CAJ | 학술논문

为研究地震作用下山岭隧道仰坡的动力响应特性及仰坡坡体和衬砌结构的相互作用，设计并完成了隧道洞口段大型振动台模型试验。试验结果表明，地震作用下仰坡的加速度反应存在显著的非线性放大效应和趋表效应；当输入地震波幅值超过0.6g 时，土体的非线性反应明显增强，加速度放大系数显著降低，表现出放大效应饱和的特性，且沿坡体竖直向上，加速度分布逐渐表现出平均化的趋势；隧道洞口段仰坡水平向动力反应受隧道结构存在的影响较小，可简化为自然边坡进行分析；仰坡的动力失稳是影响衬砌结构安全性的重要因素，当输入地震波幅值较小时，竖直向地震作用下衬砌主要受力部位受力要大于水平向地震作用，当幅值较大时，水平向地震动对衬砌结构的影响则明显大于竖向地震动；均质仰坡的破坏部位主要位于仰坡坡肩至坡面上部，破坏过程表现为地震力诱发-坡肩土体拉裂张开-坡肩土体倾倒崩塌-崩塌的土体沿坡面滑落碰撞-形成碎屑流堆积于坡脚。模型试验的结果能为山岭隧道洞口段的理论分析、计算和设计提供指导和依据。
위연구지진작용하산령수도앙파적동력향응특성급앙파파체화츤체결구적상호작용，설계병완성료수도동구단대형진동태모형시험。시험결과표명，지진작용하앙파적가속도반응존재현저적비선성방대효응화추표효응；당수입지진파폭치초과0.6g 시，토체적비선성반응명현증강，가속도방대계수현저강저，표현출방대효응포화적특성，차연파체수직향상，가속도분포축점표현출평균화적추세；수도동구단앙파수평향동력반응수수도결구존재적영향교소，가간화위자연변파진행분석；앙파적동력실은시영향츤체결구안전성적중요인소，당수입지진파폭치교소시，수직향지진작용하츤체주요수력부위수력요대우수평향지진작용，당폭치교대시，수평향지진동대츤체결구적영향칙명현대우수향지진동；균질앙파적파배부위주요위우앙파파견지파면상부，파배과정표현위지진력유발-파견토체랍렬장개-파견토체경도붕탑-붕탑적토체연파면활락팽당-형성쇄설류퇴적우파각。모형시험적결과능위산령수도동구단적이론분석、계산화설계제공지도화의거。
A large-scale shaking table model test is conducted to study the dynamic behavior of entrance slope and its interaction with lining structure of mountain tunnel under earthquake loading. Test results show that the acceleration response of tunnel entrance slope exhibits obvious amplification effect and surface effect along both vertical and axial directions. Significant nonlinear behavior is observed when the earthquake loading amplitude is larger than 0.6g;and after that, amplification factor decreases with the increase of input loading amplitude and additionally the distribution of acceleration becomes more even in the slope body. It is also found that the dynamic response along axial direction of entrance slope does not affect much by existence of tunnel structure; thus it could be evaluated by treating the entrance slope as a natural slope for simplification. On the other hand, however, the potential instability of entrance slope has much influence on the safety of tunnel structure. When the loading amplitude is relatively small, internal force induced by vertical acceleration is larger than that caused by horizontal acceleration. As the loading amplitude becomes larger, the horizontal component of earthquake plays a dominant role in affecting the lining structure. The failure surface is located at the upper part of entrance slope, especially on the shoulder. The failure process could be described as five steps:(1) earthquake excited;(2) slope shoulder cracked due to tensile failure;(3) the cracked rock of shoulder toppled and collapsed downwards;(4) the collapsed rock fell along the slope and crushed to debris; (5) rock debris accumulated at the slope toe. The experimental result provides valuable basis and guidance for analysis, calculation and design of mountain tunnel portal.