纤维加筋淤泥固化土的邓肯-张模型

为了改善水泥固化疏浚淤泥土的强度、变形和稳定性，促进在水利和岩土工程中的应用，将聚乙烯醇短纤维和水泥一起掺入淤泥中，对不同纤维掺入比和围压下的试样进行20组排水三轴试验，研究纤维对淤泥固化土工程性质和邓肯-张模型参数的影响.结果表明，掺入纤维后固化淤泥土的应力-应变关系呈现出双曲线变化特征；随着纤维掺入比增加，黏聚力显著增长，内摩擦角几乎保持不变.根据实测数据和回归分析方法，建立纤维淤泥固化土的邓肯-张E-B模型，获得初始切线模量及体积模量随纤维掺入比幂函数型增长的经验公式.邓肯-张E-B模型能够较好地拟合实测的应力-应变曲线.
Abstract: Short polyvinyl alcohol fiber together with cement was mixed to sludge in order to improve strength, deformation and stability of cement-solidified dredged sludge and promote its application in hydraulic and geotechnical engineering. Twenty groups of samples with different fiber mixing ratio were conducted under different confining pressure in drained triaxial compression test in order to analyze the influence of fiber on the engineering properties and Duncan-Chang model parameters of solidified sludge. Results show that after fibers are mixed in, the stress-strain relationship of solidified sludge exhibits hyperbolic characteristic. The cohesion dramatically increases with fiber mixing ratio while the friction angle almost remains unchanged. Duncan-Chang E-B model was constructed for fiber reinforced solidified sludge based on experimental data and regression analysis method. The empirical formulas of initial tangent modulus and bulk modulus were formulated to increase with fiber mixing ratio by means of power function type. Experimental stress-strain curves can be well fitted by Duncan-Chang E-B model which considers fiber mixing ratio.