Architectural Engineering Commons^™

"Putting A Fence Around" Architectural Engineering Undergraduate Research Projects, Edmond P. Saliklis

Architectural Engineering

The purpose of this paper is to provide practical suggestions of how to design and most importantly, how to limit the scope of proposed projects such that that an architectural engineering student can successfully participate in undergraduate research. Throughout the paper, the pedagogical benefits of such research projects will be emphasized. This paper will provide ideas and encouragement to faculty who may be hesitant to undertake research with undergraduate students. The paper closes with several successful case studies.

Two Alternative System Reliability Approaches To The Serviceability Condition Assessment Of Spillway Gate Systems On Dams, Allen C. Estes, Stuart D. Foltz

Architectural Engineering

Two competing methods were introduced for analyzing the condition of a structural system. The results produced by both were very different. In the weighted average approach, the system condition index will always be somewhere between the condition of the best and worst component in the system. In the traditional reliability approach, the condition index will always be lower than the condition of the worst member in a series system and higher than the condition of the best member in a parallel system. A traditional reliability approach works extremely well for a strength-based system where the importance factors of the components …

Ubc 97 And Aci 318-02 Code Comparison - Summary Report, Chukwuma Ekwueme, John Lawson, Mehran Pourzanjani, James S. Lai, Bob Lyon

Architectural Engineering

Introduction

Recognizing there have been questions on the differences between the alternate slender wall design procedures in 1997 UBC and in ACI 318-02, the SEAOSC Board authorized a Task Group to provide a comprehensive review of the two design procedures. The ACI procedure was adopted by IBC 2000 and subsequent code editions. As quoted in ACI 318R-02 Commentary Section R14.8, Section 14.8 is based on the corresponding requirements in the UBC and experimental research of the Test Report by SCCACI-SEAOSC.

This summary report includes review of source documents, code comparison, and background of the design provisions under UBC and under …

"Tilt-Up Building" And "Tilt-Up Wall Panel With Openings", John W. Lawson

Architectural Engineering

No abstract provided.

Teaching Pedagogy 101, Ronald W. Welch, Allen C. Estes

Architectural Engineering

What are the basics to consider in becoming an effective teacher? So you are a new faculty member just assigned a course and a textbook. Your only teaching experience is as a TA filling in for your traveling professor while teaching directly from your personal course notes taken when you took the course. Sound familiar? Where do you go? Who do you call? How do you quickly prepare yourself to be an effective teacher? Or maybe you have a few years of teaching experience and want to improve your performance as a teacher. Where do you start in preparing the …

Load Rating Versus Reliability Analysis, Allen C. Estes, Dan M. Frangopol

Architectural Engineering

The most common approach to assess the safety of a bridge is load rating. However, this approach cannot quantify the bridge safety in probabilistic terms or fully quantify the structural risk to the bridge. Reliability methods have become an increasingly popular and gradually accepted approach to assess the safety of structures. These methods account for the randomness and correlation of all relevant variables and failure modes in the analysis. This study performs both a load rating analysis and a reliability analysis on the same highway bridge, compares the results, and discusses the strengths and limitations of each approach.

Project-Based Independent Study Capstone Course, Ronald W. Welch, Allen C. Estes

Architectural Engineering

This paper describes a unique project-based course used successful by the ABET-Accredited Civil Engineering Program at the United States Military Academy (USMA) to greatly enhance the academic program. The three general project classifications available within this senior course are service-based (i.e., USMA, the Army, local community, etc.), competition-based (i.e., steel bridge, concrete canoe, timber bridge, Big Beam), and research-based. The exceptional student work provided at little to no cost to the client has opened up a ground swell of service and research projects now constantly offered to the program coordinator by prospective clients. We believe these independent study projects are …

Teaching Lessons Learned: Shock And Awe In The Civil Engineering Classroom, Allen C. Estes

Architectural Engineering

No abstract provided.

Bridge Deck Replacement For Minimum Expected Cost Under Multiple Reliability Constraints, Mark G. Stewart, Allen C. Estes, Dan M. Frangopol

Architectural Engineering

The present paper investigates the effect of limit state selection (strength versus serviceability) on bridge deck life-cycle costs and thus on optimal repair strategies. Such a comparison may then help determine whether safety or functionality (or both) are important criteria when optimizing bridge life-cycle performance and costs. The structural element under consideration is a reinforced concrete bridge deck; namely, a State Highway Bridge in Colorado. Two limit states are considered: ultimate strength and serviceability. The exceedence of either of the limit states considered herein will result in deck replacement; namely, if the reliability index falls below a target reliability index …

Updating Reliability Of Steel Miter Gates On Locks And Dams Using Visual Inspection Results, Allen C. Estes, Dan M. Frangopol, Stuart D. Foltz

