摘要
研究目的:为研究地震作用下地震高烈度区软岩隧道加速度动态响应的基本规律,以拉林铁路杰德秀2号隧道工程为背景,设计进行了1∶50比例隧道结构模型的振动台试验。通过输入白噪声、EL波和汶川波,测试模型结构的动力响应,分析各个测点峰值加速度的放大系数随高程变化和不同地震烈度条件下的变化规律,并通过快速傅里叶变化得到功率谱频谱曲线,分析模型结构的加速度动力特性,对比各个加载工况下加速度频域响应曲线,研究模型结构频域动力响应的基本规律。研究结论:(1)地震高烈度区软岩隧道其场地高程效应的表现形式与一般场地表现不同;(2)随着地震动幅值的增大,各测点峰值加速度放大系数呈减小趋势,在0.15g加速度激励下表现出最大值,且不同频率特征地震波激励对高程效应形态的影响基本一致,仰拱处地震响应最大,在进行隧道抗震设防时,应加强对仰拱部位的抗震措施;(3)围岩土体对加速度放大效应较为显著,而隧道衬砌结构对加速度的放大效应效果不太明显,地层的响应特性在很大程度上决定着衬砌结构的地震响应特性;(4)功率谱密度曲线显示出不同地震波激励下模型结构响应峰值相差不大,但峰值所对应的频率值不同,高频段地震波对衬砌结构影响较小,低频段地震波对衬砌结构影响较大;(5)本研究成果可为地震高烈度区隧道抗震设计建设提供一定的理论参考。
Research purposes:In order to study the basic law of dynamic acceleration response of soft rock tunnel in high seismic intensity area under earthquake action,shaking table test of 1∶50 scale tunnel model was designed and carried out on the background of Jiedexiu No.2 tunnel project of Lasa-Linzhi Railway.Through input white noise,EL wave and the wave of Wenchuan,the dynamic response of model structure is tested,the change rule of peak acceleration amplification coefficient of various points with the change of height and different seismic intensity is analyzed,the power spectrum is obtained by fast Fourier change spectrum curve,the acceleration dynamic characteristics of the model structure are analyzed,the acceleration response curves in frequency domain under various loading conditions are compared,and the basic law of dynamic response in frequency domain of the model structure is studied.Research conclusions:(1)The site elevation effect of soft rock tunnel in high seismic intensity area is different from that of general site.(2)With the increase of ground motion amplitude,the peak acceleration amplification coefficient of each measuring point shows a decreasing trend,and shows a maximum value under 0.15g acceleration excitation.The influence of seismic wave excitation with different frequency characteristics on the elevation effect form is basically the same,and the seismic response at the inverted arch is the largest.When conducting tunnel seismic fortification,the seismic measures at the inverted arch should be strengthened.(3)The amplification effect of surrounding rock soil on acceleration is obvious,but the amplification effect of tunnel lining structure on acceleration is not obvious.The response characteristics of stratum largely determine the seismic response characteristics of lining structure.(4)The power spectral density curve shows that the response peaks of the model structure under different seismic waves are similar,but the corresponding frequency values are different.The high frequency seismic
作者
李仁强
马至刚
衣忠强
朱宝龙
吴红刚
LI Renqiang;MA Zhigang;YI Zhongqiang;ZHU Baolong;WU Honggang(China Railway No.9 Group Co.Ltd,Shenyang,Liaoning 110000,China;Southwest University of Science and Technology,Mianyang,Sichuan 621010,China;No.6 Engineering Co.Ltd,China Railway No.9 Group,Shenyang,Liaoning 110000,China;Northwest Research Institute Co.Ltd of C.R.E.C,Lanzhou,Gansu 730000,China)
出处
《铁道工程学报》
EI
北大核心
2022年第9期56-63,92,共9页
Journal of Railway Engineering Society
基金
国家重点研发计划(2018YFC1504901)
甘肃省自然科学基金(21JR7RA738)
中铁九局集团第六工程有限公司科技发展项目(KJ-2021-05)
关键词
软岩隧道
振动台试验
加速度响应
频谱曲线
soft rock tunnel
shaking table test
acceleration response
spectrum curve
