The output of column design doesn't specify minimum reinforcement as per clause 26.5.3.1 (a) or 26.5.3.1 (b) of IS456:2000.
However in detailed output it does provide following details as per clause Cl. 39.6, IS456:2000:
SECTION CAPACITY BASED ON REINFORCEMENT REQUIRED (KNS-MET) ---------------------------------------------------------- Puz : 2201.76 Muz1 : 18.91 Muy1 : 18.91
INTERACTION RATIO: 0.93 (as per Cl. 39.6, IS456:2000)
SECTION CAPACITY BASED ON REINFORCEMENT PROVIDED (KNS-MET) ----------------------------------------------------------
I have been assuming that wherever minimum reinforcement is less than 0.8% in output, minimum reinforcement must have been calculated as per clause 26.5.3.1 (b) of IS456:2000.
however the results as per clause 39.6 of IS456:2000 at the end of output has created confusion.
There is no option to set minimum reinforcement in column design.
the input data is below.
Please clarify.
-----------------------------------
STAAD SPACE JCO MESSSTART JOB INFORMATIONENGINEER DATE 26-May-22END JOB INFORMATIONINPUT WIDTH 79UNIT METER KNJOINT COORDINATES4 -0.45 0 11.78; 8 4.95 0 11.78; 25 -0.45 0 0.93; 43 -0.45 0 10.28;50 3.25 0 3.53; 54 3.25 0 0.93; 55 4.95 0 10.28; 60 4.95 0 3.53;64 4.95 0 0.93; 65 9.87 0 10.28; 72 9.87 0 2.68; 74 9.87 0 0.93;169 9.87 0 7.28; 172 9.87 0 5.58; 183 -0.45 -1.5 11.78; 184 4.95 -1.5 11.78;191 -0.45 -1.5 0.93; 194 -0.45 -1.5 10.28; 196 4.95 -1.5 10.28;197 4.95 -1.5 0.93; 198 9.87 -1.5 10.28; 199 9.87 -1.5 0.93;212 4.95 -1.5 5.58; 213 -0.45 -1.5 5.58; 214 9.87 -1.5 5.58;236 9.87 3.186 5.58; 254 9.87 3.031 0.93; 263 9.87 3.04394 10.28;292 3.25 0 6.93; 293 -0.45 0 6.93; 294 4.95 0 6.93; 295 3.25 0 5.58;296 -0.45 0 5.58; 297 4.95 0 5.58; 298 4.95 3.186 5.58; 299 4.95 3.031 0.93;300 4.95 3.04394 10.28; 305 -0.45 3.186 5.58; 306 -0.45 3.031 0.93;307 -0.45 3.04394 10.28; 308 4.95 2.9986 11.78; 309 -0.45 2.9986 11.78;316 2.25 3.186 5.58; 317 2.25 3.031 0.93; 318 2.25 3.04394 10.28;319 2.25 2.9986 11.78; 320 7.41 3.031 0.93; 321 7.41 3.186 5.58;322 7.41 3.04394 10.28; 336 12.07 0 10.28; 337 12.07 0 2.68; 338 12.07 0 5.58;339 12.07 0 7.28; 340 12.07 3.186 5.58; 341 12.07 3.04394 10.28;342 12.07 -1.5 2.68; 343 12.07 -1.5 5.58; 344 12.07 -1.5 10.28;350 12.07 3.08933 2.68; 351 9.87 3.08933 2.68;MEMBER INCIDENCES4 4 43; 6 4 8; 38 25 296; 61 293 292; 62 43 293; 64 43 55; 67 292 295;68 50 295; 71 54 50; 75 55 8; 76 294 297; 78 60 297; 81 64 60; 86 169 172;88 72 172; 93 72 74; 192 72 337; 214 50 60; 254 292 294; 262 65 336; 263 55 65;288 25 54; 289 54 64; 290 64 74; 292 295 297; 296 169 65; 300 169 339;305 172 338; 321 4 183; 322 8 184; 