Mathematical Simulation Research On The Bearing Performance Of Socketed Pile

The socketed pile is an important foundation form of rock foundation in the mountainous region. After introducing the bearing mechanism, calculating method of ultimate tip resistance and ultimate side resistance, allowable bearing capacity calculation method and the displacement calculating theory of pile top, the author research the influence of the rock-socketed depth and ratio of depth to diameter on the bearing performance of the socketed pile by the mathematical simulation method with ANSYS finite elemens software. The obtained achievements are listed as follows.(1) The socketed pile should be designed to avoid four kinds of failure modes as the prerequisite, such as pile material yield, pure shear failure traffic piles-rock interface, and general shear failure of rock mass at the end of pile. Design elements include the designing pile strength, bearing capacity of pile and the pile top displacement calculating of three parts.(2) Socketed pile vertical bearing capacity from the pile top is undertaken by side resistance and tip resistance, and side resistance play a role before end resistance. In order to make the pile side and pile tip to the "equal safety", should be accurate calculation of ultimate side resistance and ultimate tip resistance on the basis of partial coefficient method to determining its allowable bearing capacity.(3) The ultimate side friction is the ultimate shear strength of piles-rock interface and embedded in the rock pile. Side Area of the product, Ultimate bearing capacity of pile tip is ultimate tip resistance and pile at the end of the product. Among them, the ultimate shear strength of piles-rock interface and ultimate tip resistance can be determined by the method of reduced rock block saturated uniaxial compression strength.(4) Greater depth within a certain range helps to improve the ultimate strength. But when rock-socketed depth reached a certain value, continue to increase the depth of the rock-socketed has small role in raising capacity, that is, under certain conditions exist the best rock-socketed depth.(5) The relationship between different diameter and pile side friction depends on the increasing Side Area to increase the value of side friction, whether or not sufficient to make up for the side friction due to decreasing resistance coefficient calculated to reduce the side friction value. Thus, blindly raising diameter of pile to increase the ultimate strength is not necessarily applicable.(6) Methods of finite element analysis of ANSYS software using simulation socketed pile bearing behavior is an economical and reliable, simple and practical method of calculation, not only to better reflect the load transfer law between pile-soil-rock , and mathematical simulation results is corresponding to standards calculated and static test, thus ensure the credibility of the research results and accuracy.The paper is a useful attempt on researching socketed pile load-transfering mechanism and bearing behavior. And there are important theoretical and practical significance for improving the socketed pile designing theory and method and guiding the design and construction of socketed pile.