First Draft of Final Report

ENGR 103 - Spring 2017

Freshman Engineering Design Lab

“The Honeywalk Project” Final Report

Date Submitted: May 17, 2017         

 

Submitted to:	Eugenia Victoria Ellis, genaellis@drexel.edu
Group Members:	Spencer Kociba, smk442@drexel.edu
	Ilana Gorberg, ing28@drexel.edu
	William Reil, wer32@drexel.edu
	Julia Coleman, jsc338@drexel.edu

Abstract:

Conservation of the environment is undoubtedly an important issue facing the planet in the near future. Combustion of fossil fuels, deforestation and overrunning present ecosystems to make space for new commercial and residential spaces all contribute to the destruction of the earth. Cities are considered to be entirely steel and concrete, but the addition of greenspaces has been proved to improve local environment and resident health. To maximize the small amounts of natural spaces in urban settings, sidewalks for human foot traffic must be improved to save as much plant life as possible while still seamlessly providing paths for travel. Additionally, more efficient and environmentally-conscious materials and production thereof need to be accounted for in walkway improvements. Currently, existing elevated sidewalks are modeled after smallscale bridges and still require significant amounts of concrete and steel, and other alternative sidewalks require ousting large sections of greenspace. The Honeywalk Project was designed to further these elevated sidewalk designs and fit the criteria mentioned above. The Honeywalk functions as an elevated walkway with minimal points of contact with the greenspace to allow for grass and other plants to grow below the traffic of feet without the mass removal of native plants. The Honeywalk is easily reproducible and can interlock with other pieces, creating a web of hexagons that act as a sturdy platform and provide more pathway options than a standard sidewalk square. 

1     Introduction

1.1 Problem Overview

Urbanization has had a catastrophic impact on the environment. Between burning fossil fuels, creating noise pollution, and promoting high amounts of traffic (both via automobiles and human foot traffic), the local ecosystems are completely eradicated to make room for new roads and buildings. Greenspaces, parks, squares and plazas are difficult to come by in large cities. Most urban construction projects require a large amount of surface area to work with in order to create a strong and safe foundation and thus, must remove large areas of greenspace. In one particular experiment, data were found to suggest a “link between cities and social stress sensitivity.” [1]. In another study supported by the Japan Society for the Promotion of Science, it was determined that compared to a standard urban landscape, short walks through nature “improved

mood...heightened positive affect...induced a feeling of subjective restoration [and] vitality.” [2]. If more greenspaces were to be added to urban settings--for example, in Drexel University of Philadelphia--there was a possibility for improvement of the mental health of the community in the general area. 

At the time of this project, it was not yet possible to develop buildings or roads that did not require any removal of vegetation; however, it was hypothesized that perhaps a design for an elevated walkway (with minimal points of contact with the ground) could be a viable solution. A structure that required a smaller surface area while still fulfilling its function was the basis for the idea for the Honeywalk Project. Additionally, materials production and construction needed to be considered in the structure design (fossil fuels burned in the mixing, transportation and placement of standard concrete sidewalks undoubtedly have a negative impact on the local environment). It was determined that a prototype for an elevated, environmentally friendly, and easily reproducible sidewalk could be a possible solution to enhance urban greenspace and conserve natural ecosystems. 

1.2 Existing Solutions

New sidewalk solutions have had many problems.  Most of the newer sidewalks had been made from flexible rubber and were often composites of old tires and recycled plastics.  The city of Santa Monica, California had been a leader in these rubberized sidewalks with the panels manufactured by a company called Terrecon Inc.  Terrecon originally set out to create a sidewalk that would resist the potential destruction that tree roots could do to sidewalks.  With regular concrete sidewalks, tree roots had the potential to grow and rip through existing sidewalks.  Terrecon thought that rubberized sidewalks would be effective in keeping walkways flat and preventing tree roots from bursting through them.  While Terrecon had a good idea in using recycled materials for their walkways, they misjudged the effectiveness of the material that they used.  The sidewalks built have had major defects.  Tree roots still grew under the sidewalks making what should have been a level surface, into a wavy walkway that was somewhat difficult to traverse [3].  The Honeywalks that have been designed are sure to avoid this same disaster.  In addition to being made out of plastic instead of concrete, the Honeywalk is elevated above the ground.  This design will protect the grass underneath it, while also remaining flat no matter what the conditions.

