Preliminary Study On The Influence Of Rheological Properties On The Stability Of Loess Slope

The loess distribution in the central and western regions of China is widespread and deep.Due to the over-exploitation of the loess forest and the long-term soil erosion in the history,the loess slope is formed in the western and western loess regions,which seriously restricts the western region Facilities development.Rheological properties are one of the main mechanical properties of loess materials.The existing engineering examples show that many of the loess slopes in nature have shown obvious rheological phenomena before the instability,that is,the instability of the slope is related to the rheological properties of the slope soil.Therefore,how to consider the rheological properties of slope soil in slope stability analysis is very important for the development of slope engineering.In this paper,the influence of loess rheological properties on slope stability is studied,and the slope stability analysis method considering loess rheological properties is compared with traditional ideal elastic strength reduction method and limit equilibrium method.By analyzing the difference of the potential sliding surface position,the difference of safety factor and the size of slope displacement calculated by the three methods,the similarities and differences of the three methods are obtained.Through the calculation and analysis of the slope model with different slope height and different slope footer,the following conclusions:1.The stability of the three slope stability analysis method is calculated by a slope through the slope of the entire slope of the arc surface,which limit balance method and the ideal elasticplastic strength reduction method to calculate the sliding surface position is almost the same The potential sliding surface of the slope calculated by the rheological reduction method is closer to the slope surface at the top of the slope and closer to the bottom of the model at the lowest point of the sliding surface.By analyzing the ideal elastic-plastic strength reduction method and the rheological strength reduction method,it can be found that the potential sliding zone calculated by the rheological strength reduction method is always in the ideal elasticplastic strength reduction method And the latent sliding zone calculated by the rheological strength reduction method is smaller than the slope width of the slope calculated by the ideal elastic-plastic strength reduction method.2.In the safety factor calculated by the three methods,the safety factor calculated by considering the strength reduction method of the rheology is the smallest,and the safety factor obtained by the limit equilibrium method is the largest.The size of the slope safety factor calculated by the ideal elastic-plastic strength reduction method is Between the two.The safety factor calculated by the limit equilibrium method and the ideal elastic-plastic strength reduction method is close to the slope safety factor,the difference is about 1%-2%,the safety factor calculated by the rheological strength reduction method and the safety factor calculated by the other two methods The difference is larger,the difference is about 8%-10%,indicating that the rheological properties of the slope stability of a greater impact.3.Considering the strength reduction method and the ideal elastic-plastic strength reduction method,the slope displacement calculated by the rheological strength reduction method when the reduction coefficient is less than the safety factor calculated by the rheological strength reduction method Value is large,and the difference between the two slope stability is stable,does not change with the increase of the reduction coefficient.When the reduction coefficient is larger than the safety factor,the slope displacement calculated by the rheological strength reduction method is obviously larger than that calculated by the ideal elastic-plastic strength reduction method,and the difference between the two decreases with the increase of the reduction coefficient.Therefore,in the process of slope displacement monitoring,the rheological properties of slope soil should be taken into account when setting the slope displacement warning value.