THE MATINA BAMBOO FOOTBRIDGE: BUILDING A RESILIENT COMMUNITY The Matina communities in Davao City, Mindanao is crisscrossed by a river and until the end of June 2011 it has to rely on a makeshift bridge for their access to the main street. The makeshift bridge made of bamboo poles tied together was unsafe and got flushed away each time the river flooded. The municipality was in reservation to construct a safer and sturdier bridge due to uncertain legal status of the Arroyo Compound. Hence, through facilitation of the Philippine Alliance and a network of community architects, the community were able to build a 23 meter span bamboo footbridge, the first of its kind in the Philippines.
A COMMUNITY’S STRUGGLE
The Aroyo Compound at Barangay 74-A Matina Crossing is located on the Southwest part of Davao City. Total land area of Arroyo compound is 24 Ha covered by 13 Emancipation Patents (EPs) after the Operation Land Transfer of 1972 (PD 27) that were cancelled by the Supreme Court in 2006. Hence, the tenure status of this land as now is informal. Around 9.8 Ha portion of the land is occupied by the Matina Crossing Federation (Matina Fed), a group composed of three community associations namely, Saint Paul Neighbourhood Associations, Saint Benedict XVI Neighbourhood Association, and Matina Balusong Neighbourhood Association (MABANA). Matina Fed represents 488 urban poor families that consist of food vendors, drivers, construction workers, masseurs, shop-keepers, security-staffs, and other urban professions. Since November 2009 the Matina Fed is a member of the HPFPI (See Box 1). Matina Fed initiates to build a bamboo footbridge that was pronounced during a design workshop at the community on February 2010 with attendance of some community architects from Southeast Asia region. Further, the federation members actively take the lead in all activities related to their footbridge project, including processing papers, permissions and requests to the municipality; procuring materials; mobilizing community people to provide free labour as well as food for the workers during construction; and undertaking workshop preparations in the community.
On December 2010 the communities faced a demolition threat that was purported by a claimant of the land. The demolition did not finish-off and was dubbed as illegal. In fact, the community managed to respond quickly and halt the process. Despite of the rising insecurity, the community was eager to continue to settle and invest on their land through the bamboo footbridge project. One of the Philippine Alliance’s thrusts in its development initiatives is to explore alternative building technologies and materials that are low-cost, community-friendly, environmentally sound, and locally available – i.e. technologies that can easily be managed, handled-by and transferred to the communities. Globally, there is also an increasingly growing appreciation for bamboo as an environmental-friendly and
sustainable building material, among many others, owing to its fast growing and renewable properties. The presence of a rich resource of experience and expertise in bamboo construction, in many parts of the world, including Southeast Asia, would guide the process of exploration and development of the bamboo technology for application on this community-driven upgrading project.
BAMBOO FOR CONSTRUCTION
Bamboo is a family of grass (Gramineae) that grows around the equator belt both within the tropics to the sub-tropics. There are more than 1.200 species of bamboo divided into 90 genera (INBAR-FAO 2007). Just like grass, bamboo sustains adverse soil. Nature bamboo stands can be found from coastal land up to altitude 3.800 meter.
In Southeast Asia, bamboo is deeply rooted in the culture of people, it is adopted in folklores in a manner of almost spiritual. Its utilisation is extensive, from kitchen and household utensils to houses and bridges. In terms of structural properties, bamboo has good strength in bending, tension, and
BOX 1. A MULTI-FACET COLLABORATION
The Homeless Peoples’ Federation Philippines Inc.(HPFPI) is a network of 200 urban poor community associations and saving groups across the regions of Luzon, Visayas, and Mindanao. Since its inception in 2002 until now HPFPI have spread to 14 cities and 16 municipalities nation-wide. The NGO Philippine Action for Community-led Shelter Initiative (PACSII) is providing managerial and operational supports for Homeless Peoples’ Federation Philippines Inc. (HPFPI). HPFPI-PACSII together referred as the Philippine Alliance (HPFPI-PACSII 2010).
In the regional network, the Philippine Alliance is affiliated to the Asian Coalition of Housing Rights (ACHR) that is based in Bangkok, Thailand. ACHR was founded on 1988 as a common platform for Asian housing activists to facilitate exchanges and collaboration (ACHR 2010). ACHR provides financing and technical assistance through the 3-year Asian Coalition for Community Action (ACCA) programme that was launched on 2009. The Matina bamboo community footbridge is implemented through the facility of ACCA.
