Review on the Ways and Characteristics of Expressway Subgrade Widening

Sonja Grabner-Kräuter

Highway Landscape Design, California American University California, American

Abstract: The old road widening reconstruction project and the construction of a new highway construction is difficult, the process is complex, high quality requirements of the characteristics. Due to the old road sub- grade settlement has been basically stable, and new road subgrade settlement time is short, of new and old roadbed combination will produce uneven settlement, so as to produce a longitudinal crack, resulting in ce- ment concrete panel under ｌｏａｄ have broken slab, asphalt concrete pavement has the reflection crack, greatly affect the quality of driving, not only to meet the needs of vehicle, will increase the car's fuel consumption and tire wear, increase transportation costs, increase the transportation time, and even endanger the safe driv- ing, also increased the road maintenance cost. The urgency of the highway widening technology research of expressway expansion project of subgrade widening mode and its features are reviewed, forming reasonable Expressway Widening Engineering of philosophy, in order to lay the foundation for the theoretical research and engineering practice.

Keywords: Expressway; Expansion project; Widening of subgrade; Pavement splicing; Widening way; Differential settlement