TRIVEC Measurements in the Inverse Analysis of the Long-Term Stability of a Constrained Landslide

When an active creeping landslide is constrained by a retaining structure, it has "nowhere" to go and its downhill movement in the vicinity of the structure may be even reversed (provided the anchor forces are sufficiently large). This intuitively implies that the landslide has been stabilized. However, because the landslide is slowing, the viscous part of the shear strength on the sliding surface may decrease, eventually leading to increase in compressive stresses in soil in front of the structure. If these stresses exceed the passive earth pressure, this can ultimately lead to a failure and the landslide will simply "overflow" the structure. In this paper we propose an inverse analysis procedure for a long-term stability analysis of such a landslide. The procedure is based on the curve fitting of the observed displacement data and back-calculation of earth pressure changes from retaining wall deflections measured using a TRIVEC system. Its application is illustrated on an example of the landslide stabilization project in Combe Chopin, Switzerland.