e-mosty September 2017: Mersey Gateway Bridge. Arenales Bridge. Mersey Gateway Bridge. Arenales Bridge. BLWT. | Page 28

3. DESIGN 3.1 Bridge Design Criteria Quick facts, also refer to Figure 4: The tropical regions of western Nicaragua are not only subject to substantial seasonal rainfall, but also tropical storms and hurricanes moving west across the Caribbean. The high water levels of the Esteli River and high winds accompanying these storms are the primary design criteria for the bridge layout and lateral capacity, respectively. The vertical loads on the footbridge are derived from the AASHTO Guide Specifications for the Design of Pedestrian Bridges. The design pieces together several resources that encompass the Bridges to Prosperity design philosophy as agreed upon by the Technical Advisory Board. In addition to the AASHTO code mentioned, the organization use the latest editions of AISC Steel Design Specification, ACI 318, ASCE 7, and NDS National Design Specification for Wood Construction. The bridge is expected to support an average of 250 pedestrian, animal, and moto crossings per day.      The walkway is supported by six 32mm diameter wire rope cables that each have a total length of 195m from anchor to anchor. The clearance between the walkway and the highest known water level is a minimum of 3m above the full width of the river. The bridge walkway is 1m wide and made of steel crossbeams and a timber deck. The steel towers are 9.5m tall, supported on 3m tall concrete pedestals. The total concrete volume for all foundations and anchors is 127m 3 . Figure 4: Arenales Suspension Bridge Rendering 3/2017