Experimental Study On Optimization Design Of Air Booster Vacuum Preloading For Dredger Fill

Into the 20th Century,vacuum preloading became a mature technology.It replaced traditional surcharge preloading method and become the most convenient and economical foundation treatment technology.But at the same time,the shortcomings of vacuum preloading are also emerging,especially the problems such as insufficient reinforcement of deep soil.In recent years,researchers use air booster vacuum preloading method originate from pneumatic fracturing and blasting pressure technologies to reinforce the dredger fill.The method has simple construction operations and its consolidation effect for dredger fill is better than traditional vacuum preloading method.This method can effectively relieve the clogging of prefabricated vertical drainage(PVD).Besides,it can further prompt the consolidation degree of soil in the late stage of vacuum preloading.At present,there is less research on the air booster vacuum preloading method.The conceptions of booster position,booster pipe type,booster time and booster occasion all are dark.This paper takes the dredger fill of Wenzhou,Zhejiang province as research object to study these uncertain parameters by laboratory test.Using the parameters obtained from the study to achieve cost saving,improve the effect of treatment of soil as the goal.The experimental results show that the bottom air booster vacuum preloading can obtain more uniform soil strength than the vertical air booster vacuum preloading;the material of the booster tube has little influence on the effect of the soil reinforcement;the activation of booster system can greatly prompted the effect of soil consolidation when the soil consolidation degree is 40%;in addition,it can also obtained that the optimum booster time of 1.5 hours is best for soil treatment compare with other booster time.Experimental result of these parameters can help increase practice foundation treatment effect and reducing the cost.