摘要
针对盾构中管片与围岩之间的注浆层刚度过低产生地层沉降和岩体坍塌等一系列安全问题,探究一种可靠便捷的冲击回波无损检测方法来检测识别注浆层刚度缺陷。利用大型有限元软件MSC.MARC,对不同注浆层刚度SGS(管片-注浆-围岩)模型的冲击瞬态过程进行有限元模型瞬态响应模拟,得到不同工况下冲击响应的时程曲线。并通过FFT变换,分析不同刚度注浆层条件下冲击响应的频谱特征。研究结果表明:采用冲击回波法识别盾构中不同刚度注浆层的方法是可行的。该模型能够较准确地模拟出应力波在SGS模型中的传递及其特征,并与理论公式相吻合,且不同刚度注浆层条件表现出了不同的频谱特征,为以后利用冲击回波法识别低刚度注浆层提供了理论参考。
Since the security problems of the grouting layer between segment and surrounding rock in tube shield,would result in subsidence of strata and collapse of rock,a reliable and convenient non- destructive testing method,Impact Echo method,is explored. Finite element software MSC. MARC is used to simulate the transient response of the SGS（ Shield segment- grouting- surrounding rock） model transient process of impact. Impulse response time history curves are obtained separately in different kinds conditions. By the FFT transformation,spectral characteristics of the impulse response in different stiffness grouting conditions are analyzed. The results show that using Impact Echo method to identify the defect abut stiffness of grouting is feasible.The propagation and reflection of the mechanical wave in SGS can be accurately simulated by the FEM model,and this model coincides with the theoretical formula. In addition,different stiffness grouting conditions show different spectral characteristics,which provides a theoretical reference to identify the low stiffness grouted by impact echo method.
出处
《铁道科学与工程学报》
CAS
CSCD
北大核心
2015年第6期1420-1426,共7页
Journal of Railway Science and Engineering
基金
江苏省"企业博士聚集计划"2011年度立项资助项目(JS2011JH24)
南京市建设系统科研项目计划项目(201210)
