含隐患土石堤坝的三维波场数值模拟及其特征分析

Three-dimensional numerical simulation and characteristic analysis of wavefield for earth-rock dam contain hidden troubles

含隐患土石堤坝的三维波场特征分析,是利用波动测试信号反演识别土石堤坝内部隐患的前提和基础。为了获得含不同类型隐患的波场特征和波动测试信号的畸变规律,本文采用有限元数值方法对含隐患土石堤坝的三维波场进行模拟分析,结果表明隐患体的位置与堤坝表面接收到的波场信息有密切相关性,隐患正上方测点的时程曲线相位与测线上其他测点的时程曲线相位具有明显差异,且散射波起跳时间较周围测点提前,据此可初步判断隐患体沿测线方向的位置。为验证这一波场特征,采用模型试验对无隐患土石堤坝和含渗漏通道的土石堤坝分别进行了波动测试试验,结果表明:坝顶同一测线接收到的波动信号,对于无隐患堤坝仅存在直达波;对于含隐患体堤坝,由于散射波与直达波的叠加,在含隐患测点上方的波动信号发生畸变,发生信号畸变的测点与实际设置隐患位置完全对应。由此可见,数值模拟结果与试验结果在反应隐患的位置和波动测试信号特征上具有相同的变化规律。

Three dimensional wavefield characteristics analysis of the earth-rock dam with hidden troublesis the premise and foundation to identify the hidden troubles of the earth-rock dam by the use of wavetest signals. In order to obtain the wavefield characteristics and the test signal distortion rule of varioustypes of hidden troubles, the three dimensional wave-field characteristics of the earth-rock dam containinghidden troubles is simulated and analyzed based on the finite element numerical method in this paper. Theanalysis results show that the position of the hidden trouble body and the wave field information receivedby the dam surface are closely related, the phase of the time-distance curve above hidden troubles andthe curve phase of other measuring points on measuring line has obvious difference, and scattered wavetake-off time is around the measuring point in advance, the position of hidden body could be judgmentalong the survey line direction. To verify such wave field characteristics, the model test experiment ofearth-rock dam with hidden troubles and leakage passage are carried out. The results show that there is on-ly direct wave for dam without hidden troubles, and there is a distortion wave signal for dam containingthe hidden trouble, due to scattering wave and direct wave superposition, and the measurement points ofsignal distortion and the top of set the actual hidden trouble corresponds exactly. Therefore, the numericalsimulation results and test results have the same change rule on the characteristics of the test signal.