摘要
为充分利用青岛地区上软下硬地层中相对较好的地质条件,对双侧壁导坑法进行了改进。改进工法将开挖导坑减少到6个,缩短了工期。同时,实现了“以锚代撑”,减少了支撑用量。改进工法使中隔壁落于下部坚硬岩层上,并打设锁脚锚杆,下部岩体采用放坡开挖,并保留岩肩以保证中隔壁受力稳定。为了验证改进工法的可行性与安全性,对现场实测数据进行了详细分析。结果表明:地表沉降随隧道开挖过程逐渐增大,最大值为-43.49mm;拱顶沉降和净空收敛最大值分别为-18.61mm和-17.76mm。监测数据均未超过施工警戒值,施工过程安全,从而达到减少工序转换、降低支撑费用的目的。
In order to make full use of the relatively good geological conditions in the upper soft and lower hard strata in Qingdao area, the construction method of double sidewall pilot tunnel is improved. The optimized method decreases the number of pilot tunnels to 6, which simplifies construction steps and shortens the construction period;meanwhile, it replaces support with bolt and reduces the support usage. The improved construction method enables the center diaphragm to fall on the lower hard rock layer, and a locking bolt is installed. The lower rock layer is excavated by slope, and the rock shoulder is retained to stabilize the stress of the center diaphragm. In order to verify the feasibility and safety of the improved construction method, the field monitoring data are analyzed in detail. The results show that the surface settlement gradually increases with the tunnel excavation process, and the maximum value is-43.49 mm. The maximum vault settlement and clearance convergence are-18.61 mm and-17.76 mm respectively. The monitoring data do not exceed the construction alarm value, and the construction process is safe. Therefore, the purpose of reducing process conversion and cost is achieved.
作者
朱丹晖
李东阳
李梦
ZHU Danhui;LI Dongyang;LI Meng(China Railway Engineering Design and Consultant Group Co.,Ltd.,Jinan,Shandong250022,China;School of Mechanics&Civil Engineering,China University of Mining&Technology(Beijing),Beijing100083,China;China Communications Press Co.,Ltd.,Beijing100011,China)
出处
《施工技术》
CAS
2021年第11期88-91,共4页
Construction Technology
基金
国家自然科学基金(41771083)。
关键词
地铁车站
双侧壁导坑法
中隔壁
上软下硬地层
监测
数据分析
subway stations
double sidewall guiding pit method
center diaphragm
upper-soft and lower-hard strata
monitoring
data analysis
