Gauge Newsletter January 2020 | Page 53

be considered seriously. To minimize the effects from vortex shedding, many wind resistance techniques have been used in Burj Khalifa. If the tower has a uniform shape along its height and is in a steady wind, vortices form in a well-organized pattern and hit the building violently. Therefore, the Burj design includes variation of its cross-section with its height. Every tier of the building is different than the segment above or below it. In addition, the corners of the outer buttresses are softened and take a tapered shape as they rise. Moreover, the tower has oriented relative to the wind directions as it gets the minimum wind effect. SHANGHAI TOWER (CHINA) Shanghai Tower is the tallest building in China and the second tallest in the world. It dwells in harmony with the other two skyscrapers nearby; the Jin Mao Tower of 420.5m and Shanghai World Financial Centre of 492m. Its architectural height is 632m and this tower has the highest observation deck of the world with a height of 562m. This was designed by the Chinese architect Jun Xia of Gensler. Construction of Shanghai tower began in November 2008 and was completed in 2015. This tower has 128 storeys above the ground and 5 storeys below the ground. Shanghai Tower claims to be one of the world’s greenest skyscrapers and has won awards for its sustainable practices and energy efficiency. The building is designed with two glass facades, inner and outer whose purpose is to maximize the natural sunlight through the curtain walls and reduce the reliance on man-made light sources. It reduces the energy cost for electricity. Glass material is selected for the facades as it minimizes light pollution too. Therefore, the exterior facade is a staggered one with 12% of the visible light reflection. Heat transfer and solar heat gain coefficients of the facade were studied through energy efficiency analysis methods when designing the facades. Moreover, there are 21 annular lobbies (atriums) between inner and outer facades to reduce the cost of energy of indoor air conditioning and heat supply systems. Used indoor air is spilled out to atriums before being exhausted from the building. During warm months, temperature above the occupied level of the atrium is maintained below the outdoor ambient temperature which reduces the cooling load requirement for the offices, hotels and observation zones. Similarly, during winter season atriums proceed to reduce the required heat loading. From left to right- Shanghai World financial Centre, Jin Mao Tower, Shanghai Tower Atrium Design Shanghai Tower GAUGE Magazine University of Peradeniya Page 51