桩承式路堤土拱效应计算方法比较

桩承式路堤土拱效应对路堤的荷载传递和沉降变形性状有重要影响,桩土应力比是评价土拱效应的重要参数.通过模型试验及现场测试对目前已有的土拱效应计算方法进行了比较.结果表明:对于平面土拱,Terzaghi方法计算结果与模型试验结果最大值比较接近,Low方法计算结果整体上与模型试验结果吻合较好;对于空间土拱,Hewlett方法及陈云敏方法计算结果与现场实测结果均比较接近;英国规范BS8006推荐方法的计算结果与模型试验及现场实测结果的差异均较大.该研究成果可为桩承式路堤设计提供有益的参考.

Comparision of Calculating Methods of Soil Arching in Piled Embankments

Soil arching has significant influence on behaviors of piled embankments.The stress concentration ratio is an important parameter to assess the soil arching.The results of model test and field test were compared with the calculated results of analytical methods.It shows that:(1) For 2D situation,Terzaghi's method can be used to predict the upper bound value of the stress concentration ratio.Low's method is by far the most relevant when compared to the model test results.(2) For 3D situation,the results obtained from Hewlett's and Chen's methods are in fair agreement with the field measurements.(3) It seems that the method for 2D situation in BS8006 underestimated the stress concentration ratio.However,the method for 3D situation in BS8006 overestimated the stress concentration ratio.The conclusions can provide valuable reference for the practice.