Troutdale Observation Deck
| dc.contributor.author | Kristof, Evan | |
| dc.date.accessioned | 2021-10-14T17:52:39Z | |
| dc.date.available | 2021-10-14T17:52:39Z | |
| dc.date.issued | 2021-06 | |
| dc.description | 105 pages | en_US |
| dc.description.abstract | The City of Troutdale has planned to construct Sandy Riverfront Park on a reclaimed site just north of downtown Troutdale, which previously housed an old water treatment plant. The park will be part of Troutdale’s Urban Renewal Project, which aims to create a natural space for walkers and bicyclists to enjoy the local flora and the Sandy River. The city requested a cantilevered deck designed at 30% to provide a commanding view of the river and serve as a rest area for park visitors. The design considerations include cost-effectiveness, minimal deck deflection, minimal obstruction to existing site conditions, and ease of access for long-term maintenance tasks. The proposed cantilever deck design was based on a “short and wide” layout, with a longer width parallel to the trail and a comparatively shorter cantilever length. After several design iterations and feedback from the City of Troutdale, the proposed design was restructured into a roughly square deck, with a width of 18’ and a cantilever length of 17’. The reasoning behind this ultimate design includes enhancing the view of the Sandy River and providing enough space for both visitors and amenities, such as benches. Materials involved in the design were chosen based on client preference, ease of maintenance, and overall resiliency. The decking material chosen was pultruded fiberglass paneling, the same material that will be used in the elevated walkway from the Sandy Riverfront Park Trail plan. These panels are a plastic product reinforced with fiberglass and are appropriately referred to as “fiberglass reinforced plastic” (abbreviated as FRP). The material is lightweight, weather-resistant, and manufactured to be ADA-compliant and slip-resistant. FRP can also be manufactured in grate panels, allowing easy maintenance and superb drainage. Six steel stringers support the decking; all six utilize the wide flange beam shape due to its universal application in most designs and high flexural strength-to-weight ratio. These stringers will be spaced 3.4’ on-center to keep the deflections of the deck panels within the allowable tolerance, while minimizing the number of stringers utilized. There will be two reinforced concrete girders below the steel stringers; these girders will span the 17’ cantilever distance and an additional 1.5 times the cantilever distance (25.5’), with a total girder length of 42.5’. The additional length extends behind the cantilever as the “backspan”, and acts as a balance against the bending force exerted on the cantilevered portion. This backspan will be buried below grade from beyond where the deck ends, and the weight of the topsoil will provide additional resistance against bending. Since the girders will be in contact with soil throughout their service life, they will be constructed of reinforced concrete. This material was chosen for its extensive corrosion resistance when compared to steel, as well as its great compressive strength. Since the site is sloped, a standalone retaining wall is recommended to prevent soil erosion from the loading on the deck. The retaining wall will be located at the beginning of the cantilever. The structure will be founded upon spread footings of reinforced concrete and connected to the backspan portion of the girders. This style of foundation was selected for its simplicity in construction. There was also a lack of deep soil data at the site - if more data was available, it could guide deep pile foundation design instead of spread footing design. Included in this report is the 30% design plan set and a construction cost estimate. This preliminary design report informs the City of Troutdale the magnitudes of cost and construction efforts needed to bring the project to completion. As such, the design may be modified according to the preferences and vision of the City. | en_US |
| dc.identifier.uri | https://hdl.handle.net/1794/26757 | |
| dc.language.iso | en_US | en_US |
| dc.publisher | University of Oregon | en_US |
| dc.rights | Creative Commons BY-NC-ND 4.0-US | en_US |
| dc.title | Troutdale Observation Deck | en_US |
| dc.type | Terminal Project | en_US |