| Slope stability has always been a focus of geotechnical engineering research,and its analysis methods are varied.The traditional analysis methods take the landslide body as a whole and analyze the force and deformation of the slope from a macro perspective,while some scholars analyze its deformation mechanism from a micro perspective.Due to the limitation of calculation cost,the scale of the current micro model is limited.In this paper,macroscopic and mesoscopic methods are combined to analyze the mesoscopic mechanism of slope failure,and the internal mechanism of slope failure is analyzed from the mesoscopic level.The slope failure is analyzed by analyzing the changes of internal porosity,stress,displacement,velocity and contact force between particles in the process of slope failure.The main research works are as follows:(1)The micro-parameters were calibrated by the macroscopic stress-strain curve and the internal friction Angle and cohesion force were used to calibrate the micro-parameters so as to make the calibrated micro-parameters more accurate.The linear contact modulus,contact modulus and stiffness ratio were calibrated.(2)Strength reduction method was used to analyze the reduction rule of meso-parameters,and code of macro and meso-strength reduction function was written.(3)The continuous-discrete numerical model building method is studied.The sliding crack surface of the slope was found by establishing the failure model of the continuous element slope,and the coupling area was selected and the size of the coupling area was determined according to the position of the failure surface of the continuous element slope.(4)The changes of velocity,displacement,shear stress,principal stress,particle contact force and porosity of the sliding body,the sliding plane and the particle inside the stable body during slope deformation and failure are analyzed.The results show that :(a)the velocity and displacement of the particles increase during the formation of the slip plane,and the velocity remains unchanged while the displacement continues to increase after the formation of the slip plane.(b)The contact between particles increases first and then decreases after the formation of the slip surface.The shear stress and principal stress also increase first and then enter the stage of residual stress.(c)A meso-analysis of the particles inside the slope was carried out through the measurement circle.The study showed that the particles were first compacted and then separated during the formation process of the landslide,the shear stress inside the measurement circle first increased and then decreased,and the bond stress between particles was destroyed when the slip plane passed through the measurement circle.(d)In the process of landslide formation,the voids in the slope first decrease,and the voids gradually increase with the continuous increase of failure.(5)The meso-mechanism of slope failure under different influencing factors is analyzed.The results show that the inflection point of the porosity change rate indicates the formation of the sliding crack surface of the slope.At the same time,the shear strength inside the particles increases gradually with the formation of the slope slip surface,and the shear stress between the particles decreases gradually when the slip surface penetrates the slope.If the value of shear stress increases and remains unchanged,it indicates that the slope will not be unstable and in a safe state.At the same time,the study on the strength parameters of soil slope shows that the bond force has a great influence on the stability of slope... |
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