MTI/MoDOT Transportation Geotechnical Research Program - Task 3

Status

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Sequential Number

Identification Number

Matching Research Agency

Missouri Department of Transportation (MoDOT) and University of Missouri

Principal Investigator

Student Involvement

Project Objective

The objective of this task is to quantify the relationship(s) between costs and risks and identify optimum risk-cost balances and minimally accepted risks for bridge foundations and earth slopes to accurately reflect MoDOT priorities.  Specifically, this task will establish generally accepted target risk levels for different limit states and structure types based on the costs and consequences involved.

Project Abstract

This project is one component of a comprehensive research program to develop new and improved LRFD specifications, and associated commentary documents, for design of bridge foundations and earth slopes. This specific portion of the work focuses on analyses of appropriate target risk levels for bridge foundations and earth slopes in different conditions.  Analyses will include economic and risk analyses to develop preliminary recommendations for target risk levels that achieve a balance between cost and risk. These recommendations will then be vetted among top level MoDOT leadership to invoke agency priorities. Following this vetting process, final target risk levels will be established and subsequently used in other portions of this work to develop design specifications that will achieve the target risk levels.

Anticipated Benefits

This outcomes from this task will serve as a key source of potential cost savings in the sense that designing for lower risk generally involves greater cost.  Fundamental analyses performed for this task to balance the target risk levels for different limit states and structures with the costs associated with reducing the target risk level will allow MoDOT to routinely make the most effective and reliable use of limited funds both possible and practical. 

Milestones

Relationship to other Research/Projects

This project is one component of a comprehensive research program to develop new and improved LRFD specifications for design of bridge foundations and earth slopes. Funding for this program is to be provided by the Missouri Department of Transportation, NUTC, and the University of Missouri – Columbia and Missouri University of Science and Technology. The program includes four broad tasks that, when integrated, will allow MoDOT to realize substantial and continuing cost savings for design of bridges and earth slopes. Task 1 includes activities to improve site characterization practices through a comprehensive laboratory and field investigation to quantify variability and bias in relevant design parameters. Task 2 includes a program of field load testing for bridge foundations and assessment of current and improved methods for design of bridge foundations. Task 3 involves assessment and evaluation of risks for bridge foundations and earth slopes and development of appropriate target risks for bridge foundations and earth slopes. In Task 4, the results of Tasks 1 through 3 will be integrated with analyses to develop new and improved LRFD methods for design of foundations and earth slopes. The principal deliverables from this program will be two new design specifications (one for Bridge Foundations and one for earth slopes), and three commentary documents to accompany the specifications. The commentary documents will detail the results of research produced in Tasks 1 through 3, provide justification for the new specifications, and provide guidance for implementation of the new specifications in MoDOT practice. 

Technology Transfer Activities

Technology transfer for this portion of the research program will be achieved through publication of one or more papers at technical conferences or in refereed journals. 

Transportation Research Board Keywords

Bridge foundations, design, embankments, risk management