Research On Peneration Resistance And Capacity Mechanism Of Jacked Pipe Pile Based On Real-time Monitoring Data

The jacked pile is more used in pile foundation engineering.Static pressing is a process of continuous soil squeezing and replacement.The pile of static pressure is mostly a hollow pipe pile,so the crowding effect and soil will appear in the process.Therefore,the study of jacked pile lacks the support of field experiments.This dissertation mainly deals with installation.characteristics and bearing mechanism in the process of jacked pile.Firstly,the method of static analysis and the Terzaghi bearing capacity formula were used to explain the development of the soil plug.Based On the Mohr-Coulomb principle,the solutions of cavity expansion theory are derived.It is found that the displacement is about 0.1-0.2 times and the range of squeezing effect is 2-4 times of pile diameter.Due to the development law,a formula for estimating the pile-sinking resistance is derived.At the same time,the relations hip between pile-sinking resistance and bearing capacity of pile foundation is judged by combining the field data.Secondly,ABAQUS is used to prove the development of soil plug,and the difference between.jacked pile and closing pile has been found.The transformation relationship between pile bearing capacity and pile sinking resistance is verified by the dead load experimental.When the pile spacing is 3 times of the pile dimeter the stress increase is about 7%.Due to the influence of compaction effect,the pile-sinking resistance will become larger.Finally,the whole process of static pressure pile was monitored in real time which verified the reliability of the calculation formula of the limit height of soil plug.The reliability of the calculation formula of the soil plug limit height is verified by on-site measurement.The improved conversion formula,was proved by dead load experrimental.With the help of the static cone penetration test and the immediate measurement results of sensors,it is found that the crowding effect on pile sedimentation resistance during pile construction increases by about 18%.The achievements in this dissertation can be valuable references for the design and construction of jacked pile.