Determination of Finite Element Modelling Errors for Box Culverts Using Field Load Tests

Abstract

Buried culverts have been in service more than half a century and their age raises questions about their reliable serviceability for the new standard vehicles. The gross weight and axle spacing of these trucks play an important role on the performance of the buried culverts where the culvert is covered with shallow fill heights. Field live load tests were conducted by driving a loaded truck over some culverts at slow speed while recording data at the critical locations of these culvert. Finite element (FE) models were developed and calibrated using field load test results. Live load distribution formulations were adopted from AASHTO LRFD Bridge Design Specifications for different fill heights. Two- and three-dimensional FE models were modelled and loaded separately to compare the critical section forces. The results showed that the error using two different FE modelling approach yields more than 100% error for the maximum section forces when fill heights is between 60 cm and 120 cm. This study is aimed to highlighting the inherent error in numerical modelling of buried reinforced box culverts for design or rating purposes.