Update LADOTD policy on pile driving vibration management.

The main objective of this project was to update the current Louisiana Department of Transportation and Development (LADOTD) policy on pile driving vibration risk management with a focus on how to determine an appropriate vibration monitoring area. The current best practice of managing the risk of pile driving by federal and state highway agencies was identified by conducting a comprehensive literature review and a questionnaire survey. Ground vibration data were collected from previous pile driving projects in the state of Louisiana, which were statistically analyzed on the basis of the scaled-distance concept to develop regression equations for predicting ground vibration Peak Particle Velocity (PPV) values. A rational procedure for determining an appropriate vibration monitoring distance (VMD) was developed for Louisiana’s local conditions based on a 99 percent prediction-level regression equation for predicting PPV values. The findings (the threshold PPV limits and the VMD) obtained from the empirical scaled-distance concept were further verified with dynamic finite element method (FEM) simulations. The results from this study indicated that the vibration criteria specified in the current Louisiana’s special provision are generally too conservative (i.e., a PPV limit of 0.2 in/s for residential buildings and a pre-construction survey distance of 500 ft.) and should be revised. Regarding the threshold PPV limits, the results suggest that 0.5 and 0.1 in/s should be used for a general scenario (neither historic buildings nearby nor loose sandy soil layers present) and for a special scenario (either a historic building or a loose sandy layer existing near pile driving sites), respectively. Consequently, VMDs of 200 and 500 ft. are recommended for general and special scenarios, respectively. The values of VMD in the case of a large pile driving hammer (i.e., its rate energy larger than 100,000 ft-lbf) being used were also recommended. The pre-construction survey distance was suggested to take the same value as the VMD. A specification draft was developed on the basis of the major findings from this study, which is included in Appendix E and ready to be implemented by LADOTD in future pile driving projects.