海相区深厚软基轻质路堤变形数值分析

Numerical analysis of the deformation of deep soft foundation light embankment in marine area

为解决海相深厚软基易发生不均匀沉降、变形大的问题,以马来西亚柔佛海峡碧桂园森林城市中的路桥工程为背景,对发泡聚苯乙烯置换路堤填土方案的可行性进行了探究。建立了置换区发泡聚苯乙烯路堤数值模型,分析了置换前(后)路基的基底应力、侧向土压力及沉降变形,明晰了发泡聚苯乙烯的最佳置换厚度。结合发泡聚苯乙烯路堤现场监测结果,验证了该数值模型的适用性。研究结果表明:采用发泡聚苯乙烯置换海相深厚软基区路堤可以显著减少路基上覆荷载、改善路基不均匀沉降及保证桥台与路堤的稳定;根据不同厚度发泡聚苯乙烯对海相深厚软基的置换效果和经济适用性,确定了发泡聚苯乙烯的最佳置换厚度。

In order to solve the problem of uneven settlement and large deformation of thick marine soft clay foundation,this paper explores the feasibility of replacing the embankment fill of the expanded polystyrene with the background of Country Garden Road and Bridge in Johor Bahru,Malaysia.The numerical model of the expanded polystyrene embankment in the replacement zone is established.The basement stress,lateral soil pressure and settlement deformation of the subgrade before and after the replacement are analyzed.The optimal replacement thickness of the expanded polystyrene material is clarified.The applicability of the numerical model is verified by the results of the on-site monitoring of the expanded polystyrene embankment.The results show that the use of the expanded polystyrene to replace the embankment in the deep soft foundation of the sea can significantly reduce the overlying load on the subgrade,improve the uneven settlement of the subgrade and ensure the stability of the abutment and embankment.The optimal replacement thickness of the expanded polystyrene can be determined by the replacement effect with different thickness of the expanded polystyrene according to the economic applicability.