Trial Load Analysis Confirm Arch Dam Model Tests

Stress and stability analyses for the 645-ft-high New Bullards Bar arch dam in California were conducted by two independent approaches: (1) Three-dimensional trial load method; and (2) structural model tests. Utilization of more than one accepted and proven method for evaluating structural designs of large arch dams is suggested. Of particular significance is the design of a high arch dam in a wide and unsymmetrical site. Stress conditions in New Bullards Bar Dam were determined for two combinations of loads representing the normal and extreme loading conditions. The same loading conditions, except for temperature changes, were simulated in the model. Results of the analyses and the model tests which included magnitude and distribution of normal and principal stresses at faces of the dam, and deformations of the arch and its foundations, facilitate not only a comprehensive review of behavior of the structure but also comparison and verification of reliability of the two methods.