Yang, Mijia

This research studied the possibility of harnessing solar energy through right-of-way associated structures, such as noise barriers and snow fences. A detailed survey was conducted of the general public, farmers, and utility companies to determine their acceptance of such an initiative. A large percentage of the general public, farmers, and utility companies welcomed the idea of harnessing power using right-of-way associated structures. Furthermore, a detailed structural design for the solar noise barrier and snow fence were created. The effects of the solar panels installed on noise barriers or snow fences in terms of noise reduction, glaring, impact and crash responses, and snow-drift responses were studied, and the potential influence on traffic safety was summarized. To make the generated energy usable, a convenient connection with the power grid through modularized controllers and inverters was developed and tested in a lab setting. It was verified through the lab testing that such a prototype can realize the proposed functionalities very well. Based on the developed system and including cost of materials, construction, and maintenance, a cost-benefit model was created to analyze the possible scenarios for MnDOT to implement such a system and to guide MnDOT in its decision.

Many state Departments of Transportation (DOT) across the US; including MnDOT; are experiencing problems associated with loose anchor bolts used in support structures (e.g.; overhead signs; high-mast light tower (HMLT); and tall traffic signals). Specifically; MnDOT inspection crews have found loose nuts at most anchor bolt locations; even at some newly installed signs. Many of these nuts became loose in less than two years; even after being tightened by the maintenance crew following current recommended procedures. This situation has placed great strain on the resources from the districts' maintenance group and also causes concerns related to inspection frequency and public safety. This project investigated causes of the loose anchor bolts and proposes solutions based on site surveying; field monitoring; laboratory study; and numerical analysis. The research team found that the tightening process proposed in AASHTO's specification is a sufficient alternative for MnDOT; though it requires modification in three key areas: defining snug-tight; accounting for grip length; and recommending verification procedures. The research team quantified snug-tight values; and defined the relationship between torque; tension; and nut rotation through empirical constants. Recommendations are made for a new specification for MnDOT structures.