摘要
设计中的某市区小净距隧道下穿小区多层楼房,采用数值方法研究了小净距平行隧道下穿施工过程。研究结果表明:隧道施工到楼房最近点前,楼房基础发生的超前沉降占总沉降的13%～24%,研究断面封闭前基础沉降占总沉降的56%～63%,而研究断面初期支护全断面封闭后发生的沉降仅占总沉降的12%～24%;当隧道左右线均穿过楼房最近点并施工完毕后,楼房基础区域地表最大沉降值为16.5 mm,基础局部沉降为0.0004 L,基础倾斜值为0.00042;右线隧道施工导致隧道拱顶上方围岩塑性区扩展至右线隧道地表。上述规律表明,隧道施工可能导致地表出现开裂,应对地表沉降进行观察和监测,同时优化施工工序,缩短右线隧道初期支护全断面封闭时间,从而有效控制地表的总沉降量,减小对既有房屋的影响。
A designed tunnel with a small clear distance will be constructed beneath multistoried buildings, so a numerical method was used to analyze its effects. Results indicate that the advance settlement ratio tor the toundation is 13%-24% of total settlement before construction and reaches 56%-63% of total settlement before section clousure. The settlement after the clousure of the full face section of the primary support only covers 12% --24% of total settlement. The maximum ground settlement at the foundation area of the building is 16.5mm after the left and right lines pass through the nearest point and construction is finished, with a foundation local settlement of 0.0004L and inclination of 0.00042. The plastic area spreads to the earth surface during construction of the right tunnel. The above laws indicate that some cracks may occur because of the tunnel construction, which is why observation and measurement on the earth surface is essential. Meanwhile, the construction process should be optimized with a shortened closed time of the primary support in a whole section so the total settlement of the earth surface can be controlled effectively and effects on existing buildings can be minimized.
出处
《现代隧道技术》
EI
北大核心
2011年第5期30-38,共9页
Modern Tunnelling Technology
关键词
小净距隧道
下穿施工
多层建筑
Parallel tunnel with small clear distance
Construction beneath
Muhistoried building
作者简介
赵东平（1979-），男，工学博士，主要从事隧道及地下结构设计、复杂隧道数值分析等工作，E-mail：dpingzhao@163.com
