噴射式 桁網의 開發에 관한 硏究 - Ⅰ

Development of Hydraulic Jet Dredge - I

In order to find the excavating performance of water-jet nozzle on the sand, the authors were carried out the excavating experiment with the model nozzles which were semi circular sectioned nozzles and rectanglar nozzle in water tank. The results were as follows. 1) Excavating maximum depth and width on the sand by the water jet were straightly increased in proportion to the velocity of water jet and the section area of nozzle, and that, by the nozzle distance from the excavating point on the sand, the depth was decreased, while the width was increased straightly. 2) Rectangular nozzle which the thick of hole is Imm, was a little bit better than the circular nozzle of the same sectioned area on the excavating performance. 3) Empirical equations between the velocity of water jet, the distance of nozzle, and the maximum excavating depth and width by angle of nozzle were expressed as linear, they were as follows on the 45' angle of the rectangular nozzle(1 x 12mm); D=0.0093V0 - 0.23H + 5.7 W=O.0147V0 + 1.06H + 10.2 where, D is the maximum excavating depth(cm), W is the maximum excavation width(cm), V0 is the velocity ot water jet(cm/s); 926≤ VO≤1504, H is the distance(cm) from nozzle tip to waterjetted point on the surface of sand.