Part B: Site Investigation
‘… if you do not know what you should be looking for in a site investigation, you are not likely to find much of value’ (Glossop 1968, p. 113).
The term site investigation is conventionally used in civil engineering practice (e.g. Dumbleton & West 1974; Weltman & Head 1983; Hawkins 1986; Fookes 1997; bxsI 1999; Simons et al. 2002) to describe a range of studies and investigations undertaken to assess the topography, geology, geomorphology and geotechnical ground conditions of a site or an area for the purposes of engineering design. In hilly and mountainous areas, landslide and slope stability assessments usually form important elements of these studies, and are often undertaken as part of a terrain evaluation. This terrain evaluation includes office-based desk studies and field-based assessments, and comprises techniques designed to investigate, classify and interpret:
landscape and landforms;
geological structure, rock types and soil types;
geomorphological processes, ground conditions and geohazards (including landslides) prior to embarking on any subxsurface ground investigation;
groundwater conditions; and
surface drainage patterns.
Figures & Tables
This book provides a complete guide to the study, design, construction and management of landslide and slope engineering measures for mountain roads, with an emphasis on low-cost. The geographical focus of the book is on the tropics and sub-tropics, but is also highly relevant to other regions where heavy rain, steep slopes and weak soils and rocks combine to create slope instability. The causes and mechanisms of landslides are described, and the hazards they pose to mountain roads are illustrated. Methods of desk study, field mapping and ground investigation are reviewed and illustrated, with an emphasis on geomorphological and engineering geological techniques. The design and construction of alignments, earthworks, drainage, retaining structures, the stabilization of soil slopes and rock slopes, and the control of erosion on slopes and in rivers and streams are covered. Slope management as part of road maintenance and operation is reviewed, and procedures for risk assessment and works prioritization are described.