Architectural Engineering

As both reliability analyses and systematic inspection programs for the world’s infrastructure gain increased usage and prominence, it becomes more important to use the information from routine visual inspections to update lifetime reliability assessments and resulting life-cycle inspection/repair strategies. The Army Corps of Engineers currently uses reliability analyses to economically justify the major rehabilitation of navigation structures. This paper illustrates how the Condition Index visual inspections for locks and dams can be modified and used to update the reliability analysis of a steel miter gate. The miter gates on two existing locks and dams along the Mississippi River are used …

Updating Bridge Reliability Based On Bridge Management Systems Visual Inspection Results, Allen C. Estes, Dan M. Frangopol

Architectural Engineering

Bridge management systems have become increasingly sophisticated over the past decade and provide valuable information about the structural condition of all bridges in the national database. At the same time, reliability methods have gained increasing prominence and are used to forecast life-cycle performance over many decades of structural life. Such reliability analyses need to be updated based on the results of inspections. Specifically targeted nondestructive evaluations are the preferred solution, but are not always available for every bridge. This paper examines how the visual inspection data provided from bridge management systems already in place can be used to update the …

Structural Design Practice Assumptions And Code Interpretation, Craig Baltimore

Architectural Engineering

No abstract provided.

Correlating Off-Axis Tension Tests To Shear Modulus Of Wood-Based Panels, Edmond P. Saliklis, Robert H. Falk

Architectural Engineering

The weakness of existing relationships correlating off-axis modulus of elasticity E to shear modulus G12 for wood composite panels is demonstrated through presentation of extensive experimental data. A new relationship is proposed that performs better than existing equations found in the literature. This relationship can be manipulated to calculate the shear modulus G12 of orthotropic specimens such as wood-based panels solely from off-axis tension (or compression) tests. The proposed relationship reduces to classical theory for the isotropic case. In all cases tested, the newly proposed relationship is a better fit to the data than the traditional orthotropic elasticity equation.

Finite Element Simulation Of Retrogressive Failure Of Submarine Slopes, A. Azizian, Radu Popescu

Architectural Engineering

To simulate earthquake-induced, retrogressive submarine slope failures, element removal capabilities of a finite element program are used to model a soil mass that fails and then flows away, causing upper parts of slope to fail retrogressively due to loss of support. It is explained how an initial failure leads to subsequent failures of a flat or gently sloping seafloor. Effects of a silt layer and gently sloping seafloor on the extension of retrogression in a sand deposit are studied. The extension of failure increases significantly for a gently sloping seafloor with the presence of a silt layer.

Hershey Arena: Anton Tedesko’S Pioneering Form, Edmond P. Saliklis, David P. Billington

Architectural Engineering

Civil engineering structures are part of our cultural heritage. The story of who we are can be told, in part, by what we have built. There have been pivotal moments in civil engineering design history wherein a master engineer creates a pioneering structure. One major example is Anton Tedesko’s 1936 Hershey Ice Arena, the first large-scale thin shell concrete roof in the United States. Tedesko left all his papers, including the original design and analysis calculations of the Hershey shell, to the Princeton Maillart Archives. These documents, as well as other archival materials and photographs, provide insight into the design …

Finite Element Modeling Of Guastavino Tiled Arches, Edmond P. Saliklis, S. J. Kurtz, S. V. Furnbach

Architectural Engineering

An investigation of Rafael Guastavino's arches has been conducted by means of finite element modeling and laboratory experimentation. A novel method of modeling laminated masonry tile construction via the finite element method has been devised. This technique takes advantage of the layered shell element features found in commercially available finite element programs. Historical Guastavino tiles have been tested to obtain material properties. These modem techniques have been employed in conjunction with Guastavino's original empirical design criteria to provide a better understanding of these historically significant structures.

Finite Element Assessment Of The Effects Of Seismic Loading Rate On Soil Liquefaction, Radu Popescu

Architectural Engineering

The influence of frequency content of seismic excitation on the extent and pattern of pore-water pressure build-up in saturated soil deposits is addressed. Seismic acceleration time histories are generated as uniformly modulated nonstationary stochastic processes, in accordance with prescribed response spectra and prescribed modulating functions. Based on numerical examples, it is shown that the interplay between the frequency content of seismic excitation and the dynamic characteristics of the soil system and their evolution during and after the earthquake have important implications on the dynamic response.Key words: seismic motion, frequency content, finite elements, soil dynamics.

