Analysis Of The Seepage Characteristics And Stability Of Colluvial Soil Highway Slope In Dabie Mountain

In the process of highway construction encountered a lot of colluvial soil slope problems in Dabie Mountain. It not only causes damage to the mountain’s weak ecological environment which is difficult to restore if we just excavate the soil, but also resulting some unreasonable project cost. Therefore, The reasonable and reliable local solutions of highway loose colluvial soil slope under rainfall infiltration is one of the important technical problems to be solved in rainy mountain highway construction. In this paper, the local stabilization measures are studied comprehensively through the combination of soil experiments, numerical analysis and field monitoring methods,focus on the engineering background that the mountain area affected by rainfall. The main research efforts have been carried on in the aspects as follows:(1)The summary and analysis of the basic theory of saturated-unsaturated seepage calculation under the rainfall infiltration. Based on the saturated-unsaturated seepage basic concepts, the energy conservation law and Darcy’s law, the saturated-unsaturated seepage equation is derived, and discussed the boundary conditions of seepage calculation. The basic theory of rainfall infiltration is further analyzed.(2)Experimental research on the engineering character of colluvial soil. The water content of slope impact on the soil shear strength parameters directly, thereby affecting the stability of the slope. Based on the study of the typical colluvial soil’s physical properties and mechanical properties.Focus on the analysis of the quantitative relationship between shear strength parameters of soil and soil water content. And analyzed the impact of soil water content on slope stability through a numerical example.(3)The analysis of the infiltration characteristics and stability of the transient seepage of slope under rainfall. In this paper, the different transient seepages of slope are calculated under the different rainfall conditions and drainage conditions, applying two-dimensional finite element software. And the result is used to study the distribution and development law of pore water pressure, volumetric water content, flow paths under the same condition. According to the conclusions of the transient analysis of slope, the slope dynamic laws of stability is analyzed under rainfall. And study the slope stability under different drainage conditions.(4)Analysis of slope water transport and deformation with monitoring system. Referring to the Slope monitoring system setting and test principle, the monitoring system on the typical colluvial soil slope has been designed and construction. The long observation data is used to study the distribution and development law of pore water pressure and slope deformation under the actual rainfall conditions. Further, several stability measures to prove the stability of the colluvial soil slope are presented.Preliminary results of this study show that the suitable arrangement of drainage drill and slope retaining structures can solve the highway colluvial slope stability problems. It provides a feasible measures for resolving environment problems and unreasonable project cost that caused by the mountain highway slope excavation.