Experimental Analytical And Theoretical Investigation Of Corrugated Metal Culvert Behavior

Download or read book Experimental, Analytical and Theoretical Investigation of Corrugated Metal Culvert Behavior written by Kyong Yun Yeau and published by . This book was released on 2010 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Corrugated metal culverts have been used as drainage structures for many years. The service life time or safety of culverts is decided by load rating factors based on the culvert wall strength and soil cover depth over the culvert. However, culvert load ratings evaluated by current methods can not represent culvert condition very well due to its deficiencies. To ensure successful performance over the design life, corrugated metal culverts must be designed and evaluated using an improved load rating method. The main objective of this study was to evaluate and improve current load rating procedures for corrugated metal culverts. This objective is achieved by testing 39 in-service culverts under static and dynamic loads, by evaluating the response of test culverts using available theoretical methods and numerical simulations, and by evaluating and advancing the current analysis tools and load rating methods based on the analytical and experimental evidence generated in this research. The experimental program was conducted to investigate the influence of several parameters on the field performance of culverts. These parameters include cover depth, various static and dynamic load applications, and existing condition, size, shape, and other properties of corrugated metal culverts. Experimental results showed that maximum culvert deflections decreased nonlinearly with increasing cover depth. Deflections and strains were nearly zero in deep culverts with cover depth larger than 13 ft (4 m). Under static and dynamic truck loading, culvert deflections and strains increased significantly when the cover depth was less than about 6.5 ft (2.0 m). Responses of some of the test culverts were simulated using the two-dimensional finite element program CANDE and three-dimensional finite differential program FLAC3D. Deflections predicted from CANDE analysis were larger than deflections measured in the field. However, the moments and thrusts calculated from experimental strains were similar to those calculated using CANDE. Deflections and thrust forces predicted by FLAC3D program were very similar to experimental results. According to numerical simulation results, important factors affecting culvert behavior are cover depth, culvert size, corrugated metal thickness and soil properties especially the elastic modulus of soil. Experimental data and available theoretical studies were used to evaluate the current load rating methods. Recommendations are made to improve the analysis and evaluation procedures for corrugated metal culverts. Recommendations are based on an extensive review of load rating procedures and design practices, experimental data from 39 test culverts, and theoretical and numerical investigations. The recommended load rating procedures do not consider the effect of cover depth. New capacity reduction factors are introduced for culvert wall and seam, which require different appraisals for wall and seam during annual inspections. The effect of external live loads on load rating procedures is eliminated when load rating factors for deep culverts and culverts subjected to low live load stresses are considered.