Studies On Settlement Of High Fill Loess With Considering The Compaction Degree

With rapid development of the project of “Fill to build the city”,the loess high fill project has become an important research topic in the process of city construction in Loess Hilly Area.The prediction of settlement of loess high fill has become one of the most important research areas,but the studies on consolidation settlement under high stress are still short.Based on this, this paper simulates the variation of soil compaction degree and moisture content to do high pressure consolidation test and probes into the effect of changing compaction degree and moisture content on the deformation law of the loess under the action of vertical pressure,and forecasts and analyses the settlement of losess high fill.The main results show that the dependent variable of the loess has a close relation with the moisture content and compaction degree under the action of vertical pressure.At the beginning of the trial,with the increase of vertical pressure, the variable is increasing.But when the vertical pressure increases to 400 kPa, the increasing rate of the strain increases gradually.When the vertical pressure increases to 1600 kPa, the variation of the variables is no longer significant.With the increase of vertical pressure,the loess which is the smaller degree compaction has high strain rate;The greater the moisture content of the loess is, the greater the increase rate of the strain is.When the water content is larger than the optimum water content, the increase range is especially obvious.Through further analysis, it can be found that the stress-strain relationship of the test loess can be fitted by the function relation.Then we can find the estimation method of soil stress under different stress levels,and the prediction method of consolidation and compression settlement of soil under different vertical pressurecan be proposed.Based on the existing high embankment settlement calculation method,this paper proposes the summation method of considering the step loading layerwise which is in accordance with high fill layer filling characteristics to calculate the loess high embankment settlement.While calculating 100 metres loess high fill consolidation settlement,we can find that the number of the layered summation method considering the step loading is larger than that of the other methods.Due to the predicted values in more than 2m, we must reserved for this part of the height when the high embankment building to prevent engineering accident.To predict loess high fill settlement in the rainy season and dry weather conditions,we can find that the rainy season and the dry weather has great influence on the loess high fill settlement.And the influence of the moisture content of the lower soil fill on the settlement is much more than that of the upper layer soil.Above all,we should considered comprehensively about this impact when reserving the fill height.