Analysis Of Bearing Properties Of Cast-in-place Bored Piles Based On A Project

In recent years,with the rapid development of domestic urban construction,more and more requirements have been placed on the design and construction of pile foundations in the project.There are many types of pile foundations,and the requirements for bearing capacity of single piles are also increasing.At the same time,with the popularization of overburden countermeasures,the situation of one column and one pile is increasing day by day.The problem that engineers need to consider urgently is how to significantly increase the pile-side resistance and pile-end resistance.In addition,in some areas such as the coast,due to the restrictions of groundwater and other factors,the conventional pile type and construction technology are limited in use,and new technologies and new processes that can apply underwater and underwater environments and various geological conditions are needed.Bottom-enlarged cast-in-place piles have unique advantages in solving the above problems.This article is based on a project in the southern suburbs of Beijing.On this site,four types of piles of mechanical bottom-enlarged piles,cast-in-place Piles with expanded branches and bells by 3-way extruding arms,AM Visible Screw-Drilled Under-Reamed cast-in-situ pile,and drill-diverging and clearing one-piece piles are used.The load bearing characteristics of the in-situ tests of these four types piles were analyzed.The main contents of the paper are as follows:(1)The load-settlement curves,pile tip bearing capacity,and axial force of pile shafts were studied in detail for a project with four types of bottom-enlarged cast-in-place test piles,and the bearing capacity of the four types of bottom-expanded piles was analyzed.By comparing the similarities and differences between the bearing capacity characteristics of the four types of piles,the reason for its occurrence was explored.(2)Using PLAXIS 3D finite element software to perform numerical simulations on four types of bottom-enlarged cast-in-place piles,comparing the data of in-situ test data to prove its rationality,and continue to load on single piles until their constructions to further study the expansion of loading characteristics of the bottom-enlarged cast-in-place piles,and the conclusions obtained agreed the in-situ test results.