地震研究

对金沙江上游特米大型古滑坡的成因及古地震参数反分析进行研究。在野外详细地质地貌调查及¹⁴C年代测定的基础上,确定特米大型古滑坡是由地震触发形成,滑坡曾形成堰塞坝堵塞了金沙江,其形成时间约为7 210 BP。基于Newmark法分析了触发特米古滑坡的地震震级与震中距之间的关系,结合地质地貌调查,初步推断地震震中位于特米滑坡下游雄松—苏哇龙活动断裂上(栋索到拉扎西段),地震震级为7.0～7.4级。

The formation mechanism of Temi large-scale ancient landslide in the upper Jinsha River and back analysis of paleoseismic parameters was studied. Based on field geological and geomorphological investigation and ¹⁴C dating,we determined the Temi large-scale ancient landslide was triggered by earthquake,it had formed the landslide dam and blocked the Jinshajiang River at around 7 210 BP. Then the relationship between magnitude of earthquake that induced Temi large-scale ancient landslide and epicenter distance was analyzed by Newmark method. Combined with geological and geomorphological surveys,we preliminary concluded that the epicenter of the earthquake was located at the Xiongsong-Suwalong active fault of the downstream of the Temi landslide(Dongsuo to Lazhazi section),and the magnitude of it is 7.0～7.4.

引言
1 区域地质背景
2 特米滑坡基本特征
3 地震参数的反分析
4 结论

图1 研究区位置及区域断裂(据Chen等(2013)修改)(1722～1980年)<br/>Fig.1 Map of the location of the study area and regional faults (revised based on Chen et al.,2013)(1722～1980)

图1 研究区位置及区域断裂(据Chen等(2013)修改)(1722～1980年)
Fig.1 Map of the location of the study area and regional faults (revised based on Chen et al.,2013)(1722～1980)

图2 研究区地层岩性及滑坡位置<br/>Fig.2 Formation lithology and the location of landslides in the study area

图2 研究区地层岩性及滑坡位置
Fig.2 Formation lithology and the location of landslides in the study area

表1 研究区近300年以来发生的主要地震<br/>Tab.1 The main earthquakes occurred in the study area in the recent 300 years

表1 研究区近300年以来发生的主要地震
Tab.1 The main earthquakes occurred in the study area in the recent 300 years

图3 湖相沉积、特米滑坡和滑坡坝溃决堆积物的空间位置分布<br/>Fig.3 Spatial distribution of lacustrine deposits and accumulation masses of Temi landslide and landslide dam outburst deposits

图3 湖相沉积、特米滑坡和滑坡坝溃决堆积物的空间位置分布
Fig.3 Spatial distribution of lacustrine deposits and accumulation masses of Temi landslide and landslide dam outburst deposits

图4 特米滑坡地貌形态及堆积特征<br/>Fig.4 Landform and accumulation characteristics of Temi landslide

图4 特米滑坡地貌形态及堆积特征
Fig.4 Landform and accumulation characteristics of Temi landslide

图5 特米滑坡堆积体上游湖相沉积<br/>Fig.5 Lacustrine deposits at upstream of accumulation mass of Temi landslide

图5 特米滑坡堆积体上游湖相沉积
Fig.5 Lacustrine deposits at upstream of accumulation mass of Temi landslide

图6 特米滑坡原始地形线、堆积体地形线及滑动面<br/>Fig.6 Initial landform line、accumulation mass landform line and sliding surface of Temi landslide

图6 特米滑坡原始地形线、堆积体地形线及滑动面
Fig.6 Initial landform line、accumulation mass landform line and sliding surface of Temi landslide

表2 特米滑坡14C年代学实验结果<br/>Tab.2 14C geochronology test results of Temi landslide

表2 特米滑坡14C年代学实验结果
Tab.2 14C geochronology test results of Temi landslide

表3 原始斜坡岩石物理力学参数<br/>Tab.3 Rock mechanics parameters of initial slope

表3 原始斜坡岩石物理力学参数
Tab.3 Rock mechanics parameters of initial slope

表4 不同工况条件下使用不同方法所得原始斜坡稳定性结果<br/>Tab.4 The results of stability of initial slope by different methods under different working condition

表4 不同工况条件下使用不同方法所得原始斜坡稳定性结果
Tab.4 The results of stability of initial slope by different methods under different working condition

表5 不同临界加速度条件下Newmark法分析结果<br/>Tab.5 Results of the Newmark analysis under different critical acceleration

表5 不同临界加速度条件下Newmark法分析结果
Tab.5 Results of the Newmark analysis under different critical acceleration

图7 给定震级(MW)条件下可能导致斜坡失稳的最大震中距圆图<br/>Fig.7 Maximal distance from Temi landslide of earthquakes that can trigger slope failure for a given magnitude(MW)

图7 给定震级(MW)条件下可能导致斜坡失稳的最大震中距圆图
Fig.7 Maximal distance from Temi landslide of earthquakes that can trigger slope failure for a given magnitude(MW)

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备注

引言

1 区域地质背景

2 特米滑坡基本特征

3 地震参数的反分析

4 结论

期刊信息