Approximately 50% of the structural plate corrugated metal pipe structures under the jurisdiction of the Ohio Department of Transportation (ODOT) are of the pipe-arch configuration. Because these structures have experienced numerous problems, the ODOT established a research project to identify and determine the causes of these problems. The initial phase of this project involved a field inspection of 890 pipe-arch structures. The inspection was conducted by each of the 12 ODOT district offices. The inspection consisted of a visual examination plus limited dimensional measurements. Specific areas that received a rating included (a) the amount of structure distortion, (b) the occurrence and severity of multiplate and bolt erosion and seepage, (c) the occurrence and extent of cracking of the multiplates, (d) the condition of the pavement over the structure, and (e) the condition of the channel bottom. A statistical analysis of the field data was performed to determine the dominant modes of structure failure and interrelationships between the structural failures and such variables as age, depth of cover, gauge of the multiplate, and geographic location. Attempts were also made to determine whether one failure mode influenced another (e.g., Distortion of the structure causing cracking, or vice versa). Results of the statistical analysis show that the dominant modes of failure or deterioration are (a) fairly heavy corrosion of the multiplates and fasteners (27%), (b) significant distortion or flatness of the structure's crown (12%), and (c) cracking of the multiplate at the corner radius bolt line (3%). Interrelationships were demonstrated with correlation coefficients of 0.9 or greater for (a) age versus durability, (b) durability versus geographic location, and (c) shape problems contributing to cracking problems, and so on.
Abstract