| Rock-socketed pile is a special pile that is extensively applied in mountainous areas. As its high bearing capacity, small settlement and weak interactional effect, it is suitable for heavily loaded construction, such as high-rise building or large span bridge. Although rock-socketed pile has been used for many years in practice, some problems about the bearing capacity and related mechanism still need more research. In the point of historical view, the bearing capacity of rock-socketed pile is considered mainly being related to the underlying rock of the pile bottom. In the 1970s and 1980s, many scholars realized that the large portion of the capacity of the rock-socketed pile is from the pile shaft resistance. Through a great deal of site tests and laboratory tests, it has been gradually found that the shaft resistance is the important counteracting force to carry on the applied load outside and should not be ignored.In this thesis, differences between the rock-socketed pile and non-rock-socketed pile are discussed firstly. Then the mechanism in the interface of the pile shaft and around rock has been analyzed. The effect of pile hole side roughness upon the shaft resistance and the major influence factors on pile side roughness are analyzed in detail.According to the behavior of the rock-socketed pile and the characteristics of Chongqing, the numerical analyses have been done by the ANSYS finite element method software and axis symmetrical two-dimensional model. The distributions of shaft resistance along the pile shaft of different depths, effects of rock strength on shaft resistance and effects of the pile bottom sediment on pile bearing behavior are researched. The effects of the pile hole side roughness on shaft resistance are also simulated.Major influence factors on the shaft resistance are studied by the orthogonal experiments. It is found that the around rock strength is the most import factor and the functional relationship between the unit shaft resistance and rock uniaxial compressive strength is obtained. |
