About the authors Richard G. Ahlvin's career has been predominantly in the area of research into the behavior of soils. His schooling has ranged from a structural civil engineering degree, through much of a degree in mechanical engineering, to an advanced degree in highway engineering, all from Purdue University. In addition, Mr. Ahlvin has taught elementary and advanced surveying, testing materials, and engineering mechanics at Purdue and soils for transportation facilities at Mississippi State University Extension at Vicksburg. He is a licensed professional engineer. Vernon Allen Smoots is a...