Award-winning project: Steel Pipe Column Project for the Intermediate Ventilation Shaft at Jiangxinzhou on Phase II of Nanjing Metro Line 4
Award-winning company: Jiangsu Tongzhou Foundation Engineering Co., Ltd.

Award details:
Jiangsu Tongzhou Foundation Engineering Co., Ltd. undertook the Steel Pipe Column Project for the Intermediate Ventilation Shaft at Jiangxinzhou on Phase II of Nanjing Metro Line 4 on April 5, 2022. There are a total of 26 steel pipe columns and 12 stiffened columns; the installation verticality requirement for steel pipe columns is 1/1000, and for stiffened columns it is 1/800. The bored pile foundation uses underwater C40 concrete, and the steel pipe columns are filled with C50 micro-expansive concrete. The steel pipe columns consist of two parts: the upper steel pipe concrete column and the bored cast-in-place pile. The upper steel pipe section dimensions are Φ900mm×20mm (wall thickness), made of Q390B steel, with the longest steel pipe column reaching 43.84m. The lower bored pile is a Φ2500 bored cast-in-place pile foundation, with a maximum hole depth of 70m. The stiffened columns consist of two parts: the embedded square column and the bored cast-in-place pile. The stiffened column is 860*860*4730mm, with a plate thickness of 30mm, made of Q390B steel, embedded below 42m below natural ground level (4 of which are embedded below 38m). Jiangsu Tongzhou Foundation Engineering Co., Ltd. deployed more than 20 pieces of equipment including full-slewing drilling rigs, rotary drilling rigs, crawler cranes, excavators, and loaders, and over a hundred management and construction personnel for the construction. The project was successfully completed ahead of schedule on September 20, 2023, with the verticality of the steel pipe columns meeting the design requirements. The company received commendation from the general contracting company.