摘要
在黄土地区地铁车站振动台试验中,测得模型体系加速度反应与位移反应,模型结构应变反应,地表沉降及土与结构间动土压力。分析了模型地基的边界效应、模型地基与结构的加速度反应规律及模型结构对地基地震反应的影响特征;归纳了不同峰值加速度及频谱特性地震动作用下,模型地基水平位移反应规律;并对模型体系地表沉降进行了分析。最后,根据现场观察及影像资料,对试验中模型地震破坏特点进行描述。结果表明:地震动向上传播时,模型地基加速度傅里叶谱低频部分增大,高频部分减小;在较大地震动下,土与结构动力作用较强,模型结构动力反应受周围土体控制;模型结构对地震动在地基中传播特性无显著影响;地震动具有一定方向性,且随着输入峰值加速度增大其方向性更加显著。研究结论可为黄土地区地铁车站、区间隧道及地下商业街等地下结构的抗震设计及相关理论研究提供可靠资料。
A series of shaking table tests on underground station in loess ground were performed, in which the structural acceleration, the strain, soil acceleration, displacement of soil foundation and soil pressure were measured. The simulative effect of boundary, the rules of acceleration responses of model system, and the influence of structure on the responses of model site were analyzed. Meanwhile, the horizontal displacement distribution-rules of model site were revealed and the settlement at surface of model site was analyzed. The seismic damage characteristics of model structure were summarized by observation after the test. The results show that the Fourier spectrum values of accelerations increase at low-frequency components and decrease at high-frequency components form bottom to top of soil. The seismic responses of structure are controlled by surrounding soils in severe earthquake because of strong soil-structure interaction. The seismic propagation in model site is not significantly influenced by structure, and the directional characteristics measured in the surface of ground are more obvious with the increase of PGA of input motions. The results could provide references for aseismic design and theoretical research of underground structures in loess area.
出处
《土木工程学报》
EI
CSCD
北大核心
2016年第11期79-90,共12页
China Civil Engineering Journal
基金
国家自然科学基金(41472267)
西安市地下铁道有限责任公司科研基金(D4-YJ-042014048)
中央级公益性科研院所基本科研业务费专项(DQJB14B05)
关键词
黄土地区
地铁车站
振动台试验
地震反应
动力分析
地震破坏
loess area
subway station
shaking table test
seismic response
dynamic analysis
seismic damage
