Up to the present time, earth-rock work in hydraulic construction has been carried out with equipment which operates on the basis of a cyclic technical scheme. Construction experience indicates that cyclic technicalschemes for performing earth--rockwork are labor-consuming and call for significant expenditures of resources and time. In recent years, at ferrous and nonferrous metallurgical enterprises, in the coal industry, and at quarries from which construction materiais are extracted, the progressive eyelic-flowline and flowline have been introduced [1][2][3][4][5][6][7][8][9][10][11]. Investigations carried out by several institutes belonging to the mining industry have revealed that the use of cyclieflowline techniques in earth--rock work makes it possible to increase the productivity of labor by a factor of 2 to 3 and to reduce the cost of this work by 20%.In hydraulic construction, the cyclic-flowline and flowline techniques could find application primarily for the construction of embankment dams, especially in the extraction and conveyance of the earth and rock material from the quarries to the dams, for exploitation of gravel--sand and rock quarries to obtain aggregates for concrete, and for constructing canals by placing soils in fills.In the flowline technique, use is made of continuous-action machines, and in the cyclic-flowline technique, a combination of cyclic-and continuous-action machines is used: excavators, loaders, dump trucks, crushers, and belt conveyors or any other types of continuous-transport machines, whichare the main links in the cyclic-flowline technique.The extraction of soft andgravel--sandsoils by cyclic-flowline and flowline techniques can be carried out by means of mass-produced equipment and without any additional technical operations. In the excavation of semirock and rock material, for transport by ordinary belt conveyors it is necessary to crush the rock to a size less than 600 mm, or use should be made of special belt conveyors adequate for transport of rock material over 600 mm in size. These special belt conveyors are being developed at the present time [ii]. The characteristics of conventional belt conveyors are presented in Table 1 [I].

Hydraulic construction experience gained during the last few years bears witness to the development of construction of embankment dams, whose cost can be substantially reduced through suitable organization of the construction work and me of modern progressive equipment, especially for transporting materials. A summarized description of the earth-rock work volumes for some embankment dams is presented in Table i [9].The volumes of earth--rock work at five of themost representative quarries of nonmetallic materials of the Ministry of Power and Electrification (Mindnergo) of the USSR amounts to 1.5-2.5 million mS/yr at each enterprise. The haul distance for earth--rock materials from the quarries to the embankment dams is usually in the 3-5-km range, and the haul distance for the rock to the concentrating plants processing it is of the order of 2-a km. Up to the present time, earth and rock for construction of embankment dams. as well as nonmetallic materials from quarries, have been transported by dump trucks, up to 27 tons in carrying capacity, at a haulage cost of 12-15 kopecks/ton-kin. This makes it necessary to construct and maintain costly roads with rigid pavements, especially for large-capacity machines, as well as to construct and maintain maintenance-mechanical shops, filling stations, fuellubricant storehouses, and other service enterprises. Truck transportation calls for a large number of workers, especially drivers, and. consequently, for increased construction of residential buildings and enterprises for these personnel.In the construction of embankment dams, thc cost of hauling earth--rock materials may amount to up to 60% of their total cost. This situation occurs to the same extent in the quarrying of nonmetallic materials. In the last few years, in Soviet and foreign practice, to transport rock from quarries to concentrating--grading plants, as well as stripped soil to dumps, along with truck transport use has been made of conveyors. The operating e~cperience of several mining enterprises in the ferrous and nonferrous metallurgical industries, construction materials enterprises, and coal industzy enterprises indicates that conveyor transport exhibits various substantial technicoeconomic advantages in comparison with truck transport [1][2][3] 7]: The demand for workers is reduced (on account of the decrease in the number of operating persons); the number of trucks is lowered; the transportation cost is reduced by a factor of 1.5-2; the labor productivity of the persormel is considerably increased; progressive flow-line techniques are introduced in earth--rock work in the quarry--dam line in the construction of embankment dams, and in the line from the quarry to the crushing--grading plant in the exploitation of nonmetallic materials; the coefficient of utilization of the main mining equipment is increased through reduction of the dead time of the equipment in the flow-line method; and possibilities are opened up for reducing the transportation distance of the mined mass to the ground surface on acco...

The cyclic-flow technology in the construction of high earth dams is the most effective, providing an increase in the rate of construction, reduction of construction time, and decrease of labor consumption. One of the labor-consuming processes in earth-dam construction is the transport of materials from borrow pits to the dam. With the existing cyclic technology it is accomplished mainly by dump trucks. In the cyclic-flow technology of earthworks the material is transported from the borrow pit or quarry by continuous mechanisms, particularly conveyors. This type of transport in comparison with vehicular is less labor-consuming and cheaper [I]. However, on the existing belt conveyors it is possible to transport material with a panicle size to 400 mm [2], and in the case of a flexible suspension of the conveyor rollers up to 600 ram. The quarry rock obtained by blasting has a size to 1600 mm and more [3].Conveyors that can transport ran-of-pit rock larger than 600 mm are presently being developed. Presently, large rock before delivery to the conveyor belt is crushed to transportable pieces. In this connection, loosening of the rock in the quarry by drilling and blasting is arranged so that the rock has a minimum quantity of oversize pieces larger than 400 ram. The existing traditional drilling and blasting technology in quarries does not always meet these requirements. Blasting is usually done in vertical boreholes on a selected face.The physical and mechanical properties of rocks, their tensile strength, block character of the rock mass and especially fracturing are not taken into account completely in a number of cases when calculating the parameters of drilling and blasting operations. The classification of rock masses [4] according to the degree of fracturing and content of large pieces is given in Table 1.