Civil Engineering Reference
In-Depth Information
is the integrated evaluated result of whether structure member or structure system satisfies
each functional requirement, which will be expressed as A, B, C, or D.
Table 2.8
Assessment of bearing capability of structures or members
Bearing capability
R
/
γ
0
S
No.
Types of Structures or members
a
b
c
d
Reinforced concrete roof trusses, brackets,
roof beams, platform girders and columns,
1
.
0
<
1.0,
0.92
<
0.92,
0.87
<
0.87
1
medium or heavy crane beams; general
members and braces of steel structure;
masonry structures or members
Steel roof trusses, joists, beams, columns,
<
1.0,
<
0.95,
2
connections and details of medium or
1
.
0
<
0
.
90
0.95
0.90
heavy crane beams
General reinforced concrete members (including
3
1
.
0
<
1.0,
0.90
<
0.90,
0.85
<
0.85
floors, cast-in slabs, beams, etc.)
Notes: 1) If steel member or connector has fractures or sharp angle notches, it will be rated as c or d
according to the basic principle of assessment, based on its impact on bearing capacity.
2) For welding crane beam, if fatigue cracking appears in or near the connective weld at top flange, or
appears in the transverse welding seams of the web in tensile region at the ends of stiffening ribs or the
tensile flange; or if there are any steel components welded to the tensile flange, it will be rated as c or d.
3) For masonry structures or members that have obvious stress cracks in compression, in bending, in
shear, etc., it will be rated as
c
,or
d
, according to the basic principle of assessment based on degree of
damage.
Table 2.9
Assessment of crack width of concrete structures or members reinforced
with rebar of Grade I, II, III
Service conditions of
Crack width (mm)
No.
structures or members
a
b
c
d
General
0
.
40
>
0.40,
0.45
>
0.45,
0.70
>
0.70
Normal
members
1
indoor
Roof trusses
0
.
20
>
0.20,
0.30
>
0.30,
0.50
>
0.50
environment
and brackets
Crane beams
0
.
30
>
0.30,
0.35
>
0.35,
0.50
>
0.50
Outdoor or high
2
0
.
20
>
0.20,
0.30
>
0.30,
0.40
>
0.40
humidity indoor environment
Note: “Outdoor or high humidity indoor environment” refers to the structures or members exposed to
following service conditions: rain, always affected by steam and condensate water indoors, or contacted with
soil directly.
Table 2.10 Assessment of crack width of prestressed concrete structures or
members reinforced with rebar of Grade II, III, IV
Service conditions of
Crack width (mm)
No.
structures or members
a
b
c
d
General
0
.
20
>
0.20,
0.35
>
0.35,
0.50
>
0.50
Normal
members
1
indoor
Roof trusses
0
.
05
>
0.05,
0.10
>
0.10,
0.30
>
0.30
environment
and brackets
Crane beams
0
.
05
>
0.05,
0.10
>
0.10,
0.30
>
0.30
Outdoor or high
2
0
.
02
>
0.02,
0.05
>
0.05,
0.20
>
0.20
humidity indoor environment
