PSI - Issue 64

Abheetha Peiris et al. / Procedia Structural Integrity 64 (2024) 588–595 Peiris, Harik, et.al. / Evaluation of Historic Truss Bridges 00 (2019) 000–000

591

4

Table 2. Unique truss factor Number of similar truss bridges in KY

Factor X 1

1 2 3 4

8 6 4 2 1

more than 4

3.2. Age factor, X 2 The magnitude of the age factor ( X 2 ) is based on the age of the truss bridge as shown in Table 3. The selection of the years 1910 and 1935 as dividing lines is based on the trusses being 100 and 75 years old, respectively, when the initial assessment was carried out in 2010 (O’Connell, L. et al. 2013). The oldest truss bridge in the database was constructed in 1868; 12 additional bridges were built prior to 1910. Over half of the bridges (49) were built during the 1910-1935 period, while the remainders (32) were constructed after 1935.

Table 3. Age Factor Year Built

Factor X 2

Before 1910 1910 – 1935 After 1935

4 2 1

3.3. Unique feature factor, X 3 The Unique Feature Factor ( X 3 ) captures the unique structural and/or decorative features. Structural features encompass elements such as tubular beams, pin connections, eye bolts, and stone abutments. Aesthetic features refer to decorative portals, decorative rails, and decorative piers, among other attributes. Table 4 presents the magnitude of X 3 based on the number of unique features identified on the bridge. Five (5) bridges had 3 or more unique features, 14 had two unique features, and 32 had only one unique feature. Stone abutments and/or piers were the most common feature with 27 bridges having them. Pin connections were also found on 24 bridges.

Table 4. Unique feature factor, X 3 Number of Unique Features

Factor X 3

> 3

4 3 2 1

2 1

None

3.4. Historic feature factor, X 4 The Historic Feature Factor ( X 4 ) accounts for the number of historic features a truss bridge possesses. Qualifying features include being within or close to a historical area or district, being named after a historically significant person, being built and/or designed by a historically famous person and/or company, being a former railroad bridge, and being constructed by the Public Works Administration or other agency of historic importance. This factor ( X 4 ) is based on a bridge’s number of historic features (Table 5). Thirteen (13) bridges had 2 or more historic features; 32 additional bridges had only one historic feature, and the remaining bridges (49) did not have any historical feature associated with them.

Table 5. Historic Feature Factor Number of Historic Features

Factor X 4

> 2

8 4 1

1

None