329 25 191; 332 43 194; 334 55 196;335 64 197; 336 65 198; 337 74 199; 350 297 212; 351 296 213; 352 172 214;379 172 236; 391 74 254; 397 254 351; 409 65 263; 416 236 263; 448 236 340;468 263 341; 480 293 296; 481 294 55; 482 297 298; 483 64 299; 484 299 298;485 55 300; 486 298 300; 493 296 305; 494 25 306; 495 306 305; 496 43 307;497 305 307; 498 300 308; 499 8 308; 500 307 309; 501 4 309; 502 305 316;503 306 317; 504 307 318; 505 309 319; 506 299 320; 507 298 321; 508 300 322;520 316 298; 521 317 299; 522 318 300; 523 319 308; 524 320 254; 525 321 236;526 322 263; 527 317 316; 528 316 318; 529 318 319; 530 320 321; 531 321 322;560 337 342; 561 338 343; 562 336 344; 563 338 340; 564 336 341; 566 337 350;571 340 341; 572 350 340; 573 351 236; 574 351 350; 576 337 338; 577 338 339;578 339 336; 579 297 172;*****************************************************************************START GROUP DEFINITIONFLOOR_ROOF2 397 416 448 484 486 495 497 498 500 502 TO 508 520 TO 531 572 TO 574_WT1 416 448 468 571END GROUP DEFINITION*****************************************************************************DEFINE MATERIAL STARTISOTROPIC CONCRETEE 2.17185e+07POISSON 0.17DENSITY 23.5616ALPHA 1e-05DAMP 0.05G 9.28139e+06TYPE CONCRETESTRENGTH FCU 27579ISOTROPIC DUMMYE 1POISSON 0.3DENSITY 1ALPHA 1.2e-05DAMP 0.03G 7.88462e+07END DEFINE MATERIAL*****************************************************************************MEMBER PROPERTY*******334 335 351 483 485 493 561 TO 564 PRIS YD 0.45 ZD 0.45*******560 566 PRIS YD 0.4 ZD 0.65*********************4 75 192 214 262 292 300 305 448 468 498 500 529 574 PRIS YD 0.3 ZD 0.25*******67 68 71 527 528 530 531 572 576 PRIS YD 0.4 ZD 0.3*******6 38 61 64 78 81 86 88 93 254 263 288 TO 290 296 397 416 484 486 495 497 502 -503 TO 508 520 TO 526 571 573 577 TO 579 PRIS YD 0.45 ZD 0.3*******62 76 480 481 PRIS YD 0.5 ZD 0.3321 322 329 332 336 337 350 352 379 391 409 482 494 496 499 -501 PRIS YD 0.4 ZD 0.4*****************************************************************************CONSTANTSMATERIAL CONCRETE ALL*****************************************************************************MEMBER RELEASE61 67 71 192 214 292 300 527 TO 531 574 START MPZ 0.95214 254 300 527 TO 531 END MPZ 0.95*****************************************************************************SUPPORTS183 184 191 194 196 TO 199 212 TO 214 342 TO 344 FIXED*****************************CUT OFF MODE SHAPE 50*****************************************************************************DEFINE REFERENCE LOADSLOAD R1 LOADTYPE Mass TITLE REF LOAD CASE 1SELFWEIGHT X 1 LIST 4 6 38 61 62 64 67 68 71 