以12根抗拔桩承载力为研究对象,利用4参数的贝塔分布拟合出抗拔桩承载力试计比(承载力实测值和计算值的比)的概率分布.通过K-S检验法检验指出:贝塔分布的拟合精度优于常见的正态分布、对数正态分布和极值I型分布.利用蒙特卡罗法计算出抗拔桩承载力的可靠度指标,计算结果表明:承载力试计比的均值、荷载组合、荷载比和安全系数对可靠度有显著的影响.最后利用荷载抗力系数设计法给出了抗拔桩的抗力系数.
The bearing capacities of 12 anti-uplift piles were collected,and the probability distribution of partial factor(the ratio of the measured values of bear capacity of anti-uplift piles and their corresponding calculated values) was fitted utilizing Beta distribution.The results through the K-S test indicate that the fitting accuracy employing Beta distribution is better than employing normal distribution,lognormal distribution and extreme value I distribution.The results from calculation of reliability indices based on Monte Carlo simulation method show that the mean of partial factor,loading combinations,loading ratios and factors of safety have significant influence on reliability indices,while the reliability index is insensitive to coefficient of variation of partial factor.Finally,the resistance factors of anti-uplift piles were given according to load and resistance factor design method.