Lahcen Bahi

Enhancing Geophysical Signals Through the Use of Savitzky-Golay filtering method

Resumen En la cuenca de Sidi Chennane en Marruecos, existen inclusiones esteriles de caliche que dificultan la extraccion de las rocas fosfatadas y que son dificiles de detectar. La resistividad de los caliches excede un valor de 200xa0Ω-m contra 150xa0Ω-m para la roca fosfatada. Se realizo un trabajo de prospeccion electrica de tipo Schlumberger en una zona de 50 ha en la cuenca de fosfatos de Oulad Abdoun. Se obtuvieron modelos del perfil geologico mediante el filtro de Savitzky-Golay, y se logro localizar las inclusiones de caliche y las estimaciones de calculo de las reservas de los fosfatos se encuentran muy circunscritas.

The Influence of Spectral Responses on the Structures Heights

The earthquakes are abrupt and sudden, and, in few seconds, they can lead to huge casualties. Nowadays, several approaches can be used to better know the seismic movement than we can expect when and where will have an earthquake. These approaches kind, always begins with a full study of the seismic action: the seismic birth, the wave formation and propagation, accelerometers and associated spectrum representation, etc.

The Liquefaction Potential of Sandy Silt Layers Using the Correlation Between Penetrometer Test and SPT Test

Liquefaction is a hazardous and temporary phenomenon by which a soil saturated with water loses some or all of its resistance. The undrained conditions and a cyclic load increase the pores water pressure inside the soil and therefore a reduction of the effective stress.

Numerical Simulations of Ground Improvement Using Stone Columns in “Bouregreg Valley”

The soil is generally a heterogeneous material with very variable characteristics. Soil’s main issues are reflected through low bearing capacity and significant deformations (settlement) under loads. For Geotechnical experts, such problems present a challenge in many Moroccan regions like Rabat (Bouregreg Valley) and the northern regions. To overcome these defects, stone columns are used as a soil improvement technique to reduce settlement and to increase the foundations’ bearing capacity on soft clay soil. The benefits arise from the fact that there is a partial replacement of the compressible soil by a more competent material (compacted stone aggregates). Moreover the stone columns are highly permeable and act as vertical drains facilitating the soft soil’s consolidation and improving the foundation’s performance. Numerical modeling is a simple and effective method to approach the real behavior of soils reinforced by stone columns. It allows settlement analysis, lateral deformation, vertical and horizontal stresses in order to understand the behavior of columns and soil. It also has the advantage of integrating the settlements of the underlying layers, especially those of least resistance. The aim of this paper is to study the numerical simulation’s results. The properties of the soft soil correspond to “Bouregreg valley”-soil. This paper is structured as follows: the first part provides the soil conditions and the parameters related to columns and the second part presents 3D finite element analyses that study the stone columns’ performance. These 3D analyses aim to clarify the most important parameters, the influence of the constitutive models and the column geometry. The study also shows the mechanisms of functioning and interactions of stone columns vis-a-vis the various parameters characterizing the granular material “ballast” and the surrounding soil.