基于滑面正应力修正的边坡安全系数解答

SOLUTION OF SLOPE SAFETY FACTOR BY MODIFYING NORMAL STRESSES OVER SLIP SURFACE

首先,对边坡滑动面正应力分布作初始假设;然后,用含有2个待定参数的修正函数对其修正,使滑体整体满足所有力与力矩平衡条件,推导出边坡安全系数计算公式。该法计算过程简单,无需迭代,适合任意形状滑动面,且为严格的极限平衡解,值得在工程中推广应用。

An initial assumption is made on normal stress distribution along the slip surface,which is subsequently modified with a function involving two parameters to be determined to satisfy equilibrium conditions of all the forces and moments for the whole sliding body,and the formula of the slope safety factor is then derived. This method enjoys merits of straightforward computation process, no need of iteration, accommodating arbitrary shape of slip surfaces and the solutions being within the context of rigorous limit equilibrium.1 Duncan J M. State of the art:limit equilibrium and finite-element analysis of slopes[J]. J. Geotech. Engrg.,ASCE,1996,122(7):577～596 2 Janbu N,Bjerrum L,Kjaernsli B. Soil Mechanics Applied to Some Engineering Problems[R]. Oslo:Norwegian Geotechnical Institute Publication,1956 3 Lowe J,Karafiath L. Stability of earth dams upon drawdown[A]. In:Proc. of 1st Pan-Am. Conf. on Soil Mech. and Found. Engrg.[C]. Mexico:[s. n.],1960,537～552 4 U. S. Army Corps of Engineers. Stability of slopes and foundations[R]. Vicksburg,Miss.:U. S. Army Corps of Engineers Engineering Manual,1967 5 Janbu N. Slope stability computations[A]. In:Hirschfield E,Poulos S ed. Proc. of Embankment Dam Engineering[C]. [s. l.]:[s. n.],1973,47～86 6 Morgenstern N R,Price V E. The analysis of the stability of general slip surfaces[J]. Géotechnique,1965,15(1):79～93 7 Spencer E. A method of analysis of the stability of embankments assuming parallel interslice forces[J]. Géotechnique,1967,17(1):11～26 8 Fellenius W. Calculation of the stability of earth dams[A]. In:Proc. 2nd Congr. Large Dams[C]. Washington D C:[s. n.],1936,445～462 9 Bishop A W. The use of the slip circle in the stability analysis of earth slopes[J]. Géotechnique,1955,(1):7～17 10 Fredlund D G,Krahn J. Comparison of slope stability methods of analysis[J]. Can. Geotech. J.,1977,14(3):429～439