Ar443 Building Frames Lecture Notes

7/28/2019 Ar443 Building Frames Lecture Notes

1/23

COURSE OUTLINE

I. Design of Steel Members

A. Beams

B. Columns

Example 1

C. Connections

Example 2

II. Reinforced Concrete

B. WSD

Beam

A. Definition of Terms

Column

Examples 3, 4, & 5

C. USDBeam

Column

Examples 5 and 6

III. Building Frame System

B. Structural System

A. Code Design Criteria

C. Vertical IrregularitiesD. Plan Irregularities

IV. NSCP Provisions

B. Material Specification

A. Design Philosophy

C. Flexural Members

D. Beam-Column

E. Beam-Column J oints

F. Rebar Details48

A. CODE DESIGN CRITERIA

Procedure and Limitations for the Design of Structures Zoning - Indicate the effective peak ground acceleration

0.40g for Zone 40.20g for Zone 2

Site Characteristic

A factor greater than or equal to 1.0 introduce to the baseshear formula to account for the variability of soil conditions.

OccupancyA factor greater than or equal to 1.0 introduce to the baseshear formula to account for the importance of the structure

ConfigurationImplies the type of plan and vertical irregularity

Structural System and HeightImplies the response of the building under lateral load

Building Frame Systems




2/23

COURSE OUTLINE


A. Beams

B. Columns

Example 1

C. Connections

Example 2


B. WSD

Beam


Column

Examples 3, 4, & 5

C. USDBeam

Column

Examples 5 and 6





IV. NSCP Provisions



C. Flexural Members

D. Beam-Column


F. Rebar Details49


Two Major Parameters in the Selection of Design Criteria Occupancy Structural Configuration

Four Categories of Occupancy Essential Facilities

Occupancies having surgery and emergency treatment areas Fire and police stations Garages and shelters for emergency vehicles and emergency

aircraft Structures and shelters in emergency preparedness centersAviation control towers Structures and equipment in communication centers and other

facilities required for emergency response Standby power-generating equipment for Category 1 facilitiesTanks and other structures containing housing or supporting

water or fire-suppression material or equipment required forthe protection of category I, II or III structures.





3/23

COURSE OUTLINE


A. Beams

B. Columns

Example 1

C. Connections

Example 2


B. WSD

Beam


Column

Examples 3, 4, & 5

C. USDBeam

Column

Examples 5 and 6





IV. NSCP Provisions



C. Flexural Members

D. Beam-Column


F. Rebar Details50


Four Categories of Occupancy Hazardous Facilities

Occupancies and structures therein housing or supportingtoxic or explosive chemicals or substances

Non-building structures housing, supporting or containingquantities of toxic or explosive substances.

Special Facilities Buildings with an assembly room with an occupant capacity >1000 Educational buildings with a capacity of 300 or more students Buildings used for college or adult education with a capacity > 500 Institutional buildings with 50 or more incapacitated patients, but

not included in Category IMental hospitals, sanitariums, jails, prison and other buildings

where personal liberties of inmates are similarly restrainedAll structures with an occupancy 5,000 or more persons Structures and equipment in power-generating stations and other

public utility facilities not included in Category I or Category IIabove, and required for continued operation.





4/23

COURSE OUTLINE


A. Beams

B. Columns

Example 1

C. Connections

Example 2


B. WSD

Beam


Column

Examples 3, 4, & 5

C. USDBeam

Column

Examples 5 and 6





IV. NSCP Provisions



C. Flexural Members

D. Beam-Column


F. Rebar Details51


Four Categories of Occupancy Standard Facilities

All structures housing occupancies or having functioned notlisted in Category I, II or III above and Category V below.

Miscellaneous Facilities

Private garages, carports, sheds, agricultural buildings, andfences over 1.8 meters high.





5/23

COURSE OUTLINE


A. Beams

B. Columns

Example 1

C. Connections

Example 2


B. WSD

Beam


Column

Examples 3, 4, & 5

C. USDBeam

Column

Examples 5 and 6





IV. NSCP Provisions



C. Flexural Members

D. Beam-Column


F. Rebar Details52

Description of Lateral Force Height

Resisting System Limit (Z4)

B. BASIC STRUCTURAL SYSTEM

1. Bearing Wall System

a structural system without a complete vertical load-carrying spaceframe. Bearing walls or bracing systems provide support for all ormost gravity loads. Resistance to lateral load is provided by shearwalls or brace frame.

