Crack characteristics and prevention measures of large pump stations in Yangtze River to Huaihe River Diversion Project during construction

Abstract

To meet the requirements of water conveyance, pumping stations in the Yangtze River to Huaihe River Project are designed with ultra long and large integral pouring structures, making temperature control and crack prevention much more difficult than other water diversion pump station projects. In order to explore the temperature stress and cracking characteristics during the construction of this seamless pumping station, the feasibility for crack prevention measures with easy operation and reasonable temperature control are demonstrated. Selecting the Zongyang Pumping Station as the research object, based on finite element simulation calculation of pouring process during construction, considering the influence of real environment, materials, structure, and various temperature control measures, the temperature and stress field, crack risk are analyzed. The result show that the ultra long bottom plate, thick side wall and upstream wall of the inlet channel layer are the key points for structure crack prevention; the tensile stress is mostly between 2.0 MPa and 3.0 MPa, exceeding the allowable tensile strength of concrete during construction; By adopting a combination of surface insulation, water cooling and temperature control pouring with differentiated control, the risk of cracking can be greatly reduced. The temperature control and crack prevention measures tailored to local conditions are feasible, which can provide reference for the structure crack prevention design of integral pouring pump stations in other water diversion projects.

Keywords

integral pump stations / temperature stress simulation / crack risk / differentiating control temperature