BAMBOO BRIDGE IN CAFE DEL MAR

Location : Bali, Indonesia Year : 2019 Status : Postponed Stage : Detailed Engineering Design Building Type : Bridge Scope of Works : Design Development, 3D Modeling, Drafting, Site Visit Programs : Sketch Up, Autocad Principal Architect : Effan Adhiwira, EFF Studio

Bamboo bridge Cafe del Mar located in Cafe del Mar Beach Club, Canggu, become one of the facilities in this beach club. This bridge look like a strange object, but when look deeply, this bridge is very unique and complex. The original idea from the principal architect generate this kind of form that never be made in bridge typologi. The combination between bamboo and modern materials such as cable and concrete affirms that this bridge is very unique.

This bamboo bridge connect the beach club and beach itself. The beach club and beach separated with river with around 30 meters wide. Beach club invalid if the visitors can’t go to beach, so this bridge facilitate it. The bridge nit only provide the visitors, but the local residents to go to temple across the river. There is already a bridge, but the conditions is not good and further than this bridge. This bridge land in sand, and the river water level isn’t stable, so abrasion become problem in this bridge. The foundation become very important to make this bridge still in their posisition.

The design process is interesting. Start with simple mock up from the principal architect, I developed to the bigger scale. The hyperbolic paraboloid (hypar) become the main structure. This hypar prop the arch structure up. In the both ends, this structure held by another structure. This structure make sure the hypar and the arch stady. The base section, the structure that held the hypar and the arch function as a stair.

Cremona structure hold the hypar and the arch structure from below. This bridge structure is also supported with cable structure. Bamboo as a wide span structure has a negative side, the length of a bamboo is limited, so to achieve certain length that more than the length of the bamboo, bamboo is connected with another bamboo. This kind of structure will lose their strength.

Hypar structure also have tendency to bend. The cables support the hypar to maintain their shape. The cables provide with a turnbuckle to adjust the tightness.

In this project, I was responsible to develop the design, mockup making, drafting the detailed engineering design, and check the site. I went to the site to look the existing and to mark the foundation coordinate. This mark would be drilled by the contractor to plant the anchor. This anchor will connected with the bamboo and the concrete base.

The foundation at the end of the bridge uses a 2.5 meter deep foundation. It is used to guard against abrasion. With a foundation that is deep enough, the bridge can still stand when the sand surface have abrasion.