Illustration1. Light-framed walls with shear panels

Wood structural Panels -------------------------------- 20All other light-framed walls ---------------------------- 20

2. Shear wallConcrete --------------------------------------------------- 50Masonry ---------------------------------------------------- 50

3. Light steel-framed bearing walls tension bracing --- 20

4. Braced frames where bracing carries gravity loadSteel -------------------------------------------------------- 50Concrete --------------------------------------------------- ***Heavy Timber -------------------------------------------- 20





6/23

COURSE OUTLINE


A. Beams

B. Columns

Example 1

C. Connections

Example 2


B. WSD

Beam


Column

Examples 3, 4, & 5

C. USDBeam

Column

Examples 5 and 6





IV. NSCP Provisions



C. Flexural Members

D. Beam-Column


F. Rebar Details53

2. Building Frame System

a structural system with an essentially complete space frameproviding support for gravity loads. Resistance to lateral load isprovided by shear walls or brace frames.

Illustration



1. Steel eccentrically braced frame ------------------------ 75

2. Light-framed walls with shear panelsWood structural Panels -------------------------------- 20All other light-framed walls ---------------------------- 20

3. Shear wallConcrete --------------------------------------------------- 75Masonry ---------------------------------------------------- 50

4. Ordinary braced frameSteel -------------------------------------------------------- 50Concrete --------------------------------------------------- ***Heavy timber --------------------------------------------- 20

5. Special concentrically steel braced frame ------------ 75






7/23

COURSE OUTLINE


A. Beams

B. Columns

Example 1

C. Connections

Example 2


B. WSD

Beam


Column

Examples 3, 4, & 5

C. USDBeam

Column

Examples 5 and 6





IV. NSCP Provisions



C. Flexural Members

D. Beam-Column


F. Rebar Details54

3. Moment-Resisting Frame System

a structural system with essentially complete space frame providingsupport for gravity loads. Resistance to lateral load is providedprimarily by flexural action of members.

Illustration Description of Lateral Force HeightResisting System Limit (Z4)

1. Special moment-resisting frameSteel -------------------------------------------------------- NLConcrete --------------------------------------------------- NL

2. Masonry moment-resisting walls frame --------------- 50

3. Concrete intermediate moment-resisting frame ----- ***

4. Ordinary moment-resisting frameSteel -------------------------------------------------------- 50Concrete --------------------------------------------------- ***

5. Special truss moment frames of steel ----------------- 75






8/23

COURSE OUTLINE


A. Beams

B. Columns

Example 1

C. Connections

Example 2


B. WSD

Beam


Column

Examples 3, 4, & 5

C. USDBeam

Column

Examples 5 and 6





IV. NSCP Provisions



C. Flexural Members

D. Beam-Column


F. Rebar Details55

4. Dual System

is a combination of moment-resisting frames & shear walls or bracedframes. Moment-resisting frame shall be designed to resist 25 % of thebase shear & 75 % for theshear walls/braced frame.

Illustration


Resisting System Limit (Z4)1. Shear wall

Concrete with SMRF ------------------------------------ NL

Concrete with steel OMRF or concrete IMRF ---- 50Masonry with SMRF or steel OMRF ---------------- 50Masonry with concrete IMRF ------------------------- ***Masonry with masonry MMRWF --------------------- 50

2. Steel eccentrically braced frameWith steel SMRF ----------------------------------------- NLWith steel OMRF ---------------------------------------- 50

3. Ordinary braced frame

Steel with steel SMRF ---------------------------------- NLSteel with steel OMRF ---------------------------------- 50Concrete w/ concrete SMRF or concrete IMRF -- ***

4. Special concentrically braced frameSteel with steel SMRF ---------------------------------- NLSteel with steel OMRF ---------------------------------- 50






9/23

COURSE OUTLINE


A. Beams

B. Columns

Example 1

C. Connections

Example 2


B. WSD

Beam


Column

Examples 3, 4, & 5

C. USDBeam

Column

Examples 5 and 6





IV. NSCP Provisions



C. Flexural Members

D. Beam-Column


F. Rebar Details56

5. Cantilevered Column Building System

a structural system relying on cantilevered column elements forlateral resistance.

Illustration



Cantilevered column elements -------------------------- 10






10/23

COURSE OUTLINE


A. Beams

B. Columns

Example 1

C. Connections

Example 2


B. WSD

Beam


Column

Examples 3, 4, & 5

C. USDBeam

Column

Examples 5 and 6





IV. NSCP Provisions



C. Flexural Members

D. Beam-Column


F. Rebar Details57

6. Shear Wall-Frame Interactive System

a combination of shear walls and frames designed to resist lateralforces in proportion to their relative rigidities, considering interactionbetween shear walls and frames on all levels.

