高边坡土体强度参数对设计坡比的影响及不同填土接触面与潜在滑动面之间的关系

Influence of the High Slope of Soil Strength Parameters on the Design of Slope Ratio and the Relationship between Different Fill Contact Surface and Potential Sliding Surface

对于民航机场这样的高边坡填方体无论是地基建设常用的粗颗粒土还是细颗粒土,其强度参数和填方体的围压都有着明显的非线性关系。分析了高填方边坡的各区域的围压大小,按照围压大小区域的划分得出了各区域的非线性强度参数,计算出在满足安全系数前提下的最佳坡比。发现按照非线性强度参数得到的坡比明显小于常规计算得到的坡比,地基建设所用的填方料显著减少。另一方面机场高填方地基的道槽区和土面区常用的碎石土和黏性土的渗透率等各方面性质有着很大的差别,会给边坡的稳定性带来影响。分析了在不同坡比、气候条件、地下水位线高度下的边坡潜在的滑动面和碎石土和黏性土接触面之间的关系后发现,高边坡潜在的破坏面总是倾向于在碎石土和黏性土的接触面上,所以在进行高边坡的稳定性防护工作时应尤其注意两种土体接触面之间的防护工作。

Whether it is coarse or fine granular soil which use by the foundation construction in high slope of fill body civil aviation airport,there is obvious nonlinear relationship in strength parameters and confining pressure of high slope.The confining pressure of each high fill slope area is analyzed.Division of the regional nonlinear strength parameters is given according to the confining pressure area.It is concluded that the regional nonlinear strength parameters by the confining pressure area to the size of the partition.The safety factor for the best slope ratio is calculated,and the slope ratio got by parameter of nonlinear strength is less than ordinary calculated.Fill material used in the foundation construction is significantly reduced.On the other hand,there are big differences between gravel soil in channel slot area and cohesive soils in soil surface area of high fill foundation at the airport whatever permeability or other aspects.The differences will affect the stability of the slope.The relationship between contacting surfaces of gravel soil and cohesive soil and potential slope sliding surface under the condition of different slope ratios,climate conditions and underground water level height were explored.The results show that high slope potential failure surface is always tend to be in the gravel soil and cohesive soil contact surface.So the protection work between two kinds of contact surface of soil should be paid particular attention to when making the stability of high slope protection work.