جستجوی مقالات مرتبط با کلیدواژه "seismic pounding" در نشریات گروه "عمران"

The topic of pounding of adjacent structures has greatly attracted the attention of researchers in recent years. Among the observed damages due to the earthquake, one could refer to those damages induced by pounding of the adjacent structures which is a prevalent phenomenon. The reason for this issue is the lack of separation joint or its inadequacy between two adjacent buildings. When an earthquake occurs, difference in the structures' frequencies would result in difference in their reaction relative to the ground acceleration and pounding would take place. In this article the effects of site soil type, structure type, its height and distance from the fault on the separation joint for the steel and reinforced concrete moment resisting buildings with 3, 5, 8 and 12 stories are investigated. The structural models are first designed by structural design software and then are analyzed under various time histories using Seismostruct software. The obtained results show that the highest hazard risks corresponding to collision between the adjacent buildings belong to areas near the faults located on soft soil types and collision of two buildings with different types is the most severe collision. Different conditions have been discussed in this paper and based on the results, some editions to criteria of seismic design code of Iran has been proposed considering to distance to active faults, soil conditions and type of structure.

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 4.65 million time-history analyses were carried out over the considered models within OpenSees software framework. Various separation distances effects are also studied. The response of considered structures is obtained by means of Hertzdamp contact element. The models have been excited using 25 earthquake records with different peak ground accelerations. The probability of collision between neighboring structures has been evaluated. An efficient combination of analytical and simulation techniques is used for the calculation of the separation distance under the assumptions of non-linear elasto-plastic behavior for the structures. The results obtained through Monte Carlo simulations show that use of the current provision’s rule may significantly overestimate or underestimate the required separation distance, depending on the natural vibration periods of adjacent buildings. Moreover, based on the results, a formula is developed for stochastic assessment of required separation distance.

The present paper addresses the comparative study of two adjacent single-degree-of-freedom structures for elastic and inelastic systems with and without pounding. The study is also carried out in the presence and absence of tuned mass damper under (TMD) seismic excitations. The tuned mass damper considered for the present study is a passive device attached to single main structural unit in the simplest form as soft storey at the top of main system. Total eight models have been considered depending upon the presence and absence of pounding as well as TMD in the analysis. The entire numerical simulation is carried out in time domain form by considering the inputs of four real earthquake ground motions. Outcome of the present study indicates that elastic adjacent structural system always overrates the pounding forces than the inelastic adjacent structural units. The use of TMD reduces the pounding forces in the adjacent structures. During pounding, the results show that the structural displacement response is much more sensitive for inelastic systems mostly under consideration or ignorance of TMD. One of the observations is that there is large amount of variation in the structural energy formation of adjacent structures while considering or ignoring the pounding as well as TMD.