新旧路基变形协调是高速公路改扩建工程路面结构耐久的关键技术。采用FWD落锤式弯沉仪、PFWD便携式落锤弯沉仪和DCP对济青高速改扩建工程新旧路床进行了快速无损检测，对路床顶面回弹模量进行了反算。结果表明：济青高速旧路路床顶面回弹模量大于60 MPa，满足现行规范对特重交通沥青路面路基回弹模量的要求，拓宽车道路床顶面回弹模量大于90 MPa，为旧路基处理方案设计提供了依据。
Coordination of deformation of new and old subgrade is a key technology for durability of pavement structure in highway reconstruction and expansion projects. The FWD drop-weight deflection meter, PFWD portable drop-weight deflection meter and DCP were used to conduct fast and non-destructive testing of the new and old road beds in the reconstruction and expansion project of Jinan-Qingdao Expressway, and the elastic modulus of the top surface of the road bed was back calculated. The results show that the elastic modulus of the top surface of the old road bed of Jiqing Expressway is greater than 60 MPa, which meets the requirements of the current specifications for the elastic modulus of the extra-heavy traffic asphalt pavement subgrade. The elastic modulus of the top surface of the widened road bed is greater than 90 MPa, which provides a basis for the design of the old roadbed treatment scheme.
