Analysis of structure calculations for branch pipes subject to high hydraulic pressures of Huizhou pumped storage station

The reinforced concrete branch pipe subject to high hydraulic pressures of Huizhou storage pumped station, because of its PD value exceeding 6000, complex structure form, complex hydrological geology and engineering geology, is the key and formidable problem of the project. Based on permeable tunnel design theory, the followings are computed separately: the branch pipe excavation country rock crustal stress field in the construction period; the steady seepage of high pressure branch pipe, the concrete line’s stress-strain and country rock safety in the operation period; the concrete line’s stress and strain in the emptying inspection period of high pressure branches. The high pressure branch’s reinforce steel is also computed.