Based on the thought of conservation of energy

using the modeling method of radial slice method

assuming a virtual displacement

a mathematic model of landslide stability calculation is established

so as to provide a new method for landslide stability analysis. Based on the virtual displacement ds

the gravitational potential energy change △U and the friction energy dissipation △W on sliding surface are deduced; and then the landslide stability coefficient is defined as Sc = △W/△U; finally

the mathematic expression of landslide stability coefficient Sc is obtained in two cases of considering groundwater and without considering groundwater. Through the example analysis

and comparing the calculation result with Janbu method. The results show that

without considering the groundwater

calculation results of energy method and Jianbu method is relatively close; and the former stability coefficient is slightly higher; the differential ratio is 0.19%; under the condition of considering the influence of groundwater

the differential ratio is 9.77%; the stability coefficient calculated by energy method is lower; namely

in the energy method

the influence of groundwater on landslide stability coefficient is greater. Based on example 1

the main parameters of the model are analyzed on the sensitivity of the stability coefficient of Sc. Finally

the similarities and differences between the energy method and JianBu method are essentially contrasted.