Journal of Civil and Environmental Engineering

This paper deals with the study of the physical and hydro-mechanical characteristics of a porous limestone rock. It concerns a historic rock located at "El-Haouaria artificial caves" on the seacoast in the Northeast of Tunisia. The rock, object of study in this work, has undergone serious alterations, thus compromising the safety of the monuments. This paper focuses on the mechanical behavior of a sedimentary rock with a variable porosity; covering a wide range varying from 25% to 55%. This study is interested in identifying the mineralogical composition and the microscopic structure of the main rocks constituting the historic monument. Several tests were carried out and they showed that the rock’s mineralogical composition was calcite and quartz. The grain dimensions constituting the rock are variable. Its porosity is inter-granular and connected. This porosity changes over time due to weather conditions. Unconfined compressive tests and tensile tests were carried out on several samples with various porosities and in some cases in various saturation states. The performed tests showed the effect of both porosity and water content (suction) on strength characteristics. However, despite the rock’s dependency on the water content, the role of porosity remains more emphasized. Then, porosity seems to be the main factor affecting resistance properties due to the increase of the porosity and due to its variation as a source of humidity. A ‘’Li and Aubertin’s Model’’ was applied to predict the compression and tensile strength dependency on porosity. It highlighted a strong concordance between experimental and analytical model results. All strength characteristics evolutions with porosity and suction make up essential results obtained in this study. This will provide us with the required input data for modeling in order to predict cave structure degradation and eventually to monitor crack propagation.

In this research, new connection types were suggested, and their behaviors were determined using full-scale experiments. T-shaped combinations created using the IPE standard profile and T-shaped elements are different from those in the literature, which utilize welded plates. Thus, problems occurring at the welds of connections such as the occurrence of fracture points and inability to perform well in place are expected to be eliminated. To recommend the use of weld-less T connections, knowledge of the behavior of the connections was needed. In addition, in this research, the effects of changes in the dimensions of the connection members on the connection behavior were examined for the T-connection type. This provided information about the optimum sizes of the connection elements. The main parameters observed were the evolution of the resistance, stiffness, rotation capacity, ductility of a joint, and energy dissipation. The aim was to provide the necessary data to improve Eurocode 3 and efficiently use residue IPE standard profiles, rather than send them back to the consumption cycle.