Slope Stability Analysis Of Filling Subgrade Based On Mesomechanics

With the in-depth economic globalization and implementation of 13th Five Year Plan,China’s road traffic infrastructure has set off a new wave of construction,and infrastructure construction and road safety is of great significance.As road support structure,filling subgrade’s engineering characteristics and stability analysis are important issues in the study of subgrade and pavement engineering.The filling soil’s mechanical properties are complex,and usually the laboratory tests are used to study it.However,it is difficult to analyze the mechanical properties and damage mechanism of the soil by conventional methods.As for the stability analysis of filling subgrade,although there are the limit equilibrium and finite element methods,they still can not simulate the dynamic instability of slope failure of the whole process.As a kind of discrete element method,particle flow code can do the discretization,according to which we can do a better job in simulating the specimen model of discontinuous medium,analyzing mechanical properties and microcosmic failure mechanism,and observing dynamic process of slope instability,which makes up for the shortcomings of other methods.The main work of this paper are as follows:Based on the study of the stability of the embankment slope,the mechanical properties of clay were tested according to the discrete element theory and the discrete element software PFC,and the reliability of this method was verified by comparison with laboratory tests.To build a method system of studing filling subgrade,different parameters were chose to be monitored by programming languages FISH based on different simulation requirements.The mechanical properties of subgrade fill were tested.Virtual triaxial tests were carried out by PFC2D,and the virtual test parameters were calibrated.The stress and strain curves were obtained.The cohesive force c=18.1kPa and the internal friction angle φ=18.1°.The influence of the microscopic parameters of the particles on the macro characteristics of the soil was studied.Virtual CBR tests were carried out,the test conditions and compaction were simulated,the meso mechanism of the CBR test process was studied,and the influence of microscopic parameters on the CBR test results was further analyzed.Finally,the subgrade slope model was established,the suitable criterion of slope instability was selected,and the stability analysis were carried out by the method of strength reduction and gravity increase to acquaintance the mechanism of destabilization.The safety factors were calculated as 1.39 and 1.67.Then,two results of the these methods were compared,and the further improvement of the methods and ideas were discussed.