Rehabilitation of Timber Railroad Bridges Using Glass Composite Fabrics

This paper presents a detailed outline pertaining to the rehabilitation of three timber railroad bridges located along the South Branch Valley Railroad (SBVR), in Moorefield, West Virginia. All three timber bridges were at least 50 years old, and acquired major renovations for adaptation to modern railroad traffic applications, i.e. 20 percent increase in load carrying capacity to accommodate the weight of a 315 kip locomotive. The refurbishment consisted primarily of piles, pile caps, and bridge stringers that were in an advanced state of decay. These sections were refurbished either in-situ or by temporary removal and prompt on-site renovation. The renovation consisted of: 1) Complete removal of loose/decayed material; 2) Existing cavity replenishment with consistent bulk adhesive; 3) Proper application of selected primer; 4) Suitable wrapping of resin soaked fabric on piles, pile caps, and bridge stringers; and 5) Reinsertion of original bridge stringers after refurbishment with glass composite wraps. Load testing results from a portion of these initial bridges revealed that renovations accounted for relative stiffness values that are approximately double in comparison to the original substrates. The above renovation technique is non-intrusive, structurally sound, and economical proficient. Currently, an on-going monitoring program of the renovated bridge structures should provide us with a wealth of technical information, and establish the durability of the proposed renovation methodology.