MECHANISM FOR INITIATION AND DEVELOPMENT OF JIETAI TEMPLE LANDSLIDE IN BEIJING

Jietai temple landslide is located in the north wing slope of Maanshan mountain, Mentougou district of Beijing. The rock mass of the slope is weaker. Cracks is well developed. Rock mass of the slope is strongly unloaded and weathered severely after it had experienced several tectonic movements. The slope has daylighting bedding planes. Weak interlayers, weak structural surfaces and faults are well developed. All these discontinuities provided cutting and slipping surfaces for the landslide. Because the dip angle of the beddings is greater than that of the slope, the slope cant slide down along the bedding surface. Thus, the slope is a creep deformable body and controlled by specific discontinunity structures. Two coal mines locate in the middle of the mountain slopes. The mining activities such as excavation and blasting caused the slope rock mass to form and creep gradually and eventually to collapse locally. . Consequently, the slope creeped, relaxed and slipped along the weak planes. Rainfall water could infiltrate into the slope easily. Slope deformed and slipped more and more until its failure.