Study On Stability Of Different Shape Slopes And Its Application

With the development of large-scale constrution projects, more and more engineering slopes have appeared in all kinds of construction fields, which are always a essential factor in deciding whether the project are economical and reasonable or not. Landslide and rockfall as the common type of slope failure are affected by the slope shape factor,such as slope angles, slope length, slope height and the surface shape of slope, ect. However, one of the most important factor is the slope shape. Therefore, It is necessary to investigate the effect of slope shape on slope stability.In the paper, the current situation of shope research is reviewed and summarized, the stability of different shape slopes is studied by theoretical analysis and numerical simulation and compared with in-situ slopes. The main results are as follows:1,The spatial mechanics of round and oval slopes is analysed by elastic mechanics,and the relationship among critical slide angle, rock mass, elastical modulus in circular direction of the circular rock, excavated radius, and friction coefficient is derived.The results shows that the deeper the pit slope excavated is,the greater the critical slide angle is .Moreover,a mathematical formula of the optimum shape and optimum angle of the pit slope is obtained based on the basic theory of elasticity.2,The slope shape is defined originally by axis ratioλ(λis equal to alb, a stands for major axies,while b minor axies), whenλis equal to 0, the surface of the slope is plane,asλis respectively equal to 1/5,1/4,1/3,1/2, the surface of the slope is ellipse;whileλis equal to l,the surface of the slope is round.3,whenλis equal to 0, as the surface of the slope is round,some results as follow are obtained by numerical simulation.①for a certain slope, the position of each of the critical slip circles is related only toλcφ, and the slip surface becomes deeper as the relative magnitude ofλcφincreases;②For a certainλcφ, maximum depth, D, of the critical slip surface for a certainλcφvalue is increased proportional to Ho, but the magnitude of D/H0 is independent on Ho, this independence of the relation betweenλcφand D/H0 can also be proved by mathematically. Note that D/H0 is a dimensionless paramater to describe maximum depth of the critical slip surface;③For a certainλcφ, internal friction angleφ'at failure (F is equal to 1.0) remains constant although cohesion c'increases as the size of the sliding mass increases.④when h unchanged, the safety factor F decreases with the increase ofα; whileαunchanged, the relationship between the satety factor F and slope height h is similar to the relationship between the satety factor F and dip angle a.4,Whenλis respectively equal to 1/5,1/4,1/3,1/2,1, as the surface of the slope is concave (including round and oval). The relationship among shope shape, slope angle, slope height and safety factor is analysed by three-dimensional discrete element program (3DEC).(DAs h keep constant,the slope safety factor increases and decreases with the increase ofλ, the slope safety factor reaches the maximum value asλis equal to 1/3;②Asλkeep constant,the slope safety factor decreases with the increase of slope angleα, which is similar to the relationship of plane slope;③As slope angleαkeep constant,the slope safety factor decreases with the increase of slope height h。...