Study the relative contribution of materials, reinforcement and concrete layers at different levels of cyclic deformation of masonry walls reinforced with shotcrete

Document Type : Original Article


1 PhD student, Department of Civil Engineering, Semnan University, Semnan, Iran

2 Associate professor, International Institute of Earthquake Engineering and Seismology, Tehran, Iran

3 Assistant Professor, Department of Structural Engineering, Building & Housing Research Center, Tehran, Iran

4 Assistant Professor, Qazvin branch, Islamic Azad University, Qazvin, Iran


In masonry buildings, walls are the main structural members that deal with lateral forces. The important point in seismic retrofitting projects is identify the most effective method of improving in various levels of displacement. Therefore, in this study based on laboratory results, 12 reinforced and unreinforced walls are subjected to cyclic load, and based on the optimum values for the calibration parameters modeling results with available experimental results, in first step, with change in the specification of reinforced and unreinforced walls, An estimate of the contribution of each component in the improvement of three displacement levels, displacement in the yield point, displacement corresponding to the maximum resistance and the final displacement is made. In the second step, with change in the thickness of the layer masonry materials in unreinforced brick walls and, with change in the thickness of the masonry, concrete, diameter rebar and the distance between the bars, in reinforced brick wall, analytical values are determined. Finally, in the third step the amounts proposed in first step is compared with the amounts extracted in step two that have been derived analytically. In unreinforced walls computing values for the share of masonry materials resistance in three levels of displacement is estimated at around 97%. In reinforced and unreinforced walls the most share in resistance in displacement of the yield point and displacement corresponding to the maximum resistance was for concrete. In the final displacement limit in one way reinforced walls, the most share is for resistance has for masonry material and in two way reinforced walls, the most share is for resistance has for reinforcement. Average computing error of the analytical values obtained from step two in the walls was, about 7.5% is obtained.


Main Subjects

[1] Ghiassi, B., Soltani Mohamadi, M. and Tasnimi, A.A. (2011). Linear Homogenization and Mechanical Characterization of Strengthened Masonry Elements with Concrete Overlay. Journal of civil and surveying engineering, Volume 45 (Issue 4), Page(s) 455-466. (in Persian)
[2] Improvement Network brick walls with steel and concrete lining. (2011) Tehran: (Poly Copy) (in Persian)
[3] Kalali, A. and Kabir, M.Z. (2011). Out-of-Plane Performance Based on Homogenization & Micromechanics Approach. Journal of civil and surveying engineering, Volume 45(Issue 2), Page(s) 203-217. (in Persian)
[4] Hashemi, E.S. (2013). Numerical investigation of the behaviour of masonry walls reinforced with shotcrete. Master's degree in earthquake engineering. Road, Housing & Urban Development Research Center, Institute of Building and Housing.
[5] Shing, P. B., M. Schullar, and V. S. Hoskere. (1990). Strength and Ductility of Reinforced Masonry Shear Walls. Fifth North American Masonry Conference.
[6] Larbi, A., and H. G. Harris. (2013). Seismic Performance of Low Aspect Ratio Reinforced Block Masonry Shear Walls. Proceeding of Fourth U.S. National Conference on Earthquake Engineering, Vol. 2.
[7] Magense, G., and Calvi, G.M. (1992). Cyclic Behavior of Brick Masonry Wall.  Proceeding of the  WCEE, Madrid-Spain, Page 3517-3522.
[8] Jankulosvki, E., and Parsanejad, S. (1995). Earthquake Resistance of Unreinforced Clay Brick Masonry Wall. Proceeding of the Second International Conference of Seismology and Earthquake Engineering, Tehran, Iran.
[9] Yoshimura, K., and et al. (1996). Effect of Vertical and Horizontal Wall Reinforcements of Seismic Behavior of Confined Masonry Walls. Proceeding of the  WCEE, Mexico, Paper No. 191.
[10] Magenes, G. (1996). In-Plane Cycle Testing on Reinforced Masonry Shear Wall. Proceeding of the  European Conference on Earthquake Engineering, Rotterdam.
[11] Amjad, M. A. (1996) Elasticity and Shrinkage of Cement Sand Mortar Produced in Riyadh. JKAU:Eng. Sci, Vol. 11, Page. 91-105.
[12] Tasnimi, A.A. (2006). Behaviour of confined and non - confined masonry brick buildings. Institute of natural disasters. Tehran, Iran. (in Persian)
[13] Sideris, K. K., Manita, P. (2004).  Estimation of Ultimate Modulus of Elasticity and Poisson Ratio of Normal of Concrete. Cement & Concrete Composites, Page 623-631.
[14] Kheder, G. F., and Al-Windawi, S. A. (2005). Variation in Mechanical Properties of Natural and Recycled Aggregate Concrete as Related to the Strength of their Building Mortar. Materials and Structures, Page. 701-709.
[15] Hemant, B., and et al. (2007). Stress-Strain Characteristic of Clay Brick Masonry under Uniaxial Compression. Journal of Materials in Civil Engineering, ASCE, Page 728-739.
[16] Ghiassi, B., Soltani, M. M., Tasnimi, A. A. (2012). A Simplified Model for Analysis of Unreinforced Masonry Shear Walls under Axial, Shear and Flexural Loading. Engineering Structure, Science Direct, Vol.42, Page 396-409.
[17] Iranian resources and engineering management, IREMCO. (2010). Experiences and lessons learned on seismic rehabilitation. Elmoadab press, Tehran, Iran. (in Persian)
[18] Page A. W. (1978). Finite Element Model for Masonry. Journal of structural division, Vol. 104, No. 8, Page 1267-1285.
[19] Lourenco P.B., Rots G. (1997). Multisurface Interface Model for Analysis of Masonry Structures. Journal of Engineering Mechanics, Vol. 123, No. 7, Page 660-668.
[20] Final reports 20 samples brick wall. Tehran University, Tehran. (in Persian)