NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the committee responsible for the report were chosen for their special competences and with regard for appropriate balance.
This study was supported by the National Science Foundation under Grant No. CMMI-0946245. The opinions, findings, and conclusions or recommendations contained in this document are those of the authors and do not necessarily reflect the views of the National Science Foundation. Mention of trade names or commercial products does not constitute their endorsement by the U.S. government.
International Standard Book Number-13: 978-0-309-27824-9
International Standard Book Number-10: 0-309-27824-4
Library of Congress Control Number: 2013932381
Additional copies of this report are available for sale from the National Academies Press, 500 Fifth Street, NW, Keck 360, Washington, DC 20001; (800) 624-6242 or (202) 334-3313; http://www.nap.edu/.
Cover: Cover design by Michele de la Menardiere. Top left is a screw conveyor (used to remove material excavated from a tunnel) of the world’s largest tunnel boring machine being constructed for tunnelling beneath downtown Seattle. Top right is the inside of an underground utilidor in Amsterdam; courtesy of H. Admiraal. Middle left is a laser scanned image of a building foundation under construction; courtesy of Y. Hashash. Bottom is a train departing from a Washington, D.C. underground Metro station.
Copyright 2013 by the National Academy of Sciences. All rights reserved.
Printed in the United States of America.