With the development of road tunnel construction and assorting with muti-lanes freeways, extra-large cross-section and low flat-ratio road tunnel become a new shape in recent years.

And based on the monitoring data in the entrance slope of the extra-large cross-section and cow flat-ratio tunnel,this paper applied the time series by the method for dealing with mutation to forecast the deformation of slopes.

To reduce the influence of the surface settlement and deformation of the buildings and the underground facilities caused by the subway station construction, that has a large flattened cross-section, it has to evaluate the contingent surface settlement and deformation correctly and help us to choose the better construction approach.

Taking for example of the excavation Pansteel Baima iron ore mine,the construction method and precautions for large section tunnel in fracture weak strata were introduced.

This paper is based on the construction of linjiangmen station tunnel of the Chongqing Jiaoxin Light Railway, the demolition shock absorption applied to urban shallow covered large section tunnel in hard rocks under complicated conditions is introduced.

The numerical simulation of constructional mechanical responses of highway tunnel with large cross section;