中国与尼泊尔抗震设计规范主要地震动参数对比分析

Comparative anysis on the main parameters of ground motions in seismic design codes in China and Nepal

随着中国在尼泊尔承担的铁路等工程项目日益增多,了解中尼抗震设计中地震动参数取值异同,在满足尼泊尔抗震规范条件下进行工程抗震设计是非常重要的。通过对比中尼两国工程抗震规范,分析了尼泊尔国家建筑规范(NBC)的抗震设防标准、地震区划、场地类型和地震反应谱等相关内容并与中国抗震设计规范进行对比。最后,分别总结了中尼地震动参数选取方法。研究结果表明,NBC规范将建筑物分为Ⅰ、Ⅱ和Ⅲ三个重要级别,将全国主要分为四个地震区,根据不排水剪切强度、剪切波速、标贯试验3个主要指标,将土壤划分A、B、C、D 4种类型;NBC采用最大考虑地震及设计基准地震两级地震水准;NBC将最大考虑地震下的反应谱,折减至设计基准地震,最后基于结构的延性情况进行最终折减得到最终设计反应谱。本文研究成果可为尼泊尔工程项目抗震勘察设计和施工提供参考。

With the increasing number of railway and other engineering projects undertaken by China in Nepal,it is very important to understand the similarities and differences of the seismic design codes in China and Nepal and to carry out the seismic design of the project under the condition of meeting the seismic codes in Nepal.By comparing the seismic codes of China and Nepal,this paper analyzes the relevant contents of the national building code(NBC)of Nepal,such as the seismic fortification standard,seismic zoning,site type and seismic response spectrum,and the differences of the two countries’seismic design codes.Finally,the selection methods of ground motion parameters in China and Nepal are summarized respectively.The results show that the NBC code divides buildings into three important levels:Ⅰ,ⅡandⅢ,and divides the whole country into four seismic regions.According to the three main indexes of soil shear wave velocity,standard penetration test and undrained shear strength,the soil is divided into four types:A,B,C and D.NBC uses a two-magnitude earthquake scale,namely the maximum consideration earthquake and the design basis earthquake;NBC reduced the response spectrum under the maximum consideration of earthquake to the design reference earthquake,and finally made the final reduction based on the ductility of the structure to obtain the final design response spectrum.The research results of this paper can provide reference for seismic investigation,design and construction of engineering projects in Nepal.