ABSTRACT
ABSTRACT: In the suburb of Dushanbe, Republic of Tajikistan of ex-USSR, an earthquake of magnitude 5.5 took place on January 23, 1989. In this event, extensive liquefaction developed in the loess deposit of Aeolian origin in the gently sloping hilly terrain and lead to a series of catastrophic landslides accompanied by a large-scale mudflow. In contrast to the hitherto known cases of liquefaction which have usually occurred in water-sedimented sand deposits, the liquefaction in Tajik was unique and novel in that it occurred unexpectedly in wind laid deposit of silt in a semi-arid region. The reasons for such liquefaction are thought to be the collapsible nature of highly porous loessal silt which had been wetted by irrigation water over the past year. The complete collapse of the loess structure due to the additional action of the seismic shaking appears to have lead to the catastrophic landslide.
