海洋平台大直径钢管桩溜桩区间计算方法

Pile running interval calculation method of large-diameter steel pipe piles on offshore platform

溜桩作为海洋平台大直径钢管桩施工过程中常见的工程事故,影响成桩质量和工程进度。本研究对溜桩区间进行合理的预测和判断,结合工程实际对溜桩产生的原因进行分析。采用静力平衡方程求出溜桩发生时的钢管桩入泥深度;计算钢管桩第二次溜桩区间时考虑了溜桩对桩侧摩阻力的影响,并将桩侧摩阻力分成三个影响区计算;使用积分学方法,对沉桩阻力做功进行计算;利用功、能原理列出钢管桩能量方程,求出溜桩长度,进而得出溜桩区间。实例计算与实测结果对比显示,新计算方法的溜桩区间计算结果与实际情况误差范围为8%～16%,具有较高的准确度。新计算方法计算结果与现场实测数据吻合较好,可为工程中预测钢管桩溜桩区间提供参考。

In offshore platform engineering, pile running often occurs during the driving process of large-diameter pipe piles and it will affect the quality of pile-forming and engineering process. This study aims to make predictions and assessments of pile running intervals. The causes of pile running in practical engineering were first analyzed. The pile-running depth of steel pipe piles was calculated using static equilibrium equation. While calculating the second pile running interval, the influence of pile running on skin friction was considered and was divided into three influential areas. The work of pile-sinking resistance was calculated using integral calculus. The transformation equation of energy of piles was given by using the principle of work and power to obtain the length and then the interval of pile running. The calculation obtained in the actual case study was compared with the measured results. The comparison indicates that with an error range of 8%-16%, the proposed method has higher accuracy in pile running interval prediction. This can provide a reference for predicting the interval of pile running in projects, since the calculated results are in higher conformity with the measured data.