STRUCTURAL DESIGN PROJECTS

Structural design projects



Table of Contents

Introduction3

Structural Design of building4

Selected Buildings And Identification Of Periods6

Steel MRFs8

Structural Roof Systems9

Concrete Structure Design10

Process of Floor Selection11

Floor-zone thickness12

Mechanical System13

Electrical and Lighting Systems13

Dining Area14

Incandescent Requirement:14

Compact Fluorescent Requirement:15

Special Construction Considerations15

Calculations15

Floor Systems19

Columns21

Supplementary Structural Systems22

Exiting Lateral Systems22

Existing Building Lateral Loads25

Lateral System Design Problem Statement25

Solution Method - Design Criteria27

Structural Depth Study34

Building Expansion Layout34

Base Condition Modeling35

Load Analysis Expanded Layout39

Wind Analysis, Flexible Structure39

Iterative Design Process for Load Application41

Summary of Revised Structural System44

Façade Study Breadth Study One44

Glazing Detailing to Resist Earthquakes45

Facade Connection Detail46

Conclusion and Recommendations48

Appendix A: Building Information51

Appendix B: Lateral Loads Existing Building53

Appendix C: Modified Structural System Calculations58

Structural design projects

Introduction

The fundamental period of a building is a key parameter for the seismic design of a building structure using the equivalent lateral force procedure. As the building period cannot be analytically calculated before the building is designed, periods from the empirical period formulas recommended in seismic design codes or from finite element analysis with assumed mass and stiffness are used during the preliminary design stage. In most building design projects, empirical building period formulas are used to initiate the design process. The period from the empirical period formula also serves as a basis to limit the period from a finite element model by applying the upper bound factor, Cu, suggested in the 2003 NEHRP Recommended Provisions for Seismic Regulations for New Buildings and subsequently in ASCE 7-05 2.

These formulas remained in the code until UBC-82 5. From the ATC 3-06 project 6, the period formulas for reinforced concrete and steel moment-resisting frames (RC MRFs and steel MRFs hereafter) were calibrated based on identified building periods from the 1971 San Fernando Earthquake. Seventeen steel MRFs and 14 RC MRFs were used for this calibration. The form of the formulas for the RC and steel MRFs in ATC 3-06 6 were developed based on the assumption that lateral forces are distributed linearly over the height of a building and that the deflections of the building are controlled by drift limitation.

The calibrated building formulas in ATC 3-06 6 were reflected in BOCA-87 7 and UBC-88 8 with minor refinement. The same form of the formula is also applied to other structural types in UBC-88 8. More recently, Goel and Chopra 9-11 calibrated the formula for MRFs in the code and developed a new formula for shear wall buildings with measured (or apparent) building periods from several earthquake events. In their study, 42 steel MRFs, 27 RC MRFs, and 9 shear wall buildings were used.

In the study of shear walls 10, it was found that the building period formula for shear walls should be a function of equivalent shear area and building height rather than a function of only building height. Hence, rather than calibrating parameters in the existing code formula, a new formula was suggested.

Structural Design of building

While the building period formulas have been calibrated and revised over the past 30 years, the number of data points that were used for the previous calibrations was limited to take account the wide variability ...