关键词: 地震滑坡, 砂土液化, 充填楔, 地震陡坎, 等时性, 群发性

Abstract:

Seismic landslides are divided into three categories, namely high rupture or serious landslide, landslide associated with the
separated shear surface rupture, landslide in stream facies. In the southwest China, landslides are divided into four types: lapsed,
tractive, sliding, and collapsed landslide according to the characteristics of seismic landslides. Some special geological phenomena are
found during the investigation of the characteristics of landslides in Kushuiguazi, Maoxian, Sichuan Province. The special features are:
(1) the upstream boundary thrust of landslide lake sediments and landslide groove body distribution of lake sediments show that
Kushuiguazi landslide damming events have occurred. As a result, part of the landslide is covered by lake sediments and part of it is
present, showing different covering phenomena from several other areas; (2) liquification phenomenon is found in Kushuiguazi
landslide and regular arrangement of carcks are noticed; (3) the upright scarp is discovered in the lower part of the landslide. Soils on
both sides are different in color and composition. The left side consists of silty soil, while the right side is dominated by gravel soil;
(4) cracks parallel to the sliding direction are found in the middle and lower slope; (5) the field investigation on the upper slope found a

filling wedge that consists of the large, rounded particles derived from the overlying soil. Synthesis of all kinds of features, indoor tests
and statistics analysis of data, Kushuiguazi landslide of Maoxian may be earthquake induced based on features that cannot be
explained by landslide associated with self-weight such as sand liqu fication, filling wedge, earthquake and steep scarp, fractures
parallel to the sliding direction. Also, the occurrence of lots of landslides at the same time point to earthquake as cause of the Kuguazi
landslide. The results of this study can provide some basis for the study of seismic landslides.

Key words: seismic landslide；sand liquification；filling wedge；earthquake scarp；isochronous；mass