分级加载条件下粉喷桩联合土工格栅加固软基的数值模拟

Numerical Simulation of Soft Foundation Improvement by DJM Pile Combined with Geogrids under Multi-stage Loading

结合粉喷桩联合土工格栅在淮盐高速公路试验路软土地基加固中的应用,采用大型非线性有限元程序ABAQUS分析了分级加载条件下加固后软基的变形特性,计算结果表明,联合加固方法比单一的粉喷桩加固方法更有效。通过数值计算结果与同期的现场实测数据对比后发现两者误差很小,说明所采用的本构关系、计算方法和模型是合理可行的,数值模拟能较好地反映软基加固后的变形规律,同时分析了土工格栅筋材模量的大小对加固效果的影响。并总结了粉喷桩联合土工格栅加固高速公路软土地基的一些重要结论,为今后的工程应用提供了有益的理论依据。

Adopting the general-purpose nonlinear finite element program ABAQUS, deformation properties based on soft foundation improvement by Dry Jet Mixing （DJM） pile combined with geogrids under multi-stage loading in Huaiyan expressway test road were analyzed. The analysis result shows that combined improvement method is more effective than the single DJ-M pile method. According to numerical calculation results compared with field observed data, the error is negligible between them, which is shown that constitutive relationship, calculation method and calculation model are proved to be reasonable and feasible. It also shows that numerical simulation reflects deformation behavior of soft foundation improvement effectively. Improvement effect of modulus of geogricls was analyzed at the same time. Some important conclusions about soft foundation improvement by DJM pile combined with geogrids were summarized, providing instructive theoretical basis in soft foundation improvement engineering application for the lucre.