考虑工程场地非均匀分布特征的管桩竖向承载力估计方法研究

Research on the Estimation Method for Vertical Bearing Capacity of Pipe Piles Considering Non-Uniform Distribution Characteristics of Construction Sites

摘要: 工程场地非均匀性是影响管桩竖向承载力差异的关键因素，传统的设计配桩忽略了工程场地中土层分布的非均匀特征，往往导致管桩设计承载力与工程实际存在偏差。针对这一问题，本文提出一种考虑工程场地非均匀分布特征的管桩竖向承载力估计方法。首先通过工程勘察获取管桩几何参数与场地土体力学参数数据集，计算参数统计特征并构建空间权重矩阵，基于上述基础构建土体力学参数随机场，量化同一土层内部参数的空间变异性，随后将随机场模拟的多组土体参数代入承载力计算公式，得到多组承载力结果，最终通过统计分析明确承载力分布特征。工程实例验证表明：所提方法构建的土体参数随机场与实测数据规律高度吻合，能够精准反映工程场地非均匀分布特征引发的承载力不确定性；该场地管桩竖向承载力均值为16009.7 kN，5%分位值为15703.3 kN，95%分位值为16209.6 kN，大概率区间15703.3 kN~16209.6 kN，可用于工程配桩的设计取值。研究成果为管桩竖向承载力的可靠性设计与工程风险评估提供了科学技术路径。

Abstract: The non-uniformity of the construction site is a key factor affecting variations in the vertical bearing capacity of pipe piles. Traditional pile design methods overlook the non-uniform distribution characteristics of the site, often leading to discrepancies between the designed bearing capacity of pipe piles and actual engineering conditions. To address this issue, this paper proposes an estimation method for the vertical bearing capacity of pipe piles considering the non-uniform distribution characteristics of construction sites. First, the geometric parameters of pipe piles and the dataset of soil mechanical parameters of the site were obtained through engineering investigation, the statistical characteristics of parameters were calculated and the spatial weight matrix was constructed. On this basis, the random field of soil mechanical parameters was established to quantify the spatial variability of parameters within the same soil layer. Then, multiple groups of soil parameters simulated by the random field were substituted into the bearing capacity calculation formula to obtain multiple groups of bearing capacity results. Finally, the distribution characteristics of bearing capacity were clarified through statistical analysis. Engineering case verification shows that the random field of soil parameters constructed by the proposed method is highly consistent with the law of measured data, and can accurately reflect the uncertainty of bearing capacity caused by the non-uniform distribution characteristics of construction sites; the average value of vertical bearing capacity of pipe piles in this site is 16009.7 kN, the 5% quantile value is 15703.3 kN, the 95% quantile value is 16209.6 kN, and the high-probability interval of 15703.3 kN~16209.6 kN. The results can be utilized for engineering pile design values. This research provides a scientific and technological pathway for the reliability design of pipe pile vertical bearing capacity and engineering risk assessment.