Bridge Lifetime System Reliability Under Multiple Limit States, Allen C. Estes, Dan M. Frangopol

Architectural Engineering

A system reliability approach to minimizing the life-cycle cost of a deteriorating structure offers significant advantages such as a rational assessment of the assumed risk of failure, and an understanding of the importance and contribution of individual components to the overall reliability of the structure. The reliability of a structural system as a whole is the measure of its overall performance. This measure has to include both ultimate and serviceability limit states. A system model of a structure traditionally consists of a series-parallel combination of strength-based component limit states. Serviceability limit states however, can play a tremendously important role in …

Minimim Expected Cost-Oriented Optimal Maintenance Planning For Deteriorating Structures: Application To Concrete Bridge Decks, Allen C. Estes, Dan M. Frangopol

Architectural Engineering

Civil engineering structures are designed to serve the public and often must perform safely for decades. No matter how well they are designed, all civil engineering structures will deteriorate over time and lifetime maintenance expenses represent a substantial portion of the total lifetime cost of most structures. It is difficult to make a reliable prediction of this cost when the future is unknown and structural deterioration and behavior are assumed from a mathematical model or previous experience. An optimal maintenance program is the key to making appropriate decisions at the right time to minimize cost and maintain an appropriate level …

Using Condition Index Inspection Results To Update The Reliability Of Miter Gates For Navigation Locks, Allen C. Estes, Dan M. Frangopol, Stuart D. Foltz

Architectural Engineering

In an effort to ensure public safety, many civil engineering structures undergo various inspections to assess their condition or performance. Comprehensive procedures for using routine inspection data to update reliability assessments have not been developed. This paper illustrates how the Condition Index inspection data from a specific miter gate on a Corps of Engineers navigation lock can be modified and used for this purpose.

An Optimized Lifetime Reliability-Based Inspection Program For Deteriorating Structures, Allen C. Estes, Dan M. Frangopol

Architectural Engineering

No matter how well they are designed, all civil engineering structures will deteriorate over time and a program of lifetime inspection, maintenance and repair represents a substantial portion of the total lifetime cost of most structures. An optimized inspection program is the key to making appropriate repairs at the right time to minimize cost and maintain an appropriate level of safety in a structure. When a visual inspection will not provide the necessary level of information, some other non-destructive evaluation method is often needed. This study summarizes a methodology for optimizing the timing, the frequency, and the type of inspection …

Empirical Prediction Of Shear Modulus And Young's Modulus Of Plywood Panels, Edmond P. Saliklis, Bora Tokyay

Architectural Engineering

No abstract provided.

Optimum Lifetime Planning Of Bridge Inspection And Repair Programs, Dan M. Frangopol, Allen C. Estes

Architectural Engineering

This study proposes a general methodology for determining the optimal lifetime planning of bridge inspection and repair programs based on minimizing the expected cost while maintaining an acceptable level of reliability. For individual bridges, this methodology determines the optimum inspection technique. and the numbers and timing of inspections and repairs. The methodology is demonstrated initially on a simple structure. Then. the method is applied to the optimial planning of inspection and repair programs for an existing bridge. The proposed approach to the problem of lifetime bridge maintenance is shown to be a viable method for optimizing inspection and repair investments …

Repair Optimization Of Highway Bridges Using System Reliability Approach, Allen C. Estes, Dan M. Frangopol

Architectural Engineering

As reliability based methods gain increased acceptance, there is greater opportunity to use scarce resources more efficiently while maintaining a prescribed level of reliability of a structure throughout its service life. The goal is to provide management decisions that will balance lifetime system reliability and expected life-cycle cost in an optimal manner. This study proposes a system reliability approach for optimizing the lifetime repair strategy for highway bridges. The approach is demonstrated using an existing Colorado State highway bridge. The bridge is modeled as a series-parallel combination of failure modes, and the reliability of the overall bridge system is computed …

Life-Cycle Cost Design Of Deteriorating Structure, Dan M. Frangopol, Kai-Yung Lin, Allen C. Estes

Architectural Engineering

A lifetime optimization methodology for planning the inspection and repair of structures that deteriorate over time is introduced and illustrated through numerical examples. The optimization is based on minimizing the expected total life-cycle cost while maintaining an allowable lifetime reliability for the structure. This method incorporates: (a) the quality of inspection techniques with different detection capabilities; (b) all repair possibilities based on an event tree; (c) the effects of aging, deterioration, and subsequent repair on structural reliability; and (d) the time value of money. The overall cost to be minimized includes the initial cost and the costs of preventive maintenance, …

Lifetime Bridge Maintenance Strategies Based On System Reliability, Dan M. Frangopol, Allen C. Estes

Architectural Engineering

This study proposes a methodology for a system reliability-based condition evaluation of existing highway bridges. The approach is illustrated for an existing steel bridge located in Colorado. USA. An optimum lifetime repair strategy based on minimum expected cost is developed. The initial optimum repair strategy is updated using both biennial visual inspections and specific non-destructive evaluation testing.

Reliability Of Reinforced Concrete Girders Under Corrosion Attack, Dan M. Frangopol, Kai-Yung Lin, Allen C. Estes

Architectural Engineering

Corrosion of reinforcement is a major problem affecting a large number of reinforced concrete structures. At present, most reliability-based design studies of reinforced concrete structures do not consider the effects of corrosion. In this paper, we present a reliability-based approach to the design of reinforced concrete bridge girders that are under corrosion attack. Both reserve and residual reliability constraints are satisfied. The approach is based on the American Association of State Highway and Transportation Officials (AASHTO) standard specifications for highway bridges and on data of chloride corrosion of steel in concrete. First, the effects of corrosion on both moment and …