Project - To build a Foot-over bridge 160 ft long and 8 ft wide
Project Site - Pyramid Valley International Center, Bangalore
Client - Pyramid Valley International Center
Project-team - Ar. Bharathi, Er. Bhasker, mr. Chandrashekhar (Managing Trustee of the Center)
Design and Execution - Wonder Grass initiatives
Structural design support - Er. BL Manjunath
Project Time-frame - June to November' 2013
A proposal to build a foot-over bridge spanning a valley in a campus of Pyramid Valley International Center at Bangalore, gave us an opportunity to build a really large-span structure and push the structural potential of bamboo as a building material a step further, as we understood it.
It was the blessings from Bramhishri Patrijee that we really set ourselves onto the challenging task of building of the bridge. I guess it was his faith in the idea of sustainability and its relevance in a place of spiritual development that gave this project a big push. the pyramid valley team comprising of Ar. Bharathi, Engineer Bhaskar and Mr. Chandrashekhar showed a sense of confidence in Wonder Grass team to deliver a project of this scale.
The project brought with it a sense of thrill, excitement and a great deal of anxiety too, for the Wonder Grass team. This structure was for us fulfillment of a long cherished dream to build large span structures using bamboo as principal material for construction, a demonstration and show-case of structural potential of bamboo to people at large.
The whole process from conception to finish of this bamboo bridge is almost a story with many twists and turn, learning's and unlearning's, challenges-thrills-anxieties-joys of working together and lot more. It would be interesting to put that whole process down and share it those who would like to know.
Some features of the project though are very interesting and inspiring in retrospect. There are some things we could have done better, that i think would be worth mentioning
1. Design conception -
It was an experiment of evolving a design within the artisan team themselves with participation from Vaibhav. The design ideas were sketched, developed, discussed and deliberated upon by the artisan team of Wonder Grass. Each one sat down with a brief to develop a design of a bridge that could be built. The design-ideas were discussed, they understood good points explored in each design and what could-should be avoided.
Two design ideas which the group found made 'sense', something that could probably be built as bridge, were then refined in the form of a model. The models were made to scale. The idea of scale was at first difficult to grasp and understand, but intuitively they took to it.
The models were made and then tested with loading. There was a discussion on two models and how they behaved in loading, what could be done and how we can go about it.
2. Prototyping of Structural components
The bridge threw-onto us challenges in fabrication, transportation and erection of the structural components which were supposed to span large spaces. What was required was to prorotype different components of the structural system, make it to the actual scale, load-test it and on failure explore options.
What really wasnt there for us, time !! we were always in our heels, trying to design a solution for different junctions, developing details and joinery methods.
3. Experimentation for large-span Arched Members:
We had two major challenges in terms of developing a structural components, one is to build an arched member which would be 75ft at the base and rise to almost 25ft at the center. This was to be achieved using bamboo poles, which have varying diameters, wall-thicknesses and curved ones.
(to be continued...)