坝体结构及流变对高面板坝应力变形影响分析

Influence Analysis of Stress and Deformating Caused by Dam Structure an Rheology in a High Dam

高面板堆石坝在运行过程中面板容易出现挤压破损,坝体变形过大和变形长期不稳定是主要原因。影响堆石体和面板应力变形的因素较多,主要包括坝体堆石料分区和参数、面板分期及浇筑时机、坝体流变、垫层料表面的处理。基于实测变形反演堆石料本构参数和流变参数,运用反演得到的参数对面板堆石坝坝体和面板应力变形影响的因素进行敏感性分析,得出:提高下游次堆石的填筑标准,能有效减小高面板坝面板上部的顺坡向拉应力;面板分期能减小面板蓄水后的挠度,且最大挠度点往高高程偏移;坝体填筑完成后面板浇筑前预留的时间越长,大坝蓄水引起的变形越小。设置挤压边墙能有效减小面板中部的坝轴向应力和顺坡向应力,同时也能减小面板的挠度;面板最大挠度、坝轴向应力和顺坡向应力在坝体流变作用下逐步增大,并逐步趋于稳定。

In the process of operation, the face slab of high CFRD is easily to be damaged, the big deformation and instable deformation of the dam body is the main cause of the damage of the face slab. There are many factors that affect the stress and deformation of CFRD, which mainly include dam body zoning, material parameter; face slab stages,time of casting, dam body rheology and the treatment of cushion surface. Inversion of constitutive parameters and rheological parameters of rockfill based on the measured deformation,Tthe influence factors of the stress and deformation of the CFRD are analyzed by using the parameters of the inversion,. draw the following conclusions: 1, Improving the downstream rock filling standards can effectively reduce the tensile stress along the slopeof upper part of panel in a high CFRD; 2, Face slab stages can reduce the deflection after the storage and the maximum deflection point shifts to the high elevation; 3, The longer of timefrom the dam filling to pouring the panel, the smaller of deformation which is caused by the water storage. 4, Setting extrusion side wall can effectively reduce the stress of panel, but also can reduce the panel deflection. 5, The panel maximum deflection, axial stress and dam slope stress increases gradually in the rheological effect, and gradually stabilized.