1.3 Project Objectives

The primary objective of the project was to research, design and develop a prototype for a single sidewalk piece that would satisfy several requirements: minimum surface area of a greenspace removed per sidewalk piece, composed entirely of recycled material, ability to be easily mass produced, and be able to interconnect safely with other pieces. In order to satisfy the first condition, the recycled material and its structure must have also allowed air, water and sunlight to reach the greenspace underneath. For the second criterion, transparent and translucent recycled materials were researched for their ability to allow light to pass through and its strength. The walkway was decided to consist of many “blocks” or pieces--much like the standard square or rectangular sidewalk blocks--that would be able to be easily attached and placed next to each other. That required a single design that was capable of folding to provide a wheelchair accessible ramp to the elevated sidewalk. The locking mechanism and overall design was determined to be created in Fusion 360 (an Autodesk application) and 3D printed to scale.

The secondary objective for the Honeywalk Project was a walkway proposal for Myers Hall (a dormitory of Drexel University in Philadelphia, PA that was scheduled to be leveled and turned into a green space) [4]. The proposal was to include an approximate project timeline and walkway design created in AutoCAD as an on-campus application for the Honeywalk at the urban university.

2     Technical Activities

2.1 Design and Mechanism

The Honeywalk (design shown in Figure 1) was a six-sided figure with holes and grooves that allowed for comfortable walking while not destroying plant life.  The sides of the Honeywalk piece were slanted to allow a ramped piece to be flush with a level and elevated piece.  The holes of the Honeywalk piece were designed in order to allow rainwater to be able to reach the grass underneath.  The grooves on the Honeywalk served two functions.  It provided traction so that pedestrians would not slip while walking on the Honeywalk under slippery conditions.  As seen in Figure 1 below, the grooves were oriented toward the middle of the Honeywalk.  This design served to filter any rainwater towards the center of the Honeywalk and allowed it to slip through the holes instead of staying at the surface.  The Honeywalk was made of a clear plastic material to allow for sunlight to reach the plants beneath.

The interlocking mechanism consisted of a latch that swung 180॰ to bridge the gap between the two adjoining Honeywalks and popped into a space on the adjacent walkway piece, locking the two Honeywalks together.  The same latch design was reproduced on each of a single

Honeywalk’s six sides and offset to the right, so side-by-side Honeywalks could each latch to the other.  This mechanism allowed for strong interlocking that could be iterated for any given situation that demanded a sidewalk.  

The legs of the Honeywalk were designed to support the weight of any pedestrians, ensure the lateral stability of the Honeywalk, and fold inward for easy storage.  The four legs of a single Honeywalk were designed with an outward folding portion that connected two legs to prevent the structure from sinking into the ground.  Each leg ended with a spike that punched into the ground to prevent sideways shifting of a walkway piece.  These legs folded into grooves designed underneath the Honeywalk and fit into grooves designed into the top surface so that individual pieces could be stacked in storage.  

This same interlocking structure and folding legs allowed end pieces of the Honeywalk to fold downward to form ramps for disabled users.  By placing another piece for the latches to pop into father back and having select legs fold out of the way, the Honeywalks can form a 9॰ angled ramp.  This effectively allowed for all users of all physical abilities to ascend the Honeywalk comfortably without any stair or gap to overcome.  

Figure 1: Honeywalk Piece surface in Fusion 360

2.2 Project Timeline

Figure 2 shows the revised project timeline for the group at the time this report was written. Spencer changed the project timeline for the course to include the decisions to have a walkway proposal as a deliverable, which required research on the Myers Hall plot to be done. The markings in Figure 2 do not represent the actual progress of the group, but the proposed schedule that guided the objectives for each week. 

Task	WEEK
	1	2	3	4	5	6	7	8	9	10
Course Checkpoints
Form group	X
Blog check #1		X
Design Proposal		X
Blog check #2						X
Final report draft							X
Blog check #3									X
Final report									X	X
Blog Updates/Revisions		X	X	X	X	X	X	X	X	X
Final presentation									X	X
Research
Research current walkway construction		X	X
Research strengths of recycled plastics		X	X
Research greenspaces in urban settings		X	X
Research Myers Hall plot			X	X
Design
Design locking mechanism		X	X	X
3D designs in AutoCAD			X	X	X
Walkway design proposal in AutoCAD					X	X	X	X	X
Print 1/6 scale 3D parts					X
Test printed parts in machine shop						X	X
Design revisions and reprint (if necessary)						X	X	X
Retest Printed Parts							X	X
Design revisions and reprint (if necessary)									X	X
Deliverables
Final 3D Printed Parts										X
Final Walkway Proposal										X
Final Blog updates									X	X
Final Presentation									X	X

Figure 2: Project Timeline (updated 15 May 2017)

2.3 Project Budget

At the time, 3D printing services were provided by Drexel University in the Innovation Studios (with the constraint that the print was within the size dimensions and material limits set by the College of Engineering). Due to the policy, there was no additional cost of materials to the group for the Honeywalk Project. The group was able to print the prototype scale pieces during open lab hours.

