CAJ | 학술논문

利用椭球体分析了恒定流下泥沙的起动条件，得到了椭球体卵石的无量纲起动切应力公式，建立了无量纲起动切应力与水流脉动系数、绝对隐蔽度、中轴比长轴及短轴比中轴的关系。结果表明：①通过实测资料计算出的无量纲起动切应力为0.046~0.068，说明建立的公式较为合理；②k ＝0.74、短轴比中轴为0.5时，绝对隐蔽度大于-0.5的卵石的无量纲起动切应力为0.03~0.06；当 k、短轴比中轴为定值时，随着中轴比长轴逐渐增大，无量纲起动切应力逐渐减小；在相同的中轴比长轴条件下，随着绝对隐蔽度减小，无量纲起动切应力也减小；当 k、中轴比长轴为定值时，短轴比中轴越大，无量纲起动切应力越大；③无量纲起动切应力随着内摩擦角的增大而增大；④k 越大，所需要的无量纲起动切应力越小。
이용타구체분석료항정류하니사적기동조건，득도료타구체란석적무량강기동절응력공식，건립료무량강기동절응력여수류맥동계수、절대은폐도、중축비장축급단축비중축적관계。결과표명：①통과실측자료계산출적무량강기동절응력위0.046~0.068，설명건립적공식교위합리；②k ＝0.74、단축비중축위0.5시，절대은폐도대우-0.5적란석적무량강기동절응력위0.03~0.06；당 k、단축비중축위정치시，수착중축비장축축점증대，무량강기동절응력축점감소；재상동적중축비장축조건하，수착절대은폐도감소，무량강기동절응력야감소；당 k、중축비장축위정치시，단축비중축월대，무량강기동절응력월대；③무량강기동절응력수착내마찰각적증대이증대；④k 월대，소수요적무량강기동절응력월소。
This article analyzed sediment incipient motion under steady flow by ellipsoid. It derived ellipsoid pebbles′equation of dimensionless in-cipient shear stress. Then,the relationship of dimensionless incipient shear stress,water ripple coefficient,relative hidden degree,medial axis to long axis and minor axis to medial axis was established. The results show that:a)the equation considers reasonable when the dimensionless incipi-ent shear stress ranges between 0. 046 ~ 0. 068 by the calculation;b)the pebbles′dimensionless incipient shear stress is 0. 03 ~ 0. 06. When k and c/ b is constant,the dimensionless incipient shear stress decreases with b/ a increasing. When b/ a in the same conditions and η ﹤ 0,the dimension-less incipient shear stress decreases with η increasing. When k and b/ a are constant,the dimensionless incipient shear stress decreases with c/ b in-creasing;c)the dimensionless incipient shear stress increases with internal friction angle increasing;d)the lager the k the less the dimensionless incipient shear stress.