盾构隧道“先隧后井”施工中简易井应用开口环管片变形

Deformation of Opened Segment Using Simply-constructed Well when Tunnels Followed by Well Excavation

针对电力与输水盾构隧道"先隧后井"施工中简易井应用开口环管片变形问题,文章基于弹性理论推导开口环管片变形的解析解,并通过数值模拟验证,用于实例开口环管片变形及影响因素分析。研究结果表明,盾构隧道"先隧后井"施工采用简易工作井时,井内开口环管片产生了收敛位移,最大值出现在管片开口处;数值与理论计算结果较为吻合,最大相差12%,因此开口环管片变形解析解能够表征管片实际变形情况;开口环管片竖向位移显著大于横向位移,并且随着管片位移水平的提高愈发明显;开口环管片变形受土层与简易井特性影响明显,不同影响因素贡献依次为土层摩擦角→简易井壁厚→简易井直径;管片变形值与土层摩擦角呈反向线性关系,且随简易井厚度和直径的增大近似线性增大。

The analytical solution on opened segment was deduced based on elastic theory for segment deformation of electricity and water tunnel when tunnels followed by well excavation.And the solution was used for the deformation and influencing factors analysis of the opened segment as well as the numerical simulation verification was carried out.The results show that the segment has convergence displacement and the maximum appears at the opening using simly-constructed well when tunnels followed by well excavation.The numerical calculation results are well consistent with the theoretical calculation results and the maximum difference is 12%,so the analytical solution can characterize the actual deformation of opened segment.The vertical displacement of opened segment is significantly greater than the lateral displacement,and the higher the displacement level,the more obvious it is.The influence of soil parameters and well section characteristics on opened segment deformation is significant,and the contribution order of different influencing factors is the soil friction angle,simply-well thickness and simply-well diameter.The segment deformation is inversely linear with the friction angle of the soil and linearly increase of the thickness and diameter of the simply-well.