Experimental Study On The Jetty Head Scour Law Of Hydraulic Flashboard Permeable Spur Dike

Hydraulic flashboard permeable spur dike is a new type of permeable spur dike that combine the flashboard technique and traditional permeable spur dike.It can be able to solve the problem related to water damage caused by the instability of silty sand river bed of tarim river in xinjiang.In the first place,The paper used movable bed model test and single factor control variable methods to respectively explore the relationship,which is between depth of the first?the second?the third jetty head scour and the factors.The paper used regression analysis to respectively conclude the regression equation,which is between depth of the first?the second?the third jetty head scour and the factors.Based on this,the paper chose the best test level from each group of single factor experiment and used the orthogonal experiment.The affect order of each single factor of the first?the second?the third spur dike and the optimal design scheme of three hydraulic flashboard permeable spur dikes could be got.In the second place,The paper respectively decorated three hydraulic flashboard permeable spur dikes,three well column pile permeable spur dikes,three entity spur dikes according to the optimal design scheme of three hydraulic flashboard permeable spur dikes,using them to make bed model test.The paper through measuring the point velocity in front of and behind of each spur dike,and used it to calculate average velocity of each spur dike.The paper judged the differences of reducing average velocity of water among three kinds of three spur dikes through comparing the average velocity of each spur dike.The paper made bed model test about three kinds of three spur dikes and drew topographic map about three kinds of three spur dikes through Surfer 8.0.The paper judged the differences of reducing local scour among three kinds of three spur dikes through seeing map.In the third place,the paper used some the calculated value of local scour formulas compare to the measured values.In order to explore a formula that suitable for calculating the depth of local scour of hydraulic flashboard permeable spur dike jetty.The conclusion can be listed as follow:(1)the optimal design scheme of three hydraulic flashboard permeable spur dikes could be listd as follows:The radio about the length of first spur dike?the length of second spur dike?the length of third spur dike and the width of river is 0.25?0.21?0.21 respectively;The first spur dike permeable rate is 30%,the second spur dike permeable rate is 30%,the third spur dike permeable rate is 20%;The radio about the spacing of the first spur dike between the second spur dike and the length of the first spur dike is 3;The radio about the spacing of the second spur dike between the third spur dike and the length of the second spur dike is 2.The pick angle of the first?the second?the third spur dike is 60°.(2)The slowing effect of three hydraulic flashboard permeable spur dikes is the best,the slowing effect of three entity spur dikes is the worst,the slowing effect of three well column pile permeable spur dikes is between others.The performance of reducing local scour of three hydraulic flashboard permeable spur dikes is best.The performance of reducing local scour of three entity spur dikes is worst.The performance of reducing local scour of three well column pile permeable spur dikes is between others.(3)The empirical formulas that are proposed to calculate the depth of jetty head scour of hydraulic flashboard permeable spur dike can be concluded.