浅埋暗挖地铁隧道施工地表沉降规律分析

为了研究大连地铁202标段促进路站—春光街站暗挖区间人工素填土地段单双线隧道施工地表沉降规律,通过现场实测和数据分析整理的方法,在地铁隧道开挖期间建立了地表沉降监控量测测站,运用精密水准仪进行3个月的监测,监测结果表明浅埋暗挖隧道在开挖期间地表沉降最大位置处于隧道中心线的正上方,沉降量约为25.66～31.82 mm.提出了距跨比β的概念,距跨比β的有效工程取值范围-4＜β＜4,地表沉降与距跨比β密切相关,其中-2＜β＜2地表沉降剧烈阶段,约占整体变形的67.5～77.6％,沉降速率约达0.84～0.93 mm/d.建议应加强监测频率,增加现场巡视.现场测试结果与文克尔地表沉降计算模型相吻合,监测成果对大连地铁及类似的浅埋暗挖隧道建设有借鉴作用.

Analysis of surface subsidence rule of shallow subway tunnel construction

To study the Dalian Metro section 202’s(Cujin Road station-Chunguang Street station,which is shallowly buried and covered with plain fill) ground surface settlement,the monitoring measuring station was built during the construction.After 3 months’ measuring by precision level,the data shows that the maximum point is in the center line of the tunnel of the upper part,the settlement is about 25.66-31.82 mm.we put forward the concept of the distance span ratio β,β effective value range was-4 <β< 4,surface subsidence was closely related with β,severe surface subsidence stage was-2 <β< 2,which accounted for 67.5-77.6% of the whole deformation,and settlement rate was about 0.84-0.93 mm/d.So the monitoring frequency and site tour should be strengthened.The result of field test is consistent with that of the ground surface settlement calculation model.The monitoring results have reference for Dalian subway and the similar shallow depth excavation tunnel construction.