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管涌问题是水利工程中广受关注的一大难题。通常针对管涌的研究是基于稳定水头条件下的,而非稳定流作用下,水位的升降变化与稳定流情况不同,水位势能的转变速率,施加于土颗粒的主动动量异于稳定流,导致土体发生管涌的规律也有别于稳定流情况。首先根据理论公式的计算,提出非稳定流作用下试样发生管涌破坏水头低于稳定流水头的假想;同时指出,试验过程中土颗粒的运移规律在小范围区域内具有很大的随机性。最后,在理论研究的基础上设计试验,通过控制供水水头,使水头在近似正弦曲线变化的情况下升降循环,进行管涌试验。在试验过程中监测试样内部各部位的渗流参数变化情况,对理论进行了验证。
Piping problem is widely concerned about water conservancy project a major problem. Generally, the research on piping is based on steady head conditions. Under the effect of steady flow, the change of water level is different from that of steady flow. The transition rate of water potential and the active momentum applied to soil particles are different from those of steady flow, The law of the body tube is also different from the steady flow. According to the calculation of the theoretical formula, the hypothesis that the head of the pipe under the instability flow is lower than that of the steady flow head is proposed. At the same time, it is pointed out that the migration of soil particles during the test has a large randomness in a small area . Finally, based on the theoretical research, the experiment was designed to control the water supply head and to make the water head rise and fall under the condition of approximate sinusoidal curve. In the process of testing the monitoring of various parts of the sample seepage flow parameters changes, the theory was verified.