Abstract:

With the development of multilane highways, more and more superlarge crosssection tunnels with low heightspan ratios have been built in recent years. Due to the low heightspan ratios, these tunnels are very complex in terms of excavation methods and stress distribution. However, few such tunnels have been built in China, therefore experience on the design and construction of such tunnels is quite scarce and no design standards for such tunnels are available in China. In the paper, an overview is made on the superlarge crosssection tunnels with low heightspan ratios built in China and other foreign countries and comments are made on the prevailing research topics of superlarge crosssection tunnels with low heightspan ratios, including construction methods, tunnel mechanics, surrounding rock stability and crosssection styles.

Key words:  , superlarge crosssection tunnel with low heightspan ratioconstructionoverview