Publications

Analysis of live loads on culverts using FLAC3D

D.L. Petersen, G. Li & C.R. Nelson

ABSTRACT: AASHTO Standard and LRFD Specifications differ in the manner that live loads are spread through fill onto culvert structures. Standard Specifications apply surface point loads, and spread loads at the rate of 1.75 times depth. The LRFD specifications apply live load through a tire footprint of 10 in by 20 in at the surface but attenuate with a lower coefficient (1.00 or 1.15 as a function of soil type) as the depth of fill increases. This paper reports a 3D, numerical model-based investigation of how live loads spread with depth, as a function of soil and culvert type. The investigation included: selection of appropriate soil models, verification of model predictions, and 3D analysis of about 830 buried culverts to provide a basis for development of simplified design equations for structural response. Modeling results show that live load spreading with depth depends upon depth, soil characteristics, and culvert characteristics.

Available in Continuum and Distinct Element Numerical Modeling in Geo-Engineering - 2008

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