This paper discusses the reasons why the number of karst collapses has been
increasing in Tangshan, China, since 1978. It gives the main factors that
influence the regional risk of karst collapse and the method for assessing
it. Using the risk assessment method developed, three zones in downtown Tan
gshan, with different risk levels, were delineated. Based on the risk asses
sment results, some recommendations are given on the treatment of karst col
lapse and related urban engineering issues.