广义塑性模型在海洋砂土中的适用性研究

Study on Adaptability of Generalized Plastic Model in Ocean Sand

为研究广义塑性模型在海洋砂土中的适应性,采用静、动三轴仪对海洋砂土进行了固结排水剪切及固结不排水循环剪切试验,根据试验结果拟合出砂土的广义塑性模型参数,并利用此参数对动模量和阻尼比试验进行了数值模拟,比较了试验结果与模型拟合结果的差异。结果表明,计算结果与试验测定的动模量、阻尼比与动应变的变化规律一致,该模型能很好地反映砂土单调加载的应力-应变特性及小应变阶段的循环加载条件下的变形特性。

To study the adaptability of generalized plastic model for ocean sand, the consolidation-drained shear tests and consolidation undrained cyclic shear tests are carried out by using static and dynamic triaxial apparatus. According to the test results, the parameters of the model are fitted. And the tests on dynamic shear modulus and damping ratio are simulated by the same parameters. Meanwhile it discusses that the differences between the tests and simulation. The re suits show that the simulation of generalized plastic model and tests have the same change rules of dynamic shear modulus and damping ratio with amplitude of dynamic strain; this model not only can reflect the stress-strain characteristics of sand under monotonic loading, hut also can describe the deformation characteristics of sand at the stage of small strains under cyclic loading.