Jembatan Siti Nurbaya is the most substantial bridge over the Batang Arau, located at the South of the city center spanning roughly 70m. The bridge is approximately 10m wide and is a standard concrete box girder. The bridge itself faired very well in the September 30th earthquake with no apparent damage. The approaches, which consist of soil confined by concrete retaining walls, held up during the earthquake but sustained damage. The sidewalk on the South West approach separated and settled from the concrete retaining wall approximately 12”, as a result of an earthquake in 2007. This same location settled an additional 18” in the recent earthquake. In addition to the measurable separation, the south approach suffered damage in that the entire approach dropped relative to the bridge and the pavement split in two clear cracks forming deep longitudinal voids. Additionally, the North approach currently has about a two-inch crack spanning the entire width of the bridge just a few feet from the bridge-approach connection.
This bridge could serve as a key component for tsunami evacuation for two reasons: the bridge sits approximately 26 feet above the road below therefore the bridge is approximately 30 ft above sea level, which could potentially act as an evacuation site; the second use of the bridge is to facilitate numerous pedestrians, motorbikes and even cars, over the bridge to grant access to higher ground.
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| Figure 1. Sidewalk on the South West approach separated and settled from the concrete retaining wall. | Figure 2. Deep longitudinal voids in the pavement caused by damage in the south approach. | ||
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| Figure 3. The pavement split in two clear cracks forming deep longitudinal voids. | Figure 4. Two-inch crack spanning the entire width of the bridge. | ||
