Quality Assurance For Structural Quality Assurance For Structural

Engineering FirmsEngineering Firms

Tips, Techniques & StrategiesTips, Techniques & Strategies

by by

Clifford Schwinger, P.E.

What we’ll be covering…

• Quality Assurance Programs

What we’ll be covering…

• Quality Assurance Programs

• Quality Assurance Review procedures,

tips and techniques.tips and techniques.

The Quality Assurance ProgramThe Quality Assurance Program

Defined set of procedures and standards

used to facilitate design and to facilitate

documentation of that design.

Advantages:Advantages:

• Better design

• Better drawings

• More efficient design process • More efficient design process

• Fewer mistakes

• Fewer RFI’s / change orders• Fewer RFI’s / change orders

• Increased profits

Why is a QA program important?

• Fast schedules

• More changes

Why is a QA program important?

• More changes

• Less experienced engineers detailing/coordinating

• Computers disconnecting some from reality• Computers disconnecting some from reality

• Complex Codes

• RFI’s and change orders

• Lost art of structural drafting

• The need for good communication

In the past…

A single QA review was performed after

the design was completed and before the

In the past…

the design was completed and before the

drawings went out the door…

Because of fast-track scheduling this no Because of fast-track scheduling this no

longer works.

Today…

Projects require a series of QA

reviews conducted prior to issuance

of each structural package.of each structural package.

The better the QA program, the easier The better the QA program, the easier

the task of performing QA reviews.the task of performing QA reviews.

The Quality Assurance Program

The QA program

Components:

The QA program

Components:

• Training for young engineers

• Design standards• Design standards

• Drawing and CAD standards

• Project Delivery System• Project Delivery System

• Knowledge Base

• QA reviews and ongoing QA manager • QA reviews and ongoing QA manager

involvement in project

The QA programThe QA program

1. Training for young engineers:

Weekly formal training seminars on topics

1. Training for young engineers:

Weekly formal training seminars on topics

required to provide young engineers the

skills and knowledge needed to become

more productive.more productive.

The QA programThe QA program

2. Design standards:

In-house design guides, office

standards and checklists for all topics

2. Design standards:

standards and checklists for all topics

related to structural design.

The QA programThe QA program

3. Drafting and CAD standards:

• Standardized drafting procedures

3. Drafting and CAD standards:

• Layers

• Typical details

• “go-by” drawings

• Standard blocks

The QA programThe QA program

4. Project Delivery System

Checklists and procedures:

• Project startup

4. Project Delivery System

• Project startup

• Schematic design

• Design development• Design development

• Contract documents

• Construction Administration

The QA programThe QA program

5. Knowledge Base

• Server-based database of all

knowledge related to structural

5. Knowledge Base

knowledge related to structural

engineering.

• Similar to Wikipedia• Similar to Wikipedia

The QA programThe QA program

6. Involvement of QA manager:

• QA manager familiar with projects during design.

6. Involvement of QA manager:

• Signoff by QA manager on details and framing

prior to going to CAD (ongoing QA).

• Formal QA reviews at defined milestones • Formal QA reviews at defined milestones

The Quality Assurance

ReviewReview

Strategies & tactics

Quality Assurance Reviews

In-house reviews conducted to verify that

Quality Assurance Reviews

In-house reviews conducted to verify that

design and documentation is in conformance

with procedures, practices and standards with procedures, practices and standards

mandated by the QA program.

Primary purposes of the QA review: Primary purposes of the QA review:

• Redundancy• Redundancy

• Monitor effectiveness of QA program.

QA reviews

Typical QA review schedule:

QA reviews

Typical QA review schedule:

Pile bid

Steel mill orderSteel mill order

Foundation concrete

Steel detailing

100% structural steel

100% concrete

“Issued For Construction”“Issued For Construction”

QA reviews

Primary Strategy

QA reviews

Primary Strategy

Look at:

• The big picture (load paths)• The big picture (load paths)

• Critical connection details• Critical connection details

QA reviews

Secondary strategy:

QA reviews

Look at the drawings through the eyes of a:

• Contractor

• Detailer• Detailer

• Inspector

• Engineer performing a peer review or • Engineer performing a peer review or

value engineering review.

• Building official• Building official

• Young engineer reviewing shop drawings

• Lawyer• Lawyer

QA reviews

QA review tactics:• Verify load paths

QA reviews

• Verify load paths

• Check framing

• Check special connections• Check special connections

• Look for mistakes

• Look for the subtleties

• Look at the drawings through contractor’s eyes. • Look at the drawings through contractor’s eyes.

• Review for clarity/consistency

• Look for omissions

• Look for “little” little things • Look for “little” little things

• Look for “big” little things

• Structural dwgs. match Arch. dwgs.?• Structural dwgs. match Arch. dwgs.?

QA reviews

1. Load path issues:

•Any unrealistic load paths?

QA reviews

•Any unrealistic load paths?

•Loads jumping in/out of shear walls / braced frames?

