The application of dual-purpose pile in topdown construction can not only save costs,but also make the mechanic condition of substructure walls more rational.

We have proposed a process ontology model by adopting an inheritance mechanism with overriding declaration and monotonic inheritance.

A covered excavation was adopted, which not only eliminated the problem of traffic blockage but also protected the adjacent buildings and services above the foundation pit, with much shorter construction period.

Combined with shallow tunnel of Maoshan west tunnel,this paper compares the covered excavation with open-cut method on technology and economy.