75 76 78 81 86 88 93 192 214 -254 262 263 288 TO 290 292 296 300 305 321 322 329 332 334 TO 337 -350 TO 352 379 391 397 409 416 448 468 480 TO 486 493 TO 508 520 TO 531 560 -561 TO 564 566 571 TO 574 576 TO 578SELFWEIGHT Y 1 LIST 4 6 38 61 62 64 67 68 71 75 76 78 81 86 88 93 192 214 -254 262 263 288 TO 290 292 296 300 305 321 322 329 332 334 TO 337 -350 TO 352 379 391 397 409 416 448 468 480 TO 486 493 TO 508 520 TO 531 560 -561 TO 564 566 571 TO 574 576 TO 578SELFWEIGHT Z 1 LIST 4 6 38 61 62 64 67 68 71 75 76 78 81 86 88 93 192 214 -254 262 263 288 TO 290 292 296 300 305 321 322 329 332 334 TO 337 -350 TO 352 379 391 397 409 416 448 468 480 TO 486 493 TO 508 520 TO 531 560 -561 TO 564 566 571 TO 574 576 TO 578*******MEMBER LOAD38 61 62 64 68 71 78 81 88 93 192 214 254 262 263 288 TO 290 296 300 305 480 -481 576 578 UNI GX 1338 61 62 64 68 71 78 81 88 93 192 214 254 262 263 288 TO 290 296 300 305 480 -481 576 578 UNI GY 1338 61 62 64 68 71 78 81 88 93 192 214 254 262 263 288 TO 290 296 300 305 480 -481 576 578 UNI GZ 13*******FLOOR LOAD_ROOF2 FLOAD 4.25 GX INCLINED_ROOF2 FLOAD 4.25 GY INCLINED_ROOF2 FLOAD 4.25 GZ INCLINED_WT1 FLOAD 4.25 GX INCLINED_WT1 FLOAD 4.25 GY INCLINED_WT1 FLOAD 4.25 GZ INCLINED_ROOF2 FLOAD 0.75 GX INCLINED_ROOF2 FLOAD 0.75 GY INCLINED_ROOF2 FLOAD 0.75 GZ INCLINED_WT1 FLOAD 5 GX INCLINED_WT1 FLOAD 5 GY INCLINED_WT1 FLOAD 5 GZ INCLINEDEND DEFINE REFERENCE LOADSFLOOR DIAPHRAGMDIA 1 TYPE RIG YR 3 3.186*******************************************************************************BASE 0CHECK SOFT STORY 1893 2016CHECK IRREGULARITIES CODE IS1893 2016*******************************************************************************MEMBER CRACKED4 6 38 61 62 64 67 68 71 75 76 78 81 86 88 93 192 214 254 262 263 288 TO 290 -292 296 300 305 397 416 448 468 480 481 484 486 495 497 498 500 502 TO 508 -520 TO 531 571 TO 574 576 TO 578 REDUCTION RIY 0.35 RIZ 0.35321 322 329 332 334 TO 337 350 TO 352 379 391 409 482 483 485 493 494 496 -499 501 560 TO 564 566 REDUCTION RIY 0.7 RIZ 0.7*****************************************************************************DEFINE IS1893 2016 LOADZONE 0.24 RF 5 I 1 SS 2 ST 5 DM 0.05 GL 0 HT 3.186 DX 12.52 DZ 10.85********************************************************************************SEISMIC LOAD CASES USING EQUIVALENT STATIC PROCEDURELOAD 1 LOADTYPE Seismic-H TITLE EQUI STATIC SEISMIC LOAD X+ECC1893 LOAD X 1 DEC 1.5 ACC 0.05******************PERFORM ANALYSISCHANGE******************LOAD 2 LOADTYPE Seismic-H TITLE EQUI STATIC SEISMIC LOAD X-ECC1893 LOAD X 1 DEC 1.5 ACC -0.05******************PERFORM ANALYSISCHANGE******************LOAD 