Construction Of Rock Socketed Pile And Large Tonnage On Reclaimed Foundation Static Load Test Research

This paper combined with practical engineering research on beach recently deep backfill pile foundation construction and bearing capacity problem.The project includes cinema artificial island and Vitoria bay 2 projects,all using the impact of rock socketed piles into the hole.The ground by sea reclamation formed by the original soil,foundation soil and backfill soil is composed of two parts,and the recent deep backfill backfill,some under consolidation problem,easy to produce the uneven settlement and negative friction.The complexity of the foundation causes difficulties in construction.How to overcome the unfavorable geological conditions of the site and select the appropriate filling pile construction technology,how to obtain the bearing capacity of the large tonnage bearing pile,is the key problem of the project.The main work and research results are as follows:1.Deep gravelly strata and reclamation reclamation reclamation soil by slurry wall bored pile(grouting)technology is suitable;through the test to prove the feasibility of pile technique;construction area prior to foundation treatment(such as the use of vacuum preloading method etc.);to ensure the construction quality of silt,silt layer to be used,through the mud layer steel tube protection measures;2.The maximum Tonnage Static Load Test(maximum loading 20000kN)was carried out in this area.Based on the results of pile testing,Artificial Island reclamation field consists of mud bag and non mud bag two kinds of formation structure,current pile testing results have been covered by the mud bag structure and stratum broken unfavorable situation with exist at the same time,meet the requirements of bearing capacity.In the static load test,the loading is increased on the basis of the bearing capacity of the design,most of which exceed the control value of the design strength of the concrete of the pile body,indicating the bearing potential of the pile under the engineering condition;3.About the problem of negative friction,according to the static load analysis of pile testing results,the artificial island area deep filling pile construction project is completed,when there is no two time backfill,but does not consider the negative friction;when there are two backfill,side pile due consideration of negative friction pile,the middle part does not consider the negative friction fill the positive friction is not considered.Siltite cinema artificial island project bearing layer with good integrity,mainly provided by the rock bearing capacity of pile foundation,and backfill formation by dynamic compaction,the positive and negative friction are not considered,therefore,as long as the control of embedment depth,sediment thickness,pile for the three main factors that have high guarantee rate of bearing capacity.