Research on large deformation mechanism and its control of a loess tunnel entrance
On the background of construction process of a loess tunnel entrance excavation, large defor-mation on the tunnel top and adjacent slope was monitored and the maximum deformation was about 41.8 cm. Based on the detailed analysis of tunnel construction technology, site monitoring measurement and theoretical analysis method were used to deeply investigate the deformation mechanism induced by the tunnel excavation. And the relevant control measures were proposed. Conclusions deriving from monitoring results and theoretical research were shown as follows: (1) crown settlement and near-surface crack increased rapidly after eight days since monitoring points were disposed. (2) When the front slope was excavated, a larger vertical free-face was formed, that is the main inducement of the large deformation of the loess mass. (3) Construction method was optimized on the reference of monitoring information and practical engineering. Moreover, secondary lining scheme was putting forward. After supporting scheme being optimized, construction process in tunnel entrance, as well as mechanical characteristics and deformation of supporting system, were reproduced by using numerical simulation technique MIDAS. (4) Construction effect indicated that, monitoring measurement combined with numerical simulation was a valid method for determination of construction scheme in loess tunnel entrance, and it could be regarded as a reference for similar projects.
L.L. Gao S.C. Wu G.L. Fan Y.H. Wang
School of Civil and Environment Engineering, University of Science and Technology Beijing, Beijing, State Key Laboratory of Rail Traffic Control and Safety, Beijing Jiao Tong University, Beijing. Chin
国际会议
The 2nd ISRM International Young ScholarsSymposium on Rock Mechanics(第二届国际岩石力学青年学者研讨会)
北京
英文
615-620
2011-10-14（万方平台首次上网日期，不代表论文的发表时间）