User's Query:
Asper IS: 1893 2002 Clause 7.11.1 Storey Drift limitation with partial safety
faxctor of 1.00 shall not exceed 0.004 times the storey height or H/250
In addition
as per IS:875 Storey drift limitation with partial safety faxctor of 1.00 shall
not exceed 0.002 times the storey height or H/500
How can we
sort out the sme in one file while checking results?
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Response:
Story drift is calculated as the relative horizontal displacement
of two adjacent floors in a building. Inter-story drift can also be expressed
as some factor times the story height. The allowable factor
generally varies from
one country code to another and may
also vary depending on the type of loading. As for example, in IS 1893: 2002
for seismic loading the allowable limit for inter-story drift is 0.004 times
the story height whereas in IS 875 for wind loading it is 0.002 times the story
height.
The drift at a particular story level in either lateral direction
is calculated as the average of all the joint displacements present in that
floor level. However if floor diaphragm is present the drift is calculated at
the centre of mass (i.e. master joint) of the floor. There has been new feature
implemented in STAAD.Pro by which you can check
inter-story drift the
following command needs
to be issued
after PERFORM ANALYSIS command.
General Format:
LOAD LIST
<ld>
PRINT
STORY DRIFT <factor>
Please refer to the attached model. In this model the following commends
has been used.
LOAD LIST 8 TO 11
PRIST STOREY DRIST 0.002
Here is STAAD.Pro output:
STORY HEIGHT
LOAD AVG. DISP(CM )
DRIFT(CM ) RATIO STATUS
------------------------------------------------------------------------------------------
(METE) X Z X Z
BASE= 0.00
ALLOW. DRIFT = L / 500
1 0.00 8
0.0000 0.0000 0.0000 0.0000 L /999999 PASS
9 0.0000 0.0000 0.0000 0.0000 L /999999 PASS
10 0.0000 0.0000 0.0000 0.0000 L /999999 PASS
11 0.0000 0.0000 0.0000 0.0000 L /999999 PASS
2 3.00 8
0.0746 -0.0001 0.0746 0.0001 L / 4021
PASS
9 -0.0740 -0.0005 0.0740 0.0005 L / 4054
PASS
10 0.0005 0.0533 0.0005 0.0533 L / 5632
PASS
11 0.0001 -0.0538 0.0001 0.0538 L / 5572
PASS
3 6.00 8
0.1647 -0.0005 0.0901 0.0004 L / 3330
PASS
9 -0.1625 -0.0016 0.0885 0.0011 L / 3390
PASS
10 0.0017 0.1151 0.0012 0.0618 L / 4855
PASS
11 0.0005 -0.1171 0.0004 0.0633 L / 4740
PASS
4 9.00 8
0.2271 -0.0013 0.0623 0.0008 L / 4811
PASS
9 -0.2226 -0.0029 0.0601
0.0013 L / 4988
PASS
10 0.0032 0.1561 0.0014 0.0410 L / 7316
PASS
11 0.0013 -0.1602 0.0008 0.0431 L / 6964
PASS
5 12.00 8
0.2582 -0.0023 0.0311 0.0010 L / 9641
PASS
STAAD SPACE
-- PAGE NO. 20
9 -0.2515 -0.0040 0.0289 0.0011 L / 10369 PASS
10 0.0045
0.1748 0.0013 0.0187 L / 16049 PASS
11 0.0022 -0.1810 0.0009 0.0208 L / 14412 PASS