E Hajizadeh Naddaf; B Oveisi; M.R Ghasemi; M.J Bolurchi
Abstract
The analytical models in rock mechanics represent suitable analysis of deformation and failure conditions of the samples bearing simple geometry and mechanical properties. Nowadays different methods of numerical modeling, like finite difference method (FDM), are used for analysis of continuous, non- ...
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The analytical models in rock mechanics represent suitable analysis of deformation and failure conditions of the samples bearing simple geometry and mechanical properties. Nowadays different methods of numerical modeling, like finite difference method (FDM), are used for analysis of continuous, non- and quasi- continuous behavior. This paper represents logical estimate of geomechanical properties of the Asmari formation with usage of the results of triaxial tests on intact rock samples of the upper limy part of this formation and also the finite difference methods. For this purpose, we designed some models containing simple boundary condition and only one rheological unit. To simulate the failure conditions of the samples, a geomechanical simulative software (Flac 2D) was used. The failure of samples under the experienced stress conditions in laboratory were of basic data for simulation of failure conditions by finite difference method. The results show that the cohesion coefficient and uniaxial tensile strength are of sensitive parameters in controlling the failure conditions. This study suggests that the values of Young's and Bulk modulus are 260GPa, 23GPa, respectively, when the uniaxial tensile strength and cohesion coefficient are considered 29MPa and 26MPa, respectively.
H. Bahrami; A. Uromiahy; M. Ahmadi; S. Soleymani
Abstract
In a perfect design of underground spaces, amount of total displacement from the point of stability analysis is fundamental. In empirical and numerical stability analysis periphery of excavated area is consider as a continued mass. When an underground space is excavated by blasting process, so periphery ...
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In a perfect design of underground spaces, amount of total displacement from the point of stability analysis is fundamental. In empirical and numerical stability analysis periphery of excavated area is consider as a continued mass. When an underground space is excavated by blasting process, so periphery of tunnel is damaged by that process. As a result, those materials are not continued. In this research this area named "Crashed areola". 3 dimensional distinct element methods has more adapted with this area, while compared to other numerical methods. 3DEC 4.0 which is based on this method was chosen as a numerical codes. 10th kilometers of Gavooshan tunnel which is water conveyance tunnel is considered as a case study. The part of this tunnel which studied in this research is surrounded by ophiolithic gabbro rock mass. For modeling of this tunnel two conditions were considered, first with continue media of rock mass and second discontinue media so called crash areola. One of the advantages of this part of tunnel is installation of instrumentation with very scientific methods and absence of lining in the other hand. The outputs of numerical solution were shown that modeling by considering crash areola is near to data collection by instrumentations.