Research On Bearing Capacity And Testing Technology Of Large Diameter Bored

The engineering practice shows that with the increasing number of layers of super-tall buildings,the single-pile load of the building is getting larger,so the requirements for the bearing capacity of the single pile are getting higher and the static load test of large tonnage is also increased.In the aspect of bearing capacity detection of large-diameter bored piles,there is not much local experience in large-tonnage static load test in Anhui area Therefore,it is necessary to carry out relevant research work.This project will rely on a bank office building project in Maanshan(designed single pile ultimate bearing capacity not less than 9000kN)and a 518 m super high-rise pile foundation testing project in Binhu New District of Hefei City(designed single pile ultimate bearing capacity not less than 33000kN)In-depth research work on large-diameter borehole bearing capacity and testing technology.The main research findings are as follows:(1)Summarize the previous research results of the theory of pile-soil load transfer mechanism,analyzes the limit state of piles and the limit value factors affecting the vertical compressive bearing capacity of single piles in actual engineering,and studies the bearing capacity of large-diameter bored piles.(2)Analyze the load transfer mechanism of the self-balancing static load test,study the difference between the self-balancing static load test and the traditional static load test load transfer mechanism,and verify the data equivalent conversion method and test criteria in the self-balancing static load test.(3)For the super-large tonnage self-balanced static load test,the research on the pre-embedded load box plus compensation load method was carried out.The process method of designing,installing and embedding the super-tonnage load box is proposed to meet the actual engineering needs of the super-tonnage load box.(4)In-depth analysis of the performance and mechanism of the side pile resistance and pile end resistance during the large tonnage static load test.For the large-diameter bored pile with rock-socketed shape,the influence of the rock-socketed depth on the lateral resistance of the rock-socketed pile is studied...