The Next Step for ASCE 16: Performance-Based Design of Woodframe Structures – Link for Working Groups
LRFD Load Calibration for State of Michigan Trunkline Bridges, Michigan Department of Transportation, 09/15/03 – 4/30/05, (PI’s – van de Lindt and Fu, Wayne State Univ.).
The objective of this research project is to determine what scaling of the HL93 bridge design load configuration will provide Michigan trunkline bridges designed using the LRFD bridge design code a consistent structural reliability index of 3.5. A key feature of this study will be the projection of the load effects from a limited amount of data to form a 75-year load effect distribution for moments and shears. Millions of truck loads will be used to check the adequacy of the methods developed for data projection. This will include both closed-form approaches as well as numerical statistical approaches.
Planning of NEES/E-Defense International Collaboration, National Science Foundation, 10/15/03—1/31/05, (PI – van de Lindt, Co-PI – Rosowsky, Oregon State Univ.).
project will develop collaborative linkages between the Network for Earthquake
Engineering Simulation (NEES) and the E-Defense large shake table facility
being constructed in
Development of Steel Beam End Deterioration Guidelines, Michigan Department of Transportation, 03/01/03-07/31/04, (PI – van de Lindt, Co-PI - Ahlborn).
The objective of this project is to 1) identify the common types of damage to steel beam ends and develop guidelines to assist/direct inspectors in determining when to report section losses to the structural analyst, and 2) to provide the analyst with guidelines for computing the reduced capacity of the section. These objectives will be accomplished using solid modeling / FE analysis in combination with a small experimental program. Multivariate regression will be performed based on the results of the FE analysis to revise the AASHTO/AISC design equations to provide either the same stress level or possibly safety level.
Re-Evaluation of LRFD for Engineered Wood Products: Keeping Pace with Changes in ASCE 7, 06/01 – 12/03, (Participant, ASCE/SEI Special Project carried out by the Committee on the Reliability –Based Design of Wood Structures)
The objective of this study is to determine the structural reliabilities inherent in ASCE Standard 16 for engineered wood products. The task assigned to J. van de Lindt is the assessment of structural reliability indices for wood shear walls designed to ASCE 16, subjected to wind and earthquake load. The wind portion of the study was recently completed and the seismic portion is almost completed.
Investigation of the Adequacy of Current Bridge Design Loading in the State of Michigan, Michigan Department of Transportation, 02/14/01-04/05/02,(PI’s – van de Lindt and Fu, Wayne State Univ.).
In 1972 the Michigan Department of Transportation (MDOT)
approved an increase in their design load for all bridges located on Interstate
and Arterial highways to HS25 loading. Currently the Michigan DOT still
uses the HS25 loading for the global design of these bridges. Recently,
the question of whether or not this design load adequately represents the real
truck loads on
Identification of the Ground Motion Parameters that Control Structural Damage using a Slepian Process Model, United States Geological Survey, 05/15/02-08/31/03, (PI – van de Lindt; Co-PI – Niedzwecki, Texas A&M Univ.).
A Slepian process model is a model that describes the extreme behavior of a process in terms of the covariance of the underlying process and the statistical distribution of the first derivative at level crossings. It was reasoned that if the extreme behavior of a process can be modeled using this approach it may also be possible to model the damage since it is related to the extremes. If the structural components or system can be modeled with simplified hysteretic models it should be possible to predict the expected value of the damage.
Development of a Composite Shear Wall for Resisting High Wind Loads, Federal Emergency Management Agency Hazard Mitigation Grant Program through the Michigan State Police, 11/15/01-05/15/03, (PI – van de Lindt).
Non-structural damage often occurs during wind storms due to excessive displacements which in properly engineered light-frame structures is relatively preventable. The objective of this study was the development of a low-cost, constructible, shear wall made primarily of wood that was capable of transferring forces to the foundation with minimal displacement levels. Adhesives and/or steel components were added to a basic plywood sheathed shear wall to examine the effect and make basic recommendations regarding their potential for application.
Comparison of Steel Overhead Sign Support Structures, Michigan Department of Transportation, 03/19/03-08/31/03, (PI – van de Lindt).
This is a short project, approximately 5 months, and has the objective of checking to ensure that the overhead sign support structures identified in Optimization of Cost and Performance of Overhead Sign Structures meet the 2002 AASHTO criteria. One aspect of this project includes identifying problem areas for implementation of the new design criteria.
Optimization of Cost and Performance of Overhead Sign Structures, Michigan Department of Transportation, 05/11/02-08/10/03, (Co-PI – van de Lindt; PI – Ahlborn).
The Michigan DOT is required to implement the new 2002 AASHTO Standard Specifications for Structural Supports for Highway Signs, Luminaries, and Traffic Signals. This project focuses on overhead sign support structures, particularly cantilevers. The objective is the development and application of a technique to select one or more existing designs based on expected fatigue performance. The ASCE-7 wind load is used in combination with a random vibration fatigue approach developed by Crandall and Mark (1963) to estimate the fatigue life of each structure. Wind loading, i.e. natural wind gusts, were the modeled load source. This is combined with cost estimates based primarily on steel weight to round out a decision support algorithm.
Experimental Comparison of the Behavior of In-Flange Connectors for use in Precast Concrete Double-Tee Systems, Progress Industries Inc., 08/01/02-12/20/02, (PI – van de Lindt).
Prestressed double-Tee beams are used in multi-level parking structures and in some states’ bridges. The advantage of double-Tee beams is that the flange forms the floor of the garage or bridge deck. Steel brackets, called in-flange connectors, are embedded in the flanges of the beams and are welded together on-site to facilitate system behavior of the beams. To date, placement, i.e. spacing, of these connectors has been based primarily on engineering judgment. This is primarily due to limited knowledge of their behavior under various types of loading. The objective of this study was to help to fill in this gap in engineering knowledge by testing ninety-eight flange connectors embedded in 3ft x 3ft x 4in concrete slabs: seventy (70) monotonic and twenty-eight (28) reversed-cyclic tests were performed. All specimens and test apparatus were provided by the sponsor. The test protocols included (1) monotonic tension, (2) vertical shear upward, (3) vertical shear downward, (4) horizontal shear left, (5) horizontal shear right, (6) vertical reversed-cyclic shear, and (7) horizontal reversed-cyclic shear. Six different connectors were tested using each of these seven test protocols, each in duplicate.
Development of a Nonlinear Wood Shear Wall Model for Seismic Reliability Applications, Michigan Tech Graduate School, 04/01/00 – 07/15/01 (PI – van de Lindt).
This study developed a new hysteretic model for the
dynamic analysis of wood shear walls. The model, termed a polynomial
backbone model, was developed in order to assess the seismic reliability of
wood shear walls in