behnam parmas

Summary Several newly constructed tunnels, which have been damaged by earthquake loading, have led to extensive research on the evaluation of earthquake effects on tunnels. Underground structures are increasingly being built and exploited in the context of urban expansion and development. Tunnels are one of the most important underground structures. Failure of several tunnels under earthquake loading, and especially damage to these tunnels, have been the reasons to investigate the effects of earthquake on the tunnels.   Introduction Various activities, especially during earthquake, on the adjacent structures are of particular importance. This importance will be more in the vicinity of the historical building, due to their vast material and spiritual values. In this research, using the Henkel type I and three scale accelerometers related to the earthquakes in Northridge, Tabas and Kobe, and employing the expanded FESCAM program in MATLAB environment, the historical structures of thirty-three buildings have been studied.   Methodology and Approaches In this research, nonlinear time histories analysis has been used to generalize Henkel's relationship and to calculate the exact difference. The input waves have been investigated by the researchers for use in the Henkel harmonic waves function. The Henkel function of the first type using the mentioned accelerations is used considering the amount of dissociation, the degree of strain and stress around the twin tunnels as an additive parameter to the limited element analysis of the present study.   Results and Conclusions In this paper, the operation of differentiation is expanded with the use of mathematical relations. A case study of twin tunnels is Si-o-se-pol twin tunnels. The results of this study show that the mean displacement of horizontal thirty three bridges there in comparison with the failure to consider the effect of fractionation is increased by 28.8% and the displacement rate of the thirty three bridges compared to the failure includes the difference of 11 / 30%. Moreover, the displacement of underground structures during an earthquake is less than that of the ground structures. The results of the Mann-Whitney test with the SPSS software program have shown that there is no significant difference between the seismic performance of the thirty three bridges with the effect of tunneling dispersion and without the effect of tunneling dissociation (P-value≥0.05).

In this study, to evaluate the effects of climate change on temperature, precipitation and future droughts in Shadegan Basin, output of the MPI-ESM-LR، BCC-CSM1-1 and NORESM1-M general circulation models under diffusion Scenarios RCP4. 5 and RCP8. 5 is used. The outputs of general circulation models are downscaled using LARS-WG software. To evaluation of drought, the standardized precipitation index (SPI) is used for the base period (1986-2005) and Future period (2020-2039) and in time scales of 6, 12 and 24 month. The results showed that the maximum temperature and minimum temperature increased in all months the future period under RCP4. 5 and RCP8. 5 scenarios in the Shadegan Basin. Precipitation changes do not show a general increasing or decreasing trend. The results showed that under RCP4. 5 scenario and in time scales of 6, 12, and 24-month, respectively 17. 16, 14. 70 and 18. 74 percent of all months the future period would be dry. In addition, Under RCP8. 5 scenario and time scales of 6, 12, and 24-month, respectively 16. 45, 17. 03 and 15. 21 percent of all months the future period will be dry. The months of dry under RCP4. 5 and RCP8. 5 scenarios in future period, in time scale 6-month respectively 2. 27 and 1. 56 percent will be increase, in time scale 12-month respectively 2. 77 and 0. 44 percent will be decrease and in time scale 24-month respectively 2. 00 and 5. 53 percent will be decreased. So anticipated under climate change in future period, the number of drought months is less than the number of months with normal and wet conditions.