Construction of Dams by Dumping Stones into Flowing Water

Abstract

First pdf is translation, second pdf is original Russian text. - The possibility of constructing a dam by dumping stones into flowing water is considered. Experiments are carried out with different construction methods. In total five different methods have been tested. From the hydraulic standpoint, the most rational method of construction appears to be to use only small stones in the beginning and subsequently change to larger sizes. The method gives greatest economy in total volume of the submerged dam, gives the minimum percentage of large size stones, gives a steadily increasing effectiveness of dumping, gives maximum insurance against piping due to percolation flow between the dam and the foundation and also results in the minimum total percolation flow through the body of the dam. With reference to the plan of using only large stones, it can readily be seen that the attendant expense is not justified for the initial triangular stages because the equilibrium of stones situated near the apex is determined by the coefficient of stability against sliding, rather than the coefficient of overturning. Furthermore, the large stones in the lower interior section of the triangle are outside the zone of flow action and are never subjected to the higher velocities of overflow. The method of using alternate portions of small and large stones decreases the resistance of the latter of overturning. Consequently, the large stones simply roll along over the smaller pieces and, not being able to find a hold capable of developing the requisite interlocking resistance, simply roll along the top of the dam and gradually acquiring high kinetic energy, sometimes damage and destroy previously constructed sections of the dam. The corresponding curve of effectiveness of dumping is subject to erratic changes and exhibits a series of negative slopes. At times an increment of stone actually results in a decrease in the height of the dam for the reason given above. The final volume of a submerged dam constructed of alternate portions of small and large stones is greater than the volume of a similar dam section constructed entirely of small stones.