With the development of city construction

it is common to see more and more cross construction phenomena of the ground engineering and the underground engineering

which unavoidably contributes to the effect of the new construction on the existing construction. Therefore

on the premise of ensuring the safety of the existing construction

how to construct new projects has become one of the important issues for numerous scholars. In this paper

the finite element numerical simulation analysis method of ABAQUS and the simplified specification corner-points method are applied to analyze comparatively an engineering construction adjacent to the existing underlying tunnel. On this basis

the effects of the pit excavation and its subsequent construction on the underlying existing tunnel are evaluated. The field monitoring data demonstrate that the two methods

i.e. the numerical analysis method and the traditional theory of soil mechanics method

are coincidently available in such engineering construction which has clear boundary and explicit load and can secure engineering. The research also shows that the two-dimensional analysis model not only has the smaller calculation workload

but also has more security compared with a three-dimensional model considering practical engineering conditions.