管型座二期混凝土施工工艺分析

Analysis on the Construction Technology of the Second Stage Concrete of the Stay Cone

管型座为灯泡贯流式水轮机的主要部件,其二期混凝土施工场地狭窄,预埋件、支撑件多,分层多,钢筋密集,浇筑过程中的变形控制要求高,腹部不易振捣密实,管型座混凝土浇筑时,采用分层浇筑。分层浇筑后的层间结合部位和一、二期混凝土以及二期混凝土与管型座接触部位易渗水。因此,浇筑全过程都需监视管型座变形和位移情况。若有异常,要及时采取相应的补救措施。老挝南欧江一级水电站管型座二期混凝土浇筑完成后,经复测,其变形量符合设计和规范要求,混凝土浇筑完成后,采用捷特JTG300全断面出浆、可重复式接触灌浆管进行接触和接缝灌浆。机组发电后,未出现任何渗水,且机组振动小。其经验总结对以后类似的二期混凝土浇筑有一定的借鉴作用。

The stay cone is the main component of bulb turbine,which the second stage concrete construction site is narrow with many embedded parts and supporting parts,many layers and dense reinforcement.The deformation control requirements during the casting process are high,and the abdomen is not easy to vibrate and compact.When casting the stay cone concrete,it is casted in layers.After layered casting,the joint between layers,the first and second stage concrete and the contact part between the second stage concrete and the stay cone are easy to seep water.Therefore,the deformation and displacement of the stay cone should be monitored during the whole casting process.In case of any abnormality,corresponding remedial measures shall be taken in time.After the completion of the second stage concrete casting of the stay cone of the Nam Ou 1 Hydropower Station in Laos,through retesting,its deformation meets the design and specification requirements.After the completion of the concrete casting,the JTG300 jet full section slurry outlet and the repeatable contact grouting pipe are used for contact and joint grouting.After the operation of power generation,there is no water seepage and the generator unit vibration is small.The summary of the experience can be used for reference for similar second stage concrete casting in the future.