Influence Of Soil-related Distance On Reliability Of Pile Foundation Bearing Capacity

In the process of reliability analysis of geotechnical engineering,the geotechnical parameters of geotechnical soil must first be determined.In the traditional sense,the soil parameters are regarded as independent random variables,and the autocorrelation of geotechnical soils is not considered.As a result,the calculation results are: the soil parameter variance estimation value and the failure probability are too large,which makes the calculation reliable.The small index causes the calculation results to be inconsistent with the actual results,resulting in an increase in engineering costs and a decrease in safety.In addition,it will also affect the application and promotion of reliability theory in geotechnical engineering.Therefore,when studying the reliability of geotechnical engineering,the soil parameters should be based on the random field of the spatial distribution,and the spatial variability and autocorrelation of the soil parameters should be considered given the characteristics of the randomness of the soil parameters.Study the reliability of geotechnical engineering.Based on the random field theory,this study takes two pile foundation reliability design as an example,and selects the static penetration test data of the engineering site to determine the characteristics of the random field parameters.On this basis,the random field theory is introduced to describe the distribution characteristics of the side friction and the pile end resistance.The recursive space method is used to calculate the correlation distance between the pile end resistance and the side friction resistance of the surrounding soil layer.The representative value of the side frictional resistance takes into account the influence of the correlation distance.In the process of calculation,the Monte Carlo method is combined with Matlab software to compile the failure probability calculation program,and the random input and output variables that affect the reliability index of pile foundation stability are sampled 10,000 times,and then the single pile vertical which is more in line with the actual project is obtained.A reliable indicator of bearing capacity.Among the factors affecting the reliability of single pile bearing capacity,whether the correlation of soil parameters is considered is more obvious.Through the calculation and analysis of the correlation distance of soil parameters,considering the correlation distance can reduce the dispersion of soil parameters,that is,the correlation of soil parameters is enhanced,which can improve the accuracy of calculation results.Based on the random field theory,the recursive space method is used to calculate the correlation distance of soil parameters and the Monte Carlo method is combined with Matlab software to solve the failure probability of single pile,and the corresponding reliable indicators are obtained.The results show that in the analysis of the reliability of bearing capacity of single pile,the numerical calculation of soil parameters based on random field theory not only considers the spatiality of soil parameters but also considers the correlation of soil parameters more realistically.Therefore,considering the influence of the relevant distance on the value of the soil layer parameters,the calculated reliability index of the pile foundation is higher.Design results can reduce engineering costs while maintaining structural safety.Considering the influence of the correlation distance also provides a reference for studying the reliability design method of pile foundation.