| The structure of piles foundation-trimmer beam-retaining wall is generally applied to high-steep slopes, severely eroded riverbanks, unstable and deep underlying-bedrock slopes. The structure not only can solve the problem of the lower bearing capacity of retaining wall foundation but also increase the stability of the slope. Though the structure is widely used, there are still some defects in the design theory that need further study.This dissertation is based on an engineering project—the highway from Ankang to Chongqing. Considering in situation of the slopes and the loads acting on the structure, the author analyzes the current design theory of the structure and proposes some suggestions on it. The main results and conclusions can be expressed as follows.(1) Classification of different loads acting on the structure is discussed. The calculating method of earth pressure and the thrusting force of landslide acting on the structure are discussed as well.(2)In the aspect of internal force of the pile foundation underpinning, some disadvantages do exist in the current calculation theory. So, taking the slope status and forces acting on piles into account, the author develops two new calculation modes: bearing pile foundation-trimmer beam-retaining wall structure and anti-slide pile foundation-trimmer beam-retaining wall structure.(3)In allusion to the double piles foundation-trimmer beam-retaining wall structure, "II" structure computation model is suggested and internal forces of the structure is computed in the structural mechanics methods.(4)Taking a slope in the highway from Ankang to Chongqing as prototype, the author used "FLAC3D" software to make a numerical simulation analysis of the pile foundation-trimmer beam-retaining wall structure. The result of the simulation shows that the two new calculations methods are reasonable and feasible. This design theory of pile foundation-trimmer beam-retaining wall is applied in the real engineering project. |