3 LOADTYPE Seismic-H TITLE EQUI STATIC SEISMIC LOAD -X+ECC1893 LOAD X -1 DEC 1.5 ACC 0.05*****************PERFORM ANALYSISCHANGE*****************LOAD 4 LOADTYPE Seismic-H TITLE EQUI STATIC SEISMIC LOAD -X-ECC1893 LOAD X -1 DEC 1.5 ACC -0.05*****************PERFORM ANALYSISCHANGE*****************LOAD 5 LOADTYPE Seismic-H TITLE EQUI STATIC SEISMIC LOAD Z+ECC1893 LOAD Z 1 DEC 1.5 ACC 0.05*****************PERFORM ANALYSISCHANGE*****************LOAD 6 LOADTYPE Seismic-H TITLE EQUI STATIC SEISMIC LOAD Z-ECC1893 LOAD Z 1 DEC 1.5 ACC -0.05*****************PERFORM ANALYSISCHANGE*****************LOAD 7 LOADTYPE Seismic-H TITLE EQUI STATIC SEISMIC LOAD -Z+ECC1893 LOAD Z -1 DEC 1.5 ACC 0.05*****************PERFORM ANALYSISCHANGE*****************LOAD 8 LOADTYPE Seismic-H TITLE EQUI STATIC SEISMIC LOAD -Z-ECC1893 LOAD Z -1 DEC 1.5 ACC -0.05*****************PERFORM ANALYSISCHANGE********************************************************************************SEISMIC LOAD CASES USING MODAL RESPONSE SPECTRUM PROCEDURELOAD 9 LOADTYPE Seismic-H TITLE LOAD CASE 1 (+X DIR AND +ECC)SPECTRUM CQC IS1893 2016 TOR DEC 1.5 ECC 0.05 X 0.024 DAMP 0.05SOIL TYPE 2**************************************LOAD 10 LOADTYPE Seismic-H TITLE LOAD CASE 2 (-X DIR AND +ECC)SPECTRUM CQC IS1893 2016 TOR DEC 1.5 ECC 0.05 X -0.024 DAMP 0.05SOIL TYPE 2**************************************LOAD 11 LOADTYPE Seismic-H TITLE LOAD CASE 3 (+X DIR AND -ECC)SPECTRUM CQC IS1893 2016 TOR DEC 1 ECC -0.05 X 0.024 DAMP 0.05SOIL TYPE 2**************************************LOAD 12 LOADTYPE Seismic-H TITLE LOAD CASE 4 (-X DIR AND -ECC)SPECTRUM CQC IS1893 2016 TOR DEC 1 ECC -0.05 X -0.024 DAMP 0.05SOIL TYPE 2**************************************LOAD 13 LOADTYPE Seismic-H TITLE LOAD CASE 5 (+Z DIR AND +ECC)SPECTRUM CQC IS1893 2016 TOR DEC 1.5 ECC 0.05 Z 0.024 DAMP 0.05SOIL TYPE 2**************************************LOAD 14 LOADTYPE Seismic-H TITLE LOAD CASE 6 (-Z DIR AND +ECC)SPECTRUM CQC IS1893 2016 TOR DEC 1.5 ECC 0.05 Z -0.024 DAMP 0.05SOIL TYPE 2**************************************LOAD 15 LOADTYPE Seismic-H TITLE LOAD CASE 7 (+Z DIR AND -ECC)SPECTRUM CQC IS1893 2016 TOR DEC 1 ECC -0.05 Z 0.024 DAMP 0.05SOIL TYPE 2**************************************LOAD 16 LOADTYPE Seismic-H TITLE LOAD CASE 8 (-Z DIR AND -ECC)SPECTRUM CQC IS1893 2016 TOR DEC 1 ECC -0.05 Z -0.024 DAMP 0.05SOIL TYPE 2***************************************LOAD 17 LOADTYPE Seismic-V TITLE LOAD CASE 9 (Y)SPECTRUM CQC IS1893 2016 Y 0.024 DAMP 0.05SOIL TYPE 2*******************************************************************************PERFORM