The Strength Characteristic Of Loess And The Research Of The Effect Of Joint On The Stability Of Loess Soil Slope

Nowadays there are many railways being constructed in the west, we should deal with loess in these projects. We have already done some research about the engineering property of loess; we have already known something about collapsibility, structure strength of loess. This paper mainly discus the factors affect the loess soil slope stability and how these factors exert their influence, however most of these factors can not be taken into consideration of in the project design during the construction of the railways in the west. The chief content are the strength property and engineering characteristic of loess, the research of the relationship between the structure strength and the water content of loess soil, summarize the existing method dealing with the loess soil slope stability and the characteristic of slope collapse, generalize the factors that affect the loess soil slope stability, research the effect of joint on the slope stability. The frequently used method of slope stability analysis is circular arc slide method, this method can not consider these above factors, numerical analysis can consider some of these factors, flac is a limited difference numerical process, it is most adaptable to large strain geo-engineering project, it has many constitutive model about soil and rock, it supports the user written constitutive model, this paper calculate the effect of strength parameter variation on the slope stability using flac2D, research the effect of alteration of slope configuration such as slope angle slope height on the slope stability. Examine the effect of joint angle on the slope stability. The result is that the large angle joint has a lower effect on the slope stability than the small angle joint, and analyze the shear stress in the representative zone along with the sub step excavation, calculate the rule when the slope have joint and the application of anchorage cable. Because of the obvious structure strength of loess; we should take into consideration of the structural strength of loess in the calculation. There has already some result of constitutive model about structure clay, this paper refers to the constitutive model capable to describe the damage of soil structure introduced by Shen Zhu-jiang, redact the process of this constitutive model using the fish language of flac. This model can not consider the effect of water content on the slope stability, we need to make some improvements to introduce a constitutive model that can consider this factor.