Sheridan College
Architectural Technology
ARCH29969 - STUDIO 3

MODULE 10: STRUCTURES: THEORY AND SYSTEM DESIGN

By the end of this Module, students will:

• understand how basic structure is dealt with in commercial buildings and what information is included;
• understand and relate load-bearing design to your working drawings;
• apply the concept of lateral resistance in buildings, and design your lateral structure in your working drawings;
• perform steel super-structure preliminary layouts;
• establish steel member size estimates using 'rule of thumb' resources;
• develop the ability to design and draft a steel structural plan;
• develop foundation plans based on given criteria.

TABLE OF CONTENTS

1.0 Load-Bearing Capacity

2.0 Lateral Stability

3.0 Standards and Nomenclature

4.0 Steel Super-structure Framing

5.0 Concrete Framing Systems (containing class project information)

6.0 Architectural Coordination

7.0 Foundations (containing class project information)

1.0 Load-bearing Capacity

• Exterior walls: do they contribute to the structural stability and loading capability of the building? How does structure REALLY fit in?
• Interior walls: an opportunity, or just more issues to deal with?
• Steel: the simple truth? Think Greek architecture, and wood-frame construction.

Photos to discuss: finished building is above, the following PDF shows the steel structure inside.

2.0 Lateral Stability

• Definition: Lateral Load.
• Definition: Moment.
• Resistance to lateral forces means the use of DIAGONAL force resistance, and the use of load-bearing SHEAR WALLS. Additional information here.
• Design issues: exterior walls, interior walls, aesthetics.

Photos to discuss: finished building from first example, close-ups of lateral framing. Photo above is a local renovated building, additional photos of the shear wall framing here.

3.0 Standards and Nomenclature

Review these diagrams. At the least, the diagram below summarizes our structural system that we could use for our class projects:

4.0 Steel Super-structure Framing

Before you embark on sizing your structural framing system, an understanding of a particular term is necessary:

TRIBUTORY AREA

We must know what this means in order to understand how structural calculations work, and tie this to the theory of structure in general.

4.1 Design Criteria

All the links below are taken from "The Architect's Studio Companion". Design Criteria for the Selection of Structural Systems should be your first step:

TASCpg20-23.pdf

A Summary Chart of relevant systems:

TASCpg24.pdf

The subsequent pages are the various charts to read based on your building data:

TASCpg87-105

4.2 Span Ranges

TASCpg27.pdf

4.3 Steel Beams and Open-web Steel Joists (OWSJ)

TASC_BeamsOWSJ.pdf

4.4 Steel Columns

TASC_Columns.pdf

4.5 Steel Decking

TASC_Decking.pdf

4.6 Lateral Design Criteria

TASCpg35.pdf

5.0 Concrete Framing Systems

5.1 Overview - Plate Construction

For the purposes of the class project, we will only review three systems, the most relevant ones in construction, and the most common (regardless of what you see as constructed in the Davis campus ;) ).

5.1.1 One-way Slab

5.1.2 Two-way Slab

5.1.3 Two-way Flat Slab

5.2 Design Performance Criteria

ALL groups are to use these parameters for the concrete framing of the basement, and the ground floor framing up to the second floor framing slab. We will be using the TWO-WAY FLAT SLAB system for the ground floor and second floor slab ONLY. The rest of your floors above will be structural steel.

CONCRETE COLUMN AND SLAB SCHEDULE

6.0 Architectural Coordination

6.1 Framed Openings

Don't forget about duct shafts, rooftop fan units, access hatches, and generally any opening larger than 750mm x 750mm.

6.2 Column Baseplates

Baseplates become an issue when you are dealing with interior finishes, and trying to bury steel members within walls or finish coverings.

6.3 Plates and Welds

Whether the connections are designed using plates and welds to resist moment (first line drawing), rigid (second line drawing), or shear forces (third drawing), remember these items take up space and require clearances when you place your cladding on your structural frame.

6.4 Lintels

This is especially important when you have openings within shear walls, or load-bearing shear columns. The most common opening: doors!

7.0 Foundations

7.1 Overview

We do not have the knowledge to design commercial foundations, so two 'estimate' foundation schedules have been developed for this stage of the project.
We also have not completed the required soils analysis.  So, we need to explore these foundations in both a deep and shallow option.

Each team will develop two foundation options.  Team Member 'A' will develop shallow foundations, and Team Member 'B' will develop deep foundation systems.

7.2 Shallow Foundations

Strip footing: continuous concrete slab below a foundation wall width and depth will be determined by soil bearing capacity and local building codes. (Ching, 3.09)

Step footing: strip footings that change levels to accommodate sloping grade or soil conditions. (Ching, 3.17)

Pad Spread footing: thick reinforced concrete slab or pad below a column. (Ching, 3.16)

7.2 Deep Foundations

Grade Beam: reinforced concrete beam at ground level supported by concrete piers and located around the perimeter of a building. (Ching, 3.09)

Mat foundation: heavily reinforced concrete slab under an entire building or part of a building spreading a number of points loads over a larger area. (Ching, 3.09)

Caisson: used where suitable bearing is far below the surface.  Deep shafts are drilled, preferably to bedrock and then filled with concrete.  A bell shaped enlargement will be made if the bottom of the caisson does not rest on bedrock. (Ching, 3.26)

Piles: slender structural units driven into the ground transmitting loads by frictional surface resistance and / or direct bearing. Piles can be made from wood, steel H’s (wide flange sections), precast concrete, cast in place concrete. (Ching, 3.24)

7.3 Design Performance Criteria

Regardless of the foundation type, remember to include for these items:

• provide 80mm deep depressions at all entrances for integration of drainage mats;
• provide 200mm checks in foundation structures as they rise above grade, to account for all exterior doors into, and out of, the building.

SHALLOW FOUNDATION FOOTING SCHEDULE - STUDENT "A"

DEEP FOUNDATION FOOTING SCHEDULE - STUDENT "B"