摘要: |
American Association of State Highway and Transportation Officials (AASHTO) Load and Resistance Factor Design (LRFD) Bridge Design Specification, through AASHTO SCOBS T-14 committee (Steel Bridges) have recently developed design provisions for use of Concrete Filled Tube (CFT) columns for bridge elements, such as columns in substructure. In the case of High Speed Rail (HSR), about 60 to 70% of the HSR infrastructure consists of elevated bridge structures. In one recent case in California, a segment of the High-Speed Rail (HSR) consists of elevated bridge structures with spans of about 110 to 150 ft. with columns, ranging in height from very short to as tall as 100 ft. Use of pre-fabricated sub-structure elements could significantly reduce cost and expedite the HSR project delivery. U.S. DOT has identified the use of HSR as a strategic area for addressing mobility challenges. Development of an efficient substructure system for HSR is therefore urgent and will result in significant savings. The recent adaptation of CFT columns by AASHTO LRFD Bridge Design Specification is a first step. Development of efficient substructure system for HSR using CFT columns, demands development of cap beam system and their connection to CFT columns.
This project is a joint investigation with University of Washington. The FIU project will concentrate on development of a connection capable of connecting cap beam system to CFT column, while University of Washington will concentrate on developing a pile cap system that could be utilized in conjunction with CFT columns. Together, these two projects, combined with existing information about CFT columns, will provide an economical substructure alternative system for HSR that will be presented to HSR authority for additional development and implementation. |