穿越溶洞盾构隧道管片变形特征研究

Research on Deformation Characteristic of Shield Tunnel Segment Crossing Karst Cave

文章基于椭圆离心率理论,采用数值计算分析方法,研究了穿越溶洞盾构隧道管片变形特征,主要研究结论如下:(1)当盾构隧道从上方和下方穿越喀斯特地区时,中心溶洞直径越大,盾构管片变形后椭圆的离心率越小,椭圆的形状越趋向于圆形;随着溶洞与隧道距离的增加,盾构管片变形后椭圆的离心率越大,椭圆形状越扁。(2)当盾构隧道从侧方、斜向上45°和斜向下45°穿越喀斯特地区时,中心溶洞会加大隧道变形,中心溶洞直径越大,盾构隧道管片变形越大,盾构管片变形后椭圆的离心率也越大,椭圆形状越扁。

Based on the theory of elliptical eccentricity,the deformation characteristics of shield tunnel segments crossing karst caves are studied by numerical calculation analysis method.The main conclusions are as follows:(1)When the shield tunnel crosses the karst area from above and below,the larger the diameter of the central karst cave,the smaller the eccentricity of the ellipse after the shield segment deformation,and the shape of the ellipse tends to be more circular;with the increase of the distance between the karst cave and the tunnel,the eccentricity of the ellipse after the shield segment deformation is larger,and the shape of the ellipse is flatter.(2)When the shield tunnel crosses the karst area from the side,at an angle of obliquely upward 45°and obliquely downward 45°,the central karst cave will increase the tunnel deformation,the larger the diameter of the central karst cave,the greater the deformation of the shield tunnel segment,the greater the eccentricity of the ellipse after the shield segment deformation,and the flatter the shape of the ellipse.