敞开式TBM护盾半径适应性设计

为了研究敞开式岩石隧道掘进机（TBM）护盾半径与开挖洞径的适应性问题，建立护盾与洞壁接触理论模型；基于护盾与洞壁接触间隙的变化规律，结合有限元力学性能分析和实际工况，提出护盾半径的设计方法. 结果表明：底侧护盾最下部应与最小洞壁保持5~10 mm的间隙，在水平位置附近与洞壁相切接触，护盾半径由开挖洞径上、下限共同决定；顶护盾的设计半径应比隧洞开挖半径小30~50 mm，其和洞壁的最大间隙与两者的半径差呈正相关关系，受开挖洞径大小影响微小；底护盾半径设计应保证护盾底部与最小开挖洞壁底部接触，护盾半径应比隧洞开挖半径小15~50 mm.

Adaptive design of shield radius for open type hard rock TBM

The contact model of shield and tunnel was established in order to analyze the adaptive design of shield radius with tunnel radius for open type hard rock tunnel boring machine (TBM). The shield radius design method was proposed based on the change law of the gap between shield and tunnel, considering finite element analysis of mechanical properties and actual working conditions. Results show that the gap between shield and minimum tunnel at the bottom should be 5 to10 mm. At the horizontal location, the shield should be tangent to the tunnel. The radius of shield is decided by both the minimum and the maximum tunnel radius. The radius of roof shied should be 30 to 50 mm smaller than the designed tunnel radius. The maximum gap between shied and tunnel is positively correlated with the radius difference between them, which is affected by tunnel radius. The bottom shied should be contact with the minimum tunnel radius in the bottom, and the bottom shied radius should be 15 to 50 mm smaller than the designed tunnel radius.