Design And Optimization Research In Liquefaction Resistance Of Stone Columns Foundation For Highway

Basing on the summary of history, research fields of sand liquefaction, stone columns grounds some problems to design liquefied ground treated by stone columns are introduced.In this article the potential for liquefaction of gravel column composite foundation is evaluated by treating the soil as if it were sand field . theory research indicates that the drainage , the stress concentration of the gravel column and the embankment loading can have a substantial influence on the liquefaction resistance of sands. Modifications to the typical free-field liquefaction analysis procedure to account for existence in the drainage and the stress concentration due to the gravel column and the embankment loading are suggested. In the field of stone column stabilization scope,the author firstly analyses the pore-water pressure-stress-strain characteristics of sand in the different parts of ground . Secondly the ground is divided into three regions:reinforced region,liquefaction region and interim region . For every region strength index is analysed through stress-strain characteristics. Then the minimum fasten width witch ensures the embankment steady during and after earthquakes is got through stability analysis.While In the field of stone column handling depth,excess pore water pressure is calculated in the ground in the condition of the liquefaction sand do not penetrated by stone columns,through witch the thickness of the loose sands is get witch do not liquefy because of the effect of stone columns under the compound grounds . Then if 2~3m loose sands are reserved under the non-liquefaction layer ,analysis indicates that it can reduce the effect of earthquake because that loose sands liquefy and prevent the transversal wave from passing through.. by this two sides research stone column handling depth is get.At last the effects of the ground treated by stone columns are summed up in the whole of Lian-Xu highway,Xu-Su highway and Ning-Jin-Yan highway. In addition an typical example is analysed using preceding text's idea.