•Any unrealistic “rigid” diaphragms?•Any unrealistic “rigid” diaphragms?

•Any loads on the structure not in the computer model?

QA reviews

Example: Unrealistic distribution of lateral

QA reviews

Example: Unrealistic distribution of lateral

loads between lateral load resisting elements.

QA reviews

Example: Braced

QA reviews

Example: Braced

frame forces not

making sense (due to

rigid diaphragm

assumption in

computer model).computer model).

QA reviews

2. Check framing (gravity and lateral):

QA reviews

Check:

• Typical framing to verify model• Typical framing to verify model• Major load carrying members• Wind and seismic loads• Wind and seismic loads• Unique framing not in computer model

QA reviews

Items requiring special attention:

Elevators

Escalators

Folding partitions

Special hang pointsEscalators

Facades

Davits

Special hang points

Rooftop MEP loads

Heavy hung piping

Stairs

Monumental stairs

Hangers

Special loads on joists

Horizontal loads from

riggingHangers

Theater rigging

rigging

Catwalks

Expansion jointsExpansion joints

QA reviews

3. Check connections:

QA reviews

• Critical connections

• Unusual connections• Unusual connections

• Connections w/ complex geometry

• Connections w/ large reactions

QA reviews

4. Look for mistakes:

QA reviews

• Wrong reactions

• Members too small

• Improper framing configurations• Improper framing configurations

• Not enough reinforcing steel

• Punching shear problems• Punching shear problems

• Missing structural integrity reinforcing steel

• Missing sections and details

• Mistakes in sections and details• Mistakes in sections and details

QA reviews

Carelessness can result

in objects obscuring

QA reviews

in objects obscuring

important text. Errors like

these can cause these can cause

structural failures.

QA reviews

Slab opening added near column; girder shifted to

avoid opening; girder now connecting to beam but

QA reviews

avoid opening; girder now connecting to beam but

beam and beam reaction not revised.

QA reviews

Spandrels at openings are unbraced and take lateral

wind loads. Design accordingly. Facade braces and

QA reviews

wind loads. Design accordingly. Facade braces and

kickers can’t be used to brace facade at stair

openings.openings.

QA reviews

5. Look for subtleties:

QA reviews

• Column splices at inappropriate locations (mid-

height of 80’ unbraced height).

• Columns mistakenly assumed to be braced by • Columns mistakenly assumed to be braced by

mezzanines.

• Floors diaphragms w/ insufficient strength/stiffness • Floors diaphragms w/ insufficient strength/stiffness

to brace columns (see next slide)

QA reviews

Floor diaphragms need sufficient

QA reviews

Floor diaphragms need sufficient

strength & stiffness to brace columns.

QA reviews

6. Look at drawings through the eyes of a contractor:

QA reviews

• Everything shown that will allow contractor to build

structure without having to guess or issue RFI’s?

• Every linear foot of building perimeter covered by a • Every linear foot of building perimeter covered by a

section?

• Everything clearly indicated?• Everything clearly indicated?

• Can drawings be interpreted by someone who’s not an

engineer?

QA reviews

7. Review for clarity & consistency:

QA reviews

• Look for conflicts between framing plans and

sections/details.

• Inconsistencies with framing• Inconsistencies with framingGroup similar beams

Consistency = simplicity = economy

• Drafting inconsistencies• Drafting inconsistencies

QA reviews

8. Look for omissions:

QA reviews

• Missing things often hardest to find

• Missing:• Missing:

Reactions

Section and details

Dimensions and elevationsDimensions and elevations

Sizes

Reinforcing steel

QA reviews

9. Look for “little” little things:

QA reviews

spelling mistakes!

“FABRICATOR MAY PROPSE ALTERNITIVE MOMENT

CONNECTIONS THAT MATCH MOMENT AND SHEAR

WALUES LISTED IN SCHUDULE.”

QA reviews

10. Look for BIG little things:

QA reviews

Some “small” drafting errors can cause structural failures.

QA reviews

11. Do structural dwgs. match architectural dwgs.?

QA reviews

11. Do structural dwgs. match architectural dwgs.?

• Slab edges• Slab edges

• Columns

• Slab openings (see next slide)• Slab openings (see next slide)

QA reviewsQA reviews

Slab opening

cutting off load path

to edge column; to edge column;

opening not shown

on structural on structural

drawings!

New challenges:

• Architectural and MEP changes after structural

design is completed and QA reviews

performed.performed.

• Changes during construction that slip through

the cracks of the QA process.the cracks of the QA process.

• BIM

Summary

Six elements of a QA program

Summary

Six elements of a QA program

• PDS

• Design standards

• Drawing standards

• Knowledge base

• Training for engineers• Training for engineers

• Multiple and ongoing QA reviews during design

QA reviews serve two purposes

• Redundancy• Redundancy

• Monitor effectiveness of QA program.

QA is a continual processQA is a continual process

Thank you!

QUESTIONS?