图像应变测量技术在土石坝振动台试验中的应用

Application of Image Strain Measurement Technology in Shaking Table Model Test of Core-wall Rockfill Dam

采用有限元与广义交互验证方法相结合的数据平滑方法,开发了一套适合于土工试验模型应变测量计算的程序,通过三点弯曲梁实例验证了程序的正确性和可靠性,并将该方法应用于心墙堆石坝振动台模型试验的应变测量计算中,获得了模型坝的位移场和应变场,探讨了心墙堆石坝模型的地震破坏机理。结果表明,模型坝破坏过程大致分整体变形、坝坡滑移变形和破坏三个阶段,其中坝坡滑移变形阶段的标志是坝体由整体运动转为上下游坝坡分别向两侧滑动,空库时模型坝的破坏模式是上下游坝坡浅层破坏。

Based on the data smoothing method which combines with finite element and general interaction validation method, strain measuring and program of geotechnical test model is developed. The correctness and reliability of the program is verified by three-point bending beam experiment. And then this method is applied to the strain measuring calculation of core-wall rockfill dam shaking table model test. At the same time, the displacement field and strain field of model dam is obtained. Meanwhile, earthquake damage mechanism of core-wall rockfill dam is discussed. The results show that the failure process is roughly divided into three stages, namely overall deformation stage, dam slope slipping deformation stage and failure stage; the start of the second stage is that overall movement turns to sliding along the upstream and downstream slope respectively; failure pattern of the model dam is shallow damage along upstream and downstream slope at empty reservoir condition.