不同填充材料的STC加筋体水平循环剪切试验及数值模拟

Experimental and Numerical Study of Scrap Tire Columns Filled with Different Geomaterials under Cyclic Shear

为研究不同填充材料对废旧轮胎柱(scrap tire columns,STC)加筋体循环剪切性能的影响,利用自行研制的土工合成材料循环剪切试验机,分别得到河砂、碎石、壤土3种填充材料的STC加筋体在竖向压力100 k Pa、最大水平剪应变2%条件下的循环剪切滞回曲线。试验结果表明:河砂、碎石STC的等效动剪切模量和等效阻尼比在数值上基本接近,且均优于壤土STC的动力参数,考虑到减振消能效果以及填筑过程的便利性,河砂STC具有较好的实际应用优势。采用ABAQUS有限元程序,分别选用Mohr-Coulomb、Mooney-Rivlin和Rebar本构模型来模拟土石填筑料、橡胶超弹性材料和帘线钢丝材料,数值重现了3种填筑料STC加筋体的应力-应变滞回曲线,数值模拟结果与试验结果的规律基本一致。由模拟所得的循环剪切过程中STC加筋体能量变化曲线可知:填充材料主要起"消能"作用,轮胎则主要起"加筋"作用。

To investigate the effect of filler types on cyclic shear behavior of scrap tire columns (STC) reinforced geomaterials,a series of horizontal cyclic shear tests,with a vertical pressure of 100 kPa and a maximum shear strain of 2%,were conducted on STC reinforced river sands,gravels and loam soils,respectively.Test results show that STC reinforced river sands and gravels almost have the same values of equivalent dynamic shear moduli and equivalent damping ratios,which are better than those of STC reinforced loam soils.In consideration of dynamic behavior and construction convenience,STC reinforced river sands have a good advantage in practical application.Moreover,the stress-strain hysteresis curves were reasonably established based on the FEM simulation by the code of ABAQUS.Constitutive models of Mohr-Coulomb,Mooney-Rivlin and Rebar were selected to simulate the mechanical behaviors of geomaterials,rubbers and rebars,respectively.From the simulated energy-time variation curves during the cyclic shear,it is found that the inside filling geomaterials mainly play a role of energy dissipation,and scrap tires mainly act for reinforcement.