The city of Tangshan lies on the edge of the North China Tangshan Fault in the east (Fig. 1). Movement on the Plain, south of the Yanshan mountain range in north Tangshan fault was the cause of the 1976 earthquake. eastern China (Fig. 1). It also lies at the centre of what The greater part of the city is underlain by thick was probably the most devastating earthquake in alluvial deposits which comprise various combinations recorded history. On 28 July 1976 the city was almost of clay, silt, sand and gravel. These superficial deposits totally destroyed by an earthquake of magnitude 7.8 cover an irregular bedrock topography of Ordovician whose epicentre lay almost exactly below its centre. The limestone and Permo-carboniferous sandstone, shale total number of deaths will never be known but it was and coal. A series of hills of weathered and eroded undoubtedly of the order of 240 000 (Chen-Yong et al. bedrock are present in the central and northern districts 1988) and may have been as high as 650 000 (Jennings of the city where they have been uplifted between the 1980). The number of those injured was about 700 000. Tangshan and Dou He River Faults.
The Tangshan region lies at the intersection of two A major effort was made to reconstruct the city after fault systems, the east—west trending Yinshan—Yanshan the earthquake and this included taking into account belt and the north-northeast trending Ji-Liu fault block engineering geological factors in the reconstruction system which consists