Landform Analysis and Ground Penetrating Radar Interpretation in Support of Arctic Civil Construction and Design: ABSTRACT

Abstract

Ground penetrating radar (GPR) is a successful and cost effective tool for imaging near surface features in arctic environments for the purpose of civil construction. Landform analysis was conducted in arctic regions to investigate soil conditions for drill pad and facility construction and to locate borrow material sources. Items of concern are the depth of the permafrost active layer and the existence of unfrozen (talik) zones that are potential hazards to site stability. GPR was used in conjunction with soil borings, frost probing and surface mapping to identify and characterize arctic landform features. GPR was also used to map the lateral extent and thickness of sand and gravel beds, and to determine depositional environments of Holocene near surface sediments. The GPR surveys provide insight into the regional geology since the last glacial period. A basal diamicton deposited during the Pleistocene is currently being incised by fluvial systems. A series of fluvial terraces was observed in the field and GPR lines clearly image a depositional architecture of migrating stacked fluvial channels that is targeted for construction materials. The GPR data also image a previously undetected older incisement interpreted as glacial outwash or possibly estuarine fill. Soil borings will determine suitability ofmore » this deposit for borrow materials. GPR in combination with orthophoto mapping and field work facilitates the classification of soil type, active layer thickness, and talik locations that will aid in facility location and design. It has also led to an understanding of the regional depositional history, which is being used to predict sand sources for construction materials.« less