RR 22.01.00-3.3 IS 1893 2016 Seismic Irregularities Checks
STAAD.Pro can now check for vertical and plan irregularities per the IS 1893 2016 code for structures with defined rigid floor diaphragms.
For IS 1893 2016, the program can check horizontal irregularities (torsional and reentrant corners) per Table 5 and vertical irregularities (mass irregularities and irregular modes of oscillation) per Table 6.
IS 1893 2016 Example Output
An example output section of an IS 1893 2016 seismic irregularities check:
-IRREGULARITY CHECKS
STAAD.PRO IRREGULARITIES CHECK - ( IS1893-2016 ) v1.2
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Including Amendment no. 2 November 2020
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--TORSION IRREGULARITY CHECKS
Torsion Irregularity Check
Ref: Table 5 (i) - Ratio Limit(s): Lower-1.20 Upper-1.40
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edi : Design Eccentricity
esi : Static Eccentricity
bi : Floor/Diaphragm plan dimension perpendicular to force direction
For Details Refer Clause 7.8 IS1893:2016-Part-1
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Using edi = 1.5esi + 0.05bi
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Displacement of extreme points of diaphragm(dia.) in X dir.
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Dia. Node Max. Disp. Node Min. Disp. Avg. Disp. Max./Avg. Status
(mm) (mm) (mm) Disp.
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1 7 0.4984 2 0.4662 0.4823 1.0333 PASS
2 12 2.4871 9 2.3990 2.4430 1.0180 PASS
3 16 6.1637 13 6.0157 6.0897 1.0122 PASS
Using edi = esi - 0.05bi
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Displacement of extreme points of diaphragm(dia.) in X dir.
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Dia. Node Max. Disp. Node Min. Disp. Avg. Disp. Max./Avg. Status
(mm) (mm) (mm) Disp.
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1 2 0.4984 7 0.4662 0.4823 1.0333 PASS
2 9 2.4871 12 2.3990 2.4430 1.0180 PASS
3 13 6.1637 16 6.0157 6.0897 1.0122 PASS
Using edi = 1.5esi + 0.05bi
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Displacement of extreme points of diaphragm(dia.) in Z dir.
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Dia. Node Max. Disp. Node Min. Disp. Avg. Disp. Max./Avg. Status
(mm) (mm) (mm) Disp.
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1 3 0.2699 2 0.2383 0.2541 1.0622 PASS
2 10 1.0087 9 0.9347 0.9717 1.0381 PASS
3 14 2.0463 13 1.9160 1.9812 1.0329 PASS
Using edi = esi - 0.05bi
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Displacement of extreme points of diaphragm(dia.) in Z dir.
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Dia. Node Max. Disp. Node Min. Disp. Avg. Disp. Max./Avg. Status
(mm) (mm) (mm) Disp.
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1 3 0.3916 2 0.2319 0.3118 1.2562 WARNING*
2 10 1.3253 9 0.9131 1.1192 1.1841 PASS
3 14 2.5782 13 1.8732 2.2257 1.1584 PASS
*** WARNING: The floor is irregular. Please ensure conformance
with Cl. 7.1, Table 5, Sl No. (i) sec-i.a or sec-i.b.