The Finite Element Analysis Of Embankment On Soft Grounds Reinforced By Geogrids

In recent years, the grading reinforced technology is obtained widespread application in the water conservation, the railroad, the road, the harbor and in the architectural engineering. The project of reinforcing road soft soil ground with geogrid also raise more. But the mechanism of reinforced is not clear actually. The computational method is not mature. The fundamental research falls behind the project practice obviously. Therefore, it is very extremely ssential to do further the thorough system research to grill reinforcement roadbed work mechanism which unifies the concrete project, the theory basis is provided for design andh construction reasonably that use grill reinforcement soft soil ground.The soil body Duncan - Zhang model parameter, muscle earth contact face unit parameter as well as geogrid unit parameter which is needed in the finite element method calculation has been determined by the room experiment. The method which simulate the change of value c and f of the soft soil through the use of the room direct shear test has been proposed, and the stability of the subgrade under step loading condition has been studied through the use of finite element method, according to the change of soil intensity target under differente soil solidifies. And confirmation of the accuracy of the finite element model has been carried on. The problem whether to lay down the geogrid, the placing position and how many layers has been analysised using finite element analysis method.The study indicated that, laying the geogrid can control the lateral displacement of the soft soil ground effectively. The maximum lateral displacement of the soft soil ground increases along the depth of the ground with the increase of the geogrid layers. In the vertical direction the slope foot of the subgrade, laying down the geogrid can reduce the lateral displacement of the soft soil ground in the scope of 3 meters' depth, reinforcement effect of the geogrid is not so obvious to the soft soil ground below 3 meters' depth. Comparing with laying down a layer of geogrid, the reinfoecement effect of the geogrid will not be so obvious when laying down multilayered geogrid, if only lay down a geogrid, the restraint effect to the displacement will be be best when laying on the ground, reinforcement can also reduce the vertical displacement of the soft soil ground, but the effect is limited. When laying down multilayered geogrid, the endogenic force each earth labor grill received has to be smaller than the pulling force received when placing only a layer of geogrid. The material function displayes most obviously when placing only a layer of geogrid. When placing two or five layers of geogrid, The tensile strength of the material, especially the upper reinforcement material, has not displayed fully.