加卸载对下方既有盾构隧道影响实测与分析.pdfVIP

第14卷　 第4期 南京工程学院学报(自然科学版) Vol.14,No.4 2016年12 月 Journal of Nanjing Institute of Technology(Natural Science Edition) Dec. ,2016 　 　 doi:10.13960/ j.issn.1672-2558.2016.04.011 投稿网址:http:/ / 加卸载对下方既有盾构隧道影响实测与分析 沈国根,鄂俊宇,丁建峰,王燕平 (扬州市隧道管理处,江苏扬州215000) 摘　 要:对扬州市“春江花月夜”实景演出改建工程加卸载引起的下伏既有瘦西湖隧道变形规律进行监测与分析. 测试结果表明,卸载范围内的地表土体出现隆起现象,而岸边土体发生轻微沉降;由于隧道拱顶上方竖向土压力减 小,隧道拱顶发生轻微上浮;隧道收敛变形呈水平向压缩、竖向拉伸模式.隧道上方加载后,隧道上述变形向相反趋 势发展.本次监测到的既有瘦西湖隧道变形均较小,表明改建工程建设加卸载对下伏既有瘦西湖隧道影响在可接 受范围之内. 关键词:卸荷;盾构隧道;地表沉降;拱顶沉降;周边收敛 中图分类号:TU472 Effect of Unloading and Loading on the Existed Shield Tunnel Underneath SHENGuo-gen, EJun-yu, DINGJian-feng, WANG Yan-ping (Tunnel Management Bureau of Yangzhou City, Yangzhou215000,China) Abstract:The deformation of Slender West Lakeshield tunnel caused by loading and unloading of “Moonlit Night stage reconstruction was measured. The results show that surface soil within the scope of the unloading area upliftand the soil outside of unloading area subsidence. Reducing of earth pressure on top of the vertical tunnel vault results in the tunnel vault floatingslightly. The tunnel convergence deformswith a horizontal compression and a vertical stretch mode. After loading on the top of the tunnel, the tunnel deformation has an oppositetrend.The measured deformation of Slender West Lake tunnel is small, which suggestthat the influence ofstage reconstructionon the Slender West Lake Tunnel existing underlying iswithin an acceptable range. Key words: unloading; shield tunnel; surface subsidence; crown settlement; convergent deformation 　 　 随着我国城市隧道工程的大规模建成,邻近下方既有隧道的开挖工程案例日益增多.开挖等因素 造成的卸荷效应会使下方盾构隧道的管片发生变形,而相关规范对隧道的变形要求极其严格.例如, 《上海市地铁沿线建筑施工保护地铁技术管理暂行规定》要求地铁结构最终绝对位移不能超过20 mm,