Analysis on Concrete's Measures for Qin river Inverted-Siphons in winter

摘要

The inverted siphon is thin-walled concrete structure, and cracks will appear according to temperature loads. Generally speaking, the temperature difference between the internal and external and the basic difference of temperature are considered as the main factors influencing the cracks. Using the basic theories of temperature and stress field of concrete, the 3-D FEM is adopted to simulate the stresses field of Qin river inverted siphon during construction. Through analyzing the time-space variation law, the site that cracks easily appear is obtained.In the part of the middle line of the South- North Water Transfer Project, for the first time, the quality of concrete surface has been improved obviously through the method of external insulation board. The temperature control method of posting template outside the high-pressure polyethylene insulation board is economically reasonable and technically feasible in terms of crack control measures, thus it can serve as valuable reference for other similar projects