ANALYSIS*******************************************************************************CHANGE*******************************************************************************MEMBER CRACKED4 6 38 61 62 64 67 68 71 75 76 78 81 86 88 93 192 214 254 262 263 288 TO 290 -292 296 300 305 397 416 448 468 480 481 484 486 495 497 498 500 502 TO 508 -520 TO 531 571 TO 574 576 TO 578 REDUCTION RIY 1 RIZ 1321 322 329 332 334 TO 337 350 TO 352 379 391 409 482 483 485 493 494 496 -499 501 560 TO 564 566 REDUCTION RIY 1 RIZ 1*****************************************************************************LOAD 18 LOADTYPE Dead TITLE DLSELFWEIGHT Y -1 LIST 4 6 38 61 62 64 67 68 71 75 76 78 81 86 88 93 192 214 -254 262 263 288 TO 290 292 296 300 305 321 322 329 332 334 TO 337 -350 TO 352 379 391 397 409 416 448 468 480 TO 486 493 TO 508 520 TO 531 560 -561 TO 564 566 571 TO 574 576 TO 578*******MEMBER LOAD38 61 62 64 68 71 78 81 88 93 192 214 254 262 263 288 TO 290 296 300 305 480 -481 576 578 UNI GY -13*******FLOOR LOAD_ROOF2 FLOAD -4.25 GY INCLINED_WT1 FLOAD -4.25 GY INCLINED*****************LOAD 19 LOADTYPE Live TITLE LLFLOOR LOAD_ROOF2 FLOAD -3 GY INCLINED_WT1 FLOAD -10 GY INCLINED******************************************************************************LOAD COMBINATIONS****************************LOAD COMB 100 DL+LL18 1.0 19 1.0 LOAD COMB 101 DL+LL+SL(+X)18 1.0 19 1.0 9 1.0 LOAD COMB 102 DL+LL+SL(-X)18 1.0 19 1.0 10 1.0 LOAD COMB 103 DL+LL+SL(+X)18 1.0 19 1.0 11 1.0 LOAD COMB 104 DL+LL+SL(-X)18 1.0 19 1.0 12 1.0 LOAD COMB 105 DL+LL+SL(+Z)18 1.0 19 1.0 13 1.0 LOAD COMB 106 DL+LL+SL(-Z)18 1.0 19 1.0 14 1.0 LOAD COMB 107 DL+LL+SL(+Z)18 1.0 19 1.0 15 1.0 LOAD COMB 108 DL+LL+SL(-Z)18 1.0 19 1.0 16 1.0 LOAD COMB 109 DL+LL+SL(+Y)18 1.0 19 1.0 17 1.0 LOAD COMB 110 DL+LL+SL(-Y)18 1.0 19 1.0 17 -1.0 LOAD COMB 111 DL+SL(+X)18 1.0 9 1.0 LOAD COMB 112 DL+SL(-X)18 1.0 10 1.0 LOAD COMB 113 DL+SL(+X)18 1.0 11 1.0 LOAD COMB 114 DL+SL(-X)18 1.0 12 1.0 LOAD COMB 115 DL+SL(+Z)18 1.0 13 1.0 LOAD COMB 116 DL+SL(-Z)18 1.0 14 1.0 LOAD COMB 117 DL+SL(+Z)18 1.0 15 1.0 LOAD COMB 118 DL+SL(-Z)18 1.0 16 1.0 LOAD COMB 119 DL+SL(+Y)18 1.0 17 1.0 LOAD COMB 120 DL+SL(-Y)18 1.0 17 -1.0 ****************************LOAD COMB 121 1.5DL+1.5LL18 1.5 19 1.5 LOAD COMB 122 1.2DL+1.2LL+1.2SL(+X)18 1.2 19 1.2 9 1.2 LOAD COMB 123 1.2DL+1.2LL+1.2SL(-X)18 1.2 19 1.2 10 1.2 LOAD COMB 124 1.2DL+1.2LL+1.2SL(+X)18 1.2 19 1.2 11 1.2 LOAD COMB 125 1.2DL+1.2LL+1.2SL(-X)18 1.2 19 1.2 12 1.2 LOAD COMB 126 1.2DL+1.2LL+1.2SL(+Z)18 1.2 19 1.2 13 1.2 LOAD COMB 127 1.2DL+1.2LL+1.2SL(-Z)18 1.2 19 1.2 14 1.2 LOAD COMB 128 1.2DL+1.2LL+1.2SL(+Z)18 1.2 19 1.2 15 1.2 