Assessment of the collapse mechanisms of tufa deposits

This research assesses the collapse mechanisms of tufa deposits. The city of Antalya, located on the Mediterranean coast of Turkey, has been settled on tufa deposits. By the end of 1980s, the area behind the tufa cliffs became the site of high-rise residential buildings. Some of these buildings have suffered from foundation instabilities, which have given rise to cracking and fissuring of the walls, and overall tilting. The collapsible behaviour upon loading and/or wetting of some tufa deposits has caused foundation settlement

A preliminary method for assessing sea cliff instability hazard: study cases along apulian coastline

The instability processes of sea cliffs are the result of the influence of different hazard factors that depends mainly on the coastal morphology. For this reason, the hazard associated to instability processes affecting cliffs can be carried out by means of different methodological approaches. In particular, the presence of a beach at the cliff toe, which dampens the impulsive impact of sea waves and reduces the marine processes of erosion on the cliff, allows to analyze it as a generic rocky slope with same morphology and identical geo-structural characters. Among different stability methods, heuristic approaches can provide a preliminary evaluation of the stability conditions of cliffs and a zonation of the cliff portions most susceptible to instability phenomena. In presence of fractured, anisotropic and discontinuous rocky cliffs, the stability analyses through a deterministic approach are difficult to be performed. This paper presents a procedure to assess the stability conditions of three rocky cliffs located along the Apulia coast based on a heuristic slope instability system, the Slope Mass Rating (SMR) of Romana (1985). This model was used to individuate the most unstable areas on the cliff walls, mostly prone to rockfall hazard. This procedure is particularly useful, as can address more detailed study on the cliff portions most susceptible to block detachment

Engineering geological characterization of the Antalya karstic rocks, southern Turkey

This study encompasses engineering geological characterization of the Antalya karstic foundation rocks, particularly tufa, whose mechanical behavior is highly variable. The Antalya tufa rock has no well-developed discontinuity systems. It is variably porous, and is composed of different rock types with variable structures. To reveal the engineering geological parameters and to develop a thorough engineering geological database, which is not available in the literature for the Antalya tufa rock, geological observations, engineering geological site investigations, mineralogical analyses, field (plate load tests) and laboratory geomechanics tests have been performed. The physico-mechanical properties such as porosity, seismic wave velocity, uniaxial compressive strength, Young's modulus, deformation modulus, tensile strength, cohesion, angle of internal friction and other petrographic characteristics such as organic matter content and rock fabric that are expected to have a significant influence on its behavior were determined. Regression analyses have been performed to obtain relationships between the engineering geological parameters of the Antalya tufa rock. A number of good correlations (R-2 >= 0.75) obtained by regression analyses indicated that the Antalya tufa rock types could be differentiated better by using the strength parameters (namely, uniaxial compressive and tensile strength) and the index parameters (namely, unit weight and porosity)