摘要
G318线天全段处于深切峡谷区,在"4·20"芦山地震中共发生26处崩塌。该段崩塌仅有2处为地震中新增点,其余24处均为原崩塌点在地震中重新崩落。通过对崩塌的空间分布、与地震烈度、发震断裂、岩性及坡度的关系等方面的分析,总结芦山地震公路边坡崩塌的发育规律如下:1.崩塌规模以中小型为主;2.由Ⅶ度带到非地震影响区,随着地震烈度的降低,崩塌的规模减小、密度降低;3.崩塌分布表现出明显的"上下盘效应",双石-大川断裂上盘的崩塌分布密度约为下盘的2倍;4.崩塌在花岗岩及砂岩中多发;5.地貌及人类工程活动是崩塌发育的主控因素,地震是其重要诱发因素。震后崩塌具有隐蔽性及滞后性,在余震及强降雨条件下,区内"震裂岩体"变形加剧,公路沿线崩塌将进入高发期。
Tianquan section of China national highway 318 is located in the incised valley.During the Lushan Earthquake on April 20,2013,there were 26 collapses accounted along the 91 km highway.Only 2 collapses are new while the other 24 which are exist before the Lushan Earthquake fallen again this time.The development and distribution rules of collapses are obtained as follow through analyzing the positions and the relationship between collapses and seismic intensity,coseismic fault,lithology and gradient.1.The scales of the collapses are small （≤ 10 000 m3） or Medium（10 000 ～ 100 000 m3）.2.From Ⅶ zone to un-stricken area,the scale of collapses turn smaller and the concentration of collapses turn lower with the attenuation of seismic intensity.3.The distribution of earthquake-induced collapses has marked hangingwall effect,for the collapses concentration in the hangingwall of coseismic fault which named Shuangshi-Dachuan Fault nearly twice that in the footwall.4.The collapses mostly formed in granite and sandstone.5.The terrain and engineering activities are main factors which control the development of collapses while the earthquake is an inducing factor.The post-earthquake collapses is hysteretic and covert.They will occur along the highway in a very long time under the influence of rainfall and aftershock.
出处
《山地学报》
CSCD
北大核心
2013年第5期632-640,共9页
Mountain Research
基金
科技部基础研究专项(2011FY110100)~~
关键词
崩塌
芦山地震
G318线
天全
collapse
Lushan earthquake
China national highway 318
Tianquan County
