Research On The Reliability Of The Static-pressed Pipe Pile’s Beairng Capacity In Shenyang Area

An important branch of reliability of geotechnical engineering is the reliability study of pilefoundation.In our country，scientists have begun to study pile foundation reliability since the endof eighty decade, the research work has been very active and acquire many productions.But for along time, we are in the habit of using the fixed value method to design the pile foundation, thatis in accordance with the experience to determine the safety factor, thereby measuring thereliability of the structure. In this method，many variables and their characteristics which willreflect the real surrouding around the structure are not introduced into. So there are manyshortcomings they can not overcome of their own. In order to enable the project design morescientific and reasonable, and reflect the nature of the problem better, the effection of variable isintroduced and the target reliability is used to reflect the structural safety. While the current codefor pile foundation in the design is also from the fixed value method to approximate probabilitymethod of phase transition, so we must have a large number of system statistics.Just because of this，based on the work of other people and sixty-six test datas of the staticpressure pipe pile in Shenyang area, the transfer from the current deterministic design to the limitstate has been studied and the target reliability and the partial factors has been provided, the mainworks we did are in the following. A few beneficial exploration of the reliability analysis ofbearing capacity is made.Firstly, statisties is analyzed. Studied on the calculation model of ultimate bearing capacityand the limit state equations of the static pressure pipe pile, by using the method of combiningthe static loading test method and empirical formula method,deriving the variable statisticalcharacteristics of the limit state equation of the static pressure pipe pile bearing capacity, andcalculate their respective statistical parameters.Second, calculating the reliable index. Establishing the limit state equation of single pilereliability analysis of the static pressure pipe pile,and reliable index is calculated with the JCmethod.Thirdly, analyzing the main factors who influence the reliability index of the static pressurepipe pile. The influence of the total safety coefficient,load effect ratio and load combination onthe reliability indexes are discussed.Finally, researching partial factors. The target reliability index of ultimate bearing capacityof single pile of the static pressure pile is determinated, and the the corresponding optimalresistance partial coefficient is analyzed and identified.