Relation between Stability of Slope and the Urban Density: Case Study

Abstract

Themain of this work is to present a study that permits to obtain a quantitative assessment of the urban density under seismic condition on sloped land. The research of relation between the bearing capacity of soil and the urban density is based on the modeling of the physical weight of an urban composition and the limit capacity of soil. The referential urban shape is assimilated to a planar parcel situated in one big number of square plots. The vertical component of earthquake acceleration is considered as additional force to the static weight of the buildings, and the horizontal component is taken as additional force that increases the lateral force of slope. This approach permits the analysis of the global slope stability of an urbanized land. The elaboration of this study is a response to the disaster risk reduction that sustainable urban development recommends. The urban composition is characterized by a mathematical system composed by two equations represented respectively by the urban density and the site coverage ratio. This system is indeterminate because there is one unknown: the building footprint; and one correlation: the plot surface. To solving this problem, it is demanded to use loop procedure, and finite difference method that consists in introducing a random value of density, and then to comparing the obtained density with the introduced value. The study beginswith the evaluation of the weight of the floors, and thenfollows with thedistribution of the weight of all buildings, that composes one orthogonal parcel, on the global surface of parcel. This repartition gives an equivalent uniform charge. Therefore, by this simplification, it is possible to resolve the problem by static method. At last, the study finishes by the presentation of graphs showing the relation between the soil bearing and the urban density.