摘要
为有效减轻变电站等输电设施震害,保障输电工程的安全,选定了具有代表性的4个岩质边坡作为本文的研究对象,开展了不同岩性、地形、地质的地震动传播特性研究,初步确定了不同地形地质条件下边坡放大系数,并与《建筑物抗震设计规范》(QB 50011—2010)(以下简称规范)进行对比。得到以下结论:对均质和非均质成层类型边坡,其放大系数大小基本排序为:上软岩下硬岩>软岩>中硬岩>上中硬岩下硬岩>硬岩;对于覆盖土层岩质边坡,不同厚度的土层对放大系数影响很大,与均质边坡完全不同;软弱夹层岩质边坡的放大系数与均质岩质边坡基本一致,只是前者大于后者,差值都在0.1之内,说明当软弱夹层的厚度比较小时,软弱夹层对放大系数的影响与坡高、坡度、岩性无关;不同的夹层厚度对边坡的放大系数影响基本上呈半正弦形式;通过分析傅里叶谱,发现高边坡具有明显的放大效应,而低边坡却不明显;软岩的傅里叶幅值明显大于中硬岩和硬岩,而硬岩和中硬岩则基本相同,因此从频谱特性上也可以说明岩性不同,场地效应也不同,且坡高越大,这种区别就更加明显;在中低高度(80 m以下),傅里叶幅值几乎随坡度保持不变,且在此高度范围缓倾边坡的最大幅值基本相同,而对于高边坡,则会有所不同,坡度越陡,幅值越大,基本成线性增大趋势;对于非均质成层的边坡,坡高不同,傅里叶谱不相同,主频段也不相同;软弱夹层岩质边坡的傅里叶谱基本与相对应的均质边坡的傅里叶谱相同,无关坡高的影响,不同夹层厚度的傅里叶谱基本一致,说明夹层厚度对傅里叶谱的影响不大。与规范的放大系数相比,软岩类型均质边坡放大系数计算值基本与其相同,而对于中硬岩、硬岩和上中硬岩下硬岩等类型边坡放大系数计算值则都小于规范值,随着坡高及坡度的增加,计算值与规范值的差距则在�
In order to effectively reduce the damage of transmission facilities such as substation and ensure the safety of transmission engineering,four representative rock slopes were selected as the research object.The propagation characteristics of ground motions with different lithology,topography and geology were studied.The amplification coefficients of slope under different terrain were preliminarily determined and compared with the seismic design codes（GB 50011—2010）（later referred to as the code） and the following understanding and conclusions were gotten.The sorting of the magnification coefficient calculated for the homogeneous and heterogeneous types is basically as upper soft lower hard rock soft rock medium hard rock upper medium hard lower hard rock hard rock.For covering soil layer rock slope,different thickness of the soil layer has a great impact on the magnification factor.The magnification coefficient of the weak intercalation rock slope is consistent with that of the homogeneous rock slope,but the former is basically larger than the latter,and is basically within 0.1,indicating that when the thickness of the weak interlayer is relatively small,the effect of weak interlayer on the magnification factor is independent of slope height,slope and lithology.The effect of different thickness of weak interlayer of the slope on the amplification factor is basically like a half sine form.By analyzing the Fourier spectrum of the top and the foot of the slope,it was found that the high slope has obvious amplification effect,while the low slope is not obvious.The Fourier amplitude of soft rock is obviously larger than that of medium hard rock and hard rock,and hard rock and medium hard rock are basically the same.Therefore,from the spectral characteristics,it can also explain the different lithology can lead to different site effects and the higher the slope,this difference is even more obvious.At medium and low height（below 80 m）,the Fourier amplitude is almost constant with respect to the slope,and
出处
《工程科学与技术》
EI
CAS
CSCD
北大核心
2018年第1期51-61,共11页
Advanced Engineering Sciences
基金
国家重点基础研究发展计划资助项目(2015CB057905)
云南联合基金重点资助项目(U1402231)
关键词
不同地形地质
场地效应
频谱特性
抗震设计规范
岩质边坡
different topographic and geologic conditions
site effect
spectrum characteristics
seismic design code
rock slope
