摘要
采用动力有限元数值模拟的方法,设置四种不同仰坡坡度的模型,沿隧道轴向方向输入地震波,探究隧道洞口段及仰坡在不同仰坡坡度影响下的动力响应,并通过对无隧道通过的纯边坡模型与相同条件下有隧道通过的边坡模型的动力响应进行对比分析,研究隧道的存在对坡面动力响应的影响。研究结果表明：（1）由于临空面的存在,隧道洞口段的位移与加速度具有明显的放大效应。不同坡度模型的位移峰值皆位于y=0m断面的拱顶处,在距洞口y=40m后的各控制点位移差值迅速减小。（2）随着仰坡坡度的增加,同一断面处隧道的位移值随之增加,洞口段的截面变形也随之增大。（3）当坡度α≥60°时,坡面位移随着坡面高程的增加而增大;当坡度α〈60°时,坡面位移随着坡面高程的增加先增大后减小,在0.4~0.6倍坡高处达到最大,即随着坡度的增加,坡面的位移峰值也就越靠近坡顶。（4）隧道的存在对于坡面的稳定性有重要影响,这种影响在洞口附近尤为明显。
Using dynamic finite element numerical simulation,in this study,we establish models with different slope gradients（α=30°,45°,60°,and 75°）.The incident direction of a seismic wave is along the direction of the tunnel axis.As such,we studied the influence of different slope gradients on the dynamic response of the tunnel portal section and the front slope.By setting a contrast model,apure slope without any tunnel,we examined the influence of a tunnel on the dynamic slope response.The results show that：（1）In the presence of a free face,the displacement and acceleration of the portal section undergo an obvious amplification effect.The displacement peak values of different slope models are located in the section y=0m（distance from the portal）,and the displacement of each control point decreases rapidly 40 mfrom the entrance of the tunnel.（2）Along with the increase in slope gradient,the displacement value of the tunnel in the same section increases,and the deformation of the portal section also increases.（3）Whenα≥60°,with an increase in slope elevation,displacement increases;whenα60°,with an increase in slope elevation,the displacement first increases and then decreases.The peak displacement of the slope appears at 0.4~0.6of the slope height,which means that with an increase in slope gradient,peak displacement is closer to the top of the slope.（4）The existence of a tunnel has a significant influence on slope stability,which is particularly evident in the vicinity of the portal.
出处
《地震工程学报》
CSCD
北大核心
2016年第4期519-524,共6页
China Earthquake Engineering Journal
基金
中国地震局地震预测研究所基本科研业务费专项(2016IESLZ04)
国家自然科学基金项目(41562013
41472297)
甘肃省基础研究创新群体资助(145RJIA332)
关键词
黄土隧道
洞口段
仰坡坡度
动力响应
loess tunnel
portal section
slope gradient
dynamic response
