填海造陆场地基桩竖向承载特性试验研究

Experimental study on bored cast-in-situ piles embedded in thick filled soil for sea reclamation

为确定夯后填海造陆场地灌注桩的承载力和施工工艺,对桩侧注浆和未注浆两种不同工艺的试桩开展了现场静载试验和数值模拟。研究结果表明:尽管经过强夯处理,填土仍存在不均匀性,填土段桩身侧阻力普遍出现上大下小的现象,部分试桩甚至在填土段出现负摩阻力;桩侧注浆桩相较于未注浆桩具有显著优势,桩侧注浆能有效减少桩顶沉降;充盈系数对桩的承载力影响较大,随着充盈系数的增大,同一荷载下的桩顶沉降逐渐减小。此项研究为类似场地的桩基承载力和施工工艺设计提供了有益参考,对于我国填海造陆场区的桩基工程具有重要意义。

In order to determine the bearing capacity and construction process of the cast-in-place piles in the land reclamation site after compaction,on-site static load tests and numerical simulations were carried out on the test piles with two different processes:side grouting and non-grouting.The study results indicate that despite the dynamic compaction treatment,there is still non-uniformity in the filling soil,and the lateral resistance of the pile body in the filling soil section generally shows a phenomenon of upper large and lower small.Some test piles even show negative frictional resistance in the filling soil section;compared to non-grouted piles,the pile side grouting piles have significant advantages,and pile side grouting can effectively reduce pile top settlement;the filling coefficient has a significant impact on the bearing capacity of piles,and as the filling coefficient increases,the settlement of the pile top under the same load gradually decreases.This study provides useful reference for the bearing capacity and construction technique design of pile foundations in similar sites,and is of great significance for pile foundation engineering in China′s land reclamation areas.