ABSTRACT
The main objective of this paper is to present a real case occurred in residual soils from the Peruvian amazon plane, in order to show the positive effects of the stabilization with drainage and the pore pressures dissipation that previously had originated large landslides in the season of the annual water level decrease of the Amazon River. This happens in a very short time and decreases something more than 12 meters in a fast way. This effect decreases the shearing strength of the saprolitic soil underlying, producing instability in its banks and important damages in the works of civil engineering over the surface. The results of the practiced instrumentation allowed a better planing and distribution of the drains in the affected area as well as an interpretation of the registered movement with biaxial inclinometers and the water pressures with pneumatic piezometers. All of them were associated with the extensive rains of the area, the movement of the riverbed and the rapid drawdown of the water, minimizing the risk and creating better possibilities for future investments.
