真空联合堆载预压处理路基变形影响范围研究

Research on the Influence Range of Subgrade Deformation in Vacuum Combined Preloading Treatment

确定真空联合堆载预压处理路基变形影响范围是工程建设项目中的重难点。依托珠海保税区某工程,以海陆交互相软土地基为研究对象,对现场真空联合堆载预压处理路段路基变形实测数据开展分析,采用PLAXIS进行数值模拟,将实测结果与数值分析结果进行对比,并利用数值分析方法对相关不同影响因素进行分析。研究结果表明,真空联合堆载预压处理路基变形影响范围随处理时间增加而增大;随与路基距离的增大,地表水平向影响半径减小;距离处理边线越近,深层软土挤压效果越明显,距离处理边线超过15 m后深层软土挤压效果明显减弱;数值模拟结果与实测数据较吻合;地表最大影响半径随素填土模量增加而减小,随淤泥厚度增大而增大,随排水板长度增大而增大;真空联合堆载预压路基变形影响范围小于20 m。

It is important and difficult to deal with the influence range of subgrade deformation by vacuum combined preloading.In the paper,based on a project in Zhuhai Free Trade Zone,the measured deformation data of roadbed in the field of vacuum combined preloading treatment with land and sea soft soil foundation are analyzed.PLAXIS is used for numerical simulation,the measured results are compared with the numerical analysis results,and the relevant different influencing factors are analyzed by the numerical analysis method.The results show that the influence range of subgrade deformation increases with the increase of treatment time.With the increase of the distance from the subgrade,the surface horizontal influence radius decreases.The closer the distance from the treatment line,the more obvious the extrusion effect of deep soft soil,and the more obvious the extrusion effect of deep soft soil when the distance from the treatment line exceeds 15 m.The numerical simulation results are in good agreement with the measured data.The maximum horizontal influence radius of the surface decreases with the increase of the primary fill modulus,increases with the increase of the silt thickness,and increases with the increase of the drainage plate length.The deformation range of the pre-loaded subgrade under vacuum combined load is less than 20 m.