Classification of Carbonated Soils from Geotechnical Point of View (Case study: Marly Soils of Tabriz)

With the corridor development of the Tabriz city in the east direction, a large part of urban development is located in a context of uneven topography and more on marl soils, either on the surface or in the depth.
Review of scientific articles and geotechnical studies conducted at regional level indicate that in the description of Tabriz marls, no enough attention has been paid to recognize, describe and classify them; so that it is usually confined to mentioning the “marl” and describing its color. This study tries to specify some characteristics of various parameters of marls through conducting several tests in order to introduce the marl of Tabriz more and determine its position in the general definition of marl in the world; so that this study could be an introduction to a separate description and classification system that covers more distinct properties of this kind of soils and provides a more rigorous definition of it.
Marl is a simple binary mixture of clay and calcium carbonate. However, because of the vast differences in type, and origin, there is no unified definition for marl. Large volumes of lacustrine carbonate sediment outcrops, locally known as Tabriz Marl, surrounds eastern and southern regions of Tabriz city in the Azerbaijan province of Iran. Tabriz Marl is generally known as a plastic and sticky, difficult to handle, and a very poor quality subgrade and embankment material. For these reasons, considerable volumes of cut soil, produced due to numerous developing projects of urban area and industrial zones, are inevitably dumped over valleys, low-lying areas, and also on hillsides. This trend causes man- made settling and sliding soil masses, which are causing considerable property losses and damage.