COMPUTER ANALYSIS OF NEWTOWN CREEK CULVERT

The design of corrugated-metal buried structures with spans of as much as 25 ft to 50 ft (7.6 m to 15 m) has been largely empirical. Finite element methods of analysis using computers have now been developed to provide a comprehensive and potentially more realistic model of the complex soil-structure interaction problem involved. The structure was a buried arch with a 26-ft (7.9-m) span, 15-ft (4.6-m) rise, and a soil cover of 23 ft (7.0 m). This structure was then thoroughly analyzed using the available finite element computer program, CANDE, developed for the Federal Highway Administration for use in design. The predicted values depended on the soil properties, for which suitable data were not available. This agreement was obtained by selection of the values of the soil properties by successive trials based on a comparison of the computed results with the correct answers for crown deflection and thrust stress. The accuracy of the predictions is therefore not yet proven. In contrast, some characteristics of other measurements, such as horizontal movement of the springline, were not easily predicted.