Research Of Construction Technology For The Precast Reinforced Concrete Segments Of The Tunnel Shield

The shield method construction is one technique for excavation tunnel with theworld advanced level, having these merits: the fast speed in construction, high qualityin initial masonry and little influence to the environment. In the production ofprefabrication segment of shield tunnel, its technique will advance along with thedevelopment of the tunnel construction technique, especially the developing of theshield construction technique. The shield construction technique has a few types:geostatic balanced type, sturry balanced type and combination type shield. The shapesof its section have: round, elliptic, rectangular and tendem circular, and the types ofsegment also develop. In this paper, the research is on the prefabrication technique ofshield segment, grasping its procedure affecting the quality greatly so as to raise theprecision and quality of the segment in maximum extent, including mainly: thecontrolling of concrete raw material, designing of mixture ratio, production techniqueand quality inspection of the concrete, steel mould procedure, reinforcement steelprocedure, placement moulding of segment, steam curing, demoulding of segment,water curing, and the standard, method of quality inspection of the segment, theanalysis on its exterior quality. The quality controlling constituents of each link areput forward as to guide the production of the segment.At last, a brief discussion is given to the further working direction.