Design and Construction Solution of Foundation for Landmark 81—The Tallest Tower in Vietnam

This paper aims to present the design, construction, and quality control of deep foundation for Landmark 81—the current tallest tower in Vietnam and the 14^th tallest tower in the world to be completed in 2019. Before 2015, the project location was used as a dockyard near the Saigon River. Twenty-eight meters (28 m) of very soft clay has almost no load capacity (SPT N-value from 0 to 2) and, combined with the heavy weight of a 461 m tall reinforced concrete building, posed significant challenges for both structural and geotechnical design engineers and contractors. Two fully instrumented test barrette piles with Osterberg cell (O-cell) installation were carried out to study the geotechnical pile capacity. The test results of these 02 test barrette piles have been analyzed and presented. The estimation of foundation settlement including differential settlement and soil-structure interaction analysis was considered. Piles subject to permanent loads (such as dead load, live load, wind load, and especially earthquake load) are analyzed and mentioned in this paper. The paper also describes the shaft grouting technique method, construction sequences, and construction acceptance criteria for this technique. The paper will also draw some conclusions for applying of the same solution to other high-rise buildings in Vietnam and elsewhere in the world.