Page 191 - 捷運技術 第40期

捷運技術半年刊 第40 期 98年7月 185

The Manufacture and Installation of Precast U-shaped Girders

1
Wann-Rong Lin Yi-Ming Yuan 2
Abstract

The Neihu line, an extension of the Muzha line, is a medium-capacity rapid transit system in
the Taipei MRT. The Neihu line is comprised of a 10.4-km-long elevated section passing through
areas of different socio-ecological modes such as residences, parks and economic and trading
areas, of which a 6-km-long viaduct section is implemented by U-shaped girded construction.

The U-shaped girder construction adopted on the Neihu line is the first example of this
construction in domestic engineering. Its advantages are as follows:
● Design of compact section size reducing construction costs

● Construction period shortened through precast operation
● Bearing capacity strengthened by application of pre-stressing
● Column weight lowered through optimal calculation of span
● Smaller footprint providing more space to be given to vehicular traffic
● Enhanced subtlety of curves decreasing visual impact and helping highlight accompanying

landscaping
● Web quality featuring integrated functions of structure and sound insulation
This article aims to discuss how to implement design ideas with extreme conscientiousness by

adopting U-shaped girders in construction, with a view to presenting what has been learned during
the construction of the Neihu line.

Keywords: precast U-shaped girder, precast pier-cap, longitudinal strand, upper and lower steel
plate, shear steel box, elastomeric bearing pad