Abstract: As an important component of shield tunnel, segments have a significant impact on the construction cost and safety of the tunnel structure. At present, Metro shield tunnel segment whose diameter reaches 6 m, is relatively rare in China. This article briefly describes the structural parameters of this kind of segment such as thickness, width, block, etc. Its calculation model and calculation method are also described. The article takes the shield tunnel on Shenzhen Metro Line 11 as an example and makes a numerical simulation analysis and research. The result shows that the force behavior of largediameter shield tunnel segment is similar to the common diameter shield tunnel segment. And the structural reinforcement is controlled mainly by the crack. The reinforcement of some special parts of the segment should be strengthened so as to prevent the segment crack.

Key words: largediameter shield machine, segment, numerical simulation, structure calculation