摘要
依托我国西部高烈度地震区穿越大型活动断裂带隧道工程,开展穿越断层带多破裂面隧道振动台试验。根据测点加速度响应、动应变响应、位移响应和震后裂缝形态,研究隧道节段式衬砌结构和围岩在强度递增地震波激励下的能量、损伤变化特征,基于希尔伯特–黄变换(HHT),从Hilbert边际谱和瞬时能量谱角度讨论围岩和隧道结构的地震损伤发展。研究结果表明:(1)强震作用下模型土表面同震位移显著,根据破裂面两侧围岩同位错量可定义断层破碎带内的主、次破裂面。(2)断层下盘主破裂面附近隧道结构的损伤发展滞后于上盘,0.4 g地震作用下主破裂面附近隧道结构主频和边际谱峰值降幅最大达到了29.1%和87.1%,损伤发展程度远大于其他部位。(3)隧道结构以受拉开裂为主,0.2 g地震作用上盘主破裂面附近仰拱出现拉裂破坏,而拱腰在0.4 g地震作用产生拉裂破坏。(4)断层上盘围岩在0.5 g地震动下主频降幅达到34.7%,围岩损伤程度明显超过下盘和断层破碎带中部。(5)根据隧道结构破坏形态,仰拱是隧道抗震薄弱部位,出现了不同程度开裂,需要加强隧道仰拱的抗震与减震耦合设计;断层上盘交界面附近隧道结构地震损伤最为严重,断层破碎带中部隧道结构震害较轻,穿越断层破碎带隧道需分区抗震设防。本文结论可为高烈度地震区隧道工程抗震与减震设计提供一定的参考依据。
Relying on tunnel engineering crossing active fault fracture zone in high intensity regions in Western China,shaking table test of tunnel crossing multi-rupture surfaces was carried out.Based on acceleration,dynamic strain,displacement responses at measurement points and the state of cracks,the energy and damage characteristics of tunnel segmental lining structure and surrounding rock under incremental seismic wave excitation were studied.On basis of HHT transform method,the Hilbert marginal spectrum and transient energy spectrum demonstrated the damage trend of the surrounding rock and tunnel structure.The results are as follows:(1)The coseismic dislocation of the model soil surface is significant under ground motion,the major and minor rupture surfaces in fault fracture zone can be defined according to the dislocation displacement on both sides of rupture surfaces.(2)The damage evolution of tunnel structure near major rupture surface in footwall lagged behind that in hanging wall,the decrease in peak values of primary frequency and marginal spectrum of tunnel structure near the major rupture surface reaches the maximum of 29.1%and 87.1%under 0.4 g seismic excitation,and the extent of damage is much more serious than that in other parts.(3)Tunnel structure is mainly subjected to tensile cracking.The tensile cracking occurs in invert near major rupture surface in hanging wall under 0.2 g ground motion,while damage in arch waist appears under 0.4 g ground motion.(4)Surrounding rock in hanging wall decreases 34.7%in primary frequency under 0.5 g ground motion.The damaged degree significantly exceeds that of footwall and middle part of fault fracture zone.(5)According to the damage pattern of tunnel structure,invert is the weakest part which is easily cracked to varying degrees.The seismic design coupling damping design of tunnel invert are needed to focus on strengthening.Tunnel structure near interface between hanging wall and fault suffers most under ground motion,while tunnel in the middle of fault fracture zone suffers less.The seismic partition and fortification of tunnel engineering through fault fracture zone is required.The conclusions can provide certain reference basis for the seismic design of tunnels in high intensity seismic zones.
作者
张熙
申玉生
常铭宇
粟威
周鹏发
王浩鱇
ZHANG Xi;SHEN Yusheng;CHANG Mingyu;SU Wei;ZHOU Pengfa;WANG Haokang(Key Laboratory of Transportation Tunnel Engineering of Ministry of Education,Southwest Jiaotong University,Chengdu,Sichuan 610031,China;National Engineering Research Center of Geological Disaster Prevention Technology in Land Transportation,Southwest Jiaotong University,Chengdu,Sichuan 610031,China;China Railway Eryuan Engineering Group Co.,Ltd.,Chengdu,Sichuan 610031,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2023年第9期2237-2252,共16页
Chinese Journal of Rock Mechanics and Engineering
基金
四川省自然科学基金项目(2022NSFSC0424)
国家自然科学基金资助项目(52278414)。
关键词
隧道工程
断层破碎带
多破裂面
边际谱
裂缝形态
振动台试验
tunnel engineering
fault fracture zone
multi-rupture surfaces
marginal spectrum
cracking morphology
shaking table test
