500kV南京三江口长江大跨越工程试桩数据分析

Test Pile Data Analysis of Nanjing Sanjiangkou 500 kV Large Cross Span Project

通过对试桩静载荷试验出现的Q-S曲线局部陡降情况的分析,说明选择试桩位置的土层条件应具备代表性,土层差异可能导致桩承载力取值的偏差。在具体选择试桩地点时,宜对各勘察孔按勘察报告推荐值进行试算后确定。对长细比较大的端承摩擦桩,持力层的端承作用不宜按规范公式计算,应根据具体的土层条件酌情考虑。对桩身较长或桩径较粗的桩,在承载力取值时应考虑桩身自重的影响。

The analysis of steep local drop in the Q-S curve from static load test on test pile reveals that the true soil condition at test pile location should be representative, and the differences in the true soil might cause deviations in pile load bearing capability. Before deciding pile location, one should calculate with investigation report recommended values. To the end-bearing friction piles with large slenderness ratio, the conventional formulae may not be suitable for load bearing end calculation. Instead, one should take the soil condition into consideration. To longer or thicker piles, their own weights should be considered in load-bearing capability calculation.