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Engineering Design of WalkwayInfrastructure for the people ofTimor-LesteENGRFoundations of Engineering2019University of CanterburyENGR101/2018 EWB 2 Final Report iSummaryThe people of Holarua, a small mountain village located in Timor-Leste, need assistance to build walkway infrastructure to create ...

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Engineering Design of Walkway Infrastructure for the people of Timor-Leste

ENGR101 Foundations of Engineering 2019

University of Canterbury

Summary The people of Holarua, a small mountain village located in Timor-Leste, need assistance to build walkway infrastructure to create a safe and enjoyable tourism experience and to protect the local environment as tourism numbers increase. The walkway solution designed to meet this challenge is a modular timber walkway that can be built by locals with minimal training and up-front cost using locally available, sustainable materials. Consideration has been given to the areas that walkways are needed, many of which are hilly or mountainous. The walkway can have the depth of its modules halved to act as steps without affecting the overall construction, connections or maintenance. The native timber materials have a positive impact on the surrounding scenery and environment and are compatible with local customs. The design meets the requirements for the walkway infrastructure within the specifications and constraints identified.

ENGR101/2018

EWB 2.d Final Report

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Table of Contents Summary ............................................................................................................................... i Table of Contents...................................................................................................................ii The Problem Statement ........................................................................................................ 1 Research and Investigation................................................................................................... 2 Background ....................................................................................................................... 2 People of Holarua.............................................................................................................. 2 Geography of Holarua ....................................................................................................... 3 Existing Infrastructure and Resources ............................................................................... 4 Alternative Solutions ............................................................................................................. 6 Initial ideas from brainstorm ............................................................................................... 6 Duncker Diagram .............................................................................................................. 6 Decision Matrix .................................................................................................................. 7 Custom-built walkway ........................................................................................................ 8 Single-file plank walkway ................................................................................................... 9 Conclusion ...................................................................................................................... 10 Recommended Solution ...................................................................................................... 10 Joinable Pallets ............................................................................................................... 10 Design Specifications ...................................................................................................... 11 Materials .......................................................................................................................... 11 Calculations, costs and loadings...................................................................................... 11 Construction and Maintenance ........................................................................................ 12 The Design in Context......................................................................................................... 13 Final Evaluation .................................................................................................................. 14 Team Learning and Experiences ........................................................................................ 14 References ......................................................................................................................... 15

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The Problem Statement The people of Holarua, a small mountain village located in Timor-Leste, are aiming to encourage tourism in their local area to help improve their economy. They need assistance with resources and skills to be able to do so themselves. Timor-Leste is a two-season country meaning part of the year it is constantly raining; tourists visiting during the wet season will create mud and potentially damage the local environment. Walkway infrastructure needs to be built to create a safe and enjoyable environment for tourists and to protect the local environment. The walkways must: 

be able to be built by locals (so that they benefit financially during construction) and require minimal training and up-front cost



use affordable, locally available, sustainable materials



be modular in design, elevated from the ground, quick to assemble, durable and easily maintained



have a positive impact on the surrounding scenery and environment, be safe, and be compatible with local customs

Constraints to manage: 

costs for all aspects of the design and build need to be kept as low as possible, this extends to training, workplaces and tools required, materials and construction costs



the walkways must be resilient to bad weather, especially rain and being constantly wet



though a modular construction allows for regular and low-cost maintenance, the walkways must be designed to last at least 10 years before major reconstruction work is needed

ENGR101/2019

EWB 2.d Final Report

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Research and Investigation Background Holarua has a population of 6,871 according to a 2015 census (Brinkhoff, 2015). A range of languages are spoken by the people of Timor-Leste, the top three being Tetun Prasa (30.6%), Mambai (16.6%), and Makasai (10.5%). The people are mostly literate (71.5% of males over the age of 15) and the country is 78% electrified in urban areas, though only 27% electrified in rural areas (Central Intelligence Agency, 2019). Holarua experiences a wet and dry season, wet from December to April and dry from May to November. Large rivers disappear in the dry season, then quickly reappear in the wet season causing torrents and increasing the risk of flash flooding. The elevated areas of Holarua are cool, wet and misty (Ministry of Tourism, Art and Culture, 2019).

