下穿机场隧道悬臂掘进机开挖引起的地表沉降规律研究  

Surface Settlement Pattern Caused by Excavation of a Cantilever Boring Machine Under an Airport

作　　者：冯上泽 丁祖德[1] 郭永发[2] 丁文云[2] 刘正初[2] 王畅羽 FENG Shangze;DING Zude;GUO Yongfa;DING Wenyun;LIU Zhengchu;WANG Changyu(Faculty of Civil Engineering and Mechanics,Kunming University of Science and Technology,Kunming 650500,Yunnan,China;Kunming Survey,Design and Research Institute Co.,Ltd.of China Railway Eryuan Engineering Group Co.,Ltd.,Kunming 650200,Yunnan,China)

机构地区：[1]昆明理工大学建筑工程学院,云南昆明650500 [2]中铁二院昆明勘察设计研究院有限责任公司,云南昆明650200

出　　处：《隧道建设(中英文)》2024年第S2期319-328,共10页Tunnel Construction

基　　金：云南省科技计划项目(202303AA080003)。

摘　　要：为研究高铁隧道悬臂掘进机法施工过程中机场区地表沉降变化特征,以渝昆高铁下穿长水机场隧道工程为例,结合隧道下穿机场区地表位移的实时自动监测数据,深入分析悬臂掘进机法施工引起的机场区地表横向和纵向沉降规律。结果表明:1)地表沉降时程变化整体表现为平稳波动、快速发展、趋于稳定3个阶段,地表沉降的快速增加主要集中在上台阶通过监测点后至下台阶通过监测点前的时间段内;2)修正Peck公式能较好地表征悬臂掘进机施工引起的地表横向沉降分布特征,地表最终沉降为7.3~25.0 mm,地层损失率为0.16%~1.01%,横向影响范围为4.0D~5.3D(D为隧道开挖跨度),最不利区域集中在隧道两侧各1.3D,需重点监测;3)受上侧既有机场货运通道斜交、隐伏溶洞以及岩石产状等不均匀地质条件的影响,部分断面的地表沉降槽分布整体向右侧偏移;4)不同开挖阶段引起的地层损失及地表沉降量有明显差异,上、下台阶和仰拱开挖阶段引起的地层损失率依次减小,引起的地表沉降量分别占总沉降的81.3%、17.0%和1.7%;5)纵向沉降规律表明,地表纵向最终沉降曲线呈现先增大后减小的变化趋势,隧道开挖引起的地表沉降纵向影响范围为3.2D~6.0D,具体表现为开挖面前方1.3D~2.3D和后方1.4D~3.9D。In this study,a case study is conducted on the Chongqing-Kunming high-speed railway crossing underneath the Changshui airport,and the automatically monitored data in real-time of the airport surface displacement are used to analyze the lateral and longitudinal settlement patterns of the surface caused by the construction of the cantilever boring machine method.The results show the following:(1)The overall temporal evolution of surface settlement manifests in three distinct phases:gradual fluctuation,accelerated development,and stabilization.The rapid development of surface settlement concentrates in the interval after the upper bench passes through the monitoring point and before the lower bench passes through the monitoring point.(2)The modified Peck′s formula is more effective in characterizing the distribution of lateral surface settlement caused by the cantilever boring machine construction.The final settlement of the surface is 7.3 to 25.0 mm,the strata loss ratio is in the range of 0.16%to 1.01%,the lateral impact range is 4.0D to 5.3D(D is the span of the tunnel excavation),with the most unfavorable area concentrated in the range of 1.3D on either side of the tunnel,where requires particular monitoring.(3)The unfavorable conditions,including the diagonal intersection of the upper existing airport cargo access road,hidden cavities,and rock production,result in a shift in the distribution of surface settlement troughs in some sections to the right.(4)A notable discrepancy is observed in the extent of strata loss and surface settlement attributable to the various excavation phases,the strata loss rate associated with the excavation stages of upper and lower benches,as well as the invert arch,exhibits a descending order,with the respective proportions accounting for 81.3%,17.0%,and 1.7%of the total settlement.(5)The longitudinal settlement pattern demonstrates that the longitudinal final settlement curve of the surface exhibits a pattern of increase initially and then decrease.The longitudinal influence of s

关 键 词：高铁隧道 悬臂掘进机法 地表沉降 地层损失率 影响范围 

分 类 号：U45[建筑科学—桥梁与隧道工程]