In the present paper, four models (cases) of bridges approach slab are analyzed and their results are obtained by using finite element software SAFE 2014. The finite element models adopted in this study have five parameters; compressive strength of concrete (f' c ), normal modulus of subgrade reactions of soil (k), approach slab thickness (h), number of longitudinal ribs and position of applied load. The analytical results concluded that the settlement decreases with the increase of compressive

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... strength of concrete by about (8%, 14%, 19% and 24%) for (f' c ), (30, 35, 40 and 45 MPa) respectively. Also, presence of ribs layers in longitudinal direction leads to reduce the settlement by about (33%, 40% and 52%) for flat plate with (2-ribs, 3-ribs and 4-ribs), respectively. The settlement decreases with the increasing of the slab thickness (h) by about (45%, 65%, 76% and 82%) for slab thickness, (250, 300, 350 and 400mm), respectively. Furthermore, when using different values of (k), which can be considered as indicator of the soil stiffness, a significant change in settlement was recorded. This means, the settlement control depends mainly on strength, geometry of slab and modulus of subgrade reactions of soil.