Time-Dependent Reliability Assessment Of The Overhead Wharf Pile Body In Rivers With Huge Water Fluctuation Under Ship Impact Load

In the structure design reference period, ship collision, current force, pile of goods load are time-dependent parameters of stochastic processes,structure of the resistance is also gradually decay with time.Wharf structure reliability analysis usually not consider load and resistance time-varying. By conducting research on structure component capacity time-dependent reliability assessment of the overhead wharf structure in design reference period, provide real-time forecast and scientific theory for wharf structure time-varying reliability and security use.In this paper, according to the during operation characteristics of the environment overhead-erection wharf structure,based on random process theory,consider water level fluctuation change over time, berthing ship type and number of randomness impact occurred,established ship collision as the leading variable role of the time-varying load model,basic parameters time change regularity and statistical characteristic introducing to the pile body resistance calculation formula,and then the model of resistance degradation of pile body were built. Application of reliability theory, carried on bearing capacity of pile body assessment and put forward the pile foundation time-varying reliable index distribution coefficient expression. Consider the influence of time-varying load to pile body crack width, reference monte-carlo method thoughts, calculated probability upper limit value of pile body crack width change over time; Combined with the engineering practice, preliminary exploration time-dependent reliability assessment of the overhead wharf pile body in rivers with huge water fluctuation analysis and calculating methods, the following conclusions were obtained:â‘ Time-dependent reliability assessment of the overhead wharf structure in design reference period should consider load and resistance dynamicity.â‘¡Application discrete fourier transform related theory to variables fitting,can solute the load effect and time fitting problem perfectly.â‘¢Through the each time reliability index results can be seen that along with the growth of wharf structure using time,bearing capacity of pile body section reliability indexes gradually decreased. The change rule are different because of the differences resistance deterioration model and load increasing trend.The method to calculation distribution coefficient expression of time-dependent reliability index in this paper can realize the estimation of reliability index and convenient for engineering application.â‘£Crack width time-varying probability analysis, provides the basis for real-time monitoring of pile body crack.