LOAD COMB 129 1.2DL+1.2LL+1.2SL(-Z)18 1.2 19 1.2 16 1.2 LOAD COMB 130 1.2DL+1.2LL+1.2SL(+Y)18 1.2 19 1.2 17 1.2 LOAD COMB 131 1.2DL+1.2LL+1.2SL(-Y)18 1.2 19 1.2 17 -1.2 ****************************LOAD COMB 132 1.5DL+1.5SL(+X)18 1.5 9 1.5 LOAD COMB 133 1.5DL+1.5SL(-X)18 1.5 10 1.5 LOAD COMB 134 1.5DL+1.5SL(+X)18 1.5 11 1.5 LOAD COMB 135 1.5DL+1.5SL(-X)18 1.5 12 1.5 LOAD COMB 136 1.5DL+1.5SL(+Z)18 1.5 13 1.5 LOAD COMB 137 1.5DL+1.5SL(-Z)18 1.5 14 1.5 LOAD COMB 138 1.5DL+1.5SL(+Z)18 1.5 15 1.5 LOAD COMB 139 1.5DL+1.5SL(-Z)18 1.5 16 1.5 LOAD COMB 140 1.5DL+1.5SL(+Y)18 1.5 17 1.5 LOAD COMB 141 1.5DL+1.5SL(-Y)18 1.5 17 -1.5 ****************************LOAD COMB 142 0.9DL+1.5SL(+X)18 0.9 9 1.5 LOAD COMB 143 0.9DL+1.5SL(+X)18 0.9 10 1.5 LOAD COMB 144 0.9DL+1.5SL(-X)18 0.9 11 1.5 LOAD COMB 145 0.9DL+1.5SL(-X)18 0.9 12 1.5 LOAD COMB 146 0.9DL+1.5SL(+Z)18 0.9 13 1.5 LOAD COMB 147 0.9DL+1.5SL(+Z)18 0.9 14 1.5 LOAD COMB 148 0.9DL+1.5SL(-Z)18 0.9 15 1.5 LOAD COMB 149 0.9DL+1.5SL(-Z)18 0.9 16 1.5 LOAD COMB 150 0.9DL+1.5SL(+Y)18 0.9 17 1.5 LOAD COMB 151 0.9DL+1.5SL(-Y)18 0.9 17 -1.5 ******************************************************************************PERFORM ANALYSIS PRINT STATICS CHECKLOAD LIST 100 TO 120LOAD LIST 121 TO 151*******************************************************************************START CONCRETE DESIGNCODE IS13920 2016CLB 0.045 MEMB 4 6 38 61 62 64 67 68 71 75 76 78 81 86 88 93 192 214 254 262 -263 288 TO 290 292 296 300 305 397 416 448 468 480 481 484 486 495 497 498 -500 502 TO 508 520 TO 531 571 TO 574 576 TO 578CLEAR 0.045 MEMB 321 322 329 332 334 TO 337 350 TO 352 379 391 409 482 483 -485 493 494 496 499 501 560 TO 564 566CLT 0.045 MEMB 4 6 38 61 62 64 67 68 71 75 76 78 81 86 88 93 192 214 254 262 -263 288 TO 290 292 296 300 305 397 416 448 468 480 481 484 486 495 497 498 -500 502 TO 508 520 TO 531 571 TO 574 576 TO 578FC 30000 MEMB 4 6 38 61 62 64 67 68 71 75 76 78 81 86 88 93 192 214 254 262 -263 288 TO 290 292 296 300 305 321 322 329 332 334 TO 337 350 TO 352 379 -391 397 409 416 448 468 480 TO 486 493 TO 508 520 TO 531 560 TO 564 566 571 -572 TO 574 576 TO 578FYMAIN 500000 MEMB 4 6 38 61 62 64 67 68 71 75 76 78 81 86 88 93 192 214 254 -262 263 288 TO 290 292 296 300 305 321 322 329 332 334 TO 337 350 TO 352 -379 391 397 409 416 448 468 480 TO 486 493 TO 508 520 TO 531 560 TO 564 566 -571 TO 574 576 TO 578FYSEC 500000 MEMB 4 6 38 61 62 64 67 68 71 75 76 78 81 86 88 93 192 214 254 -262 263 288 TO 290 292 296 300 305 321 322 329 332 334 TO 337 350 TO 352 -379 391 397 409 416 448 468 480 TO 486 493 TO 508 520 TO 531 560 TO 564 566 -571 TO 574 576 TO 