Research On Load-Bearing Capacity Of Super-Long Group Pile Foundation Of Tianxingzhou Bridge

In recent years, it’s noticed that the load-bearing mechanism of super-long pile is different from the ordinary load-bearing mechanism of short pile in academic and engineering circles. In practical projects, according to the current rules and regulations of ordinary standards of short pile, the super-long pile design and construction has a great diffenence with the actual observations. There are many unreasonable things in the design and construction such as the comfirmation of load-bearing capacity and the selection of supporting layer. Otherwise, the calculation value of super-long pile settlement according to the standard method is far greater than the measured value. Thus, according to the current rules and regulations of ordinary standards, the design of super-long pile is not complete and unreasonable. In the thesis, according to the actual engineering of Tianxingzhou Bridge, some theoretical research on foundation of the super-long pile is done. The followings are the main work that is done in this thesis.(1) Analysis on single pile bearing capacity mechanism and the load transfer mechanism of super-long pile are done seperately. Relying on the super-long pile foundation of Tianxingzhou Bridge, through numerical simulation methods such as theoretical analysis and finite element calculation analysis, the analysis of load-bearing mechanism of super-long pile is done;(2) the pile body stress monitor is done by choosing the super-long pile foundation of Tianxingzhou Bridge as a representative to verify the calculated results of single super-long pile theoretical analysis model and the numerical calculated results;(3) Under the premise of achieving accurate and effective load-bearing mechanism of single pile, through theoretical analysis and model tests, the comparative research is done between super-long group piles and ordinary group piles, espically the differences of mechanical properties between the super-long group piles and ordinary group piles;(4) The mechanical properties research results of the super-long group piles are used in analyzing the tapical super-long pile foundation of Tianxingzhou Bridge. Then comparisons are made among the design results and the monitoring results in order to assessing the rationality of the design of pile foundation;(5) Finally, some conculsions are drawn by making comparison among all the results.