沿海填土地区通常存在软土地基，其中软土层较厚，土壤欠固结现象普遍存在。这导致了诸如承载力不足、固结周期长、沉降量大等问题。为改善欠固结软土地基的低承载能力问题，依托珠海南湾大道悬浮桩地基工程，采用Flac3D有限差分计算软件建立复合地基模型，并将计算结果与短期监测数据进行比对，以验证模型的准确性。对深厚欠固结软土悬浮桩复合地基的沉降变形特征、孔隙水压力消散特征以及土体有效应力增长过程进行了研究。研究结果表明：模型的计算结果与监测数据基本吻合，数值模型能够准确反映饱和软土复合地基的固结和沉降特征，为深厚欠固结软土地基的道路施工提供了理论参考。

Coastal reclamation areas typically have soft soil foundations with thick layers of soft soil and a common issue of soil under-consolidation. This leads to problems such as insufficient bearing capacity, prolonged consolidation periods, and significant settlement. To address the low bearing capacity of under-consolidated soft soil foundations, leveraging the Zhuhai Nawan Avenue suspended pile foundation project, a composite foundation model was established using the Flac3D finite difference numerical calculation software. The computed results were compared with short-term monitoring data to validate the accuracy of the model. Extensive research was conducted on the settlement deformation characteristics, pore water pressure dissipation characteristics, and the growth of effective stress in deep under-consolidated soft soil suspended pile composite foundations. The research findings indicate that the model's computed results closely align with the monitoring data, demonstrating that the numerical model accurately reflects the consolidation and settlement characteristics of saturated soft soil composite foundations. This provides a theoretical reference for road construction on deep under-consolidated soft soil foundations.