578GLD 100 MEMB 4 6 38 61 62 64 67 68 71 75 76 78 81 86 88 93 192 214 254 262 -263 288 TO 290 292 296 300 305 397 416 448 468 480 481 484 486 495 497 498 -500 502 TO 508 520 TO 531 571 TO 574 576 TO 578MAXMAIN 25 MEMB 321 322 329 332 334 TO 337 350 TO 352 379 391 409 482 483 -485 493 494 496 499 501 560 TO 564 566MAXMAIN 16 MEMB 4 6 38 61 62 64 67 68 71 75 76 78 81 86 88 93 192 214 254 -262 263 288 TO 290 292 296 300 305 397 416 448 468 480 481 484 486 495 497 -498 500 502 TO 508 520 TO 531 571 TO 574 576 TO 578MAXSEC 10 MEMB 4 6 38 61 62 64 67 68 71 75 76 78 81 86 88 93 192 214 254 262 -263 288 TO 290 292 296 300 305 321 322 329 332 334 TO 337 350 TO 352 379 -391 397 409 416 448 468 480 TO 486 493 TO 508 520 TO 531 560 TO 564 566 571 -572 TO 574 576 TO 578MINMAIN 16 MEMB 321 322 329 332 334 TO 337 350 TO 352 379 391 409 482 483 -485 493 494 496 499 501 560 TO 564 566MINMAIN 12 MEMB 4 6 38 61 62 64 67 68 71 75 76 78 81 86 88 93 192 214 254 -262 263 288 TO 290 292 296 300 305 397 416 448 468 480 481 484 486 495 497 -498 500 502 TO 508 520 TO 531 571 TO 574 576 TO 578MINSEC 8 MEMB 4 6 38 61 62 64 67 68 71 75 76 78 81 86 88 93 192 214 254 262 -263 288 TO 290 292 296 300 305 321 322 329 332 334 TO 337 350 TO 352 379 -391 397 409 416 448 468 480 TO 486 493 TO 508 520 TO 531 560 TO 564 566 571 -572 TO 574 576 TO 578TRACK 4 MEMB 4 6 38 61 62 64 67 68 71 75 76 78 81 86 88 93 192 214 254 262 -263 288 TO 290 292 296 300 305 321 322 329 332 334 TO 337 350 TO 352 379 -391 397 409 416 448 468 480 TO 486 493 TO 508 520 TO 531 560 TO 564 566 571 -572 TO 574 576 TO 578COMBINE 3 MEMB 62 480DESIGN BEAM 62 480COMBINE 3 MEMB 61 254DESIGN BEAM 61 254COMBINE 3 MEMB 288 289DESIGN BEAM 288 289COMBINE 3 MEMB 67 68 71DESIGN BEAM 67 68 71COMBINE 3 MEMB 78 81DESIGN BEAM 78 81COMBINE 3 MEMB 76 481DESIGN BEAM 76 481COMBINE 3 MEMB 88 93DESIGN BEAM 88 93COMBINE 3 MEMB 86 296DESIGN BEAM 86 296COMBINE 3 MEMB 577 578DESIGN BEAM 577 578COMBINE 3 MEMB 503 521DESIGN BEAM 503 521COMBINE 3 MEMB 502 520DESIGN BEAM 502 520COMBINE 3 MEMB 504 522DESIGN BEAM 504 522COMBINE 3 MEMB 505 523DESIGN BEAM 505 523COMBINE 3 MEMB 506 524DESIGN BEAM 506 524COMBINE 3 MEMB 507 525DESIGN BEAM 507 525COMBINE 3 MEMB 508 526DESIGN BEAM 508 526COMBINE 3 MEMB 397 573DESIGN BEAM 397 573DESIGN BEAM 4 6 38 64 75 192 214 262 263 290 292 300 305 416 448 468 484 486 -495 497 498 500 527 TO 531 571 572 574 576 579DESIGN COLUMN 321 322 329 332 334 TO 337 350 TO 352 379 391 409 482 483 485 -493 494 496 499 501 560 TO 564 566CONCRETE TAKEEND CONCRETE DESIGNFINISH
Please refer the below link to know the column design methodology adopted in STAAD.
