With the development and utilization of city underground space, a lot of underground circle tunnel appear in planning and construction of underground space which link underground garages and ground roads. They are named underground garage circle corridors in this paper. This kind of project can not only link and integrate regional underground parking resources but also can effectively reduce the ground traffic bypass to alleviate the ground traffic pressure, is being noticed by more and more city and area people. As an earlier planning and design institute to carry out such projects in china, we have applied several innovative design ideas and studied key problems of structure analysis in engineering practice in Wuxi and Wuhan. In aspect of innovative ideas,(1)adopting the integration of underground corridor and above composite pipe line scheme, the clever use of the upper thick soil space of corridor to form integrated pipe box, through reasonable architecture layout not only to ensure their functional requirements, but also to maximize the use of the underground space resources; (2) application of low carbon energy saving concept, setting holes in top plate of structure for natural ventilation and lighting, using combined ventilation of 'top opening of natural ventilation and semi transverse centralized mechanical ventilation system'. In aspect of study of structure key problems, (1) study of the technical measures to solve the problems on construction steps and connection of between underground corridors and the surrounding lots, subway, pedestrian crossing facilities; (2) study of protection measures and related geotechnical engineering problems on the excavation of underground corridors adjacent existing facilities, such as viaduct pier, other construction of deep foundation pit excavation and etc.; (3) study of structure mechanical analysis and calculation method of large span structure in underground intersection and crossing area. (4) study the increase of longitudinal spacirtg of structure deformation joint and the durability of concrete structure. Now part of the construction works have been completed, which have verified the scientificalness and rationality of our design ideas and technical measures.
