地铁车站中洞法施工地表沉降变形规律研究

摘要

文章以北京地铁14号线陶然桥站中部暗挖主体工程为研究对象,通过几何水准测量监测方法,对中洞法施工各施工工序引起的地表沉降变形规律进行了分析和总结.结果表明,沉降变形主要经历5个阶段,即柱洞初期支护施工沉降阶段、中洞初期支护施工沉降阶段、中洞二次衬砌底板与扣拱施工沉降阶段、侧洞初期支护施工沉降阶段及二次衬砌结构施工沉降阶段.其中第Ⅰ阶段与第Ⅳ阶段沉降值占最终沉降值比重最大,最终沉降横断面曲线呈轴对称,以中洞中线为对称轴线.%Based on the mined construction of Taoranqiao station of Beijing metro line 14,the law of surface settle-ment induced by construction procedures of the center drift excavation method is analyzed and the experience is sum-marized by means of geometrical leveling.The results show the settlement mainly undergoes five stages,i.e.,1)settle-ment stageⅠin primary support construction of the pillar pilot tunnel,2)settlement stageⅡin secondary lining con-struction of the central pilot tunnel,3)settlement stageⅢin construction of the floor and buckling arch of the central pilot tunnel,4)settlement stage IV in construction of the primary support at the side pilot tunnel,and 5)settlement stage V in secondary lining construction.The settlements of phase I and phase IV account for the largest proportion of the final settlement;the curve of final settlement is axisymmetric,with the central line of the central pilot tunnel to be the axis of asymmetry.