HYDROLOGICAL DESIGN MANUAL FOR SLOPE STABILITY IN THE TROPICS

The purpose of this manual is to familiarise the geotechnical engineer with the importance of the dynamic hydrological control on stability for the tropical slope condition, the modelling procedure that has been developed to investigate it, the use of model generated design charts in slope design, and those procedures and measurement techniques that should be adopted in addition to standard procedures to allow a better appreciation and understanding of the stability of tropical residual soil slopes. The first section provides a summary of the development and a description of the combined slope hydrology and stability modelling scheme. Results of multiple applications of the model are summarised in the form of design charts and a methodology for their application for rapid assessment of slope stability that accounts for the influence of dynamic slope hydrological conditions provided. The charts emphasise the important control the dynamic hydrological condition has on slope stability. It is therefore necessary that standard approaches to slope design and site investigation are augmented to take account of this fact. The second section of this manual provides a set of instructions that should be adopted to achieve this end. Instruction I details the scope and methodology of application of the developed design charts. Instruction 2 describes the Resistance envelope procedure. Instruction 3 provides procedures for the measurement of slope material permeability. Instructions 4, 5 and 6 therefore relate specifically to the monitoring of soil moisture conditions. (A)