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 ) v1.0
*****************************************************
--TORSION IRREGULARITY CHECKS
Torsion Irregularity Check
Ref: Table 5 (i) - Ratio Limit: 1.50
---------------------------------------
Dia. Extreme Points of Dia in X Extreme Points of Dia in Z
Node Disp. Node Disp. Node Disp. Node Disp.
(mm) (mm) (mm) (mm)
------------------------------------------------------------------------
1 12 0.04678 6 0.04678 2 0.04678 8 0.04678
2 36 0.13804 30 0.13804 26 0.13804 32 0.13804
Diaphragm DX-max/min DZ-max/min Status
--------------------------------------
1 1.0000 1.0000 OK
2 1.0000 1.0000 OK
--GEOMETRY IRREGULARITY CHECKS
Re-Entrant Corner Check.
(Ref: Table 5 (ii) - Ratio Limit: 0.15 )
------------------------------------------
Node Re-Entrant X-Proj X-Proj/Lx Z-Proj Z-Proj/Lz Status
Connectivity Node ( m) ( m)
----------------------------------------------------------------------
2-> 1 4.0000 0.3333 0.0000 0.0000 Re-Entrant
5 0.0000 0.0000 4.0000 0.3333
6-> 7 0.0000 0.0000 4.0000 0.3333 Re-Entrant
8 4.0000 0.3333 0.0000 0.0000
9-> 10 4.0000 0.3333 0.0000 0.0000 Re-Entrant
11 0.0000 0.0000 4.0000 0.3333
12-> 4 0.0000 0.0000 4.0000 0.3333 Re-Entrant
3 4.0000 0.3333 0.0000 0.0000
26-> 25 4.0000 0.3333 0.0000 0.0000 Re-Entrant
29 0.0000 0.0000 4.0000 0.3333
30-> 31 0.0000 0.0000 4.0000 0.3333 Re-Entrant
32 4.0000 0.3333 0.0000 0.0000
33-> 34 4.0000 0.3333 0.0000 0.0000 Re-Entrant
35 0.0000 0.0000 4.0000 0.3333
36-> 28 0.0000 0.0000 4.0000 0.3333 Re-Entrant
27 4.0000 0.3333 0.0000 0.0000
Diaphragm: Lx: Lz:
( m) ( m)
----------------------------
1 12.0000 12.0000
2 12.0000 12.0000
--MASS IRREGULARITY CHECKS
Mass Irregularity Check
Ref: Table 6 (ii) - Ratio Limit: 1.50
---------------------------------------
Dia. Level Mass Above Below Ratio Ratio Status
( m) ( kN) ( kN) ( kN) Above Below
---------------------------------------------------------------------
1 0.000 636.163 459.451 Base 1.385 N/A OK
2 5.000 459.451 Top 636.163 N/A 0.722 OK
***NOTE: Linear dynamic analysis needs to carried out for Irregular
Modes of Oscillation check.
***NOTE: Static Seismic Loads for relevant code needs to be defined
with Zone 4 and 5 for Irregular Modes of Oscillation check.