The Load Bearing Characteristic of the CFG Pile Composite Foundation under Large Oil Tan in Saturated Loess Ground Treatment
|School||Lanzhou Jiaotong University|
|Keywords||Saturated loess CFG pile composite foundation Large oil tank Preloading filling test Mechanical traits ADINA|
Western crude oil pipeline project is the beginning of the twenty-first century in western China following the implementation of the \In this paper, one of its key projects Lanzhou crude oil station at the end of the 15 × 10 ~ 4m to large oil tank as engineering background, saturated loess foundation for the study Saturated Loess Ground CFG pile composite foundation technology practice of the engineering analysis and theoretical studies. Paper first briefly introduced the saturated loess as well as the large oil tank foundation treatment technology and the development of profiles, recalled one of the composite foundation of CFG pile composite foundation and a large tank filled with water preload test the status quo, and referred to the CFG pile in loess reinforcement mechanism. Followed by a detailed analysis of relying on the engineering geological conditions, according to the conventional method of analysis and calculation to determine the CFG pile composite foundation construction technology and design parameters such as: pile length, pile diameter, pile spacing, and pile layout; conduct on-site pilot study, by - situ testing, laboratory and low strain detection means a comprehensive analysis of the evaluation of CFG Pile quality and reinforcement effects. CFG pile composite foundation treatment results verify the feasibility and effectiveness of large oil tank saturated loess foundation. Field measurement data, and analyzed again to study a large tank filled with water loads edge of the ring wall deformation and settlement of CFG pile composite foundation deformation, pore water pressure, pile-soil stress distribution law. The results showed that exist at the bottom of the storage tanks uneven settlement, and the position of the center of the bottom of the tank earth pressure the ring wall below the soil pressure, followed by the center of the bottom of the tank to the smallest parts of the earth pressure between the edge of the ring wall, the distribution form the circular tank flexible basis for uniform load different. Because the saturated loess layer below for the good permeability gravel layer, it can speed up outside the Netherlands due to the dissipation of pore pressure and pore water pressure varies, but in the preloading filling process changed slightly. As we all know, CFG pile composite foundation bearing traits of many factors, such as: load level, cushion material, the thickness of the replacement rate, length of the pile and the pile modulus; cushion technology is the core of the CFG pile composite foundation technology, set of cushion can be adjusted to soil stress ratio to achieve pile soil shared the upper load. Finally, based on the finite element (ADINA) depth study of CFG pile composite foundation mechanical traits of the different design parameters and load transfer law. The results show that: the influencing factors have a greater impact; additional stress distribution of CFG pile and pile friction distribution of composite foundation pile-soil stress ratio with the different changes in the relationship between the influencing factors. With the expansion of the scope of construction, the majority of loess area will usher in a new construction boom. Loess, particularly saturated loess foundation treatment technology will be a very important issue, and will have broad application prospects in the construction, and actively explore the subject, will make a positive contribution for the engineering construction.