Study of the degradation of the geometry of the railway between the pk 80 and 105 at the plateau of Settat (Morocco)

The plateau of Settat is formed by Paleozoic age formations surmounted by a subhorizontal cover made up mainly of Cretaceous sedimentary rocks formed of limestones, sandstones and clays with alternating marly limestones and marls. The study area is characterized by a dry to semi-dry climate, an endorheic hydrographic network that flows into the plain, and is affected by a hydraulic fracturing network of WNW-ESE and NE-SW directions. These factors cause repetitive and cyclical disturbances and disorders recorded on the railway section between Settat and Machraa Ben Abbou and are due to the shrinkage-swelling of the clay formations. The statistical and critical analysis of the defects identified by the device of measuring the geometric parameters of the railway, coupled with an exploitation of the Optical and Radar satellite images, made it possible to refine the geological, hydrological and structural study of the plain studied. These approaches have shown that this hazard has been favored by the existence of recent clayey and swelling formations under the influence by the climatic, hydrological and geological contrasts marked by intense hydraulic fracturing of the zone.