New method to search the most dangerous failure slope surface freely

Based on the Janbu slice method for the calculation of integral stability of slope, an improved genetic algorithm, named MIGA was proposed, which can freely search the most dangerous failure slope surface and calculate the corresponding minimum safety factor without supposing the geometric shape of the most dangerous non-circular failure surface. This improved genetic algorithm can simulate the genetic evolutionary process of organisms and avoids local minimum value compared with the classical methods. It is a global optimal algorithm, so it has higher searching efficiency than simple genetic algorithm (SGA). The safety factor calculated by MIGA is the least compared with that by other methods in engineering, and the most dangerous failure surface searched by MIGA agrees well with the reality, so its advantages are verified.