摘要
地铁近接施工安全影响是轨道交通建设所面临的重要问题,相关研究与分析对于现场施工及既有结构安全具有重要意义。以西安地铁6号线侧坡出入段线明挖上跨既有区间隧道为背景,通过对出入段线分块、分层开挖以及结构回填过程的数值模拟,得出明挖施工卸载再加载过程对下卧隧道的影响程度。计算表明,周边地层受明挖施工卸载再加载效应影响较为明显,总体变形表现为隆起抬升,最大隆起量出现在基坑底部,约为48.15 mm;下卧隧道受出入段线施工影响的最大隆起量为10.86 mm,结构差异变形量为0.008 9%,出现在右线隧道被上跨部分底部;隧道管片最大拉应力为2.13 MPa,最大压应力为4.92 MPa。隧道变形量满足结构安全要求,隧道结构应力远小于其设计强度,出入段线施工对下卧隧道影响较小。
The study of influence of Metro construction on existing structures is very important. Numerical simulation is made on portioning excavation and structural backfilling of access section of Xi＇an Metro Line No. 6 crossing above existing shield tunnels. The influence of unloading and reloading induced by open cut construction of the access section on lower shield tunnels is studied. The calculation results show that： 1） The influence of unloading and reloading induced by open cut construction of the access section on surrounding soils is obvious; the soils tend to uplifting and the maximum uplifting occurs to foundation pit base for about 48. 15 mm. 2） The maximum uplifting of lower right line shield tunnel is 10. 86 mm; and the differential deformation of structure is 0. 008 9%. 3） The maximum tensile strength and compressive strength of tunnel segment are 2. 13 MPa and 4. 92 MPa respectively. The results show that the deformations and stresses of the tunnels can meet the safety requirements.
出处
《隧道建设》
北大核心
2016年第7期826-831,共6页
Tunnel Construction
关键词
西安地铁
出入段线
近接开挖
影响性评估
明挖法
盾构隧道
Xi＇an Metro
access line
adjacent excavation
influence assessment
open cut method
shield tunnel
