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A fully coupled finite-element model is presented to simulate geothermal reservoirs in terms of the unknown variables of displacement, pore pressure and temperature using an elasto-plastic stress-strain relationship. The mathematical model combines the simultaneous mechanisms of subsidence, mass flow and heat flow through porous media by utilizing the equilibrium, fluid flow and energy flow equations. The governing partial differential equations are based upon constant physical parameters (except fluid density) and formulated for hot-water-type geothermal reservoirs. A simultaneous solution algorithm is applied to the modelling equations yielding transient and spatial distributions of the unknown variables. Application of the simulator to actual field conditions is performed by simulating the production history of a well located in the Denizli-Kızıldere geothermal field in Turkey. The results show an excellent agreement between the computed and the observed values of temperature and pore pressure variations throughout the reservoir. 相似文献
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The distribution of polygenetic and monogenetic volcanoes of the Neogene-Quaternary Cappadocian Volcanic Province (CVP) is analyzed to investigate the relationship between vent location and regional tectonic lineaments. Two fault systems exist in the province. One system (Miocene-Quaternary Tuzgölü–Ecemiş system) is oblique, whereas the other system (late Miocene–Pliocene CVP system) is parallel to the long axis of the CVP. The polygenetic volcanoes are aligned parallel to the second system but concentrate around the major faults of the first system. Regional offsets are proposed along the first fault system based on the distribution of the polygenetic volcanoes. The monogenetic volcanoes group into five geographically distinct clusters. In the western part of the CVP, the monogenetic cones are aligned parallel to the CVP system, whereas in the central part the cones are fed by dikes injected along the recent fractures of the Tuzgölü–Ecemiş system. In the eastern part, the monogenetic cones form along the radial fractures of the Erciyes composite volcano. 相似文献
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Deformability of rock masses influencing their behavior is an important geomechanical property for the design of rock structures. Due to the difficulties in determining the deformability of jointed rock masses at the laboratory-scale, various in-situ test methods such as pressuremeter, dilatometer, plate loading tests etc. have been developed. Although these techniques are currently the best and direct methods, they are time-consuming and expensive, and present operational difficulties. In addition, the influence of the test volume on deformation modulus depending on the method employed is also important. For these reasons empirical equations to indirectly estimate the deformation modulus have also been recommended by several investigators as an alternative approach. In this study; the geomechanical quality of weak, heavily jointed, sheared and/or blocky greywacke rock masses, on which very concentrated civil works are continuing at the southern and southwestern parts of Ankara (Turkey), was assessed. The deformation modulus was determined by pressuremeter tests, the possible effects of variables on the derived deformation modulus from the pressuremeter test were evaluated by numerical methods, and the comparisons between the deformation modulus of the greywackes obtained from the pressuremeter tests and their geomechanical quality (GSI and RMR) were made. Numerical simulations revealed that the presence of a disturbed annulus around the borehole causes underestimation of the deformation modulus, while the effect of length to diameter ratio of the pressuremeter probe on the deformation modulus is minor. Based on the geo-engineering characterization assessments, mainly two greywacke rock masses with different geomechanical qualities were identified. Geotechnical quality of one of these rock masses was verified by the back analysis of two slope failures. The empirical equations to indirectly estimate the deformation modulus of the greywackes using their GSI and RMR values yielded high coefficients of correlation. 相似文献
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The main objective of this study is the determination of the slope stability and excavatability category of discontinuous
rock exposed between 53+000 and 58+000 km of the proposed Ankara–Pozantı autoroad in Turkey to provide secure access. The
study area is mostly in the outcrops of highly jointed sandstone with minor layers of marl. This Maastrichtian–Eocene Group
also contains conglomerate and limestone bands of flysch character called the Pas˙ada* Group. Quaternary alluvial deposits
occur throughout the site. The area was divided into four design sectors based on cut slope locations. Rock slope stability
was assessed kinematically as well as through utilizing limit equilibrium analyses. The excavation category was determined
to range from hard to extremely hard ripping. Remedial measures for unstable rock slopes are discussed.
Received: 22 July 1997 · Accepted: 14 April 1998 相似文献