【摘要】 采用真空抽吸制样技术制备的饱和重塑黏土,在0.015～3.75%/min应变速率范围内进行了多组不固结不排水(UU)剪切试验。通过对试验结果的分析,着重探讨了应变速率和约束压力对应力-应变关系及其强度特性的影响。试验结果表明,黏土的应力-应变关系与强度特性基本上不依赖于约束压力,而受应变速率的影响较为显著,强度随应变速率的增加而增长,增长幅度可达70%,通过对数据的归一化,采用线性拟和建立了不排水强度与应变速率之间的经验关系。进而考虑应变速率对不固结不排水应力-应变关系的影响,对双曲线非线性本构模型进行了研究,详细介绍了模型参数的确定方法,并分别采用静力三轴和扭剪试验结果对模型进行了验证。更多还原

【Abstract】 A series of unconsolidated-undrained(UU) triaxial tests are performed in order to examine the effect of strain rate and confining pressure on strength and stress-strain behavior of reconstituted saturated clays.Strain rate is controlled to vary between 0.015 %/min and 3.75 %/min.It is found by comparing the experimental data that strength and stress-strain behavior are mainly affected by strain rate,however,they are almost independent on confining pressure.Undrained shear strength of the saturated clay increases with increase of strain rate;and the increase of 70 % of strength may be attained.An empirical correlation between strength and strain rate is proposed after a given normalization.Furthermore,the hyperbolic constitutive model of nonlinearity is recommended in order to take the effect of strain rate on the stress-strain relation into consideration;and the experimentally-based procedure for defining the parameters in the hyperbolic model is given.The model is verified through test data in the monotonic triaxial and torsional shear tests.更多还原