Implementation of the SmartSync Concept on the Burj Khalifa An Application of Structural Identification for Tall Buildings
The SmartSync concept, which utilizes the local area network of a building for the transmission of data, provides a flexible, cost efficient system for the full scale monitoring of tall buildings. Data collected through this system has been used to validate underlying wind tunnel and finite element models used for the design of this building and provide deeper insights into their dynamic response and effect on the comfort of their occupants. This information is then used guide long term maintenance and management. The SmartSync concept was initially demonstrated on the Burj Khalifa and has been used for its long term monitoring since 2009. Test Structure and Measured Data Since the inception of the profession, structural engineers have been tasked with the design of projects of immense size, cost and ever increasing complexity for which full scale prototyping is not possible. This forces reliance on scaled physical models and computational models fraught with approximations and assumptions and requiring considerable conservatism. Moreover, as designers push the limits of conventional structures, there are legitimate questions surrounding the extensibility of established design and construction techniques. This is especially true for tall buildings, which are lighter, more flexible and less damped than conventional buildings, resulting in dynamically sensitive structures that have complex interactions with the surrounding urban environment and their occupants. In recent decades, full scale monitoring has provided the only source of feedback to the design of these complex and expensive structures. Regrettably, post commissioning monitoring programs have not been widely adopted for buildings outside of earthquake zones, primarily due to concerns over liability and reputational harm to these high value properties. This trend must be reversed in order to take advantage of the insights monitoring can provide and that begins with providing owners with low cost, low intrusion, flexible monitoring systems. Much as conventional design methods cannot be extended readily for tall buildings, traditional approaches to instrumentation fall short as well. These approaches historically relied on centralized systems networking sensors with shielded cables. The wired system addressed the problems of synchronization and loss of data in transmission, but running cables vertically over highly partitioned tall buildings is frankly infeasible. Therefore, significant research was invested into wireless arrays using multi hop wireless transmission of the data. While this system enables distributed sensing at a reasonable expense, wireless sensing has added complexities of ensuring all sensor data is synchronized and that there is no loss of data in the wireless transmission, which can be challenging on mechanical levels, generally the only levels where sensor installations are permitted in these buildings [1]