Reliability Analysis Of Foundation Pile Under Vertical Load

With the rapid development of economy in our country, more and more high-rise buildings and Bridges and other large-scale civil engineering was build, pile foundation because it has high bearing capacity, easy construction, and the advantages of small settlement, form the basis of being more and more used in engineering.The existence of such factors as the construction, the variability of soil in pile foundation engineering, so need to pay attention to the safety and reliability of pile foundation engineering.In this paper, the reliability analysis of pile under vertical load as an example,the main research results and conclusions are as follows.Respectively using analytic method (virtual soil-pile method) and numerical simulation method of pile under the vertical load to solve the load-settlement curve (Q S curve).In the numerical simulation method, focuses on the establishment of the numerical model, the establishment of the contact surface, loading method and the results of numerical simulation of processing, etc.Localized parameters as random variables, under the action of the vertical load of pile respectively based on the analytic method (virtual soil-pile method) and numerical simulation method for the reliability analysis.Reliability analysis methods are based on the random Hermite polynomial response surface method.Analyzes the number of sample points and random Hermite polynomial order effect on the fitting precision;Pile length, pile diameter, the soil parameters variation coefficient and other factors that affect the reliability of the pile; Analytical method and numerical method in pile the similarities and differences in the process of reliability analysis.Research shows that:the number of sample points and random polynomial order has a great influence on the precision of fitting;Pile length, pile diameter and soil parameters variation coefficient of pile reliability analysis also has a great influence;Modified parameters and strength parameters all have influence on the reliability analysis of pile.Considering the spatial variation of parameters of soils is in vestigated, localized parameters as related to logarithmic normal distribution random field, under the action of the vertical load of the pile in the reliability analysis.Studied the Karhunen-Loeve series expansion method in discrete two-dimensional and three-dimensional random field problems, the application of the study area is analyzed and the truncation item number influence on the accuracy of discrete random field, is discussed in the Flac 3D how to do with the calculation and analysis of the airport, and consider the reliability calculation of pile with the airport problem such as how to make the embedded computing.Research shows that:considering spatial variability in vestigated parameters for reliability analysis of failure probability is less than random variable method analysis results.