含小净距隧道岩石边坡地震动力特性的大型振动台试验研究

发布时间：2019-02-25 11:44

【摘要】：为研究含小净距隧道岩石边坡在地震作用下的动力特性,设计了一个比尺1∶10的含小净距隧道岩石边坡的大型振动台试验模型,试验以汶川波(WC)作为振动台激振波,采用水平(x)向、竖直(z)向和水平竖直(xz)向三种激振方式,研究地震作用下边坡的加速度响应特性和动位移响应特性。试验结果表明:1)边坡加速度放大系数沿坡面向上呈现出先减小后增大的非线性变化特征,边坡会改变输入地震波的频谱成分,对高频段地震波存在滤波作用。2)x、z单向激振下边坡加速度放大系数随着加载加速度峰值的增大而增大,xz双向激振下则随着加载加速度峰值的增大而减小。3)以3/5坡高为界,此高度以下,边坡对竖向地震波的放大作用大于对水平向地震波的放大作用,在此高度以上则刚好相反。4)边坡水平方向位移主要受水平向地震波的影响,且随着激振加速度峰值的增大而增大。5)以4/5坡高为界,此高度以下动位移峰值增大趋势缓慢,此高度以上,动位移响应峰值急剧增大,且在坡顶处产生最大的水平位移。6)边坡的动位移响应与地震波的激振方向和测点位置有关。试验研究结果对含小净距隧道边坡抗震设计及其地震动力反应特性的研究有一定的指导意义。
[Abstract]:In order to study the dynamic characteristics of rock slope with small net distance under earthquake, a large shaking table test model of rock slope with small net distance is designed at 1:10. Wenchuan wave (WC) is used as shaking table excited wave in the experiment. The acceleration response characteristics and dynamic displacement response characteristics of slope under earthquake are studied by using three excitation modes, namely horizontal (x) direction, vertical (z) direction and horizontal vertical (xz) direction. The experimental results show that: 1) along the slope surface, the acceleration magnification coefficient shows a nonlinear change characteristic of decreasing first and then increasing, and the slope will change the spectrum composition of the input seismic wave, which can filter the high frequency seismic wave. 2) x, the acceleration magnification factor of the slope will change the frequency spectrum of the input seismic wave. 2) x, Z under unidirectional excitation, the slope acceleration magnification coefficient increases with the increase of the loading acceleration peak value, while that under the xz bi-directional excitation decreases with the increase of the loading acceleration peak value. 3) the slope height is bounded by 3 ~ 5 slope height, and below this height, the slope acceleration magnification coefficient increases with the increase of the loading acceleration peak value. The amplification of vertical seismic wave by slope is greater than that of horizontal seismic wave. 4) the horizontal displacement of slope is mainly influenced by horizontal seismic wave. And it increases with the increase of the peak value of excitation acceleration. 5) the peak value of dynamic displacement increases slowly below this height, and the peak value of dynamic displacement response increases sharply above this height, when the height of the slope is 4? 5, the peak value of dynamic displacement increases slowly under this height. The maximum horizontal displacement is generated at the top of the slope. 6) the dynamic displacement response of the slope is related to the direction of excitation of the seismic wave and the position of the measuring point. The experimental results are helpful to the study of seismic design and seismic dynamic response of tunnel slope with small spacing.
【作者单位】：中南林业科技大学土木工程与力学学院;中南林业科技大学岩土工程研究所;
【基金】：国家自然科学基金项目(51204125,51404309)
【分类号】：U451.5

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