含软弱夹层和均质围岩隧道洞口仰坡动力特性研究

发布时间：2018-10-23 19:46

【摘要】：针对洞口段均质围岩仰坡和含软弱夹层仰坡2种工况,开展大型振动台模型试验,分析水平和竖向激振下仰坡加速度和洞口段仰坡模型土振动特性。研究结果表明:水平向激振时仰坡存在明显加速度放大效应,竖向激振对含软弱夹层仰坡的影响不可忽视;洞口段隧道衬砌各点加速度时程曲线不一致,衬砌结构受力状态复杂;在水平向激振作用下,均质仰坡模型土坡肩土体先出现张拉裂缝,而后坡肩土体局部出现倾倒崩塌,最后沿坡面滑落堆积;含软弱夹层仰坡坡脚土体先出现挤压破碎,而后坡顶表面沿软弱夹层位置出现张拉裂缝,上覆土体沿软弱夹层滑动,最后土体大规模崩塌、滑落。本文为山岭隧道洞口段边坡抗减震研究和设计提供参考。
[Abstract]:In view of the two conditions of homogeneous surrounding rock and soft intercalation, a large scale shaking table model test was carried out to analyze the acceleration of the vertical and horizontal excitation and the vibration characteristics of the model soil in the section of the hole. The results show that there is obvious acceleration amplification effect in horizontal excited slope, the influence of vertical excitation on vertical slope with weak intercalation can not be ignored, and the acceleration time history curve of tunnel lining at different points is not consistent. The stress state of lining structure is complex, under horizontal excitation, tensile cracks appear in the soil of the soil shoulder of the homogeneous upside-slope model, then toppling and collapsing occur in the part of the soil mass of the slope shoulder, and finally the soil slides and accumulates along the slope surface. The soil of the slope with weak intercalation is crushed at first, then tensile cracks appear on the top surface along the weak intercalation, the overlying soil slides along the weak intercalation, and finally the soil collapses and slides on a large scale. This paper provides a reference for the study and design of the slope resistance and damping in the mouth section of the mountain tunnel.
【作者单位】：西南交通大学交通隧道工程教育部重点实验室;四川省交通运输厅公路规划勘察设计研究院;
【基金】：国家自然科学基金(51178398,41102220)
【分类号】：U451.2

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