A Simplified Design Approach - Simplified Design of Reinforced Concrete Buildings - page 5

1.5 PURPOSE OF SIMPLIFIED DESIGN

A complex code is unavoidable since it is necessary to address simple and complex structures in the same
document. The purpose of this topic is to give practicing engineers some way of reducing the design time
required for smaller projects, while still complying with the letter and intent of the ACI Standard 318, Building
Code Requirements for Structural Concrete . 1.1 The simplification of design with its attendant savings in design
time result from avoiding building member proportioning details and material property selections which make
it necessary to consider certain complicated provisions of the ACI Standard. These situations can often
be avoided by making minor changes in the design approach. In the various chapters of this topic, specific
recommendations are made to accomplish this goal.

The simplified design procedures presented in this manual are an attempt to satisfy the various design
considerations that need to be addressed in the structural design and detailing of primary framing members of
a reinforced concrete building—by the simplest and quickest procedures possible. The simplified design
material is intended for use by experienced engineers well versed in the design principles of reinforced
concrete and completely familiar with the design provisions of ACI 318. It aims to arrange the information in
the code in an organized step-by-step procedure for the building and member design. The formulae and
language avoid complicated legal terminology without changing the intent or the objective of the code.
As noted above, this topic is written solely as a time saving design aid; that is, to simplify design procedures
using the provisions of ACI 318 for reinforced concrete buildings of moderate size and height.

1.6 SCOPE OF SIMPLIFIED DESIGN

The simplified design approach presented in this topic should be used within the general guidelines and
limitations given in this section. In addition, appropriate guidelines and limitations are given within each
chapter for proper application of specific simplifying design procedures.

￿ Type of Construction: Conventionally reinforced cast-in-place construction. Prestressed and precast
construction are not addressed.

￿ Building Size: Buildings of moderate size and height with usual spans and story heights. Maximum building plan
dimension should not exceed 250 ft to reduce effects of shrinkage and temperature to manageable levels. 1.2 Maximum
building height should not exceed 7 stories to justify the economics of simplified design.

￿ Building Geometry: Buildings with standard shapes and geometry suitable for residential and commercial
occupancies. Buildings should be free of plan and vertical irregularities as defined in most building codes
(see chapter 11). Such irregularities demand more rigorous building analysis and detailed member design.