Structural Evaluation of Maglev Guideway Concepts

The National Maglev Initiative (NMI) resulted in four distinctly different concepts. The structural systems of the concepts varied greatly, but in general were very complex. This paper evaluates the concepts as to their performance of selected criteria: constructability, reliability, maintainability, adaptability, and durability. Three of the systems used precast, prestressed concrete for the main load-carrying element. One system used aluminum. Only one system, system concept design (SCD-1) could be readily produced in existing precasting plants. None of the systems provided for easy adjustment of operating elements after construction. These systems require construction tolerances that are much more restrictive than conventional practice. Among the stated goals of the NMI concepts were: (1) it should anticipate upgrade; (2) it should be economically and financially attractive; and (3) it should be robust in terms of its susceptibility to adverse weather and its requirement for maintenance. This paper concludes that none of the four concepts adequately met these goals. However, some concepts could achieve the desired goals by relatively modest redesign.