Study On Bearing Characteristics Of Pile In Soft Rock Foundation With Frame Wharf In Inland River

Because of the complexity of the mountain geological conditions, the interaction of piles and soil problems become the key and difficult point for wharf structure in the region. Soft rock is mainly the supporting layer for pile of wharf. The existing hard rock construction technology and construction, the design specification cannot be used in soft rock. This article is based on " twelfth five-year " national science and technololy suport plan project which named " Study on key technique of wharfs construction in canalized reach in mountain rivers "(2012 BAB05B04). Through the mudstone-concrete shear test results, it corrected the shear stress degeneration constitutive model on contact interface, and it researched on simplified calculation method for single pile socketed in soft rock, it established an single pile socketed in soft rock model under vertical load by large-scale finite element analysis software which is named ABAQUS based on the model. The main reserch word and achievements are as follows:(1)Study on the basic physical and mechanical test and the contact interface of the soft rock and concrete on soft rock under natural and saturated state.Based on some engineering example, this experiment choose the contact interface of the soft rock and concrete as object. Through collect the weathered mudstone specimen, we do the basic physical and mechanical test and the contact interface of the soft rock and concrete on soft rock under natural and saturated state.(2)Study on the shear stress degeneration constitutive model. Based on the shear stress degeneration constitutive model on contact interface, fitting to sort out the data, and do normalized processing for shear test data. In addition, we can get the relation of shear stress-shear displacement curve and normal stress on the contact interface of the soft rock and concrete.(3)Study on simplified calculation method for single pile socketed in soft rock. Based on the shear stress degeneration constitutive model, this article researches on simplified calculation method for single pile socketed in soft rock. And on the basis of engineering tests in situ observation, demonstrating the correctness and pratication of the theory. In addition, it provide certain reference in dishing for whole settlement and mechanical properties of piles socketed in soft rock under vertical load.(4)According to the typical wharf’s sectionals drawing, it established an single pile socketed in soft rock model under vertical load by large-scale finite element analysis software which is named ABAQUS. piles used the linear elastic model, soft rocl used M-C elastic-plastic model, the interface tangential stress strain relations follow the shear stress degeneration constitutive model. It analyzed the expansion of the rock-socketed pile side friction slip and shear mechanism, and compared the deformation characteristics and failure process of the soil, soft rock and hard rock by analyzing the results of numerical calculation. It also analysis the influence of strength parameters such as elastic modulus, cohesive force and internal friction Angle the depth of rock-socketed pile and the depth of rock-socketed pile to caring capacity and caring the influence law of socketed pile.