1.0.1 This standard is drafted specifically to specify and guide thedesign of cofferdam of hydropower project and guarantee the qualityof design.1.0.2 This standard stipulates principles, methods and requirementsof design for the cofferdam of hydropower p...[继续阅读]

    2.0.1 CofferdamA temporary retaining structure which is used to form a closure anddry area for construction without interference of the river.2.0.2 River-closure cofferdamThe cofferdam which is used to cut off the river completely at the fullriver by-pass...[继续阅读]

    3.1.1 Hydrological and meteorological conditions(1) The data of measured discharge, water level and water surfacegradient of river in dam site area in flood and dry periods.(2) The calculated value of maximum annual discharge and designflood hydrograph of...[继续阅读]

    3.2.1 Diversion structures refer to the temporary water retainingand releasing structures used in construction period. Diversionstructures shall be determined as Grade 3, Grade 4 or Grade 5according to the objects of protection, failure consequence, servi...[继续阅读]

    3.3.1 The flood design standard of diversion structures shall beselected in the scope of Table 3.3.1 based on the type and grade of thestructures. The flood design standards for all the diversion structuresshall be the same, in which the standard for wate...[继续阅读]

    4.1.1 The selection of cofferdam type shall conform to thefollowing principles.(1) It shall be safe and reliable, and shall meet the requirements ofstability, seepage control and erosion control.(2) The structure of cofferdam shall be simple, convenient f...[继续阅读]

    4.2.1 Local materials and excavated rock materials shall be used inpriority for earth-rock fill cofferdam, because of their goodadaptability with the foundation, convenience for construction,dismantle and flood control.4.2.2 The type of cofferdam and impe...[继续阅读]

    4.3.1 The concrete cofferdam should be built on the rockfoundation. If the concrete cofferdam is built on the overburden, thefoundation shall be well designed and treated. If concrete cofferdamis chosen, comprehensive analysis shall be carried out on the ...[继续阅读]

    4.4.1 Grouted rubble, timber crib, bamboo cage, and straw soilcofferdams apply to the projects with rich material sources. Theheight of crib, cage, and straw soil cofferdam should not exceed15 m.4.4.2 Assembly type steel sheet-pile cellular cofferdam shou...[继续阅读]

    5.1.1 The layout of cofferdam shall conform to the followingprinciples.(1) The layout of cofferdam shall meet the requirements for thefoundation excavation, arrangement of machinery, layout ofconstruction road and site as well as drainage system of founda...[继续阅读]