AJJ Engineering and Consulting

1
AJJ Engineering and Consulting
Leo Burnett High Rise Structural Design Project

• Team Members Clients
• Justin Schueler John Peronto
• Joseph Schmidt Christopher Erwin
• Annika Liem

2
Site Location
35 West Wacker Drive Downtown Chicago, IL
3
Overview

• 48 Story Office Building about 650 feet tall
• Code Guideline International Building Code 2006
  (IBC)
• ASCE 7
• AISC 13 Ed.
• Completed Tasks
• Building Frame System Analysis
• Wind, Seismic, Gravity Load Analysis
• Beam and Column Design
• 3-D Building Model (Revit Structure 2008
• Core Wall Design and Structural Analysis (SAP
  2000)
• Connection Detailing
• Foundation Design
• Creation of Complete Set of Structural Drawings

4
Building System

• Systems Reviewed
• -Pure Steel Moment Frame
• -Braced Frame
• -Tube System
• -Core Wall
• System Selected
• -Concrete Core wall with Steel Moment Frame
• -Provides solid core protection of stairs,
  elevators, and mechanical units
• -Provides open interior space free of large
  columns, and provides open exterior bays.
• -Maximized rental space and quality for future
  owner.

5
Gravity Loads

• Floor-by-Floor Loading Cases per Architectural
  Drawings

6
Wind and Seismic Analysis

• Wind Load Analysis Exposure C, proximity to
  Lake Michigan, Followed ASCE Code Procedures
  based on variables
• Seismic Load Analysis Structure Weight, Soil
  Type Hard Clay , Followed ASCE Code Procedures,
  typically south of central Wisconsin-seismic
  controls

7
Beam and Girder Design

• Used LRFD method
• Applied factored per square foot loadings
• Designs controlled by deflection limitation of
  L/360
• Selected Members
• -Girders
• W21x50 Office
• W21x68 Lobby/Entrance Floor/ Retail
• W30x99 Mechanical Area
• -Beams
• W12x16 Office/Lobby/Entrance/Retail
• W14x30 Mechanical

8
Composite Beam Design and Floor Selection

• Used LRFD method
• Applied factored per square foot loadings
• Designs controlled by deflection limitation of
  L/360
• Used Vulcraft 1.5VLR17 (4 Total Concrete Slab on
  metal deck)
• Design
• -Beams
• W10x12 Office/Lobby/Entrance/Retail W12x16
• W12x30 Mechanical W14x30
• NOTE Non-Composite sizing used for conservative
  design

9
Column Design

• Use LRFD Method
• Effective Length Factor 1.0
• Tributary Area Loading
• Axial Load Capacity Met
• Selected Members
• -Columns
• W14x61 (floors 33 48)
• W14x120 (floors 14 32)
• W14x159 (floors 1-12)

10
Connections

• 3 Types of Connections
• Steel Wide Flange Girders To Reinforced Concrete
  Core Wall (Embedded Plate)
• Steel Wide Flange Girders to Steel Wide Flange
  Columns (Full Moment Restrained
  Connection)
• Steel Wide Flange Beams to Steel Wide Flange
  Girders
• (Simple Shear)

Typical Office Floor Corner Beam and Girder
Framing
11
Embedded Plate

• Steel Wide Flange Girders Connecting to
  Reinforced Concrete Core Walls

12
Full Moment Restrained

• Steel Wide Flange Girders to Steel Wide Flange
  Columns

13
Simple Shear

• Steel Wide Flange Beams to Steel Wide Flange
  Girders

14
Foundation Design

• Geotechnical Firm Recommendations
• Reinforced Concrete Belled Pier
• Grade Beams

15
Concrete Core Wall

• Preliminary Design
• -cantilever beam analysis
• -resolved wind and earthquake
• loading values
• -determined moment of inertia
• to meet deflection limit of H/600
• Sizing

16
Core Wall Reinforcement

• Rectangular Analysis
• Treat core wall as box
• Neglect door openings
• Cantilever beam analysis

• I-Beam Analysis
• Initial Approach
• Core Wall acts as a single unit

17
Core Wall Reinforcement

• Designed as a beam column
• Core wall must resist gravity and lateral loads
• Area of Steel Required
• Designed on a per foot basis
• ACI 318-05 Code for Vertical and Horizontal
  Reinforcement
• Vertical 0.0015Ag
• Horizontal steel was sized based on the shear
  strength of the concrete
• Vertical Reinforcing Steel
• No. 5 bars _at_ 12 O.C.
• Horizontal Reinforcing Steel
• No. 4 bars _at_ 18 O.C.
• Use of an Interaction Diagram

18
3-D Building Model

• AutoDesk Revit Structure 2008

19
SAP 2000 Model

• Old Model
• Global grid is based on Architectural Drawings
• 4 created I-Beams connected by link beams
• Each flange consist of one shell element
• Issues
• Connections between individual items
• Proper functioning as one unit

20
SAP 2000 Model Updates

• Refined upper floors
• Complete remodel of flange sections and link
  beams
• Each flange consisting of 4 shell elements
• Model functions as one unit when loading applied
  to nodes

Yellow Flanges of I-Beam Green Link
Beams Pink Concrete Wall Orange - Web
21
SAP 2000 Model / Core Wall
Link Beam
22
SAP 2000 Model Updates
Loading Scenarios
Case 1
Case 2
Case 3
Case 4
Sample Analysis
23
Schedule
9/28/07 - Deliverable 1 Lateral and
Gravity Loads 10/26/07 - Deliverable 2
Initial Revit 3-D Model 11/21/07 - Deliverable
3 Beam and Composite Beam
Design 12/7/07 - Deliverable 4
Column Design 1/25/08 - Deliverable 5
Shear Wall Design 3/7/08 - Deliverable 6
SAP 2000 Analysis, Finalize Columns and
Shear Wall 4/4/08 - Deliverable 7
Creation of Detail Sheets 4/25/08 - Deliverable
8 Foundation Design 5/2/08 - Final
24
Budget Issues

• Reinforcement Calculations
• 1st Approach Caused Errors
• I-Beam vs. Rectangular Box

• Revit Model
• Constant Model Update
• Building Additional Floors for Plan Sets

• SAP 2000
• Software Use Permission Issue - Waiting Period
• Created Model From Scratch
• Determining Most Realistic Loading

25
THANK YOU!