Design and top-down construction at the Nanjing Youth Olympic Center, China

Abstract

This paper describes the design and top-down basement construction of Nanjing Youth Olympic Center in Nanjing, China. The building’s twin towers are 315 m high and are among the tallest to have had their basements constructed top-down. Designed and built for the Nanjing 2014 Youth Olympic Games, the structure was completed in just 20 months. Top-down construction was selected by the design engineer, along with various new techniques and developments of existing methods, to save time and improve safety. This paper describes the site conditions and structural design process, followed by the sequence of top-down basement construction. The design details of the diaphragm wall, foundations, columns, basement excavation and vertical load transfer are also presented. The paper aims to provide a reference for those using top-down construction on tall buildings.