In order to prevent damage the rock mass and the pre-constructed main curtain of the dam,the diversion tunnel of the Wudongde Hydropower Station adopts a new type of straight cylindrical plug instead of the wedge-shaped plug.Its structural type and the safety of the shear groove(tooth groove)layout under high water head conditions are the key issues of the project.Therefore,this paper adopted the method of three-dimensional numerical simulation to analyze the stress,deformation,plastic zone distribution characteristics,and progressive failure process of the sur-rounding rock,plug,and the contact surface between them by selecting two types of plugs:without tooth groove and with tooth groove.Sensitivity studies are also conducted on the number of tooth grooves in the plug to obtain the influ-ence law of the number of tooth grooves on the safety of the plug,demonstrate the necessity of setting tooth grooves in the plug,comprehensively evaluate the overload capacity and safety reserve of the plug,and finally determine a rea-sonable number of tooth groove schemes.The research results show that it is necessary to set tooth grooves in the straight cylindrical plug,and the use of tooth grooves can significantly improve the safety reserve of the closure body.The safety coefficients of plugs with different numbers of tooth grooves range from 3.7 to 4.6,and the increase in safety coefficient is most significant when using the 4-tooth groove scheme.When the number of tooth grooves exceeds 8,the increase in safety coefficient will be significantly reduced.Through optimization research,this paper innovatively pro-poses a new type of straight cylindrical plug shear groove layout method of "wide front and narrow back,dense front and sparse back".
维普
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