某堤坝下软土地基非线性沉降计算的改进分层总和法

Improved Layer-wise Summation Method for Calculating Nonliner Settlements of the Soft Soil of an Experimental Dam

软土地基上堤坝的沉降计算一直本是研究的热点。目前关于堤坝沉降计算中采用沉降修正经验系数,但合理计算其沉降难度仍很大。为较好解决地基沉降计算这一重要难题,通过探讨应力历史和地基土附加应力对地基土变形模量影响,采用分级加载,提出了堤坝下软土地基非线性沉降计算的改进分层总和法,该方法不仅反映应力历史和地基土附加应力对变形模量影响,而且反映地基土深度对其影响,计算参数选取也较少。通过对某试验堤坝沉降进行计算与分析,并与实测结果进行比较,证明该方法效果较好,可较准确计算堤坝沉降。

How to calculate soil foundation settlement of the dike is still an issue not well resolved inengineering design.Adopting modified coefficient method to calculate the settlement of the soft soil ofthe dam reasonably is still difficult at the present time.To solve the important question in calculation ofthe foundation settlement satisfactorily,through studying the effects of stress history and additionalstresses on foundation deformation modulus and using stepwise loading,an improved layer-wisesummation method for nonlinear settlement of soft soil is put forward.This method not only renflects theinfluences of stress history and additional stresses on foundation deformation modulus of the soft soil,butalso the effect of the thickness of the soft soil on foundation deformation modulus.At the same time theparameters of calculation of selection is few by this method.By comparing the computation and analysisof an experimental dam with actually measured and calculated settlements and results by other method,it is shown that the proposed method is reasonable and feasible and the result agreed well with theobservations.