摘要
通过振动台模型试验对穿越活动地裂缝的地铁隧道的动力响应进行研究,研究内容主要包括地铁隧道的加速度反应,土压力及应变的变化规律。分析结果表明,穿越活动地裂缝的地铁隧道在地震荷载作用中,活动地裂缝场地产生不均匀沉降,上盘沉降大于下盘区,预设地裂缝部位沉降值最大,不均匀沉降导致次生裂缝及沉降陡坎产生,地铁隧道上方场地土体产生细小裂缝;地铁隧道与活动地裂缝的加速度时程曲线均与地震动荷载加速度时程具有一致性,地铁隧道各部位加速度时程保持一致,说明在地震中地铁运动保持整体性,上盘场地的加速度峰值较大,表明在活动地裂缝中上盘区对地震动力有一定的放大效应;活动地裂缝场地中土压力呈现出动土压力性质,地震加载结束后隧道结构侧向的土压力受力状态及大小均产生变化,隧道结构顶部的土压力有较大增加;应变曲线表明,在扩大断面的马蹄形隧道结构中拱腰部位的应变增值最大,拱顶部位次之,底板的应变增值相比最小。以上成果对于合理认识跨越地裂缝的地铁隧道的地震响应特征具有重要意义,可为地铁隧道实际工程设计和施工的抗震设防提供宝贵的基础资料。
Xi?an metro tunnel passes through active ground fissures. The dynamic responses of the horseshoe shaped metro tunnel under the seismic loads were studied with the shaking table test focusing on the acceleration,the earth pressure and the strain of the tunnel. The uneven settlements occurred in the seismic tests with the largest values along the fissure. The settlement at the hanging wall was larger than that in the footwall. There were cracks in the soil above the tunnel appeared after the seismic loading. The accelerations along the tunnel were similar in every points showing that the tunnel was kept its integrity. The acceleration in the hanging wall was larger than that in the footwall showing a seismic amplification in the hanging wall. The value and direction of earth pressure changed with the seismic loads with the largest values occurred at the middle of the arch, the second largest at the top of the arch and the lowest one at the bottom of the floor.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2015年第7期1384-1391,共8页
Chinese Journal of Rock Mechanics and Engineering
基金
陕西省自然科学基金资助项目(2013JM5004)
中央高校基金重点项目(2014G2260009)
中央高校科研事业费专项资金项目(CHD2010JC072)
关键词
隧道工程
地裂缝
地铁隧道
振动台模型试验
地震响应特性
tunnelling engineering
active ground fissure
metro tunnel
shaking table model test
seismic response
