Page 521 - Advanced Design Examples of Seismic Retrofit of Structures

464 Index

Retrofit measures, URM (Continued) dead loads, 217–220, 220t
center-core rods, 94 effective width, 222–223
external reinforcement, 93–94 expected shear strengths of infill panels, 223,
ferrocement covering of the walls, 91–92 227–228t
grout and epoxy injection, 92–93 flexural and shear strength of columns, 215,
incremental seismic rehabilitation, 89–90 216t
placement of steel, polymer, or plastic grids, flexural strength of beams, 214–215, 214t
96–97 infill panels, 221–223, 224–226t
posttensioning, 95 live loads, 217–220, 221t
repointing, 92 longitudinal direction, 217
safe room, 95–96 lower-bound values, of strength, 215–217,
shotcrete, 90–91, 97–115 218–219t
strength vs. stability-based design approach, material properties, 213
86–88 thickness, 223
tying paralleled walls, 92 3D model building, 217–220, 220f
Retrofit methods, nonengineered buildings transverse direction, 217
bond beam on top of the walls, 395 Retrofitted building, concentric braces
mesh on walls surfaces, 395–396 acceptance criteria, 364
straps and reinforcing bars, 396 action calculations, 364
Retrofit options, 6–9 analysis procedure
lateral stiffness demand forces calculations, 362
concentric braces, 331–334 target displacement, 362–364
eccentric braces, 331–334, 336f capacity forces calculations
in main building, 331 linear static procedure, 364, 368t
in sports building, 331 nonlinear static procedure, 364
steel shear walls, 336 concurrent seismic effects, 364
lateral strength, 336 diaphragms, 357–359, 363t
load transfer routs completion, 337 irregularity, 357, 360–362t
local retrofit, vulnerable structural elements, modeling assumptions, 364, 366–367f
331 overturning effects, 364, 365t
preliminary assessment, 337 results
comparison, 357, 358t, 359f adding braces to the building, 368, 381f
concentric braces (see Concentric braces, base plate details, 368, 379f
retrofit options) braces in bay J/7-8 first story in main
construction cost and construction time, building, 368, 378f
357, 359f braces in bay J/7-8 floor story in main
crossed braces, 349–356, 354–355f, 356t building, 368, 377f
eccentric braces (see Eccentric braces, building after retrofit process, 384, 389f
retrofit options) demolition of infill walls, 368, 380f
reduction of mass, 336–337 foundation retrofit process, 378, 387f
steel frame building jack-arch roof with uniformity, 384,
base isolation, 337 388f
changing building functionality, 337 minimum DCRs of e braces, 378, 384t
dampers, 337 plan of the retrofitted foundation, 378, 383f
elimination/reduction in building’s plastic hinges formation in main building
irregularity, 331 under PX1, 364–368, 369f, 371t
Retrofit solutions, steel frame building with plastic hinges formation in main building
masonry infill walls under PY1, 364–368, 370f, 372t
axial and flexural strength of columns, plastic hinges formation in sports building
215–217 under PX1, 364–368, 373f, 375t
cradle-type beam-to-column connections, plastic hinges formation in sports building
221, 221f under PY1, 364–368, 374f, 376t