People of Holarua To provide the people of Holarua with walkway infrastructure that will benefit the locals and the area, questions must be asked about the area. Solutions must be able to benefit the locals during construction and support tourism generation once built. The walkway must be sustainably produced, and its construction protect the environment. If the locals are to benefit by being involved in construction, who are the local demographic? In 2015 the area of Holarua had a population of 6,871 (city population) – construction creates job opportunities for this population. The nation of Timor-Leste’s official languages are Tetun and Portuguese, however the working languages are English and Indonesian. As a first language Timor-Leste has 30.6% Tetun Prasa, 16.6% Mambai and 10.5% Makasai speakers (Central Intelligence Agency, 2019). The area of Same where Holarua is located is near densely populated areas of Makasai speakers. Subsequently the area has roughly 20-40% Mabai speakers (Brinkhoff, 2015). The western area of Same is home to a dense population of Tetum Prasa speakers as shown in Figure 1 below:

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Figure 1 - Tetum Prasa speakers (Fischer, 2012) As the area of Holarua’s locals are likely Tetum Prasa speakers caution must be taken when communicating. Emphasis must be made to communicate the purpose of the project to all locals. Employing a workforce of locals will encounter the same obstacle. To avoid problems a structure of bilingual locals acting as leadership for the project will allow for the locals to be actively involved. Communication during construction will be important for the project to run with minimal issues.

Geography of Holarua Holarua’s geography must be understood to know the conditions the walkway infrastructure will be built in. Holarura is a mountain area located 564m above sea level (Worldwide Elevation Map Finder). The island of Timor-Leste has a fry season from May to November, and a wet season December through to April (Timorleste.tl). During dry season the large rivers throughout the country have a very large decrease in water. Over wet months the rivers often become torrents and flash flooding is a possibility. An aerial view of Holarua is shown below in Figure 2.

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Figure 2 - Satellite view of Holarua (Google, 2019) Holarua is situated near the river Rib Carabum at higher altitude. The accessibility of the site can be compromised by flooding north and south of Holarua as there is a single road through the area. This road is paved which will allow for transportation of modular pieces to the area. The road does not allow easy accessibility to the mountainous tourist areas. As the elevated areas of Timor-Leste are wet and misty it is important to avoid damage to the environment. Maximising construction completed in the dry season will assist this. This will enable tourism during the popular wet period before and after construction allowing for the economic benefit of tourism to be unimpeded. Attempting construction in a wet environment will be difficult and will likely result in the damage of the environment the walkway is designed to protect. Any difficulties building in the wet season will lower the economic benefit of the project. Damaging the environment will not attract tourists. Complications during construction will increase the costs of construction.

Existing Infrastructure and Resources Knowing what level of infrastructure is present is important so that local resources and capabilities are known. Timor-Leste has total electrification of 42% with rate of 78% in urban 4

areas and 27% in rural areas (Central Intelligence Agency, 2019). The town of Same located 2.9km away is more developed and could supply power needs. Modular systems could be constructed in the neighboring town then transported to Holarua for construction. Understanding what natural resources of Timor-Leste exist helps the walkway design to be made of sustainable and local materials. Timor-Leste has many species of local woods suitable for the construction of a walkway (CABI, 2019). There are many woods that are used for timber, including: Redwood, Teak, Mahogany, Coconut, Kou (Hawaiian), Bamboo, Timor mountain gum and Moluccan Ironwood. When sourcing materials for the walkway local policies and conservation efforts are important to understand (McWilliam, 2003). Local religious beliefs promote the conservation of Lulic areas. Lulic areas are often forests, groves, coastal areas, natural springs or watercourses. Cultural beliefs restrict or prohibit damage or interference in Lulic areas. The local concept of Lulic is important for the project to be sustainability. After sourcing viable woods, Lulic beliefs are a starting point for implementing rehabilitation and reforestation practices. To employ locals the current labour workforce must be understood. In 2017 a National Employment Strategy was published (Government of Timor-Leste, 2017). The report raises issues with Timor-Leste’s workforce. There is weak contract enforcement due to the lack of structured labour regimes. Cost of labour (such as agriculture) is estimated to be double neighboring West-Timor. Low labour competitiveness, productivity and high wages make the country difficult to invest in. More positively for this project, there is a growing construction industry as shown in Figure 3 below.

Figure 3 - Value Added by Industry in the Non-Oil Economy (Government of Timor-Leste, 2017)

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The increase in the construction industry gives confidence that locals are learning and becoming effective in the line of work the walkway infrastructure demands. For the project to be economical it is important that the locals see the importance of the walkway and want to build it efficiently and to a high standard for maximum economic benefit to their community.

Alternative Solutions A brainstorming session and Duncker Diagram (table 1) produced a list of initial ideas which were then analysed using a Kepner Tregoe decision matrix (table 2).

