Page 93 - Advanced Design Examples of Seismic Retrofit of Structures

Example of a Two-Story Unreinforced Masonry Building Chapter 2 85

f UF
DCR t ¼
V tc
3005
DCR t ¼ ¼ 0:5
5953
Therefore, this wall is not vulnerable.
- For a flexible diaphragm having horizontal ties:
f UD
DCR b ¼
m b V bjs
9812
DCR b ¼ ¼ 0:39
3 8493
f UD
DCR r ¼
m r V r
9812
DCR r ¼ ¼ 1:11
1:55 5726
f UF
DCR d ¼
V dt
3483
DCR d ¼ ¼ 0:36
9549
f UF
DCR t ¼
V tc
3483
DCR t ¼ ¼ 0:59
5953
Therefore, rocking is the failure mode of this wall.
- For a flexible diaphragm without horizontal ties:

f UD
DCR b ¼
m b V bjs
19,558
DCR b ¼ ¼ 1:15
2 8493
f UD
DCR r ¼
m r V r
19,558
DCR r ¼ ¼ 2:28
1:50 5726
f UF
DCR d ¼
V dt
6944
DCR d ¼ ¼ 0:87
7958