Abstract: The vertical earth pressure on the top of rectangular trench-buried culverts is analyzed experimentally and theoretically under the condition of non-cohesive soil. Taking account of effect of the soil masses beside culverts, a new model and formulation for calculating the earth pressure is proposed. The calculated results agreed with the experimental results. The results show that the coefficient of earth pressure decreases monotonously with the increases of the depth of soil overlying culverts if trench width equals to the outer diameter of the culverts; and the coefficient increases first and decreases afterwards if trench width exceeds the outer diameter of the culverts; the coefficient is the maximum as the depth of burial becomes the height of the initial plane of equal settlement. The coefficient and the height of the plane of equal settlement increase in hyperbola with increasing ratio of trench width to culvert width. The trench width that is 7 times the diameter of the culverts is approximately the critical width between trench-buried culverts and positive-buried culverts. The coefficient increases with the increasing angle of internal friction of the soil. The height of plane of equal settlement decreases as the depth of soil overlying culverts increases. The height of plane of equal settlement decreases as the depth of soil overlying culverts increases.

Key words: rectangular trench-buried culverts, earth pressure, model experiment, plane of equal settlement, formula