摘要
以西安地铁穿越地裂缝区域为工程背景,采用振动台模型试验,模拟地震荷载作用下地裂缝场地的动力响应。试验结果表明:地震荷载作用下,地裂缝场地中的隐伏地裂缝逐渐出露,随着地震动力荷载的持续作用,裂缝在地表贯通,并在裂缝的上盘区域中生成与之相交的次生裂缝,地裂缝内部的松散充填土体沿裂缝向上运动。地震动力荷载作用下,地裂缝场地产生不均匀沉降,且地裂缝位置产生的沉降大于其两侧区域,不均匀沉降导致地裂缝两侧产生张拉力,张拉力继而使隐伏地裂缝扩展出露地表,同时伴随裂缝宽度增加。振动过程中,地裂缝场地上盘所产生的动力加速度大于场地下盘区域的动力加速度。研究结果可为地震荷载作用下地裂缝场地中的结构抗震设计提供重要参考。
The shaking table model test was used to simulate the seismic response of the ground with fissures in the region of Xi′an where metro tunnels often penetrate through the active ground fissures. It was found that the hidden fissures inside the soil body grew to appear on the surface after a while during the test and continue to expand to form through fissure lines crossing the surface. As the dynamic test continues,the secondary fissures were developed at the upper soil layer joining with the main ones. The loose soil fillings inside the fissures moved upward along the fissures. The uneven settlements occurred on the surface during the test and the largest difference of the settlements occurred just on the two sides of the fissures. The uneven settlements induced a tension between the two sides of fissures,which made ground fissures to expand its width, length and height and gradually expose to the surface. The measured accelerations at the upper layer are greater than those at the bottom layer. The results of the test may provide a guide line for the seismic design of structures in the areas of ground with fissures.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2014年第5期1024-1031,共8页
Chinese Journal of Rock Mechanics and Engineering
基金
中国科学院工程地质力学重点实验室开放基金项目(KLEG201101)
国家自然科学基金资助项目(41072222)
陕西省科技统筹创新工程计划课题(2011KTZB03–02–05)
关键词
隧道工程
地震荷载
地裂缝
模型试验
动力响应
tunnelling engineering
earthquake load
ground fissures
model test
dynamic response
