Research And Controlling On Settlement Characteristic Of Bored Pile Based Tri-linear Strain- Softening Model

With the rapid economic development, China’s construction industry continues to move forward. Various functions and styles of buildings, such as high-speed rail,light rail, bridge, high-rise and mega projects are springing up on top of the vast land of China. Large numbers of these buildings which are coming was constantly challenge the existing level of technology. Engineering and technical personnel are asked for a higher technical requirements to response this phenomenon.In this case, A large number of foundation which to meet the form of various buildings continue to emerge. Bored pile which has a wide range of applications due to mechanized operations, mechanization and simple construction. Thus, it widespread use by engineering and technical personnel. However, the pile foundation will generally buried in the soil, and the pile of soil layer play a role together. Therefore, the pile foundation is often very complex mechanical properties. At the same time, in the construction process of pile foundation, it will be accompanied by sediment. when the sediment thickness exceeds a certain value, it has certain influence on the pile bearing capacity characteristics. Even it threatens to the safety of the building. Therefore, based on the need of engineering construction and continuous use, and the theoretical study of pile foundation is very important to do. This article is in this background to choose the defective pile with bottom sediment to research and analysis, in order to provide some guidance and help for the construction of the project.This article through to analysis and research on bearing behavior is based on the tri-linear strain- softening model of pile body and pile end.Mainly in the following three aspects of work: load-transfer method(1) In view of the defects pile with bottom sediment, computation in using load transfer method, considering the defects of pile under load a certain size, will produce a piercing damage. Lateral friction resistance of pile under vertical load, will be passing through a total of three stages which are the elastic,plastic and softening. Thus the pile lateral transfer function model using tri-linear strain- softening model; and on the occurrence of the pile bottom stick into the soil, using three linear softening function model, is very much in line with the actual situation.(2) Through laboratory simulation test of the pile tip penetration, expounds the designing and production process of foundation soil, groove model, test pile and pile bottom sediment. Through the collation and analysis of test data, describes the single pile’s settlement properties of under vertical load, and with different thickness of sediment of single pile that ettlement performance under vertical load. Through the date which the indoor simulation of pile tip penetration test to collation and fitting, obtained the parameters to the tri-linear strain- softening model of pile bottom, and introduced into the MATLAB software. Eventually,the obtained load-settlement curve are compared to the measured values to verify the rationality of the selected model.(3) Finally, this paper also have a comprehensive exposition to the bottom sediment formation causes, detection methods of sediment, the post-grouting reinforcement technology, and forming a comprehensive measures to control sediment defects in bored pile construction.