黄土随机振动强度参数在地震滑坡分析中的应用

APPLICATION OF LOESS STRENGTH PARAMETERS UNDER RANDOM VIBRATION IN ANALYSIS OF SEISMIC LANDSLIDES

摘要:

地震滑坡往往是黄土地区最突出而且最严重的灾害类型。为了寻求黄土地区震害预测方法,作者选择了位于1920年海原大震10度区内的回回川滑坡进行具体研究。分析中运用了输入随机地震动时程的不规则波动三轴仪强度试验所得的参数。在稳定性分析中采用了求解临界地震系数的方法,反演得出回回川滑坡形成前原始斜坡坡角为5°-15°的安全系数为3.3,是一个相当稳定的斜坡。而在地震力作用下,在具有相当于地震烈度8度强或9度弱的地震动加速度时就产生滑动。反演结果与实际较吻合,说明本文提出的方法是分析滑坡形成规律和对黄土斜坡进行稳定性分析的切合实际且较为准确的方法。

Abstract:

Loess seismic landslides are usually the most outstanding and serious disasters type in disaster area of earthquakes. To seek for a method of predicting the earthquake disasters, the authors made a study of seismic stability analysis on the typical Huihui Chuan loess seismic landslide in Xiji county with 10 degree intensity of the great Haiyuan earthquake in 1920. In order to conform the analysis result to reality, the parameters gained from strength tests on dynamic triaxial apparatus by an irregular wave of random seismic loading was used. In the stability analysis, a method of soluting critical seismic coefficient was adopted. The result of invering the landslide is coincident with reality. For clarifying the forming rules and the stability analysis of loess seismic landslides, this paper provides a more accur ate method which is more conformable to reality. This paper brings it forth new ideas to apply strength parameters under random vibration and the method of stability analysis.