Initial ideas from brainstorm 4x4 Tracks; Concrete paths; Custom-built native wood walkway; Formed plastic boards; Gravel paths; Joinable native wood pallets; Luge; Single-file plank layout; Standard exterior plywood sections; Stepping stones; Suspension Bridgeway; Zip lines

Duncker Diagram Table 1 – A Duncker Diagram of the initial brainstorming ideas Walkway

Not a walkway

Wooden

Joinable native wood pallets Custom-built native wood walkway Single-file plank layout Standard exterior plywood sections

Not wooden

Stepping stones Concrete paths Gravel paths Formed plastic boards

Alternative track

4x4 Tracks Suspension Bridgeway

Alternative transport

Luge Zip lines

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Decision Matrix Table 2 – A Kepner-Tregoe-style decision matrix with the four leading ideas in comparison Joinable pallets

Custom-built

Single-file planks

Exterior plywood

Built by locals

Yes

Yes, with training

Yes

Yes

Material affordability

Yes

Yes

Yes

Yes

Material local availability

Yes

Yes

Yes

Maybe

Material sustainability

Yes

Yes

Yes

No, glues and treatment chemicals

Modular design

Yes

Partially, as part of design

Yes

Yes

Durable

Yes

Yes

No

No

Safety

Yes

Yes

No

Yes

Enjoyable for tourists

Yes

Yes

No

No

Minimal training

Yes

No

Minimal up-front cost

Yes

No

Elevated from the ground

Yes, with foundation component

Yes, with foundation component

Quick to assemble onsite

Yes

No

Easily maintained

Yes

Yes

Positive impact on surroundings and local customs

Yes, with proper design considerations

Yes, with proper design considerations

Hard Constraints

Soft Constraints

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From the Duncker Diagram it was clear that four of these initial ideas could be considered further. The decision matrix eliminated two more options due to hard constraints and the final two had soft constraints analysed.

Custom-built walkway The custom-built walkway works by connecting modular sections of the walkway together through two joints with a double pin mechanism down the centre (Figure 4). The design is fixed into the ground through a large wooden post which connects to a box fixed just below the walkway, this is to spread the force over a larger area when in use and in weathered conditions. There is also a small railing attached to the sides of the design, these are to stop users misjudging the distance to the edge of the walkway and falling off. The walkway also connects through a simple joint to prevent separation.

Figure 4 – A rough sketch of the custom-built walkway idea. The design is very safety conscious with safety railings and mesh wire on the walkway to avoid slips when wet. The walkway is designed for a small environmental impact and the only earthworks needed are boring a hole for every module section. The module is also removed easily as when unscrewed it will just slide out to the side. The design itself would be difficult for the locals of Holarua to understand and then construct without extensive training. The module itself would also be heavy which has the potential to not only be a safety problem but a hindrance for the builders as moving the required parts would be difficult with the available 8

transport options. Overall the custom designed walkway meets all the required specifications and constraints shown in table 2 and would be a suitable walkway for the people of Holarua.

Single-file plank walkway The single-file plank design is simple and effective, this design is the most basic of all three designs and requires only basic construction skills and understandings to build. As shown in Figure 5 the design is just modules of a 1500mm plank across two posts roughly 500mm off the ground.

Figure 5 – A rough sketch of the single file plank walkway idea The design is extremely simple and the people of Holarua would require no previous training other than having a basic idea of tools to understand the plans and therefore build. The weight of the walkway will be light making it easier for parts to be transport to difficult locations where vehicles cannot reach. The walkway being supported a post on either end means the design is prone to bending and possible breakage if excessive weight is placed on it. Being roughly around 300mm in width, this narrow design leaves little room for error and has a high potential for injury when in use. As Holarua is a very mountainous area, scaling up steep hills would be very difficult with this design as it has no possible variations to make stairs and a ramp at steep angles increases the chance of injury. Overall this design has both positive and negative attributes - it fails to meet the majority of constraints especially around safety and durability shown in table 2. 9

Conclusion The joinable pallet system is the desirable solution, having met all specifications and constraints with no conflicts - the closest other option (custom-built walkways to suit) had higher costs and more training needed, and would take more time to build. Pallets are easily constructed without the need for heavy machinery or advanced tools thus the Holarua locals can build and repair the walkways without any extensive training or specialist skills. The pallet system requires only low-cost, locally-sourced material. Overall the pallet-style system is the most viable option when considering both the specifications and constraints and has been selected as the option to move forward with.

Recommended Solution Joinable Pallets This design focuses on taking the simple structure of a regular freight pallet and modifying it to fit the required specifications. There will be two pallet types which interlock to form a solid walkway. The first will be a pallet which has an exterior L-shaped joint fixed to both of its ends. The second pallet has two slits in both its ends which slot into the L-shaped joint (see Figure 6). Once both pallets are joined they are fixed in place with screws. The structuring of having two different types of pallets instead of one makes it easier for the people of Holarua to assemble and disassemble.

Figure 6 – A sketch of the joinable pallet walkway idea. 10

Design Specifications Each pallet will have a length and width of one metre, two pallets can then be joined together...