2.4 Teammate Roles and Responsibilities

The roles for this project were categorized as several sections (also illustrated in the project timeline in Figure 2 from section 2.2): research, design of Honeywalk piece, blog updates and walkway proposal. Spencer researched strengths of recycled plastics in existence and the plots of the Myers Hall building and space; Julia researched greenspaces in urban settings; Bill designed the locking mechanism and assisted the Fusion 360 development of the Honeywalk piece; Ilana led the Fusion 360 design and researched existing solutions for eco-friendly sidewalks.

2.5 The Research

Existing solutions of the time were examined for their efficiency at the start of the project. Most solutions either fulfilled one requirement (for example, using as little surface area as possible) but not the others (not being constructed with environmentally friendly materials and processes). When evaluated with the research done on strengths of recycled plastics, it was clear that engineering a new solution was necessary.  

2.6 The Design

The work in the design portion of the project consisted of finding the right materials for the final prototype, 3D printing the small-scale model, creating the interlocking mechanism, and generating a way in which the Honeywalk could realistically function as a walkway. This included, but was not limited to, finding ways ramps could be created from these interlocking pieces and how best to create ridges on the walkway for friction. The design portion of the project was important because it creates a visual product for which people to view the Honeywalk. Rather than just a theory, the physical prototypes helped to explain what the Honeywalk was instead of just words and pictures on the screen.

3          Results

By the project’s end, three groups of deliverables were effectively produced: 3D-printed prototypes of the Honeywalk and its mechanisms, a proposal for the implementation of the Honeywalk design in the green-space that is to replace Myers Hall after its demolition, and a blog detailing the progression of the overall design and the production of these deliverables.   A 1:6 scale model of the Honeywalk concept was created to allow for easy visualization of the raised walkway.  This model was tested with scaled weights in order to check its strength when walked on.  Separate models were produced to display the folding legs and the interlocking mechanism at different scales.  The Myers Hall proposal detailed scale AutoCAD drawings of the greenspace and the approximate placement of the Honeywalk.  The blog provided a professional and accessible platform to monitor the project on a weekly basis.   

4          Discussion

The Honeywalk Project changed and evolved throughout the ten weeks of the term as some drafts of designs were found too unreasonable to complete or were not in the best interest of the team members’ responsibilities. Additionally, several components were added to enhance the presentation of the project as a whole (the walkway proposal designs). These components and their objectives were also revised to fit the tight timeline of the course and the resources available to the students at the time.

4.1 Future Changes

Overall, it was summarized by the students that, if given more time to dedicate the the project, several additions and features of the deliverables would be included. Some of these changes included building a full scale Honeywalk piece (of a transparent, recycled, and durable plastic), testing the load bearing capabilities of the pieces, and building a physical scale model of the walkway proposal. Due to the time constraints of a 10-week term, it was unfeasible to print the scale models, test load strength, analyze the data, revise the design and reprint multiple times through. A complete scale model of the Myers Hall greenspace walkway would put the students in a position to propose the Honeywalk Project to a board of potential investors as well as provide more clarity to the application of the project.  

5     References

[1]  F. Lederbogen, P. Kirsch, L. Haddad, F. Streit, H. Tost, P. Schuch, S. Wüst, J. Pruessner, M. Rietschel, M. Deuschle and A. Meyer-Lindenberg, "City living and urban upbringing affect neural social stress processing in humans", Nature, vol. 474, no. 7352, pp. 498-501, 2011.

[2]  N. Takayama, K. Korpela, J. Lee, T. Morikawa, Y. Tsunetsugu, B. Park, Q. Li, L. Tyrväinen,

Y. Miyazaki and T. Kagawa, "Emotional, Restorative and Vitalizing Effects of Forest and Urban Environments at Four Sites in Japan", International Journal of Environmental Research and Public Health, vol. 11, no. 7, pp. 7207-7230, 2014.

[3] Berg, Nate. "The Sidewalk of the Future Is Not So Concrete." Citylab. N.p., 22 May 2014. Web. 16 May 2017.

[4] A. Jones, "Myers Hall to be demolished, replaced with green space - The Triangle", The Triangle, 2017. [Online]. Available: http://thetriangle.org/news/myers-hall-demolished-replacedgreen-space/. [Accessed: 16- May- 2017].