Abstract：Taking the influence of the slope and sliding surfaces obliquities into account，a new method for determining the orientation angle of prestressed anchor cable is presented. The previous method，not considering the influence，is only a particular case of the presented method when the slope surface is parallel to the sliding surface. A range of choice for the orientation angle of prestressed anchor cable，satisfying working，constructional and structural requirements，is given. The reinforcing effect is compared between these two methods；theoretical analysis and calculation examples all confirm the advantages of the presented method over the previous one. Calculation results show that the reinforcing effect ratio of presented method to previous method is increscent with increase of the difference(absolute value) between the slope and sliding surfaces inclinations and with decrease of friction angle of sliding surface. And the increscent speed is more rapidly when the inclination angle of sliding surface is less than the inclination angle of slope surface. The presented method is especially suitable to the case when large number of prestressed anchor cables in slope reinforcement are used.
