In this study, a fuzzy logic controller is employed to synchronize the response of two adjacent buildings coupled with a magneto-rheological (MR) damper and also, to reduce the minimum separation gap required, thus avoiding pounding hazard between adjacent buildings. Adopting a coupling strategy allows us to transform two separated structures into one system coupled by a damping device, which results in a synchronised vibrating mode between the coupled structures. A number of structural configurations presenting a high pounding risk are investigated for this study. It has been found that chances of pounding are reduced along with a reduction regarding top floor displacement and maximum drift. The use of fuzzy logic controller results in optimization of the damper force. In addition, it has been also observed that the use of a single damper at the top floor reduces responses and avoids pounding of adjacent buildings.

Earthquake induced pounding between adjacent buildings could be the source of different architectural and structural damages. A minimum distance is required in references, including seismic design codes. These differences motivate an investigation to evaluate the accuracy of each criterion. In this research, the criteria mandated by modern seismic design codes are evaluated based on the separation distances predicted by nonlinear time history analyses. The study is carried out on steel and concrete buildings with different story numbers and lateral systems. A set of 7 far and 7 near – fault records compatible with the design spectrum provided in the seismic design code of Iran (Standard No. 2800 – 4th ed.) were used in the analyses. The separation distances are obtained based on SRSS and ABS compared to the criteria mandated by IBC-2009, Euro Code 8, Standard No. 2800, and NBCC 2005. Based on the results, since the ABS method results are larger than SRSS, the criterion in standard No.2800 should be reformed. It is also indicated that the criteria should be different for far and near – fault earthquakes. For moment frames, SRSS in far fault earthquakes and ABS in near fault earthquakes are suggested. For braced frames, however, a separation distance larger than or equal to one percent of the height is required in both the far fault and near fault earthquakes.

In recent times, earthquake-induced structural pounding has been intensively studied through the use of different impact force models. The numerical results obtained from the previous studies indicate that the linear viscoelastic model is relatively simple and accurate in modeling pounding-involved behavior of structures during earthquakes. The only shortcoming of the model is a negative value of the pounding force occurring just before separation, which has no physical explanation. The aim of the present paper is to verify the effectiveness of the modified linear viscoelastic model, in which the damping term is activated only during the approach period of collision, therefore overcoming this disadvantage. First, the analytical formula between the impact damping ratio and the coefficient of restitution is reassessed in order to satisfy the relation between the post-impact and the prior-impact relative velocities. Then, the performance of the model is checked in a number of comparative analyses, including numerical simulation of pounding-involved response, as well as comparison with the results of the impact experiment and shaking table experiments concerning pounding between two steel towers excited by harmonic waves. The final outcome of this study demonstrates that the results obtained through the modified linear viscoelastic model without the tension force are comparably similar to those found by using the linear viscoelastic model.

pounding between adjacent buildings is a detrimental issue for buildings in cities because they are closely located while vibrating out of phase due to different dynamic properties (mainly different mass and/or height) during earthquake excitation. This paper presents a numerical study on the pounding between the adjacent buildings with different masses during earthquake excitation. The buildings modeled via lumped mass procedure are connected by linear vico-elastic contact force model during pounding. Seismic responses of the buildings due to earthquake acceleration are obtained for different building configurations and the results are discussed and compared. pounding effect is amplified for the lighter building while pounding effect is negligible for the heavier building.

In this paper, the results of study on seismic isolated buildings and effects of seismic gaps between such buildings and adjacent buildings during earthquake have been presented. The importance of this study can be explained as, the results can be used to evaluate the effects of seismic gap between structures which are subject to earthquake. Statistic information has been obtained by analyzing buildings with three, five and seven stories that were subjected to 20 earthquake records. Gaps among buildings changed based on characteristic of them with base isolation system; it can give us a better point. Each of structures was analyzed under the selected records and it was investigated effect of impact between them during earthquake on seismic demands. In addition for studying effects of pounding on seismic demand in structures with base isolated system, 540 nonlinear time history analysis was performed. At the end we suggested a simple and effective equation that can reduce effects of pounding on adjacent buildings.

The present aim of this study is to investigate the effect of different parameters influencing pounding in highway bridges. pounding is the result of a collision between two parts of the deck and/or the deck and abutments at the separation distance during the earthquake. In the present study, the period ratio of the adjacent frames, ground motion spatial variation, and soil-structure interaction were considered as the significant parameters influencing the pounding. Accordingly, 144 different models of bridge were generated by changing characteristics of the piers and spans length, and were subjected to non-linear dynamic analysis. The results indicated that ignoring the effects of soil-structure interaction and ground motion spatial variation led to calculate unrealistic responses in the bridges. Finally, it is found that designing bridges including frames with similar or close period is not regarded as an appropriate solution to reduce the pounding effects in the bridges.

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.

This paper investigates the effect of the soil type on the torsional response of buildings experiencing torsional pounding due to earthquake excitations. Six buildings (one 4-storey building and five 6-storey buildings) with different configurations have been considered. First, pounding between different structures has been analysed for a specified soil type and the effect of the torsional pounding and the contact asymmetry on the torsional response of colliding buildings has been investigated. Then, these pounding cases have been considered for different soil types to study the effect of the soil type on the torsional response of buildings experiencing torsional pounding. Five soil types have been considered, i.e. hard rock, rock, very dense soil and soft rock, stiff soil and soft clay soil. The results of the study indicate that the earthquake-induced torsional pounding causes an increase in the peak storey rotation of the colliding buildings as compared to the symmetric pounding in all cases. Higher peak storey rotations have been experienced for colliding buildings founded on the soft clay soil, then for buildings founded on the stiff soil, then for buildings founded on very dense soil and soft rock, and finally for buildings founded on the rock and hard rock.