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CVEN 557Structural Design for Seismic
EffectProject Assignment
Group 02May 2016
Presented by: Nahid Farzana, Dinesha Kuruppuarachchi, Kapil Adhikari
Elevation view
Plan view
Seismic Design Category
Risk Category & Importance Factor
Redundancy Factor Selection
Seismic Lateral System
Gravity LoadLevel Dead Load
(kip)Live Load
(kip)Total Load
(kip)Roof 1586.88 263.5 1851
8 1535.9 658.75 2195
7 1535.9 658.75 2195
6 1535.9 658.75 2195
5 1535.9 658.75 2195
4 1535.9 658.75 2195
3 1535.9 658.75 2195
2 1552.7 658.75 2211
Gravity load Tributary area on Moment Frames
Gravity load Tributary area on Braced Frames
Load Combination
1.4 Dead 1.2 Dead+1.6 Live+0.5 Liveroof 1.2 Dead + 1.6 Liveroof + Live (1.2 + 0.2 SDS ) Dead + ρ QE + Live + 0.2
Snow (0.9 – 0.2 SDS) Dead + ρ QE
For General Load
ConsiderationFor Seismic
Load Consideratio
n
Selection of Analysis Procedure
Method of Analysis
Equivalent Lateral Force (ELF) procedure is selected to analyze the structure, based on the structure’s –
Seismic design category Structural system
Dynamic properties and Regularity
Story Shear Calculation for moment frame
Story Shear Calculation for braced frame
Seismic Lateral Load Distribution
Modeling Consideration
Modeling Consideration
Moment Frame analysis
Deflected Moment Frame under Seismic Load
Unit Load Applied on Moment Frame
Stiffness and K matrix
Stiffness of frame = 1/ Deflection
Shear Force Calculation from StiffnessShear Force is calculated under following two condition:
Maximum Deflection
Torsional Irregularity
LevelApplied force
Avg deflection
Max deflection drift Max drift
Ratio=max/avg Drift
Torsional irregularity
Roof 226.3 3.18 3.400 0.17 0.100 0.59 Less than 1.2, OK8 218.6 3.01 3.300 0.11 0.300 2.73 Less than 1.2, OK7 172.6 2.9 3.000 0.3 0.200 0.67 Less than 1.2, OK6 130.7 2.6 2.800 0.3 0.300 1.00 Less than 1.2, OK5 93.2 2.3 2.500 0.3 0.400 1.33 Less than 1.2, OK4 60.5 2 2.100 0.4 0.500 1.25 Less than 1.2, OK3 33.3 1.6 1.600 0.5 0.400 0.80 Less than 1.2, OK2 12.6 1.1 1.200 1.1 1.200 1.09 Less than 1.2, OK
IrregularitiesThere are two kinds of irregularities: Horizontal Irregularities Vertical Irregularities
There are five types of Horizontal irregularities as follows: Torsional and Extreme Torsional Reentrant Corner Diaphragm Discontinuity Out-of-plane Offset
Reentrant corner irregularity (type 2)
• There are no reentrant corners in our system. There is no reentrant irregularity
Out of Plane Offsets Irregularity (Type 4)
• There are no discontinuities of the lateral force resisting path in our system.The resisting path is continuous through all the story of the building.No out of plane offsets irregularity was found.
Nonparallel Systems-Irregularity (Type 5)
• Lateral resisting element is parallel throughout our system.Nonparallel system irregularity was not found.
There are five Vertical Irregularities:
Stiffness-Soft story and Stiffness- Extreme Soft Story Weight Vertical Geometric IN-plane discontinuity in vertical lateral force resisting element Discontinuityin lateral strength (Weak story and Extreme weak story
Stiffness-Soft Story Irregularity (Type 1a)
Stiffness-Soft Story Irregularity (Type1b)
Weight (mass) Irregularity
This irregularity exists where the effective mass of any story is more than 150% of the mass of an adjacent story. A roof that is lighter than the floor below need not be considered.
No weight irregularities is found as weight of the given story is less than 150 % of the effective mass of adjacent sides
Vertical Geometric Irregularity (Type 3)
Vertical geometric irregularity exists where the horizontal dimension of the seismic force system in any story is more than 130% of that in the adjacent story.
Since there are no geometric irregularities either in moment or braced frame, no vertical geometric irregularity were found
In-Plane Discontinuity in Vertical Lateral Force Resisting Element Irregularity (Type 4)
This irregularity exists where an in-plane offset of the lateral force resisting elements is greater than the length of those elements.Since there are no offset of the lateral force resisting element, no irregularity was found.
Steel member Selection
Beam – W 24 x 131Column -W 14 X 500
Steel member Design
Steel member DesignSpecial Moment Frames
Column Column depth Column Flange check for buckling of flange check for buckling of web
Other
Probable moments at plastic hinge
Shear at plastic hinge
Beam Vs column strength
Strengths of panel zone
Beam shear strength
Continuity plates
Beam
Beam depth
Beam Weight
Beam Flange
Clear span vs beam depth ratio
check for buckling of flange
check for buckling of web
Sample Calculations
Steel member Design
Eccentric Braced Frames - Link
Steel member DesignEccentric Braced Frames
Size of the link
determine if the axial load is significant
shear check capacity
check link length limit
check link rotation angle
check link slenderness
Check the beam outside the link
compression capacity
moment capacity
check interaction equation
Brace Design over strength factor
check slenderness for ductile members
check compression capacity
check flexural capacity
check interaction
Sample Calculations