Numerical simulation on the application of foam lightweight soil in the embankment upgrading section of highway expansion projects
In the construction and expansion projects of expressways in our country,differences in new and old standards have led to the occurrence of road sections with raised longitudinal profiles.These road sections not only need to consider the settlement of the fill width embankment but also the additional load caused by the raised section affecting the additional settle-ment of the old subgrade.This study takes a high-speed expressway construction and expansion project in Jiangsu Province as an example to expound the calculation method of the thickness of foam lightweight soil replacing the old subgrade.A numerical model of fill soil and foam lightweight soil reconstruction using finite difference software was established,and the characteristics of settlement and deformation of the foundation soil after foam lightweight soil reconstruction were compared and analyzed.It was found that the plastic increment of the subgrade soil caused by foamed lightweight soil is relatively small,and the area of plastic deformation increment was also relatively small.The control key points and considerations for the construction quality of foam lightweight soil embankments were discussed,providing a set of design and construction methods to control differential settlement for expressways built on soft soil foundations.