Arch Culvert Footing Movements

A flexibility approach is combined with a neutral point (elastic center) analysis to assess effects of differential footing displacements on the structural behavior of arch culverts embedded in deep embankments. The program was applied to a 22-ft (6.7m) arch culvert surrounded by a layer of baled straw, at Cedar Creek, California, and provided good correlations between quasi-theoretical bending moments and barrel displacements and those determined experimentally with strain-measuring devices and photogrammetrically, respectively. Large arch footing rotations are inevitable during deep embankment construction, and produce tensile thrusts at the crown. Overburden forces produce moments that augment these tensile stresses at the crown intrados. Compressive thrusts at the crown, decreased by reduction of lateral soil stresses by the straw, are insufficient to neutralize these tensile stresses. Severe intrados cracking and bowstringing at the arch crown have been observed.