Project Outline

This project aims to enhance the convenience of public transportation by establishing a connection network between Urban Railway Lines 1, 2, and 3, promote the growth of MICE-related industries through improved rail access in the northeastern region, and contribute to balanced regional development by supplying new lines to underserved areas.

The total project length is 9.218 km, including 8.795 km of mainline viaducts, eight stations, one train depot, and a 422-m entry/exit track.

BANDI is responsible for the bridge design in narrow road sections, major intersection crossings, and the Geumho River crossing section.

Structural feature

Superstructure and Substructure for Standard Bridge

Daegu Metro Line 4, Section 2 primarily passes through the old city center, where the road width is very limited at 17~22 meters. There are various underground utilities beneath the road, such as sewer boxes, electrical facilities, and communication lines. To minimize the relocation of these obstacles, the bridge foundation is planned using single cast-in-situ piles. In narrow road zones, the pier width is limited to 1.2m to maintain existing number of traffic lanes(five lanes or six lanes). Furthermore, to ensure safety during construction and to minimize impacts on nearby areas and surrounding traffic, a low-depth, lightweight enhanced PSC Box Girder has been applied as the superstructure, reducing the oppression caused by urban bridges. Rapid construction using cranes at night has also been planned.

Intersection Bridge Planning

As a bridge passing through the city center, it is necessary to secure an appropriate span length (maximum 65m) and consider a minimum curve radius (R=103m) in order to satisfy various crossing conditions, including traversing multiple intersections and existing bridges. 

Accordingly, considering the negative reaction force that occurs at curved sections, we planned a two-span and three-span continuous curved bridge using steel composite girders. In addition, we secured the structural safety due to the longitudinal rail force at the curved sections by conducting advanced analyses that reflect the characteristics of concrete track, such as track-bridge interaction analysis and dynamic analysis.

Geumho River Crossing Bridge Plan

The section crossing the Geumho River, a national river, consists of six spans and is designed as single-span bridges with a total length of 325 meters to ensure the safety of long welded rails and a steel composite girder bridge system was applied to enhance constructability, a full-span erection method was adopted.

The location of piers within the embankment and intersections has been excluded to secure the safety of the Geumho River embankment. Hydraulic impact assessment has been performed that the bridge will not significantly affect the river.

The substructure of the bridge has been designed with Y-shaped piers, which minimize interference with the river’s flow, harmonize with the surrounding environment, and provide excellent landscape value.