The Numerical Analysis And Experimental Study On Mechanical Properties And Settlement Characteristics Of Rammed Piles With Composite Bearing Base

Composite carrier rammed pile has been referred to the carrier pile.Compared with the general type of foundation construction process,it has a big advantage in terms of technology and economic efficiency and it is also widely used in the Central Plains region.Because of a series of problems arised in the design,construction and application,the application has decreased in recent years.Yet the research of composite carrier rammed pile focused on engineering practice measured empirical estimates,there has been lack of systematic research of its carrying capacity,even there is simulation study in this part,the model also are relatively simple,the practicability is not strong.So,a system of experimental research and analysis of the composite carrier rammed pile,not only can improve the design theory,but also can be combined with regional experience as a reference for engineering applications,provide a theoretical basis for its wide range of applications and create economic benefits.Firstly,for the Weiming Da Energy Technology production base of Zhengzhou,Henan,we choose some representative of composite carrier rammed piles to take single pile static load test and the analysis of pile bearing and settlement characteristics.Then,starting from the actual project,we use the ABAQUS finite element software to simulate calculation and analysis pile bearing capacity,and the results were compared with the field test to prove the feasibility of the model.At last,by changing the pile length,carrier diameter size and other factors,establishing a series model of the composite carrier rammed pile,analysis and determine the optimal selection as guidance for engineering practice.we draw the following conclusions in this article:(1)The results obtained through the field tests:Due to the Exist of the pile carrier,the bearing capacity of the composite carrier rammed pile under the same conditions can increase 50%to 200%,and can effectively limit the damage of the pile body piercing,with good economic and technical benefits;Different soil under the pile has a great influence on the settlement of the pile,the holding force characteristics of the soil are the main factors which influence the settlement;As the construction control and compaction technology of carrier has a direct relationship with the carrying capacity of the composite carrier rammed pile,construction quality must be strictly controlled.(2)The results obtained through numerical analysis:It validated the pile end bearing characteristics of composite carrier rammed pile.In the design of short composite carrier rammed pile bearing capacity,the side friction can be ignored.But when the pile length is greater than 10m,we propose to put the lateral friction reduction into the design of bearing capacity.Comprehensive consideration design and construction factors,when the carrier is about 1000mm in diameter,can effectively improve the bearing capacity and relatively economical,we recommend to applicate.