Truncated base mechanically stabilized earth walls are the MSE walls with narrow base excavation length and steep excavation slope designed to save construction cost while pushing the technological envelope of geosynthetic reinforcement development. A wall with truncated geometry of a narrow base length and steep excavation slope can significantly increase its base bearing pressure.
This report presents a case study on the evaluation of bridge decks using various non-destructive test methods. The primary interest lies in quantifying delaminated areas in deck concrete covered with asphalt overlays. Analytical and computational models are formulated to decompose the intensity of GPR scales into two categories: i) initiation and progression of corrosion and ii) delamination of deck concrete, which show good agreement with repaired areas. Parametric investigations emphasize the significance of rebar spacing and concrete cover in determining the extent of deck delamination.
CDOT has prioritized the research of select methods to evaluate the performance of the I-25 Gap work zone and future CDOT construction projects. Work zone performance measures provide comparative metrics that quantify the level of impact a work zone has on travelers, residents, businesses and workers. CDOT has identified the need to research and apply performance measures to the I-25 Gap construction project; establishing a foundation to improve the decisions that are made during planning, design and construction for the remainder of the I-25 Gap project and for future CDOT highway construction projects.
Proper structural design of pavement systems requires knowing the resilient modulus of the soil as this parameter is a proven predictor of the stress-dependent elastic modulus of soil materials under traffic loading. In addition, the R-value test is conducted using a device called a stabilometer, where the material's resistance to deformation is expressed as a function of the ratio of the transmitted lateral pressure to that of the applied vertical pressure. Both tests are expensive and time consuming; however, establishing accurate and reliable correlations between the test results and the soil's physical properties, in lieu of laboratory testing, can save a considerable amount of time and money in the analysis and quality control process. For these reasons, correlations are typically used for estimating the resilient modulus and R-value for soils. The variability of a given soil type in different regions and states requires developing modified and specific correlations for each state based on statistical analysis of the statewide soil data collected. The main goal of this research study was to develop correlations among R-value, Resilient modulus, and soil's basic properties for available AASHTO soil types in databases in Colorado.
