zipper braced frames are an innovative bracing system for steel structures. conventional inverted-v-braced frames exhibit a design problem arising from the unbalanced vertical force generated by the lower story braces when one of them buckles. this adverse effect can be mitigated by adding zipper columns or vertical members connecting the intersection points of the braces above the first floor....

Most of oil and gas offshore platforms are located in the seismic regains. So, Seismic vulnerability evaluation of the offshore platforms is one of the most important and vital issues in the structural systems. In this study, jacket type offshore platforms are studied by incorporating the pushover analyses and nonlinear time history analyses, in such a way that, first some push over analyses ar...

The proposal lateral load pattern for pushover analysis is given in two forms for symmetric concrete buildings: 1-(X/H)0.5 for low-rise and mid-rise buildings, 2- Sin(ΠX/H) for high-rise buildings. These two forms give more realistic results as compared to conventional load patterns such as triangular and uniform load patterns. The assumed buildings of 4, 8, 12, 16, 20 and 30 story concrete bui...

Seismic pounding occurs as a result of lateral vibration and insufficient separation distance between two adjacent structures during earthquake excitation. This research aims to evaluate the stochastic behavior of adjacent structures with equal heights under earthquake-induced pounding. For this purpose, many stochastic analyses through comprehensive numerical simulations are carried out. About...

accurate identification of seismic hazard and the estimation of associated seismic demands are the key components in the performance-based seismic design (pbsd). although nonlinear time history (nth) analysis is the most precise procedure to evaluate the seismic demands of buildings structures, it is relatively complex and time-consuming for routine applications. nonlinear static procedures (ns...

The writing of Iranian architectural history has, from its start, followed the principles of western historiography. Portions of this history are well expected to be neglected or unattended when writing of it takes place outside its intellectual framework that essentially reflects the Iranian throught world. To have a truly Iranian architectural historiography, one has to find the theoretical p...