(1. School of Civil and Hydraulic Engineering，Hefei University of Technology，Hefei，Anhui 230009，China；2. State Key Laboratory of Coal Resources and Mine Safety，China University of Mining and Technology，Xuzhou，Jiangsu 221000，China；3. Anhui Key Laboratory of Civil Engineering and Materials，Hefei University of Technology，Hefei，Anhui 230009，China)
Abstract：The metro line 1 in Hefei is in a close distance to piles of a viaduct foundation. Shield tunneling of the metro line 1 could therefore affect the safety of the piles of the viaduct. The stresses and the horizontal deformation of the piles and the ground settlements under different working conditions during the process of shield advancing were analyzed based on the mechanical principle of coupled springs for bridge-pile structures and the finite difference method. Close-distance shield tunneling with the nearest distance of only 0.63 m was found to have great effect on viaduct piles and the magnitude of the effect was closely related to the position of shield machine. The effects were superimposed upon the shield advancing of the twin tunnels in succession. As the shield was gradually close to the piles，the bending moments，the shear forces and the displacements were increased continuously. The maximum superimposed values of the bending moments，the shear forces and the horizontal displacements were 700.5 kN•m，159.6 kN and 2.39 mm respectively and were occurred when the head of the shield just passed the second row of piles and the shield tail just entered the first row of piles in the right tunnel. The space formed at the peripheral of lining segments in the rear of shield tail was found to be the main cause of the ground loss when jack pushed forward the shield machine. The flexural equation of piles was fitted by the displacements from the monitoring of piles. The bending moments and shear forces of piles in various advancing steps were thus calculated and the calculation method was verified by a case study.
[1] 徐 明，谢永宁. 盾构隧道开挖对邻近单桩基础的影响[J]. 华南理工大学学报：自然科学版，2011，39(4)：149–155.(XU Ming，XIE Yongning. Effect of shield tunneling on adjacent single-pile foundation[J]. Journal of South China University of Technology：Natural Science，2011，39(4)：149–155.(in Chinese))
[2] LOGANATHAN N，POULOS H G，STEWART D P. Centrifuge model testing of tunnelling-induced ground and pile deformations[J]. Geotechnique，2000，50(3)：283–294.
[3] PANG C H，YONG K Y，CHOW K Y. The response of pile foundation subjected to shield tunneling[C]// Proceedings of the 5th International Conference of TC28 of the ISSMGE. London：Taylor and Frarcis，2005：737–743.
[4] SELEMETAS D，STANDING J R，MAIR R J. The response of full-scale pile to tunneling[C]// Proceedings of the 5th International conference of TC28 of the ISSMGE. London：Taylor and Frarcis，2005：763–769.
[5] 韩进宝，熊巨华，孙 庆，等. 邻近桩基受隧道开挖影响的多因素三维有限元分析[J]. 岩土工程学报，2011，33(增2)：339–344.(HAN Jinbao，XIONG Juhua，SUN Qing，et al. Multi-factor three- dimensional finite element analysis of effects of tunnel construction on adjacent pile foundation[J]. Chinese Journal of Geotechnical Engineering，2011，33(Supp.2)：339–344.(in Chinese))
[6] CHENG C Y，DASARI G R，CHOW Y K，et al. Finite element analysis of tunnel-soil-pile interaction using displacement controlled model[J]. Tunnelling and Underground Space Technology，2007，22(4)：450–466.
[7] 王明年，崔光耀，喻 波. 广州地铁西村站近接高架桥桩基影响分区及应用研究[J]. 岩石力学与工程学报，2009，28(7)：1 396–1 404. (WANG Mingnian，CUI Guangyao，YU Bo. Research on influential partition and application of adjacent viaduct pile foundations in Xicun station of Guangzhou metro[J]. Chinese Journal of Rock Mechanics and Engineering，2009，28(7)：1 396–1 404.(in Chinese))
[8] LEE G，NG C. Effects of advancing open face tunneling on an existing loaded pile[J]. Journal of Geotechnical and Geoenvironmental Engineering，2005，131(2)：193–201.
[9] 张 恒，陈寿根，邓稀肥. 盾构法施工对地表及桥梁桩基的影响分析[J]. 地下空间与工程学报，2011，7(3)：552–557.(ZHANG Heng，CHEN Shougen，DENG Xifei. Analysis of influence of shield tunneling on ground and bridge pile[J]. Chinese Journal of Underground Space and Engineering，2011，7(3)：552–557.(in Chinese))
[10] 杨晓杰，邓飞皇，聂 雯，等. 地铁隧道近距穿越施工对桩基承载力的影响研究[J]. 岩石力学与工程学报，2006，25(6)：1 290–1 295. (YANG Xiaojie，DENG Feihuang，NIE Wen，et al. Study on effect of metro tunneling on carrying capacity of pile foundation[J]. Chinese Journal of Rock Mechanics and Engineering，2006，25(6)：1 290– 1 295.(in Chinese))
[11] 何海健，项彦勇，刘维宁. 地铁施工引起邻近桥梁桩基差异沉降的概率分析[J]. 岩石力学与工程学报，2007，26(增1)：3 257–3 265. (HE Haijian，XIANG Yanyong，LIU Weining. Probabilistic analysis of tunneling-induced differential settlement of a pile-supported urban overpass bridge[J]. Chinese Journal of Rock Mechanics and Engineering，2007，26(Supp.1)：3 257–3 265.(in Chinese))
[12] 李进军，王卫东，黄茂松，等. 地铁盾构隧道穿越对建筑物桩基础的影响分析[J]. 岩土工程学报，2010，32(增2)：166–170.(LI Jinjun，WANG Weidong，HUANG Maosong，et al. Influence of piles of structure induced by crossing tunnels[J]. Chinese Journal of Geotechnical Engineering，2010，32(Supp.2)：166–170.(in Chinese))
[13] MAIR R J. Research on tunnelling-induced ground movements and their effects on buildings-lessons from the Jubilee line extension[C]// Response of Buildings to Excavation induced Ground Movements. London：CIRIA，2003：3–26.
[14] Itasca Consulting Group，Inc.. FLAC3D manual[R]. Minneapolis，USA：Itasca Consulting Group，Inc.，2005.
[15] 张海波，殷宗泽，朱俊高. 地铁隧道盾构法施工过程中地层变位的三维有限元模拟[J]. 岩石力学与工程学报，2005，24(5)：755–760.(ZHANG Haibo，YIN Zongze，ZHU Jungao. 3D finite element simulation on deformation of soil mass during shield tunneling[J]. Chinese Journal of Rock Mechanics and Engineering，2005，24(5)：755–760.(in Chinese))
[16] 杨伯源. 材料力学(I)[M]. 北京：机械工业出版社，2009：71–73.(YANG Boyuan. Material mechanics(I)[M]. Beijing：China Machine Press，2009：71–73.(in Chinese))
2014, Vol. 33 
