1. Research Engr., Shell Development Co., Houston, Tex.; formerly, Research Assoc., Dept. of Civ. Engrg., Mass. Inst. of Tech., Cambridge, Mass
2. Engr., Bechtel Power Corp., Gaithersburg, Md.; formerly, Research Asst., Dept. of Civ. Engrg., Mass. Inst. of Tech., Cambridge, Mass
3. Prof. of Civ. Engrg., Mass. Inst. of Tech., Cambridge, Mass