In this research, Tabas area, which is located in central Iran, was selected as the study area and three geomorphic indices were calculated for its structural fronts. Through averaging these three indices, we obtained...In this research, Tabas area, which is located in central Iran, was selected as the study area and three geomorphic indices were calculated for its structural fronts. Through averaging these three indices, we obtained index of active tectonics (IAT). The values of the index were divided into classes to define the degree of active tectonics. Therefore, relative tectonic activity was calculated and their values were classified and analyzed in two groups. Regions were identified as high and moderate levels. In analyzing data and combining them with tectonic setting, the results were often associated and justified with regional geology. Our results show that the highest value is located along Shoutori fault, which shows 2 class of relative tectonic activity (high level). Also, moderate values are located along Ereshk, Ezmeighan and Jamal faults (moderate level). According to these results, Shoutori fault is the most active fault in the study area and this situation is compatible with its position as a mountain front fault.展开更多
To investigate the dynamic fracture mechanism related to blast-induced borehole breakdown and crack propagation, 2D distinct element commercial code was used. The dynamic stresses, material status and velocity vectors...To investigate the dynamic fracture mechanism related to blast-induced borehole breakdown and crack propagation, 2D distinct element commercial code was used. The dynamic stresses, material status and velocity vectors are plotted and shown to evaluate rock mass failure under blast load. This paper focuses on the propagation and dynamic effects of blast waves in continuum rock masses. In order to investigate the effect of high strain rate loading on rock mass failure, a numerical simulation was conducted. The 2D distinct element code was used to model blast load effect on rock failure and stress distribution through the rock mass due to blast wave propagation. The blast loading history was simplified and applied to the blasthole walls. Accordingly, the interaction of explosive energy transferred to the rock mass from the blasthole pressure was examined as a function of time. A Mohr-Coulomb material model was used for host rock to allow for plastic failure calculations. The conducted numerical study describes the role of dynamic stresses in blasting in a qualitative manner. On the other hand, a free face boundary was considered as a common blast operation which is conducted in surface mining.展开更多
文摘In this research, Tabas area, which is located in central Iran, was selected as the study area and three geomorphic indices were calculated for its structural fronts. Through averaging these three indices, we obtained index of active tectonics (IAT). The values of the index were divided into classes to define the degree of active tectonics. Therefore, relative tectonic activity was calculated and their values were classified and analyzed in two groups. Regions were identified as high and moderate levels. In analyzing data and combining them with tectonic setting, the results were often associated and justified with regional geology. Our results show that the highest value is located along Shoutori fault, which shows 2 class of relative tectonic activity (high level). Also, moderate values are located along Ereshk, Ezmeighan and Jamal faults (moderate level). According to these results, Shoutori fault is the most active fault in the study area and this situation is compatible with its position as a mountain front fault.
文摘To investigate the dynamic fracture mechanism related to blast-induced borehole breakdown and crack propagation, 2D distinct element commercial code was used. The dynamic stresses, material status and velocity vectors are plotted and shown to evaluate rock mass failure under blast load. This paper focuses on the propagation and dynamic effects of blast waves in continuum rock masses. In order to investigate the effect of high strain rate loading on rock mass failure, a numerical simulation was conducted. The 2D distinct element code was used to model blast load effect on rock failure and stress distribution through the rock mass due to blast wave propagation. The blast loading history was simplified and applied to the blasthole walls. Accordingly, the interaction of explosive energy transferred to the rock mass from the blasthole pressure was examined as a function of time. A Mohr-Coulomb material model was used for host rock to allow for plastic failure calculations. The conducted numerical study describes the role of dynamic stresses in blasting in a qualitative manner. On the other hand, a free face boundary was considered as a common blast operation which is conducted in surface mining.
