Study of stress characteristics and its influencing factors of embankment installation slab-culverts

The actual stress state of embankment installation slab-culvert was not accurately reflected by the calculation method of earth pressure in the prevailing Chinese General Code for Design of Highway Bridges and Culverts. So the deformation laws and stress characteristics of embankment installation slab-culvert under fill-load were studied based on field test and FEM numerical simulation. Meanwhile, the key influencing factors, such as the height of embankment fill, the characteristics of fill, the dimensions of the culvert and the elastic modulus of the ground on the structure deformation and stress characteristics were also discussed. It is shown that the bending unloading effects of the top slab, the bottom slab and the lateral walls of the culvert were generated under the fill load, the distributions of vertical earth pressure on the top slab and the bottom slab, as well as the lateral earth pressure on the walls are all nonlinear, they are significantly different form the results calculated by the code method. With the increasing of the embankment fill, the earth pressures on the mid-span of the top slab and the bottom slab, as well as the position near 7h/8 (h is the height of the culvert wall) of the walls has a trend of slow increase; however, they are rapidly increased away from the above-mentioned position. The influence of the factors on the stress state of embankment installation slab-culverts should be comprehensively considered in the design and construction procedure.