STRUCTURE DESIGN OF KEY SEGMENT FOR THE NEW TUNNEL BUILDING TECHNOLOGY ABOUT ENLARGING SUBWAY STATION WITH LARGE-DIAMETER SHIELD TUNNEL

The structure internal force of key segment about enlarging subway station with large-diameter shield tunnel is analyzed. According to the analysis results, 6 schemes about structure design of key segment are discussed. Every structure form is analyzed from 3 aspects about technical difficulties, economic cost and time cost. Conclusion shows that the structure form selection of key segment under the condition of enlarging is more related to the three factors than the normal form. Optimization about the three factors in the different enlarging condition is important about the selection of the structure of key segment. This paper points out the noticed problems on the three factors in 6 structure design of key segment. It is constructive suggestion for considering the effect about technology, economic and time collected with the key segment design under enlarging condition. And the 6 structure forms of key segment are also reference significance for similar engineering.