Concrete
Seismic Warnings
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Specified concrete grade is too low |
- Compliance with ACI 318-08 and ACI 318-11 Section
21.1.4.2, “(..) f’c, shall not be less than
3000 psi.“
- Applies to normal weight reinforced concrete columns and
beams part of Special Moment Frames
- Applies to normal weight reinforced concrete walls
assigned as Special Reinforced Concrete Structural Walls
- Prompts the designer to increase the concrete grade of
the member
|
Specified longitudinal reinforcement grade too high |
- Compliance with ACI 318-11 Section 21.1.5.2, “(..)
reinforcement resisting earth-quake induced flexure,
axial force, or both, shall comply with ASTM A706, Grade
60.”
- Applies to normal weight reinforced columns and beams
part of Special Moment Frames
- Applies to normal weight reinforced concrete walls
assigned as Special Reinforced Concrete Structural Walls
- Prompts the designer to use lower longitudinal
reinforcement grades
|
Column at the end of the beam is not in the same seismic
frame |
- Used to validate if the frame of which the beam is part
of is correctly set-up as a seismic frame
- Applies to normal weight reinforced concrete beams part
of a seismic force resisting system
- Applies to both SRFS type and direction
- Checks both ends of each beam span
- Prompts the designer to set up a consistent SFRS type
and direction between all members of the frame
|
Beam at the end of the column is not in the same seismic
frame |
- Used to validate if the frame of which the column is
part off is correctly set-up as a seismic frame
- Applies to normal weight reinforced concrete columns
part of a seismic force resisting system
- Checks the top of each column stack
- Prompts the designer to set up a consistent SFRS type
and direction between all members of the frame
|
Beam support region size is too small |
- Compliance with ACI 318-08 and ACI 318-11 Section
21.3.4.2, “(..) hoops shall be provided over lengths not
less than 2h measured from the face of the supported
member toward the midspan”
- Applies to normal weight reinforced concrete beams part
of Intermediate and Special Moment Frames
- Comes into effect if the length of the end shear design
regions is smaller than the requirement
- Prompts the designer to review the shear design regions
- Design options
|
High seismic to conventional demand on non-SFRS beams
High seismic to
conventional demand ratio of non-SFRS columns
High seismic to
conventional demand of non-SFRS walls
|
- Used to recognize when a member has a significant
contribution to the building’s lateral force resistance
but has not been assigned to the SFRS with the required
ductility properties
- Specifically apply to each member type
- The highest non-seismic design ratio from bending and
shear design is obtained
- The highest seismic design ratio from bending and shear
design is obtained
- Comes into effect when the ratio between seismic and
non-seismic values is higher than a given threshold
(default = 1.0)
- The maximum seismic/non-seismic ratio threshold that
triggers the warning is set through the Seismic to
conventional minimum demand ratio field
described below
- Prompts the designer to either include the member in the
SFRS or review the structure layout to reduce the
contribution of the member to the lateral force
resistance
|
Non-SFRS design requirements applicable in SDC D-F |
- Compliance with ACI 318-08 and ACI 318-11 Sections
21.13.1, “Requirements of section 21.13 apply to members
not designated as part of the seismic-force-resisting
system in structures assigned to SDC D, E and F”
- Applies to normal weight reinforced concrete beams,
column and walls not included in the SFRS
- Comes into effect in Seismic Design Category, SDC D or
above
- Prompts the designer to apply code prescribed
requirements on top of current design
|
Steel Static Warnings |
Additional
notional loads required when alpha Pr/Py > 0.5, C2.3
|
- Compliance with 7.3 (3) of AISC 360-05 and C2.3 of AISC
360-10 requires the stiffness of certain members to be
reduced. When the ratio of the required axial
compressive force (Pr) and the axial yield strength (Py
= Fy Ag) is > 0.5 then this stiffness must be reduced
further
- As an alternative which is the approach adopted in Tekla Structural Designer, an additional notional load of 0.001 Yi can be
applied instead
- When the program identifies that the ratio of Pr/Py
exceeds 0.5 a warning is given to alert the designer
- If this additional notional load has been dealt with by
the designer then this warning is no longer relevant and
this option allows you to switch off the warning
|
Concrete Seismic |
Seismic to
conventional minimum demand ratio
|
- Sets the maximum seismic/non-seismic ratio threshold,
which is used to trigger the High seismic to conventional demandwarnings
listed above
- Default: 1.000
|