In-Situ Measurement of Internal Earth Pressure During Landslide Movement

Abstract

Lateral internal earth pressure during landslide movement was observed in-situ at two-minute intervals. The data obtained are discussed together with other observational data for the landslide. Findings for actual landslide motion in three distinct events are summarized as follows: variation in the observed earth pressure differed with the borehole position. Variation at the onset of movement was measured in a limited number of boreholes. Large variation appeared after a certain amount of relative displacement occurred at the slip surface. There was a rapid increase in earth pressure in almost all the boreholes at the moment movement stopped. Anisotropic stresses in earth pressure that accumulated during movement were released when it stopped, and the difference in pressure before and after the sliding was small. An almost constant peak earth pressure, designated the passive earth pressure, was found in a borehole during the three events.