Cracks on the concrete segment surface of shield tunnels and measures for the Prevention of them;

Based on the outside problems of steel concrete segment,such as crack,honeycomb,pitting surface,air bubble,bad appearance and so on,this paper makes a careful analysis of the concrete segment\'s outside defects,together with the construction experience advances some measures to solve the problems,so as to control the outside quality of concrete segment.

Design and property of covering layer of functionally graded concrete segment used in shield tunneling;

Based on complex engineering environments of Wuhan Yangtze River Shield Tunnel,principles of functionally graded materials are used to design and produce the functionally graded concrete segment.