Abstract:

Two aspects are always neglected in the existing research about start-up criterion of translational gliding landslide：one is the normal component force of hydrostatic pressure at posterior border of slope，which acts on slip surface，the other is the action range of confined water. Therefore the calculation results of start-up criterion of translational gliding landslide are inaccurate. Overall force analysis are exerted on translational gliding landslide，meanwhile the conception of action range of confined water is introduced，then the modified start-up criterion is deduced. The modified start-up criterion is applied to analyze the results of physical simulation. It shows that the result of the modified criterion is about 6.0% to 15.5% larger than the traditional criterion and much  close to the observed value. The modified criterion is proved to be accurate. Mechanism analysis is applied in the differences of critical hydraulic between the test results and the calculation results obtained from the modified start-up criterion of translational gliding landslide. When the sliding surface inclination of the model slope is less than or equal to 8 degree，the test results are greater than the calculation results obtained from the modified start-up criterion because of the hysteresis of seepage and the inhomogeneity of permeability layer. When the sliding surface inclination is greater than 8 degree，the test results are less than the calculation results due to decrease of the model stability with increase in test time.

Key words: translational gliding landslide, modification of the start-up criterion, action range of confined water, physical simulation, pore water pressure