| The carbon mudstone widely distributed in the southwestern region of our country, because of its water-rational, easy weathering, low intensity, large deformation characteristics, in the past, it always be discarded as bad filler in road construction, but with the rapid development of China’s highway construction the use of carbon mudstone in the embankment filling is imperative, so how to ensure the safety during and after the project is one of the issues that road builders are most concerned about. So it is necessary to study the stability of embankment that stratified filled with carbon mudstone-soil, in order to provide a reliable basis for design and construction of highway embankment that stratified filled with carbon mudstone-soil.This article biased on the Liu Zhai-He Chi highway in Guangxi province, focus on the factors affect the stability of the embankment that stratified filled with carbon mudstone-soil, deeply study the Embankment stability in many aspects. The main contents are as follows:(1) The study of shear strength parameters of disintegrated carbon mudstone. It can be seen from the carbon mudstone direct shear test:Moisture content is the most important factor that affects the cohesion and internal friction angle of carbon mudstone, the friction angle is the main factor that affect the shear strength of carbon mudstone embankment fill material.(2) Stratified filled embankment stability research based on the limit equilibrium slice method. Base on the Swedish arc method and simplified Bishop limit equilibrium slice method, get the Swedish arc method and simplified Bishop limit equilibrium slice method that applicable to the stratified filled embankment that filled with different materials. Comparative analysis shows:the safety factor calculated by stratified filled embankment stability calculation method are smaller than the factor that calculated by the limit equilibrium slice method software, and is safer and cheaper, has a strong guiding significance for the design and construction of the actual project.(3) The study that considers the change of strength parameters on the stability of embankment. Through the Indoor embankment model test that downscaling as a certain percentage, study the strength change of material of embankment that stratified filled with carbon mudstone-soil in the condition of rainy. It can be seen from the indoor embankment model test:when it begin to rain, the safety factor of embankment decreases rapidly; when the rain is stable, the safety factor of embankment not decline rapidly; with the continued rain, the safety factor of embankment decreases rapidly as well, and the magnitude of reduce is much more than the moment that the rain beginning. At the same time, during all the test, the weight of soil and carbon mudstone,cohesion and friction angle shows a downward trend. |
