Study On Operation Behavior Of High Arch Dam Under Special Working Conditions

In order to prevent cracks in the concrete dam, taking into account therequirements of concrete construction, we must set the transverse joints when designarch dam. The transverse joints must be properly handled, such as joint grouting, tomaintain the arch dam stressed as a whole structure. When grouting, to ensure thetransverse opening width to meet the requirements, and to ensure the quality of jointgrouting, there have to be the pressure weight of a certain thickness in the groutingupper area, and its temperature should reach designed requirements, in addition tolower the designed temperature of the grouting area below the designed temperatureof arch-closure.Comparing the actual operating condition with the design condition there arethree special operating conditions in LaXiWa Hydropower Station of the YellowRiver. First, as a result of the construction schedule and the impact of the height of theconcrete cantilever, through the analysis of the temperature monitoring data of thedam irrigation zone and its cover-weight zone, it exists that local irrigationarch-closure is higher than the design arch-closure temperature so that the temperatureload will change after the local arch-closure.The change in the overall stressconditions of the arch dam under this condition and after that in the process of thecooling of the concrete the change in the opening of contraction joints are studied inthis paper.The second special condition is to study the impact on the lower part of thetransverse joints caused by the process of the cooling of the cover-weight zone on theirrigation zone, and the requirements for the concrete cooling at the cover-weightzone are also discussed.In addition, to the high arch dam, building by stages and generating power inadvance will produce a huge economic benefit. But compared to once built and oncewater storage, the real working behavior of the dam will be different from that of theconventional structure analysis,which is also one question concerned in the paper.Mainly aimed at calculation and analysis issues on the dam working behavior ofuniversal special working condition in LaXiWa concrete arch dam design, this studyseeks new reasonable analytical assessment methods. This study complements the theory and methods on local temperature load of arch dam, and plays a catalytic roleon improving the research level about the work state of stress analysis and calculationof the transverse joints of concrete arch dam.