摘要
将强度折减法引入强震作用下的海底隧道衬砌结构安全稳定性研究,利用FLAC3D软件建立了海底隧道-岩土体-海水相互作用的强度折减法数值模型,综合考虑海底隧道衬砌在强震作用下的位移、剪应变增量和塑性区变化,确定了海底隧道衬砌局部破坏的极限平衡状态和整体破坏的极限平衡状态,分析了海底隧道衬砌在强震作用下的破坏机理。结果表明:海底隧道衬砌在水平地震波的作用下,主要是围岩变形导致隧道衬砌破坏;隧道衬砌破坏位置发生在右侧侧墙中部,破坏形式为剪切破坏;隧道衬砌局部破坏的极限安全系数为1.47,整体破坏的极限安全系数为1.8,2种安全系数的极限状态可对应结构设计中的正常使用极限状态和承载力极限状态。研究成果可为海底隧道衬砌设计提供理论依据。
Strength reduction method is introduced into safety and stability research on subsea tunnel linings under strong seismiceffects. A numerical model of the strength reduction method on the interaction between subsea tunnel, soil and seawater is establishedby means of FLAC3 Dsoftware. Based on changes of displacement, shear strain increment and plasticity states of subsea tunnel liningsunder strong seismic effects, the limit equilibrium states for both local failure and overall failure of linings are determined and seismicfailure mechanism for subsea tunnel linings is analyzed. The results show that under the effects of horizontal seismic waves, subsea tunnellinings are destroyed mainly because of the deformation of surrounding rocks. The destruction of tunnel linings, which is in the form ofshear failure, takes place in the center of right sidewalls. The ultimate factor of safety of the local failure of tunnel linings is 1.47 whilethat factor of the overall failure is 1.8. The limit states of the two safety factors can correspond to the limit states of both normal usageand the bearing capacity. Research results provide the theoretical basis for the design of subsea tunnel linings.
引文
[1]毛红飞,雷洪立,施平.高烈度地震区隧道抗震设计[J].交通科技,2011(3):56-58.
[2]皇民,刘马群,王安华,等.隧道地震破坏的主要形式及影响因素分析[J].交通科技与经济,2010,12(1):60-62.Huang Min,Liu Ma-qun,Wang An-hua,et al.The research of tunnel earthquake damage forms and the reasons[J].Technology&Economy in Areas of Communications,2010,12(1):60-62.
[3]蒋树屏,方林,林志.不同埋置深度的山岭隧道地震响应分析[J].岩土力学,2014,35(1):211-216.Jiang Shu-ping,Fang Lin,Lin Zhi.Seismic response analysis of mountain tunnels in different depths[J].Rock and Soil Mechanics,2014,35(1):211-216.
[4]李伟华.考虑水-饱和土场地-结构耦合时的沉管隧道地震反应分析[J].防灾减灾工程学报,2010,30(6):607-613.Li Wei-hua.Seismic response analysis of immersed tube tunnel considering the dynamic interactions between water,stratum and structure influence of liquid parameters on the damage of buried pipeline[J].Journal of Disaster Prevent and Mitigation Engineering,2010,30(6):607-613.
[5]冉申德,钟辉虹,肖宏彬.地震荷载作用下沉管地基砂垫层液化的可能性[J].自然灾害学报,2007,16(1):123-126.Ran Shen-de,Zhong Hui-hong,Xiao Hong-bin.Liquefaction possibility of immersed tunnel’s sand ground under earthquake[J].Journal of Natural Disasters,2007,16(1):123-126.
[6]彭海阔,孟光,丁麒,等.在地震激励下动水压力对沉管隧道的影响[J].上海交通大学学报,2008,42(6):1027-1031.Peng Hai-kuo,Meng Guang,Ding Qi,et al.The influence of hydrodynamic pressure on immersed tunnel under earthquake excitation[J].Journal of Shanghai Jiaotong University,2008,42(6):1027-1031.
[7]杜修力,王进廷.动水压力及其对坝体地震反应影响的研究进展[J].水利学报,2001(7):13-21.Du Xiu-li,Wang Jin-ting.Review of studies on the hydrodynamic pressure and its effects on the seismic response of dams[J].Journal of Hydraulic Engineering,2001(7):13-21.
[8]黄光虎,滕伟福,高林.基于强度折减法的港珠澳大桥沉管隧道干坞工程高边坡稳定性分析[J].安全与环境工程,2012,19(3):111-115.Huang Guang-hu,Teng Wei-fu,Gao Lin.Stability analysis of high rock slope in the dry rock project of Hong kong-Zhuhai-Macao bridge immersed tunnel based on strength reduction method[J].Safety and Environmental Engineering,2012,19(3):111-115.
[9]郑颖人,赵尚毅,张玉芳.极限分析有限元法讲座-Ⅱ有限元强度折减法中边坡失稳的判据探讨[J].岩土力学,2005,26(2):332-336.Zheng Ying-ren,Zhao Shang-yi,Zhang Yu-fang.Study on slope failure criterion in strength reduction finite element method[J].Rock and Soil Mechanics,2005,26(2):332-336.
[10]赵尚毅,郑颖人,王建华,等.基于强度折减安全系数的边坡岩土侧压力[J].岩石力学与工程学报,2010,29(9):1760-1766.Zhao Shang-yi,Zheng Ying-ren,Wang Jian-hua.Discussion on calculation method of slope rock-soil lateral pressure based on factor of safety with strength reduction[J].Chinese Journal of Rock Mechanics and Engineering,2010,29(9):1760-1766.
[11]张黎明,郑颖人,王在泉,等.有限元强度折减法在公路隧道中的应用探讨[J].岩土力学,2007,28(1):97-101.Zhang Li-ming,Zheng Ying-ren,Wang Zai-quan,et al.Application of strength reduction finite element method to road tunnels[J].Rock and Soil Mechanics,2007,28(1):97-101.
[12]李秀地,郑颖人,袁勇,等.沉管海底隧道强度折减法分析探讨[J].岩土工程学报,2013,35(10):1778-1785.Li Xiu-di,Zheng Ying-ren,Yuan Yong,et al.Strength reduction method for submarine immersed tunnels[J].Chinese Journal of Geotechnical Engineering,2013,35(10):1778-1785.
[13]郭小红.厦门翔安海底隧道风化槽段衬砌结构稳定性研究[D].北京:北京交通大学,2011:40-47.