长江苏通公路大桥区原状淤泥质亚粘土起动试验研究

Experimental research on threshold velocity of undisturbed and muddy loam in the area of Sutong bridge on the Yangtze River

在河道中,受水压力和土体本身压力的作用,淤积物的密度增大,物理力学特性发生了很大的变化,如采用公式计算起动流速,则出现较大的偏差。针对实际工程中经常遇到的淤泥质亚粘土的起动流速问题进行了试验研究,研究在特制的矩形管道中进行。通过试验得到了起动临界状态下的摩阻流速,利用天然河道的阻力关系将摩阻流速换算到天然情况,并以河道稳定性为比较目标,与河道水流动力条件进行比较,验证了试验研究结果的合理性和有效性,这为解决河道边界淤积物的起动临界条件问题提供了一种新的思路和方法,因此无论从研究方法上还是解决实际工程问题都具有一定的创新意义。

The density of deposit in rivers increases under the action of water pressure and soil pressure, which results in large changes on the physical and mechanical properties of the soil A large difference occurs when the threshold velocity is calculated by the empirical formula So, in this paper, the experiments on the threshold velocity for muddy loam are studied in special rectangular pipes From the experiments, the frictional velocity is obtained at the critical condition Changed into the velocity for the natural river by resistance relationship and compared with the flow dynamic conditions of the river, it can be proved that the experimental results are effective and reasonable, providing a new method to solve the critical condition for the threshold velocity of deposit in rivers