Abstract

Piles are widely used in marine projects where inappropriate soils are present and soil replacement is not justified economically. Among various pile types, helical piles have been considered as a potential substitution for driven piles in offshore applications. The present paper investigates numerically the effects of tapered helices and inter-helix spaces to achieve the maximum compression capacity in homogeneous and in-homogeneous soil profiles. Both individual and cylindrical failure mechanisms were studied. Tapered helices with decreasing diameters from the top to bottom instead of the same number of identical helices were also studied. Results show that the best inter-helix spacing to helix diameter ratio is two to achieve the greatest pile capacity. Also, the compression load corresponding to 10% of the pile head settlement was found to be reasonable for computing the pile capacity. The results show that tapered helix piles offer better compression capacity than uniform helix piles with the same number of identical helices. In addition, tapered helix piles have almost similar load-settlement variation to solid frustum shape helix piles while in the latter more steel is consumed. In general, the present research highlights that using tapered helices due to their technical and economic performance is advantageous.

摘要

桩广泛用于存在不适当土壤且土壤置换在经济上不合理的海洋项目中。在各种桩类型中，螺旋桩被认为是海上应用中驱动桩的潜在替代品。本文从数值上研究了锥形螺旋和螺旋间空间的影响，以在均质和非均质土壤剖面中实现最大压缩能力。研究了单个失效机制和圆柱失效机制。还研究了从顶部到底部直径减小的锥形螺旋，而不是相同数量的相同螺旋。结果表明，最佳的螺旋间距与螺旋直径之比为2，以获得最大的桩容量。还，桩头沉降的 10% 对应的压缩荷载对于计算桩身承载力是合理的。结果表明，锥形螺旋桩比具有相同螺旋数量的均匀螺旋桩提供更好的抗压能力。此外，锥形螺旋桩的荷载沉降变化与实心平截头体螺旋桩几乎相似，而后者消耗的钢材更多。总的来说，目前的研究强调，由于其技术和经济性能，使用锥形螺旋是有利的。锥形螺旋桩与实心平截头体螺旋桩具有几乎相似的荷载沉降变化，而在后者中消耗更多的钢材。总的来说，目前的研究强调，由于其技术和经济性能，使用锥形螺旋是有利的。锥形螺旋桩与实心平截头体螺旋桩具有几乎相似的荷载沉降变化，而在后者中消耗更多的钢材。总的来说，目前的研究强调，由于其技术和经济性能，使用锥形螺旋是有利的。