Abstract:Research purposes: The laws of strata deformation induced by large diameter shield driving in the water-rich sandy gravel sensitivity in this stratum are not clearly known due to the large gap between particles, none cohesion stratum. Based on displacement of the deep soil were the Beijing underground diameter line project measured and analyzed to know the laws of the surface subsidence and the high and horizontal strata deformation induced by shield tunnel driving in the water rich sandy gravel stratum.
Research conclusions: Before remolding of the shield cutter head, the maximum surface subsidence was about 17.0 mm, the transverse influence range of the surface subsidence was about 40 m on each side of the tunnel centerline, the longitudinal influence range of the surface subsidence was about 1.25 times of the tunnel diameter in front of the tunnel working face and 4.15 times of the tunnel diameter in rear of the tunnel working face and the maximum transverse and longitudinal displacements values of the deep soil on both sides of the tunnel were 11.0 mm and 6.8mm respectively on the horizontal plane of the tunnel center. After remolding of the shield cutter head, the maximum surface subsidence was reduced to 8.0 mm or below and the horizontal displacements of the deep soil on both sides of the tunnel were also reduced. It can be seen the surface subsidence can be effectively controlled by remolding of the shield cutter head. The peck equation matched the surface groove curve before and after the remolding of the shield cutter head. However the changes took place in the strata loss rate and width coefficient of settlement trough. This research results can provide reference to the similar projects.
Teng Li, ZhangHuan. Meso-macro Analysis of Surface Settlement Characteristics during Shield Tunneling in Sandy Cobble Ground [J]. Rock and Soil Mechanics, 2012(4):1141-1160.
Yang Shujiang. Slurry Shield Construction Technology for Launching Section of South Railway Station-Provincial Stadium Running Tunnel of Chengdu Metro[J]. Tunnel Construction, 2007(6):43-46.
[3]张双亚, 陈馈.北京铁路地下直径线盾构选型[J].铁道工程学报,2007(3):70-73.
Zhang Shuangya, Chen kui. Shield Machine Type SeleMion for Beijing Underground Transit line [J]. Journal of Railway Engineering Society, 2007(3):70-73.
Zhao Baohua, Hu Xibo, Zhang Bing, etc. Study on Ground Settlement of Large Diameter Slurry Shield Construction in Water-rich Sandy Gravel Stratum [J]. Engineering Sciences, 2010(12):94-102.
[5]Peck R B. Deep Excavations and Tunneling in Soft Groun[C] //Proceedings of the 7th International Conference of Soil Mechanics and Foundation Engineering,1969.
[6] Attewell P B, Yeates J, Selby A R. Soil Movements Induced by Tunnelling and Their Effects on Pipelines and Structures[M]. Glasgow: Blackie, 1986.
[7] Mair R J, Taylor R N, Bracegirdle A. Subsurface Settlement Profiles above Tunnies in Clays[J]. Geotechnique, 1993(2):315-320.
[8]韩煊, 李宁, J. R. Standing. Peck公式在我国隧道施工地面变形预测中的适用性分析[J].岩土力学, 2007(1):23-35.
Han Xuan, Li Ning, Jamie R Standing. An Adaptability Study of Gaussian Equation Applied to Predicting Ground Settlements Induced by Tunneling in China[J]. Rock and Soil Mechanics, 2007(1):23-35.