Illustration

Descript ion of Lateral Force HeightResisting System Limit (Z4)

Concrete ------------------------------------- 50






11/23

COURSE OUTLINE


A. Beams

B. Columns

Example 1

C. Connections

Example 2


B. WSD

Beam


Column

Examples 3, 4, & 5

C. USDBeam

Column

Examples 5 and 6





IV. NSCP Provisions



C. Flexural Members

D. Beam-Column


F. Rebar Details58

1. Stiffness Irregularity / Soft Story

is one in which the lateral stiffness is less than 70 percent of that inthe story above or less than 80 percent of the average stiffness of thethree stories above.

Illustration

Softstory

Soft Story stiffness


12/23

COURSE OUTLINE


A. Beams

B. Columns

Example 1

C. Connections

Example 2


B. WSD

Beam


Column

Examples 3, 4, & 5

C. USDBeam

Column

Examples 5 and 6





IV. NSCP Provisions



C. Flexural Members

D. Beam-Column


F. Rebar Details59

2. Weight (mass) Irregularity

mass irregularity shall be considered to exist where the effectivemass of any story is more than 150 percent of the effective mass ofan adjacent story. A roof that is lighter than the floor below need notbe considered.

Illustration

Story mass >150% of the mass of adjacent story

HEAVYMASS

HEAVY MASS

HEAVY MASS

HEAVY MASS

Note: Need not be considered if the story drift under the lateral force is less than 1.3 times the story drift above

C. VERTICAL STRUCTURAL IRREGULATITIES



C. Vertical Irregularities


13/23

COURSE OUTLINE


A. Beams

B. Columns

Example 1

C. Connections

Example 2


B. WSD

Beam


Column

Examples 3, 4, & 5

C. USDBeam

Column

Examples 5 and 6





IV. NSCP Provisions



C. Flexural Members

D. Beam-Column


F. Rebar Details

Center for the Designed Environment Profession

#2 Matulungin Street, House of Architects BuildingTeachers Village, Quezon City 60

3. Vertical Geometric Irregularity

vertical geometric irregularity shall be considered to exist where thehorizontal dimension of the lateral-force-resisting system in any story ismore than 130 percent of that in an adjacent story. One-story penthousesneed not be considered.

Illustration

Story dimension >130% of the dimension of adjacent story






14/23

COURSE OUTLINE


A. Beams

B. Columns

Example 1

C. Connections

Example 2


B. WSD

Beam


Column

Examples 3, 4, & 5

C. USDBeam

Column

Examples 5 and 6





IV. NSCP Provisions



C. Flexural Members

D. Beam-Column


F. Rebar Details61

4. In-Plane Discontinuity in Vertical Lateral-Force-Resisting Element

an in-plane offset of the lateral-load-resisting elements greater thanthe length of those elements.

IllustrationShear wall

Braced frame

Shear wall






15/23

COURSE OUTLINE


A. Beams

B. Columns

Example 1

C. Connections

Example 2


B. WSD

Beam


Column

Examples 3, 4, & 5

C. USDBeam

Column

Examples 5 and 6





IV. NSCP Provisions



C. Flexural Members

D. Beam-Column


F. Rebar Details62

5. Discontinuity in Capacity / Weak Story

a weak story is one in which the story strength is less than 80 percentof that in the story above. The story strength is the total strength of allseismic-resisting elements sharing the story for the direction underconsideration.

Illustration

weakstory

weakstory

weakstory

Shear wall Braced frame Shear wall

Story strength


16/23

COURSE OUTLINE


A. Beams

B. Columns

Example 1

C. Connections

Example 2


B. WSD

Beam


Column

Examples 3, 4, & 5

C. USDBeam

Column

Examples 5 and 6





IV. NSCP Provisions



C. Flexural Members

D. Beam-Column


F. Rebar Details63

D. PLAN STRUCTURAL IRREGULARITIES

1. Torsional Irregularity (to be considered if diaphragm is not flexible)

torsional irregularly shall be considered to exist when the maximumstory drift, computed including accidental torsion, at one end of thestructure transverse to an axis is more than 1.2 times the average ofthe story drifts of the two ends of the structure.

Illustration

1

1

2

2

2 >1.20(1 +2)/2

P

M



D. Plan Irregularities


17/23

COURSE OUTLINE


A. Beams

B. Columns

Example 1

C. Connections

Example 2


B. WSD

Beam


Column

Examples 3, 4, & 5

C. USDBeam

Column

Examples 5 and 6





IV. NSCP Provisions



C. Flexural Members

D. Beam-Column


F. Rebar Details64

2. Re-Entrant Corners

plan configurations of a structure and its lateral-force-resisting systemcontain re-entrant corners, where both projections of the structurebeyond a re-entrant corner are greater than 15 percent of the plandimension of the structure in the given direction.

