从地形地貌类型复杂程度、强地震活跃水平和天然黄土动力易损特性方面综合考虑,黄土高原城乡存在潜在地震滑坡、震陷、液化、地震动放大、活断层影响等地震灾害风险。在该区域城镇化发展过程中,城镇规模的扩张普遍是向地震灾害风险更高的地域推进,这可能会使地震安全问题更加突出。本文通过分析已有的相关研究结果与抗震减灾工程实践,梳理归纳了黄土高原城镇建设中存在的特殊地震安全问题,提出了活动断层避让、黄土地震灾害区划与预测、黄土地震滑坡影响区域预测及避让、黄土震陷与液化的初判与详判、黄土场地地震动放大效应和黄土场地基桩负摩阻力与水平推力计算等工程预防措施,这些措施已被纳入《甘肃省建筑抗震设计规程》。
The potential seismic hazards, such as seismic landslides, seismic subsidence, liquefaction, site effect and influence of seismic faults, in Loess Plateau of China have to be concerned due to the complicated landform, high level of seismic activity and dynamic vulnerability of natural loess. In the urbanization process of Loess Plateau, the urban development generally expands into the region with a higher risk of seismic hazards. The situation of seismic safety in the region will become much worse. In this paper, the special seismic safety issues in the process of urban development in Loess Plateau through analyzing the existing research results and relative engineering practices were summarized. The preventive engineering measures were proposed including avoidance of active fault, zonation and prediction of loess seismic hazards, prediction and avoidance of seismic loess landslide, preliminary and detailed judgment of loess seismic subsidence and liquefaction, evaluation of loess site effect, and calculation of negative skin friction and horizontal thrust of pile foundation respectively caused by seismic subsidence and liquefaction of loess, which has been adopted by "Specification for Seismic Design of Buildings in Gansu Province".