The city of Al-Ain is located in the eastern region of the Emirate of Abu Dhabi, United Arab Emirates. The foundational bedrock of this city is mainly the Lower Oligocene limestone. It is essential therefore to understand the geological, mechanical and physical features of this rock unit in order to minimize stability problems. This paper aims to overview the geological, mechanical and physical features of the Lower Oligocene limestone. Hence, different type of tests were carried out on the selected rock block samples. The study revealed that the unconfined compressive strength of the Lower Oligocene limestone ranges from medium to low strength. The Brazilian strength values are more or less same to the point load strength index values. The sonic velocity values are in high range. The slake durability index tests for a single cycle indicate extremely high to high class. For two cycles, the test shows high to medium high class. The rock hammer hardness test exhibites quite scattering. The bulk specific gravity, the apparent specific gravity and the bulk saturated specific gravity has very limited range. The unit weigth and the water absorbsion ratio exhibite high range. As a result, the findings may be used to overcome foundation instabilities at the city.
Al-Ain city is located in the eastern part of Abu Dhabi Emirates, United Arab Emirates, Arabian Peninsula near the international border of Oman and represents one of the most urbanized city in the U.A.E (Fig. 1). Most of the foundation bedrock in this city, particularly its southern part, is made mainly of limestone beds with different interbeds of marls, all are of the Lower Oligocene age. About fifty rock block samples were described and collected from three sections on the northern part of Jabal Hafit to represent the different types of the limestone beds in this rock unit. The mechanical and physical characteristics of rocks are important information for engineering applications such as design of structures either upon or inside rock, slope instability and others. They also may controlled by their petrographic characteristics, textures, composition and environmental conditions. Number of interesting research papers were already pointed out and discuss the overall effects with respect to various rock types [13]- [33]. For this study, a great number of rock samples named the Lower Oligocene limestone were collected from different locations of Jabal Hafit, Al-Ain where the Lower Oligocene limestone is well exposed (see Fig. 1). The rock block samples were in approximately 0.50x0.50x0.50 m in size. All collected rock block samples were moved to laboratory for sample preparation. Experimental studies with rock samples were carried out under laboratory conditions. Unconfined compressive strength (UCS), Brazilian strength (BRS), point load strength index (PLSI), rock hammer hardness (RHH), slake durability index (SDI), sonic velocity (SV), unit weight (UW), bulk specific gravity (BSG), apparent specific gravity (ASG), bulk saturated specific gravity (BSSG) and water absorption ratio (WAR) tests were performed to evaluate the mechanical and physical characteristics of the Lower Oligocene limestone.