ABSTRACT:
An integrated approach to landslide hazard monitoring and data interpretation is presented. Based on geotechnical sensor data, numerical process simulation related to probable failure modes, a digital library of case histories and modelling results, and GIS tools, the approach is intended to support the data analysis and decision making of technical personnel. To improve the quality of the data derived from the numerical simulation tools for complex slopes, with variable sub-surface conditions and observed variation in displacement across the landslide surface and within the mass, a suite of tools to extract geometrical and geological data has been developed.
1 INTRODUCTION
Standard two-dimensional analyses, single mechanism considerations and direct cause-effect interpretation of monitoring data changes are often inadequate for hazard management of large slow moving landslides near critical infrastructure. This work often demands an integrated approach, incorporating monitoring using a network of variable output sensors, multi-directional monitoring, spatial and temporal data management, case history analysis, and four dimensional process modeling to understand and interpret the instrumentation results from discrete locations in space, and finite and often discontinuous intervals of time. The influences of three-dimensional geometrical variation and change (topography, structural contours and isopach complexity as well as erosion or uplift) and of key short term trigger phenomena such as pore pressure, fracture fill or frost jacking or thermal oscillation and the observable response (displacements) vary considerably; across the sliding region, with depth below surface, and in time. Large slopes and the instruments within them respond to local fluctuations in these factors and trigger phenomena, and as such average or assumed movements of the slope mass simulated by two dimensional simulation are typically in error, creating challenges in effective data interpretation and slope monitoring with discretely located and discretely sampling instruments.
