Construction Techniques for Main Spans of Renyihe Bridge

The main spans of Renyihe Bridge are a prestressed concrete continuous rigidframe bridge (single cell single box girder type) with the spans arranged as (80+4×145+80) m. The pile foundations of the main spans consist of piles each being 2.0 m in diameter and with maximum pile length up to 70 m, which are built in holes excavated manually. The highrise piers (73.5 m in maximum height) also of the main spans are designed as reinforced concrete twin columns, thinwall hollow piers that are constructed with reversible steel formwork. All segments of the superstructure box girders are cast in situ with traveling carriages with free balanced cantilever method except that Segment No.0 cast in situ on bent frame. This paper presents the successful experiences of manual excavating of holes for deep piles, building of highrise thinwall piers and construction of longspan box girders with cantilever castinsitu method in a mountain area where water is deficient, freezing spell is lengthy and disturbance of natural environment around the bridge site is very restrictive.