Abstract:Based on the example of a certain slope in Guangdong segment of Beijing¾Zhuhai Expressway,several groups of physical model tests are performed;and the factors affecting the stability of slope are analyzed. The testing results show that the main failure mode of counter-tilt slopes is a toppling one,which appears first on the top of the slope. The stability of counter-tilt slopes does not rest on terrane obliquity but on strength and thickness of terrane interface. It is also indicated that the failure characteristic of this kind of slope is similar to that of superposition cantilever;and the anti-toppling capability of counter-tilt slope increases with the increases of the parameters such as the parameters of interface (c,j),thickness,and obliquity of terrane.