糯扎渡水电站大型蜗壳结构模型试验

摘要

Combined with the design research for the large spiral case structure of Nuozhadu hydropower station ,a simu-lation material model test with a geometric scale of 1∶10 was conducted .The test results indicate that ,under the maxi-mum design internal pressure of 2 .80 MPa ,the steel liner and outer reinforced concrete can meet the strength require-ments ,and the maximum crack width on the concrete is smaller than the limit value of the related specification .Under the internal pressure of 4 .20 MPa ,the stress of steel liner and steel bar does not exceed their respective yield strength , and the spiral case structure keeps good integrity .The intersection area of spiral case roof and generator pedestal of the import section is the weak part of the spiral case structure ,certain local reinforcement measures should be taken to control the extension of cracks .%结合糯扎渡水电站大型蜗壳结构的设计研究，开展了几何比尺为1∶10仿真材料模型试验。试验结果表明，在最大设计内水压力2．80 MPa下，混凝土裂缝最大宽度小于规范规定的限值，蜗壳钢衬及外围钢筋混凝土均满足强度要求；在4．20 MPa内水压力下，蜗壳钢衬和钢筋的应力也未超过材料的屈服强度，结构保持较好的整体性，具有较高的超载能力；蜗壳顶板混凝土较薄，特别是进口段与机墩的交角处开裂相对较重，属于结构薄弱部位，应采取一定的局部加强措施。