摘要
利用相似材料模拟高速铁路隧道基底软岩，采用荷载控制和非对称正弦波循环加载方式对软岩试件进行动三轴疲劳与损伤检测综合试验。通过试验结果分析，建立了软岩3参数多项式疲劳寿命计算模型和4参数多项式累积损伤参量计算模型，获得了软岩疲劳损伤特性，即：软岩疲劳破坏表现为端部拉-剪复合破坏和中部压-剪复合破坏两种模式；疲劳破坏全过程表现为初始微孔隙压密、裂纹发生与稳定扩展以及损伤裂纹加速发展3个发展阶段；软岩疲劳寿命主要取决于本身强度和动应力水平，强度愈高、动力应力水平愈低，其疲劳寿命就越长；当动应力水平相同时，软岩疲劳寿命与其弹性模量呈线性增长关系。
Abstract
The similar materials is used to simulate the soft rock-mass on the basement of tunnel in the high speed railway.Based on the method of loading control and the cyclic loadings of non-symmetrical sine wave,the dynamic fatigue test of three axial and the damage detection test are carried on for soft rock-mass specimens.With analysis of the results of tests,the polynomial model with three parameters to calculate the fatigue life and the polynomial model with four parameters to calculate the cumulative damage are established for soft rock-masses.And then,some characteristics of fatigue damage has been obtained about the soft rock-mass,such as the fatigue failure of soft rock-mass mainly shows two composite modes those are the tension-shear on the end and the compression-shear on the central of specimen.The whole process of fatigue damage is shown three stages those are the compaction of initial micro-pore,the occurrence and stable propagation of new cracks,and the accelerating development of crack damage.The fatigue life of soft rock-mass mainly depends on itself strength and the level of dynamic stress.The higher strength of itself and the lower level of dynamic stress,the longer fatigue life of rock-mass will be.If the level of dynamic stress has not been changed,the fatigue life of soft rock-mass will be increased linearly with its elastic model.
基金项目
国家自然科学基金(51278121)
广东省教育厅重大特色创新资助项目(2014KTSCX155)
NETL
NSTL
维普
万方数据