Page 109 - Advanced Design Examples of Seismic Retrofit of Structures

Example of a Two-Story Unreinforced Masonry Building Chapter 2 101

(A) (B)

(C) (D)
FIG. 2.51 Some important points for construction of shotcreting of URM walls. (A) Overlapping
of reinforcing bars. (B) Overlapping of the reinforcement grids at top and bottom of the wall
(connection to the rigid diaphragm and the foundation). (C) Welding of the reinforcement grids
at top of the wall to the steel angles in flexible diaphragm. (D) Using proper facility for spraying
concrete with targeted pressure. (Permission from DRES.)

Accordingly, the relation for stiffness determination of shotcreted masonry
walls is based on Eq. (2.41), in which the equivalent modulus of elasticity and
shear modulus are based on regression analysis of several tests data by Ghiassi
et al. [50] according to Eqs. (2.42) and (2.43), respectively. The relations for
determination of the stiffness of masonry walls in multistory buildings follows
the same procedure as per the proposed modifications to the ASCE 41-13
relation based on Eqs. (2.12)–(2.16).
1
K e ¼ 3 (2.41)
H H
+
λE eq I m A v G eq