边坡的破坏一般表现为岩土介质的抗拉破坏和剪切破坏。基于抗剪强度指标c和φ,运用弹塑性理论和有限元强度折减方法,并结合土体强度发挥系数SEF特性(不同安全系数下的SEF值,程序计算所得塑性区的分布为判据),分析得出了土坡的整体稳定安全系数、边坡潜在破坏区的范围以及破坏时土体强度发挥的程度等结果。计算表明:边坡土体在达到其抗剪强度的80%左右时,便表现出不同程度的破坏,同时该值又接近于土体的长期强度值。相比较而言,本文方法确定的强度发挥值对分析土坡稳定性是可靠的,且意义明朗、简便易行,对类似的工程实际,具有一定的借鉴意义。
The failure of slope generally shows the tension and shear failures in slope soil. Based on the shear strength indices c and 9, the elasto-plasticity theory and the finite element method are applied in the calculation, and the numerical model of slope stability is established and the characteristics of the strength exertion factor SEF are considered. The safety factor for the integral stability of soil slope, the range of the potential failure zone and the exertion extent of the strength of the soil failure are presented. The results show that the soil slope failure occurs when the soil strength is about 80 % of the shear strength, which is close to the long term strength of the soil. The strength exertion value determined by the said method is reliable to the stability analysis of soil slope, which could be used in engineering practice.