Pipeline construction can be disruptive for rural communities in the vicinity of shale energy development and expensive for the pipeline companies, particularly if unanticipated blasting for excavating shallow pipeline trenches causes construction delays. A rock excavation index can be defined based on subsurface conditions interpreted from digital topography, geology, and soils data. Topographic data provide slope steepness and down-slope direction needed for evaluating sidehill conditions. Rock factors ranging from 0 for uncemented soil to 3 for nearby rock outcrop, weathered rock near top of ditch, or unweathered rock at any ditch depth can be created with GIS utilities as "rock factor" polygons along the pipeline centerline. Ground-condition variability requires subjective assessment and can be addressed in a limited way with use of seismic refraction surveys at truly random locations along the pipeline or at selected locations based on rock excavation factors. Rock excavation can be estimated using length-based and area-based percentages for ditch rock and right-of-way grading rock. Blasting details from actual construction records are needed to improve the accuracy of rock excavation estimation.
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