Three-Mass Structural-Isolating-Damping Model Subjected to Near- and Far-Fault Earthquakes

Document Type : Regular Paper


1 Assistant Professor, Department of Technology and Engineering, Imam Khomeini International University, Qazvin, Iran

2 Associate Professor, Technical & Engineering Faculty, University of Qom, Qom, Iran

3 Ph.D. Student, Technical & Engineering Faculty, University of Qom, Qom, Iran


Seismic base isolators and dampers are commonly used as control tools in building frames to mitigate earthquake damage. This study proposes and investigates a structural system consisting of a central fixed core and an isolated section, the two parts of which are connected to each other by a damper. In new structures, called partially isolated (PI) structures, the interaction between conventional frames with fixed bases and frames equipped with control tools including isolators and dampers is measured using a three-mass model by three simplified differential equations of motion. Validating the proposed model provided good results. The model with various modes of partial isolation and certain mass ratios was subjected to seven near-fault and seven far-fault earthquakes to be evaluated. The mean displacement, acceleration, and shear responses of the structural-isolating-damping model were compared with those of fully isolated (FI) and fully fixed (FF) structures. The results showed that by connecting the two parts, responses of the fixed part to FF structure and those of the isolated part to FI structure significantly improved. Under near-fault earthquakes, the displacement response reduction of the fixed part to FF model was estimated to be about 20% and the response of the isolated part to FI model was about 50%. Due to the functional weaknesses observed in FI structures including large displacement of the structure base, poor performance of the isolator in near-fault earthquakes, and high costs of preparing and installing the isolation system, these points were significantly resolved in PI structures.


