摘要
The impact of excavation on the reliability of anti- pull piles is studied, and three cases of reliability analysis, named reliability of ultimate limit state （ULS）, reliability of serviceability limit state （SLS） and reliability of system （SYS） are studied. The reduction factor of the pile capacity is used to calculate the reliability indices for the three cases. The ratio ξ of the pile capacity of SLS to the pile capacity of ULS has a significant influence on the reliability indices of SLS and SYS. The mean value μξ of the ratio ξ： is considered as a random variable to study the reliability indices of SLS and SYS. The numerical example demonstrates that the excavation depth and the excavation diameter are proved to have significant influences on the reduction factor of the pile capacity and the reliability indices. The reliability indices decrease with the increase in the excavation depth, and the excavation diameter has a considerable influence on the reliability index when the excavation is relatively deep. In addition, μξ has a significant influence on the reliability indices of SLS and SYS. For a more accurate estimation of μξ, further research should be conducted to study μξ.
研究了开挖对承载力极限状态(ULS) 、正常使用极限状态(SLS) 和系统可靠度(SYS) 的影响,并基于开挖条件下承载力折减系数分别给出 ULS 可靠度指标、SLS 可靠度指标和 SYS 可靠度指标的计算方法. 研究得出 SLS 承载力和 USL 承载力的比值ξ对 SLS 可靠度和 SYS 可靠度有显著影响,并将这一比值的均值μξ当作随机变量,研究了 SLS 可靠度和 SYS 可靠度. 算例分析表明: 开挖深度和开挖直径对承载力折减系数和可靠度指标有显著影响; 随着开挖深度的增大,可靠度指标有很显著的减小; 当开挖深度较大时,开挖直径对可靠度指标的影响较大. 此外,μξ对 SLY 和 SYS 可靠度指标的影响很大,要更精确地估计μξ,需对μξ进行深入的研究.
基金
The National Natural Science Foundation of China(No. 50978112)
