bearing capacity of soft clay with vertical sand compaction piles is extremely influenced by the stiffness of applied load. When load application through a rigidfooting is considered fully drained/swelling conditions for sand piles provide biggerbearing capacity than undrained/no swelling conditions. On the other hand, whenflexible load application such as embankment loading is the case, undrained conditionsgive bigger bearing capacity than fully drained/swelling condition.(2)The increase of the undrained strength of clay due to displacement and consolidation by sand pile installation should be correctly evaluated when relatively low sand replacement ratio is considered.