rt software @

In this study, a simplified approach is proposed for design optimization of the reinforced concrete frame considering the effects of chloride-induced corrosion. The objective function is to minimize the frame weight, and optimization will be conducted utilizing the genetic algorithm. The constraints of the optimization problem are set in a manner that bending moment of beams and axial force of columns are not exceeding the respective resistant values, and the maximum drift of the frame is not exceeding the code-defined allowable drift. In order to examine the corrosion effects, a 5-story reinforced concrete frame is optimized in two different time points 0 and 50 years in its service life. The zero time point indicates the sound uncorroded frame. Monte Carlo sampling method in Rt software is utilized to estimate the corrosion initiation time incorporating the involved uncertainties. At time point of 50 years, a cross-sectional area of steel bars in beam and column sections is reduced due to the corrosion effects. The proposed framework for the frame optimization is implemented in MATLAB software; and for computing the structural response during the optimization process, the linear static analysis of the structure in OpenSees software is conducted. Results indicate an ability of the proposed framework for design optimization of reinforced concrete frames considering the corrosion effects in their service life.

Study of immediate settlement of a rectangular foundation with the task of transferring structural forces to the ground, is one of the important factors in the design of structures. Due to its heterogeneous and anisotropicnature, soil parameters have highuncertainties, the omission of which in estimating the settlement of foundation, creates challenges in the analysis of structural stability. Therefore, the use of reliability methods with the ability to accept uncertainties and reliable stability analysis of geotechnical issues are welcomed today. In this study, in order to estimate the probability of failure due to settlement of rectangular foundation, first-order and second-order reliability methods as well as Monte Carlo simulations were used and the relevant analysis were performed in RT and @Risk software.The results indicate a high probability of failure related to the foundation settlement (9.5%). The second-order methods and Monte Carlo simulations provide more accurate results due to the non-linearity of the limit state procedure. In addition, the sensitivity analysis of random variables based on sensitivity vectors showed that thecontact stress (qo), has an important role in the probability of failure, and then the Poisson’s ratio is important.

One way to stability analysis of tunnel is to examine the convergence and radius of the plastic zone around it. On the other hand, uncertainties in the design parameters lead to the evaluation of the safety of structures using probabilistic and reliability methods. In this research was presented a methodology for stability analysis of two tunnels (under different conditions), by Hock-Brown and Mohr-Coulomb theory using robust reliability methods including: first order method (FORM), second order method (SORM) and Monte Carlo simulation in new RT and @Risk software. After probabilistic modeling in these two software, the results of the analysis show that the second order reliability method is more accurate than the first order method in more complex limit state functions. Also, at high values ​​of failure probability, first order and Monte Carlo simulation methods provide more realistic outputs and at low values ​​of failure probability, Monte Carlo simulation method is not recommended.In addition, the tunnel without pressure has a high probability of failure (24%), so that providing a support with 0.12 MPa pressure is efficient.