I am preposing a pedestrian bridge that will connect the San Luis Rey River Trail (A bike path that spans from one side of the town to the other) and the Melba Bishop Recreation Center (a recreation center in our town with baseball fields, a skate park, basketball courts and an elementary school directly next to it.). This submission aims to showcase both the construction process of the bridge and highlight why it's an essential addition to our community and how we can bridge the gap, providing seamless access for residents and visitors, and fostering a stronger link between fitness, education and recreation.

Supplies

For the software I used a combination of The West Point Bridge Design software, Tinkercad, Fusion 360 and Onshape (as I don't have access to Fusion on my school chromebook) For the two models used a combination of materials and techniques.

For the river bed I used:

foam core - for the overall structure of the river bed and side walls
painters calking - for filling gaps between the foam core and 3d printed parts
spray paint - for priming the riverbed and painting the sky
green flocking - for simulated grass
sand - for the sandy regions of the riverbed
glue
a variety of rocks - for the rock slurs on the south wall and to add variation on the river bed
24 gage wire - hand twisted to make the tree's trunk/branches
course foam - glued to some of the trees to make the dark green tree tops
green cotton - glued to some of the trees to make the light green tree tops
3d clips and pins - for connecting foam core pieces

For the 1:100 bridge model I used:

13 3d printed components
super glue
spray paint

For the 1:200 model I used:

18 3D printed parts
super glue
balsa wood sticks
spray paint
craft paints

Step 1: The Plan

Through the use of google maps I was able to get approximated measurements that are relevant to the bridge that I am proposing to build. Here are the measurements and other factors that I keep in consideration while designing this bridge.

Length - 76.2 Meters
Width - 3.6 Meters
Height Drop - 10 Meters
Light Rain
Support of small maintenance vehicles
Humidity from the river below

Considering this span, which is quite long for a pedestrian bridge, I opted to incorporate a pier at the bridge's center. This approach effectively divided the bridge into two 76.2 Meters sections, reducing the overall structural requirements while maintaining safety. With the assistance of the West Point Bridge Design software, I crafted a truss design that now forms the bones of my bridge. This truss design will be mirrored on both sides of the pier. These simulations that I ran gave me a proven structure behind my bridge design. Having resolved the mechanical aspects of the bridge, my attention turned to its visual appeal. To keep things simple yet aesthetically pleasing, I decided to incorporate two perforated side walls adorned with a sunrise painting. This had been done as an attempt to enhance the bridge's aesthetics as well as to serve as a safety measure. The raised sides of the bridge prevent cyclists from accidentally veering off, providing an additional layer of protection.

Step 2: Design, 2 Separate Models

To effectively showcase the various aspects of my design, I made use of two distinct models at different scales—1:100 and 1:200. The 1:100 scale model focused on highlighting half of the trusses within the bridge. I chose this scale because the creation and pathography of a 1524mm model is unrealistic for my workflow, yet I couldn't adequately represent them at a 1:200 scale due to limitations with my 3D printer. On the other hand, the 1:200 scale model provided an overall artistic representation of the bridge and demonstrated how it would fit organically into the river bed. I opted for a 1:200 scale as it was the smallest scale I felt comfortable with while still effectively showcasing the bridge's appearance. By using two scales that were exactly half of each other, I streamlined the manufacturing process. The clamps and jigs I created for gluing the models together could be easily reused for both scales as the models ended up the same length. Additionally, this ensured that both models could be displayed within the river bed diorama I specifically designed for the 1:200 scale model.

Step 3: 1:100

As mentioned earlier, this particular model has been developed with a specific focus on illustrating the internal trusses of the bridge. The model consists of 8 side pieces and 5 floor pieces, measuring approximately 762mm in length and 31mm in width. Its primary purpose is to offer a comprehensive and intricate visual representation of the structural composition of the trusses, enabling viewers to gain a deeper understanding and appreciation for the engineering complexities involved. The creation of this model was driven by the intention to highlight the fundamental significance of truss design in guaranteeing the stability and overall functionality of the bridge.

Step 4: 1:200

Likewise, the 1:200 scale model serves the specific purpose of highlighting the artistic value inherent in the bridge design. Composed of various elements, it offers a comprehensive representation of how the bridge integrates into the riverbed. Positioned strategically at the entry point of Oceanside from Bonsal, the neighboring town, this model acts as a visual marker, welcoming visitors and signaling their arrival in Oceanside. Hopefully this bridge will inspire a sense of anticipation and excitement among those approaching our town.

Step 5: Roads and Rivers

I constructed a diorama that offers a portrayal of the river bed. It attempts to capture the essence of a true pristine landscape. Within this diorama, I ensured the inclusion of essential infrastructure elements necessary for the bridge's implementation. These encompass the connection points at either end of the bridge, integrating with the surrounding environment, and the pivotal pier situated at the center. The diorama effectively showcases the envisioned bridge within its intended setting, providing you with a tangible glimpse of how it merges with the existing landscape.

Step 6: Safety Benefits

In 2020, California witnessed a staggering 216,366 car accidents, out of which 3,854 resulted in tragic fatalities—a startling statistic reported by the California Highway Patrol. As people gradually resumed their outdoor activities, these numbers have only surged further up to today. Unfortunately, the current layout of our town puts pedestrians at considerable risk, making it almost inevitable for them to navigate hazardous situations. The San Luis Rey Sun Set bridge aims to address this critical issue by providing a dedicated pathway, effectively separating pedestrians from vehicular traffic. This crucial step towards enhancing safety has the potential to protect countless lives and significantly reduce the number of accidents. By implementing the bridge, we aspire to create a community where people can move about freely, without consistently fearing for their well-being.

Step 7: Health Benefits

A significant portion of pedestrians expected to utilize this bridge are minors, as it will serve as a vital connection between multiple schools and the recreational center. By providing a safer means of access to the recreational center, I anticipate a noticeable increase in its utilization, as well as other public resources in the vicinity. Parents, now equipped with a secure pathway for their children, will likely advocate for more physical activity and encourage their kids to embrace a healthier lifestyle. This newfound safety and convenience will undoubtedly act as a catalyst, prompting families to engage in recreational activities, fostering a community that prioritizes fitness and well-being. It is my firm belief that this bridge will not only bridge physical spaces but also bridge the gap in promoting active and healthier living among the younger generation. Together, we can cultivate an environment where our children thrive, benefitting from enhanced access to essential recreational facilities.