Hollows piers having a round top with two-side sloped are often used for elevated passenger dedicated railway
lines. With the influence of sloping process, the curvature of circular formwork is different with each lift of concrete. If conven原
tional steel formwork is used, a complete set of formwork has to be prepared and fabricated according to the pier configuration, which would require high expenditure on the formwork. This paper introduces a new type of formwork with arc adjustable, which breaks through the conventional idea that the external configuration of steel formwork is not adjustable once a set of con ventional formwork is fabricated; cutting effectively the expenditure on steel and achieving satisfactory results when the form work is used on site.