重力坝坝体-库水-气幕相互作用的振动台试验

Vibration table model tests on dam body-reservoir water-air curtain interaction of a gravity dam

结合某碾压混凝土重力坝工程,模拟了坝体库水气幕的动力相互作用,振动台模型试验中测试了大坝自振频率、坝面动水压力、坝面加速度和上、下游坝面动应力响应、坝顶位移等,研究了气幕对坝面动水压力、加速度、位移等的影响,并将库水有限元模型的计算结果与模型试验成果进行比较。结果表明,气幕对坝面动水压力及其动力特性均有影响,坝前气幕的良好压缩性能对地震效应有很大的缓冲作用,能降低动水压力和坝体的动应力,改善和提高坝体的抗震性能。

In combination with a miler compacted concrete gravity dam project, model tests were performed to measure the selfvibration frequency of the dam body, hydrodynamic pressure and acceleration of the clam surface, dynamic stress response of the upper and lower dam surface, displacement at the top of the darn, etc. The influences of the air curtain on the hydrodynamic pressure, acceleration, and displacement of the dam surface are analyzed, and a comparison is carried out between the test data and calculated result by the finite element model for reservoir water. The result shows that the air curtain is of certain influences on the hydrodynamic pressure and dynamic behavior of the dam surface. The good compression performance of the air curtain in front of the dam has obvious cushioning effect on earthquakes, and it is helpful to decrease the hydrodynamic pressure and dynamic stress of the dam hedy. Therefore, the aseismie performance of the dam bedy is greatly improved.