Research Idea Details

Research Idea Scope

Problem Statement
On a national scale, increased emphasis is being placed on expansion and refurbishment of fixed-guideway transit systems, especially steel rail-steel wheel formats. This has exacerbated the need for accurate information regarding effective methods of reducing the potential adverse effects of transit-induced ground vibration. Many existing rail transit systems are in close proximity to dense residential and other vibration-sensitive development. New rail systems that are in the planning, development, and design stages are often located in urban environments very close to vibration-sensitive use. This juxtaposition of seemingly incompatible use is not “encroachment” in the traditional sense; it is actually desirable and necessary to place these systems adjacent to and within origin and destination uses such as residences, medical facilities and high-tech research and development facilities, and manufacturing areas. The ability to co-locate transit systems with origin and destination uses that do not create unacceptable adverse ground-borne vibration or noise is increasingly important.
 
Although the efficacy of the most sophisticated (and most expensive) vibration-isolation systems such as floating-slab are well documented, there is a definite need for access to comprehensive information regarding the performance and applicability of the more practical alternatives of using ballast mats, tie boots, and trenching methods of vibration isolation. This will allow the system designers, environmental analysts, funding agencies, and the affected public a better understanding of the overall effects of the rail transit system and the cost-benefit aspects of providing a transit system that is compatible with vibration-sensitive uses.
 
Proposed ResearchResearch would synthesize a comprehensive database addressing initial and long-term technical effectiveness, initial and life-cycle costs, construction concerns and delay mechanisms, and applicability preferences of using ballast mats, tie boots, and/or trenching approaches to vibration isolation of rail transit systems. The synthesis could include a meta-analysis of existing research and where new research might be required, especially in regard to performance characteristics of candidate mitigation options in various soil types.