Since 2000 CDOT has made effective use of Safety Performance Functions (SPF), Level of Service of Safety (LOSS) concept and diagnostic norms to prioritize, plan and scope safety improvements on all projects. A recent trend in road safety research, however, is to develop SPFs for each crash type. This approach is significantly more costly and labor intensive than the one used by CDOT, the benefits of this approach, however, were not well understood. It was not known if having crash type-specific SPFs will improve effectiveness of safety management, or if it will simply make the process more labor-intensive and less accessible to practicing engineers and planners. The intent of this project is to compare the effectiveness of network screening and diagnostic methods using aggregate SPFs and Test of Proportions with crash type SPFs.
The replacement of the CDOT Region 1 Twin Bridge over Smith Road and Union Pacific Rail Road (UPRR) on I-70 provided an excellent opportunity for the performance evaluation of GRS (geosynthetically reinforced soils) abutment. The performance of the GRS abutment was measured using SAA (shape accel array) for lateral deformation and vertical settlement measurement, Geokon 4810 for horizontal earth pressure, 4800 for vertical earth pressure, 4420 for separation measurement between abutment and top of sheet pile wall, 4150 for strain of anchor rod, and optic fiber for geosynthetic strain measurement.
This report presents a comprehensive evaluation on the effect of drilling fluid infiltration in claystone bedrock on the axial capacity of drilled caissons. The methodology of this research combines experimental testing and numerical simulations. The results obtained in the experimental phase are used to inform the numerical study.
