【摘要】 在大量动三轴试验的基础上,研究了不同固结条件(σ3c=100,200,400 kPa,kc=1.0,1.5,2.0)下西昌昔格达组黏土岩的动应力-动应变关系、动弹性模量、阻尼比及动强度特性。研究结果表明:西昌昔格达组黏土岩在一定条件下的动应力-动应变关系符合幂函数模型。动应力随着固结围压σ3c或固结主压力比kc增大而增大。在相同围压下,达到相同动应变时,偏压固结状态比均压状态所需要的动应力大。当其他条件相同时,动弹性模量随固结压力或固结主压力比增大而增大,随着动应变的增加而减小并趋于稳定。最大动弹性模量Ed0与σ3c/Pa、kc均有良好的幂函数关系,且对不同固结应力状态条件可以归一。阻尼比随动应变增大而增大,但增大幅度随动应变增大而迅速减小,阻尼比随围压或固结主压力比增大而减小,但它们对阻尼比影响较小。不同固结应力状态下(λ/λmax)与(1-Ed/Ed0)有良好的幂函数关系。西昌昔格达组饱和黏土岩动剪应力τd随固结围压σ3c或固结主压力比kc增大而增大,随振动次数增加而减小。τd/σm均随固结围压σ3c增大而减小,随固结压力比kc增大而增大。动剪应力τd与平均压力σm、固结主压力比kc有较好的线性关系。更多还原

【Abstract】 Based on a lot of dynamic triaxial tests,some dynamic characteristics,such as the relation between dynamic stress and strain,dynamic elastic modulus,damping ratio and dynamic strength are studied for Xigeda formation claystone in Xichang city under different consolidation stress conditions(σ3c=100、200、400 kPa,kc=1.0、1.5、2.0).It is indicated from test results that: the relation between dynamic stress and strain can be fitted with power function model under certain conditions.Dynamic stress increases with the increase of confining pressure σ3c or consolidation stress ratios kc.The Xigeda formation claystone in Xichan city produces larger strain under anisotropic consolidation stress condition than that under isotropic consolidation stress condition at the same stress condition.Dynamic modulus increases with the increase of confining pressure or consolidation stress ratios;it decreases with the increase of dynamic strain and tends to stability under certain condition.Power correlations between the maximum dynamic elastic modulus Ed0 and σ3c/Pa,kc are obtained and normalized under different consolidation stress conditions.Damping ratio increases with the increase of dynamic strain,but the variety gets smaller with the increase of dynamic strain;the damping ration decreases with the increase of confining pressure or consolidation stress ratios,but it is almost independent of them.Power correlations between(λ/λmax)and(1-Ed/Ed0) are obtained under different consolidation stress conditions.Dynamic shear stress τd increases with the increase of confining pressure σ3c or consolidation stress ratios kc,but it decreases with the increase of vibration number.τd/σm decreases with the increase of confining pressure σ3c,but it increases with the increase of consolidation pressure ratio kc.Dynamic shear stress τd has significant linear relation with mean pressure σm and consolidation stress ratios kc.更多还原