https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/23169/is-456-column-design-philosophy
Dear sir
I need little more clarification.
Please find below result of concrete design of one of the columns from the project posted in first query.
I understood the design philosophy. However my query is about the above result.
The result says to provide 0.50% of steel i.e.; 804.25 Sq mm (4-16 dia bars) against reqd steel area of 115.63 Sq mm only.
The Interaction Ratio provided also changes from 0.93 to 0.23.
Do you mean to say that only 0.50% steel is OK as against 0.80% steel??
Or do I need to check and change % steel of each and every column??
Please reply at the earliest, my project is being delayed.
Regards.
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IS-13920 L I M I T S T A T E D E S I G N C O L U M N N O. 321 D E S I G N R E S U L T S
M30 Fe500 (Main) Fe500 (Sec.)
LENGTH: 1500.0 mm CROSS SECTION: 400.0 mm X 400.0 mm COVER: 45.0 mm
** GUIDING LOAD CASE: 146 END JOINT: 183 SHORT COLUMN
REQD. STEEL AREA : 115.53 Sq.mm. REQD. CONCRETE AREA: 14440.68 Sq.mm. MAIN REINFORCEMENT : Provide 4 - 16 dia. (0.50%, 804.25 Sq.mm.) (Equally distributed) CONFINING REINFORCEMENT : Provide 12 mm dia. rectangular ties @ 95 mm c/c over a length 450.0 mm from each joint face towards midspan as per IS-13920. 2 number overlapping hoops or a single hoop with crossties are provided along Y direction. (As per IS-13920) 2 number overlapping hoops or a single hoop with crossties are provided along Z direction. (As per IS-13920) Additional 4 nos. longitudinal bars have been introduced. TIE REINFORCEMENT : Provide 8 mm dia. rectangular ties @ 200 mm c/c
SECTION CAPACITY BASED ON REINFORCEMENT PROVIDED (KNS-MET) ---------------------------------------------------------- WORST LOAD CASE: 126 END JOINT: 183 Puz : 2450.74 Muz : 66.87 Muy : 66.87 IR: 0.23
In STAAD minimum reinforcement is considered as 0.8% on the required area of concrete and not the actual area. In your case gross cross section is 400x400mm , which is 160000sqmm area. 0.8% reinforcement of that area will be 1280sqmm. But the required concrete area to resist the direct stress is 14440 sqmm. So, minimum reinforcement required 0.85 of 14440 = 115.52 sqmm. But as per design requirement 4-16dia bar has been prvided whisch is nearly 804sqmm, which corresponds to 804/160000 = 0.5% of gross area.
If you still need to increase the reinforcement to .8% of gross area, please do it manually.
Also, I would recommend using STAAD Advanced Concrete Design (RCDC) to use for such design. Please refer below link to know more about it.
https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/31797/staad-advanced-concrete-design-rcdc
Dear Sir,
I need a specific reply.
When STAAD provides %steel less than as specified in clause 26.5.3.1 (a) of IS 456:2000 in output, if it is justified under clause 26.5.3.1 (b) of IS 456:2000 or not?
If yes, please take up case for update in STAAD software to add remarks to this effect in output file.
If no, please take up case for update in STAAAD software to flash error/warning message post analysis.
Secondly, no one in my knowledge uses RCDC as it provides too conservative result.Regards
Please do reply. I have to submit my project for execution.
Regards