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ABSTRACT: This study is concerned with main causes of fault/shear formation and the utilization of various experimental techniques for their evaluating mechanical properties. In the first part, the results of several experimental studies on the formation of fault/shear zones are presented. Then, some proposals have been done how to characterize the geometry, fracturing, morphology, and internal structure of fault/shear zones and some examples are given using some rock classifications. Then, some direct shear tests were performed on the actual fault gouges and their actual characteristics have been evaluated. The characterization and evaluation of the properties of fault/shear zones using RMQR rock classification method are explored. In addition, the utilization of conventional and modified Needle Penetration Index (NPI) for assessing the characteristics of fault/shear core is investigated. Finally, the presented procedures and techniques are applied to actual fault/shear zones and they are validated. 1. INTRODUCTION Fault/shear zones commonly exist in Earth’s crust and they may be encountered almost in all engineering projects. They may cause very severe engineering problems such as heavy water in-flow, squeezing, instability. They may be pathways for leakage of radio-active wastes to the environment as shown in Figure 1. Many fundamental studies on fracture/shear zones have been done by various researchers (e.g., Cloos, 1930, 1968; Tchalenko, 1970; Roth et al. 1981; Tsuneishi, 1978). Hubbert (1951) and Hafner (1951) were first to give the first theoretical treatise of fracture/shear formations in non-cohesive materials. In engineering applications, some studies were concerned how to locate important structures outside the potential rupture zones (e.g. Cole and Lade, 1984a,b; Bray et al. 1992). Many experimental studies on hydro-mechanical properties of fractures zones and faults in several institutes (e.g. Byerlee 1990, Kutter and Rautenberg, 1979; Lama 1978; Moore et al. 1983; Rutter et al. 1986; Archambault et al. 1990). They tested several types of gouges found in fractured zones and faults under different environmental conditions such a normal pressure, temperature, water content, loading rate.

The mechanism and causes of a landslide, which blocked a road to transportation and took place in 500 m NE of Ergenekon village of Serdarli District located on the southern slopes of Besparmak Mountain Range in Turkish Republic of Northern Cyprus, are investigated in this study. The failure surface was within the melange and resulted in buckling of the road up to 2 m. Different limiting equilibrium methods and discrete finite element method (DFEM) were used for the assessment of the slope instability. The factor of safety of the slope ranges between 1.22 and 1.26 when the slope is dry. The results showed that the slope failure may occur when the pore water pressure has a value ranging between 0.25 and 0.35. A failure surface, which is a combination of discontinuities with tectonic origin, was assumed for the stability assessment of the slope by using a pseudo-dynamic version of DFEM and the results indicated that the slope becomes unstable when pore water pressure in the slope forming material becomes 0.4.

The wedge failure is one of the common forms of slope failures. In this study, the authors investigate the sliding responses of rock wedges under dynamic loads rather than the initiation of wedge sliding. Firstly some laboratory model tests are described. On the basis of these model tests on rock wedges, the theoretical model proposed previously is extended to compute the sliding responses of rock wedges in time domain. The proposed theoretical model is applied to simulate the sliding responses of rock wedge model tests and its validity is discussed. In the final part, the method proposed is applied to actual wedge failures observed in 1995 Dinar earthquake, 2007 Cameli earthquake and 2005 Pakistan-Kashmir earthquake, and the results are discussed.

Azan (Aizanoi) antique city was first established by Phrygians and later become a part of Roman Empire. This city was the first city in the world to introduce the flood protection measures by constructing dams and embankment walls. Two of the four stone masonry bridges are remaining and they are still used today. The authors have performed some site investigations and surveying of these remaining stone bridges. In this study, the response and stability of stone bridges are investigated using finite element method under various loading conditions and the results of the investigations and analyses are presented and discussed. © 2016 Taylor & Francis Group, London.