Abstract:Although cable is widely used in slope engineering,the prestress change rules in cable are not studied thoroughly and systematically yet,especial the prestress loss after lock and the lasting prestress of cable in cracked rock slopes. Based on the systematical monitoring and analysis in a slope reinforcement project,the prestress loss after lock,short-term and long-term prestess change rules are studied,and also the influence of rainfall on the cable prestress state is monitored and discussed. It is found that the prestress loss after lock is largely based upon the shrink of the cable after lock,which is affected by friction to some degree. The short-term and long-term prestress loss is nonlinear,and the prestress loss can be divided into three stages. The influence of rain on the prestress loss should be considered. If the slope is not stable,the rain can affect the stabilization of the slope and then affect the prestress state of cable,otherwise,it has no influence on the prestress state.