M Taremi, A Eftekhari, M Saeedi,
Volume 9, Issue 1 (6-2015)
Abstract
This paper presents a case study of the instability mechanism, to verify and reinforcement method adopted construct collapsed zone of Sabzkuh water conveyance tunnel in southwest Iran. The instability problems were encountered during tunnel excavation due to the failure, changes in stress field lead to deformation causing dilation and increasing the permeability of sand and gravel layers, local fault gouge zones, landslide and in turn significant reduction in shear strength and collapse in tunnel. IPE Arch Support Technique (IAST) was, used for T1 part of Sabzkuh tunnel zone in order to reinforce the ground around tunnel and to cross the zone falling. In this study, Finite Element Method was employed for the quantitative reinforcement effect with deformation modulus of ground, IPE length and size. As a result, the settlement increases as length increases and decreases with the increase of the deformation modulus of ground and IPE size.
Dr Nasrollah Eftekhari, Dr Sasan Motaghed, Dr Lotfallah Emadali, Dr Hasi Sayyadpour,
Volume 16, Issue 2 (Summer 2022 2022)
Abstract
In the variability of earthquake hazard analysis results, ground motion prediction equations play an important role. Selection of appropriate prediction relationships for the region can lead to stability and accuracy of earthquake hazard analysis results. In this study, different prediction relationships were investigated and analyzed for earthquake hazard analysis in Ahvaz city. These relationships were ranked based on the criteria of logarithmic probability, Euclidean distance and deviation information in different periods. Then the most efficient relationships were selected by data envelopment analysis (DEA) method on the basis of differences in the obtained results. Out of 67 possible relationships, 5 were identified as suitable relationships for earthquake hazard analysis in the Ahvaz urban area. Then, a special efficiency criterion was used to determine the weight of these relationships. The results of this study can help to reduce to a large extent the uncertainties involved in analyzing the seismic hazard of the area studied.