Illustration

L

B

>0.1

5B

>0.15L

Re-entrant corner






18/23

COURSE OUTLINE


A. Beams

B. Columns

Example 1

C. Connections

Example 2


B. WSD

Beam


Column

Examples 3, 4, & 5

C. USDBeam

Column

Examples 5 and 6





IV. NSCP Provisions



C. Flexural Members

D. Beam-Column


F. Rebar Details65

3. Diaphragm Discontinuity

diaphragm with abrupt discontinuities or variations in stiffness,including those having cutout or open areas greater than 50 percent ofthe gross enclosed area of the diaphragm, or changes in effectivediaphragm stiffness or more than 50 percent from one story to thenext.

Illustration

L

B

Diaphragm discontinuity






19/23

COURSE OUTLINE


A. Beams

B. Columns

Example 1

C. Connections

Example 2


B. WSD

Beam


Column

Examples 3, 4, & 5

C. USDBeam

Column

Examples 5 and 6





IV. NSCP Provisions



C. Flexural Members

D. Beam-Column


F. Rebar Details66

4. Out-of-Plane Offsets

discontinuities in a lateral force path, such as out-of-plane offsets ofthe vertical elements.

IllustrationLateral-load-resistingelement

Lateral-load-resistingelement






20/23

COURSE OUTLINE


A. Beams

B. Columns

Example 1

C. Connections

Example 2


B. WSD

Beam


Column

Examples 3, 4, & 5

C. USDBeam

Column

Examples 5 and 6





IV. NSCP Provisions



C. Flexural Members

D. Beam-Column


F. Rebar Details

Center for the Designed Environment Profession

#2 Matulungin Street, House of Architects BuildingTeachers Village, Quezon City 67

5. Nonparallel System

the vertical lateral-load-resisting elements are not parallel to or symmetricabout the major orthogonal axes of the lateral-force systems.

Illustration








21/23

COURSE OUTLINE


A. Beams

B. Columns

Example 1

C. Connections

Example 2


B. WSD

Beam


Column

Examples 3, 4, & 5

C. USDBeam

Column

Examples 5 and 6





IV. NSCP Provisions



C. Flexural Members

D. Beam-Column


F. Rebar Details68

NSCP Provisions for RC Members

A. DESIGN PHILOSOPHY

The NSCP C101-01 Section 421 contains special requirement

for the design of RC members that are part of the lateral

resisting frame subjected to earthquake motions.

These requirements were established based on the profound

engineering experiences and experiments to ensure good

performance of the structure during earthquakes.

It provides requirements to mitigate earthquake stresses by

increasing the ductility of the structure through the confinement

of concrete with reinforcing steel where plastic hinging mayoccur.

IV. NSCP Provisions



22/23

COURSE OUTLINE


A. Beams

B. Columns

Example 1

C. Connections

Example 2


B. WSD

Beam


Column

Examples 3, 4, & 5

C. USDBeam

Column

Examples 5 and 6






IV. NSCP Provisions



C. Flexural Members

D. Beam-Column


F. Rebar Details69


The NSCP C101-01 Section 421 contains special requirement

for the design of RC members that are part of the lateral

resisting frame subjected to earthquake motions.

These requirements were established based on the profound

engineering experiences and experiments to ensure good

performance of the structure during earthquakes.

It provides requirements to mitigate earthquake stresses byincreasing the ductility of the structure through the confinement

of concrete with reinforcing steel where plastic hinging may

occur.


IV. NSCP Provisions



23/23

COURSE OUTLINE


A. Beams

B. Columns

Example 1

C. Connections

Example 2


B. WSD

Beam


Column

Examples 3, 4, & 5

C. USDBeam

Column

Examples 5 and 6






IV. NSCP Provisions



C. Flexural Members

D. Beam-Column


F. Rebar Details70


Reinforced concrete structures in high seismic risk must have:

Strength, Ductility, Toughness

The performance criteria of RC members resisting earthquake:

Serviceability Limit State - material remains in the elastic

range and no damage is expected.

Minor - Magnitude 1 - 4 < 10 yrs

Control Limit - some yielding may occur and may have minor

structural damage.

Moderate - Mag. 4 - 6 -10-20 years

Survival Limit State - inelastic behavior and may have major

structural damage.

Major - Magnitude 7 and up - 100-500 years


IV. NSCP Provisions


Ar443 Building Frames Lecture Notes

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