级配碎石动态力学性能对隧道路面受力影响

具有良好温湿稳定性的级配碎石常设置在隧道路面下排出基岩上渗水。利用动三轴实验模拟基岩渗水对级配碎石层动态力学性能的影响，建立了动态回弹模型表征其力学特性，并采用非线性有限元分析了路面受力。结果表明，动三轴试验较好地模拟了级配碎石层的实际受力状态；Uzan模型考虑了材料的剪切性能，更能反映了级配碎石在隧道路面中应力状态；随含水量的变化，Uzan模型中回归系数变化呈明显的非线性特征，进而显著影响级配碎石的动态回弹模量的变化；级配碎石模量越大，路面层底的最大拉应力减小率越小；为了兼顾到级配碎石层的排水渗透功能和强度，应严格控制级配，特别是0.075mm以下的含量宜控制在5％～7％，级配碎石的回弹模量宜控制在200～300MPa之间。

Effects of Dynamic Mechanical Property of Grading Macadam on Tunnel Pavement Stress

Grading macadam with good temperature and humidity stability is laid out under tunnel pavement to drain permeability from bedrock. Dynamic triaxial experiment is used to study effects of permeability from bedrock on dynamic mechanical property of grading macadam drainage base, and dynamic spring-back model is built to token its mechanical property of the grading macadam, and nonlinear FEM is adopted to analyze stress state of pavement. The result notes that dynamic triaxial test preferably simulate the actual stress state of grading macadam, and Uzan model which considers the shear performance of material can better reflect stress states of grading macadam. Regression coefficients of the model obviously present nonlinear characteristic with moisture changed, and to further influence dynamic resilient module.More the module is larger, more diminishing rate of maximum tensile stress on pavement Bottom is smaller. To enhance draining function and strength, the gradation should been rigid controlled, and which the content of less than 0.075mm is controlled between 5～7％ and spring-back is controlled between200~300MPa are appropriate.