Methods of Making Material Surveys

This paper reports on the activity of the authors for their part of a committee assignment under the chairmanship of Mr. Finney for Committee D-5, Highway Research Board. Our part of this study has been to show how airphotos and various non-engineering maps could be used to obtain information which would assist in material surveys. This was provided for in the general purpose of the committee assignment which was to bring up to date the various methods of conducting materials surveys and make them available to the engineering public. In accomplishing this, four areas in southwestern Indiana were selected which were covered by airphotos, an agricultural soil map, a topography map, and a geology map. The four areas lie in Gibson and part of Posey counties within a few miles of each other. For each area, an independent survey was made using only the data which would be provided by the particular method when used alone. The methods used in this study are by no means new to the engineering profession. The use of agricultural soil maps for engineering soil survey has been presented before the Purdue Road School, Highway Research Board, and other organizations on pre­ vious occasions. Likewise, the importance of geology maps, topog­ raphy maps, and airphotos for use in soil and material surveys is to be found in the literature. The use of maps and literature in obtaining engineering information is the subject of a graduate course in civil engineering at Purdue University. Much of the literature on this subject is of the “it can be done” type and not the “how-to-do-it” type. Some basic principles have been set forth but procedures and techniques or “method­ ology” have not. With this in mind the secondary purpose of this study is to show step-by-step how these methods can be used and to