基于可靠度理论的嵌岩桩自平衡转化系数研究

嵌岩桩作为桩基础的重要分支，在基础工程领域已得到广泛使用，其竖向承载力通常认为由桩侧摩阻力和桩端阻力两部分组成。统计了5个实际工程中合计62组分别采用传统静载法和自平衡法的嵌岩桩竖向极限承载力对比测试数据。对测试数据进行了归一化处理之后，采用贝叶斯优化计算了服从对数正态分布的模型因子统计参数。挑选了合适的可靠度指标求解方法计算了不同自平衡转换系数对应的嵌岩桩竖向承载力的可靠度指标，分别探讨了活载效应与恒载效应比值、安全系数以及荷载效应统计参数等因素对可靠度指标的影响。结合各行业规范并考虑最不利原理确定了嵌岩桩竖向承载力合适的目标可靠度，给出了该目标可靠度对应的自平衡转换系数推荐值。

Research on Self-Balance Conversion Coefficient of Rock-Socketed Piles Based on Reliability Theory

As an important branch of pile foundation, rock-socketed pile has been widely used in the field of foundation engineering, and its vertical bearing capacity is generally considered to be composed of two parts: pile side friction resistance and pile end resistance. In this paper, a total of 62 groups of rock-socketed pile vertical ultimate bearing capacity comparison test data using traditional static load method and self-balancing method in 5 actual projects were collected. After normalizing the test data, Bayesian optimization was used to calculate the statistical parameters of the model factors obeying the log-normal distribution. The appropriate reliability index solution method was selected to calculate the reliability index of the vertical bearing capacity of rock-socketed piles corresponding to different self-balancing conversion coefficients. The ratio of live load effect to dead load effect, safety factor and statistical parameters of load effect were discussed. The influence of factors on reliability indicators. The appropriate target reliability of the vertical bearing capacity of rock-socketed piles is determined according to various industry norms and the most unfavorable principle, and the recommended value of the self-balancing conversion coefficient corresponding to the target reliability is given.