Estimation of Seismic Response of R/C Frame Structures to Vertical Earthquake Motion Considering Fixed Support and Soil-Structure-Interaction (SSI)

Year 2019, Volume: 11 Issue: 1, 7 - 17, 31.01.2019

Selçuk Baş

https://doi.org/10.29137/umagd.482482

Cited By: 4

Abstract

The present study aims to demonstrate the effects of vertical earthquake excitation on reinforced concrete frame structures (R/C) incorporating the approaches of Soil-Structure-Interaction (SSI) and rigid foundation. This effect is intended to be determined by making comparative study according to the engineering parameters of the base shear force, base axial force and overturning moment. Three earthquake time-histories currently used for the earthquake analysis of structure in literature are regarded to properly elucidate this effect. For the linear time-history analysis (LMTHA), finite element model (FEM) of a high-rise existing R/C structure designed according Turkish Seismic Code (TSC) is developed through frame, shell, solid, gap, link, linear damper elements. Similar modeling considerations are adopted for infinite soil zone. For the SSI analysis, the Direct Method (DM) is utilized, which enables to make an earthquake analysis of combined FEM (soil model+structure model) instead of separated FEM (the Substructure Method). The comparative study is carried out between the SSI and the fixed support (FS) model with fixed-supports under both only horizontal (H) and horizontal+vertical (HV) seismic motions. The difference between only H and H+V load cases for the engineering parameters that vertical earthquake motion is determined not to be effective on the base shear force, and the SSI model is recommended to be used for analysis due to resulting higher change than the FS. Therefore, no damages/failure resulting from the shear force is estimated under the vertical earthquake motion. Instead, the overturning moment is obtained with great change under H+V for all models; however, the SSI model yields to higher increase than the FS model; so, the SSI model is offered for more reliable analysis. Considerable increase in the overturning moment is predicted that vertical load bearing elements such as, columns and piers need to more strength capacity in terms of bending moment. The highest increase among the other parameters is obtained in the base axial force. However, the percentage increase is resulted as higher under H load than H+V, which means that vertical seismic motion treated as balancing effect. This lower change under H+V load case is directly pertinent to damping properties of the soil media. Therefore, design of columns and piers against axial force is recommended to be made for more safety according to the outcomes from the FS model.

Keywords

vertical earthquake motion , soil-structure interaction , fixed support system , direct method , finite element method , base shear force , overturning moment

References

• Abd Rahim. SM., Mohd Zahid, MZA., Wan Omar, WMS., Bin Ab Rahim, MA. & Faisal, A. (2016). Assessment of reinforced concrete building with soil structure interaction effect under vertical earthquake. In: Materials Science Forum, Kaohsiung, Taiwan, 2016. pp 331-336. doi:10.4028/www.scientific.net/MSF.857.331
• Abdollahiparsa, H., Homami, P., Khoshnoudian, F. (2016). Effect of vertical component of an earthquake on steel frames considering soil-structure interaction. KSCE Journal of Civil Engineering, 20, 2790-2801. doi:10.1007/s12205-016-0687-y
• ASCE (2007). Seismic rehabilitation of existing buildings, ASCE/SEI 41-06. American Society of Civil Engineers, Reston, VA
• ASCE (2010). Minimum design loads for buildings and other structures, ASCE/SEI 7-10. American Society of Civil Engineers, Reston, VA.
• ASCE (2014). Seismic rehabilitation of existing buildings, ASCE/SEI 41-13. American Society of Civil Engineer, Reston, VA.
• Aydemir, ME. & Ekiz, I. (2013). Soil–structure interaction effects on seismic behaviour of multistorey structures. European Journal of Environmental and Civil Engineering, 17, 635-653. doi:10.1080/19648189.2013.810177
• Aydinoğlu, MN. (1993). Consistent formulation of direct and substructure methods in nonlinear soil-structure interaction. Soil Dynamics and Earthquake Engineering, 12, 403-410. doi:https://doi.org/10.1016/0267-7261(93)90003-A
• Azari, B., Fatahi, B. & Khabbaz, H. (2015). Numerical analysis of vertical drains accelerated consolidation considering combined soil disturbance and visco-plastic behaviour. Geomechanics and Engineering 8, 187-220. doi:10.12989/gae.2015.8.2.187
• Bas, S. & Kalkan, I. (2016). The effects of vertical earthquake motion on an R/C structure. Structural Engineering and Mechanics 59, 719-737. doi:10.12989/sem.2016.59.4.719Eurocode-8 (1998). Design provisions for earthquake resistance of structures - Part 5: Foundations, retaining structures and geotechnical aspects. CEN European Committee for Standardisation, Brussel, Belgium.
• Far, H. (2017). Advanced computation methods for soil-structure interaction analysis of structures resting on soft soils. International Journal of Geotechnical Engineering, 1-8. doi:10.1080/19386362.2017.1354510
• Hamid Reza Tabatabaiefar, S., Fatahi, B., Samali, B. (2014). An empirical relationship to determine lateral seismic response of mid-rise building frames under influence of soil–structure interaction. The Structural Design of Tall and Special Buildings, 23, 526-548. doi:doi:10.1002/tal.1058
• IS:1893 (2000). Indian standard criteria for earthquake resistant design of structures. New Delhi, India.
• Lou, M., Wang, H., Chen, X., & Zhai, Y. (2011). Structure–soil–structure interaction: literature review. Soil Dynamics and Earthquake Engineering, 31, 1724-1731. doi:https://doi.org/10.1016/j.soildyn.2011.07.008
• Lysmer, J. & Kuhlemeyer, RL. (1969). Finite dynamic model for infinite media. Journal of the Engineering Mechanics Division (ASCE), 95, 859-878
• Manafpour, AR., Moradi, V. (2012). Investigating conventional FE modelling for dynamic soil-structure interaction under horizontal and vertical ground motions. In: The 15th World Conference on Earthquake Engineering, Lisbon, Prtugal.
• NBC105 (1994). Nepal national building code. Ministry of Physical Planning and Works Department of Urban Development and Building Construction, Babar Mahal, Kathmandu, Nepal.
• NZS1170.5 (2004) .Structural Design Actions Part 5: Earthquake Actions-New Zealand Standards PEER (2015) The Pacific earthquake engineering research center ground motion database, Berkeley, CA
• Reyes, JC. & Kalkan, E. (2011). Required number of records for ASCE/SEI 7 ground-motion scaling procedure. U.S. Geological Survey, US.
• SAP2000 (2015). SAP 2000 v17.2 Integrated finite element analysis and design of structures. Computers and Structures Inc, Berkeley, CA.
• Tabatabaiefar, HR., Fatahi, B., Ghabraie, K. & Zhou, W-H. (2015). Evaluation of numerical procedures to determine seismic response of structures under influence of soil-structure interaction. Structural Engineering and Mechanics, 56, 27-47.
• Tabatabaiefar, SHR., Fatahi, B. & Samali, B. (2014). Numerical and experimental investigations on seismic response of building frames under influence of soil-structure interaction. Advances in Structural Engineering, 17, 109-130. doi:10.1260/1369-4332.17.1.109
• TSC (2007). Specification for buildings to be built in earthquake zones. Ministry of Public Work and Settlement, Ankara, Turkey
• UBC (1997). Uniform Building Code, US
• Yu, J. & Liu, X. (2016). The influence of vertical ground motion on the seismic behavior of RC frame with construction joints. Earthquake and Structures, 11, 407-420. doi:10.12989/eas.2016.11.3.407