Introduction
The communication towers are an essential source for providing connectivity in any region. However, they have still not reached most of the rural communities and localities of the country. The primary reason for this is that the steel used for making these towers is quite challenging to transport in the rural parts of the country. Steel is expensive, and the material's manufacturing process is hazardous to the environment.
Bamboo comes as a remedy to all these issues. Bamboo, a naturally grown construction material, can be easily found in rural areas, making it a sustainable and reliable material for constructing the tower.
Bamboo generally has very good parallel-to-fibre structural properties, with allowable stresses in bending, compression and tension ranging between 10-20 MPa for most species of bamboo. Allowable shear stresses are relatively low at around 1.2 MPa which is further accentuated by bamboo’s tendency to split due to the weak parenchyma matrix. Hence the suggested characteristic tensile strengths perpendicular to the fibre are as low as 0.46 MPa. Because of these properties and the hollow nature of bamboo, joints are normally the most difficult aspect to design and also likely to be the weakest elements in the structure. It is therefore most efficient to use bamboo structural members mainly in axial tension or compression.
Characteristics of Suitable Structural Bamboo Species
The bamboo species that have traditionally been used for construction tend to have the following characteristics:
• Grow locally in abundance
• Stronger than other local species
• Large diameter (50mm–200mm)
• Grow relatively straight.
• Mature quickly (less than five years)
• Slightly more resistant to insects and fungi (lower starch content).
• Less susceptible to splitting
Shukhov Towers
Vladimir Grigorevich Shukhov (pioneer of lightweight construction) created the first Hyperboloid structures. These structures are also called as the hyperboloids of revolution. Such towers were first used as water towers to support high concentrated gravity loads. The idea of Hyperboloid lattice towers was inspired from woven baskets holding up a heavy weight. Shukhov was awarded the patent for this type of Lattice towers in 1896. The most famous of the Shukhov’s towers is the Shabalovka tower. The Shabalovka tower is 150 m high consisting of six stacked reticulated hyperboloids. Each segment of the tower was assembled on the ground and successively lifted into position, like the extension of the sections of a telescope. The Shabalovka tower was originally designed to be of 350m which would have surpassed the Eiffel tower by 50 m by using less than a quarter amount of the steel. During its 80-year history Shabalovka Tower served as support for large antennas radio and television stations.
These kinds of towers are especially suitable for economical constructions as they do not require special equipment. They also optimize the use of materials. Especially for Bamboo which has weaker connections, a greater number of simpler stronger connections can provide stability to the structure. Hence Shukhov’s Hyperboloid towers were chosen for the low-cost Bamboo telecommunication towers.
