Arching effect in laterally loaded urm walls

According to Eurocode 6 the load-bearing capacity of laterally loaded unreinforced masonry (URM) walls may be determined assuming arching effect. The rules adopted in EC6 are based on tests performed in the UK at CERAM in 1976 by Hodgkinson, Haseltine and West [2]. Based on the test results a design method was developed in which the depth of the compression zone was assumed to be 1/10th of the wall thickness. In the adopted analytical model the allowable compressive strength of the arch was taken as 1.5 times the compressive strength in axial compression neglected. Neglecting the deformation of the wall, the distributed lateral load-bearing capacity of an unreinforced masonry wall was calculated as Lf t d , where: t is the thickness ofthe wall, d f is the compressive strength of the masonry in the direction of the arch thrust and L is the distance between the rigid supports.In this paper the theory developed in the UK is analysed and compared to the results of preliminary tests which were performed at the Structures Laboratory of Eindhoven University of Technology. Moreover, a new analytical model has been developed [6] which enables a more detailed calculation of the load-bearing capacity taking into account the deformation and initial imperfections of the wall.