Sahabat Bambu (SaBa) is a bamboo advocacy group from Yogyakarta, Indonesia. SaBa mainly providing technical guidance in the design and construction of the Matina footbridge and providing primary inputs and facilitation in the training workshops. Lastly, local academic institutions also took part on the Matina footbridge project. The Department of Engineering of the University of Mindanao has been providing technical engineering computations in load and structural analyses of bamboo bridge frame and assistance in foundation works. University of the Philippines Mindanao gave input in the bridge concept design and design properties and assistance in workshops preparation.
compression, if parallel to grain (Trujillo 2009). It also has an excellent strength to weight ratio. In the academic world, some important research on structural bamboo pioneered by Professor Jules Janssen (Janssen 1981) then also by Arce-Villalobos (Arce-Villalobos 1993).
BRIDGE DESIGN AND BAMBOO TECHNOLOGIES
Considering the volatile nature of the stream, the community insisted for a “free-span” design, 23 meter between the banks to be located at the same spot as the existing makeshift bridge. The first approach to the challenge was by looking some precedents of bamboo bridges around the world, mostly designed by two bamboo construction champions, Jörg Stamm and Simón Vélez. Email contacts to bamboo experts and friends were also established. Through their generosity opinions, suggestions, and helps were obtained. It took three months to develop the design, an arch-reinforced, pre-tensioned Howe truss. A meeting with Jörg in Bali was a concluding part. The bamboo species used for the footbridge is apos (Dendrocalamus asper) with botong (Dendrocalamus latiflorus) and tungkan (Bambusa blumeana) as tertiary members. These are the native bamboo of the Philippines (Roxas 2010). The apos poles were harvested from Serawan, around 10 kilometers west of Toril, on a moderate slope of Mount Apo.
2005) and later improved by Sahabat Bambu, Yogyakarta.
Having such an investment of a public footbridge it is mindful to treat the bamboo for longer lifetime. Minimum 25 years lifetime can be expected given the bamboo is treated and protected form rain and ground contact (Janssen 2000). A treatment facility is constructed in the Matina community at the vicinity of the bridge site. This consists of 4 meters concrete portals and a topped with 6 meters bamboo portals and roof structure. The Vertical Soak Diffusion (VSD) treatment is aimed to replace the bamboo sap with 7% solution of borax and boric acid, thus the bamboo is unattractive to the pest known as bukbok (Dinoderus minutus). VSD is a system developed by Environmental Bamboo Foundation (EBF), Bali (Environmental Bamboo Foundation
Within the same three months of design development, the bamboo is being treated and the foundations are being prepared. These are a pair of reinforced concrete foundations that compensate the 5 meter difference between the two banks. The foundations designed by Eng. Joeffry Camarista would transfer the forces from the bamboo arched-frames to the ground.
CONSTRUCTION, NATURE’S TEST AND AFTERMATH
Starting from April 2011, it took one month to construct the entire bamboo structure. Two experienced bamboo carpenters from Yogyakarta brought to train the local carpenters from community and lead. Another month spent for roofing, mortar injection on primary joints, and finally to apply three-inch thick concrete flooring with steel reinforcement to ensure stability, durability, and to anchor the whole bridge to its foundations.
As the concrete flooring cured, the bamboo footbridge completed by the end of July 2011 and the date was selected for inauguration. However, a huge flash-flood on 27 July midnight swept away almost the entire community where houses were made of coco lumber and bamboo weave. Enduring the flood and coming debris, the community’s new bamboo footbridge was a crucial evacuation platform and a lifeline in the aftermath, providing access for emergency response and first aid.
The inauguration of the footbridge was postponed until 23 December in the midst of housing reconstruction process in the community. The bamboo footbridge has shown that a reliable, affordable, and sustainable community infrastructure development is possible. It is an icon of community’s resilience, the Matina communities’ ability to provide the best solution to fulfil its own development needs. REFERENCES
ACHR, 2010 Official Website, [Online]. Available www.achr.net [September 19]. Arce-Villalobos, Oscar Antonio, 1993 Fundamentals of the Design of Bamboo Structures. Eindhoven University of Technology, Eindhoven. Environmental Bamboo Foundation, 2005 Vertical Soak Diffusion Treatment Manual, EBF, [Online]. Available http://www.bamboocentral.org/index1.htm HPFPI-PACSII, 2010 Official Website, [Online]. Available www.hpfpi-pacsii.org [September 18]. INBAR-FAO, 2007 World Bamboo Resources. Rome: FAO. Janssen, Jules J. A., 1981 Bamboo in building structures. Eindhoven University of Technology, Eindhoven. Janssen, Jules J. A., 2000 Designing and Building with Bamboo. Eindhoven: INBAR (International Network for Bamboo and Rattan). ISBN 81 86247 46 7. Roxas, Cristina A., 2010 Bamboo research in the Philippines, [Online]. Available http://www2.bioversityinternational.org/publications/Web_version/572/c [7 December] Trujillo, David J. A., 2009 Axially loaded connections in Guadua bamboo, In. Proceedings of the Non-conventional Materials and Technologies (NOCMAT 2009). Bath, UK, 6-9 September