预制桩沉桩后时变承载力计算方法对比与优化

Comparison and Optimization of Calculation methods for Time-varying Bearing Capacity of Prefabricated Piles After Pile Sinking

预制桩沉桩后承载力有明显的时间效应,为此,从经验公式法(对数函数型、双曲线函数型和规范公式型)、理论解析法(固结理论和柱/球孔扩张理论)和机器学习法3个方面总结了预制桩沉桩后时变承载力计算方法的研究现状并就未来方向给出了建议。经验公式法主要考虑了超孔压消散因素,而缺少对桩周土强度恢复因素的考虑;双曲线型函数在整个时间尺度上符合桩承载力恢复规律的描述。未来可以耦合分析超孔压消散和桩周土强度恢复建立振动沉桩方式的时变承载力解析方法。未来亦可尝试其他机器学习算法,对比分析各种算法的优劣,可增加沉桩方式、桩型、桩径、土层信息等输入参数种类和收集多场景多源数据以提高预测精度。

The bearing capacity of prefabricated piles after pile sinking has a significant time effect.Therefore,the research status of time-varying bearing capacity calculation methods for prefabricated piles is summarized from three aspects:empirical formula method(logarithmic function type,hyperbolic function type,and standard formula type),theoretical analysis method(consolidation theory and column/ball hole expansion theory),and machine learning method,and some suggestions are provided for future directions.The empirical formula method mainly considers the dissipation of excess pore pressure,but lacks consideration for the recovery of soil strength around the pile;the hyperbolic function conforms to the description of the recovery law of pile bearing capacity on the entire time scale。In the future,a time-varying bearing capacity analysis method can be established by coupling the dissipation of excess pore pressure and the recovery of soil strength around the pile to establish a vibration pile driving method;other machine learning algorithms can also be tried to compare and analyze the advantages and disadvantages of various algorithms.Input parameters such as pile sinking method,pile type,pile diameter,and soil layer information can be added,and multi scene and multi-source data can be collected to improve prediction accuracy.