Main Subjects

[1] Bhaskararao A., Jangid R. (2006). “Harmonic response of adjacent structures connected with a friction damper.” Journal of sound and vibration, Vol. 292, Issue 3, pp. 710-725.
[2] Bhaskararao A., Jangid R. (2007). “Optimum viscous damper for connecting adjacent SDOF structures for harmonic and stationary white‐noise­ random excitations.” Earthquake engineering & structural dynamics. Vol. 36, Issue 4, pp. 563-571.
[3] Patel C., Jangid R. (2010). “Seismic response of adjacent structures connected with Maxwell dampers.” Asian journal of civil engineering. Vol. 11, Issue 5, pp. 585-603.
[4] Basili M., De Angelis M. (2007). “A reduced order model for optimal design of 2-mdof adjacent structures connected by hysteretic dampers.” Journal of Sound and Vibration. Vol. 306, Issue 1, pp. 297-317.
[5] Basili M., De Angelis M., Fraraccio G. (2013). “Shaking table experimentation on adjacent structures controlled by passive and semi-active MR dampers.” Journal of Sound and Vibration. Vol. 332, Issue 13, pp. 3113-3133.
[6] Huang X., Zhu H.-p. (2013). “Optimal arrangement of viscoelastic dampers for seismic control of adjacent shear-type structures.” Journal of Zhejiang University SCIENCE. Vol. 14, Issue 1, pp.  47-60.
[7] Tubaldi E. (2015). “Dynamic behavior of adjacent buildings connected by linear viscous/viscoelastic dampers.” Structural Control and Health Monitoring. Vol. 22, Issue 8, pp. 1086-1102.
[8] Tubaldi E., Gioiella L., Scozzese F., Ragni L.,  Dall'Asta A. (2020). “A design method for viscous dampers connecting adjacent structures.” Frontiers in Built Environment. Vol. 6, pp. 25.
[9] Uz M.E., Hadi M.N. (2014). “Optimal design of semi active control for adjacent buildings connected by MR damper based on integrated fuzzy logic and multi-objective genetic algorithm.” Engineering structures. Vol. 69, pp. 135-148.
[10] Kim H.-S. (2016). “Seismic response control of adjacent buildings coupled by semi-active shared TMD.” International Journal of Steel Structures. Vol. 16, Issue 2, pp. 647-656.
[11] Ok S.-Y., Song J., Park K.-S. (2008). “Optimal design of hysteretic dampers connecting adjacent structures using multi-objective genetic algorithm and stochastic linearization method.” Engineering structures. Vol. 30, Issue 5, pp. 1240-1249.
[12] Fathi F., Bahar O. (2017). “Hybrid Coupled Building Control for similar adjacent buildings.” KSCE Journal of Civil Engineering. Vol. 21, Issue 1, pp. 265-273.
[13] Shrimali M., Bharti S., Dumne S. (2015). “Seismic response analysis of coupled building involving MR damper and elastomeric base isolation.” Ain Shams Engineering Journal. Vol. 6, Issue 2, pp. 457-470.
[14] Matsagar V.A., Jangid R.S. (2005). “Viscoelastic damper connected to adjacent structures involving seismic isolation.” Journal of civil engineering and management. Vol. 11, Issue 4, pp. 309-322.
[15] Reggio A., Angelis M.D. (2015). “Optimal energy‐based seismic design of non‐conventional Tuned Mass Damper (TMD) implemented via inter‐story isolation.” Earthquake Engineering & Structural Dynamics. Vol. 44, Issue 10, pp. 1623-1642.
[16] Abdeveis A., Mortezaei A.R. (2019). “Seismic Retrofitting the Steel Storage Tanks using Single Concave Friction Isolators under the Long Period Earthquakes.” Journal of Rehabilitation in Civil Engineering. Vol. 7, Issue 2, pp. 40-53.
[17] Zhou F., Liu H., Mori M., Nobuo F., Zhu H. (2016). “Seismic response of a continuous foundation structure supported on partially improved foundation soil.” Soil Dynamics and Earthquake Engineering. Vol. 90, pp. 128-137.
[18] De Domenico D., Ricciardi G. (2018). “Earthquake-resilient design of base isolated buildings with TMD at basement: application to a case study.” Soil Dynamics and Earthquake Engineering. Vol. 113, pp. 503-521.
[19] Amin Afshar M., Aghaei Pour S. (2015). “Nonlinear Mechanic Model of Asymmetric Base-Isolated Structures Interaction against Harmonic Loads and Earthquake, and Study of Related Nonlinear Phenomena.” Modares Mechanical Engineering. Vol. 14, Issue 16, pp. 152-162, (in Persian).
[20] Amin Afshar M., Aghaei Pour S. (2016). “On inertia nonlinearity in irregular-plan isolated structures under seismic excitations.” Journal of Sound and Vibration. Vol. 363, pp.  495-516.
[21] Mahmoud H., Chulahwat A. (2015). “Response of building systems with suspended floor slabs under dynamic excitations.” Engineering Structures. Vol. 104, pp. 155-173.
[22] Mazloum A.A., Amin Afshar M. (2020). “Study and comparison of seismic behaviour of isolator-damper hybrid control system with conventional structural systems.” Journal of Rehabilitation in Civil Engineering. Vol. 8, Issue 2, pp. 01-17.
[23] Conner j.j., (2003). “Introduction to structural motion control.” Pearson Education, Inc., United Kingdom.
[24] AISC Committee. (2010). “Specification for Structural Steel Buildings.” American Institute of Steel Construction, Chicago-Illinois.
[25] A.S.o.C. Engineers, (2013). “Minimum Design Loads for Buildings and Other Structures.” Standard ASCE/SEI 7-10, Amer Soc Of Civil Engin,.
[26] Naeim F. (2001). “Dynamics of Structures, Theory and Applications in Earthquake Engineering. Earthquake Spectra, Vol. 17, Issue 3, pp.  549-550.
[27] FEMA P695, (2009). “Quantification of building seismic performance factors.” prepared by the applied technology council for the federal emergency management agency, Washington, D.C.
[28] Elnashai A. S., Di Sarno L. (2015). “Fundamentals of Earthquake Engineering.” John Wiley & Sons, United States.
[29] Bhandari M., Bharti S., Shrimali M., Datta T. (2016). “PERFORMANCE OF BASE ISOLATED BUILDING FOR EXTREME EARTHQUAKES.” structural engineering convention, Chennai, INDIA.