基于隧道衬砌脱空模型的叩击信号特征分析

为分析叩击法在隧道衬砌脱空中的信号特征,获取叩击信号对脱空病害的关联参数,在对隧道衬砌脱空病害分析的基础上,建立多种工况的实体模型用以叩击信号分析。该模型厚5~45 cm以5 cm递增,分脱空5 mm、20 mm、完整衬砌3类情况,共计27种工况。对叩击信号的时域响应时长、频宽、频峰数量等8项参数进行统计分析,确定了获取稳定的波场信号所需的震源锤类型;并分析了8项参数对脱空情况、脱空大小的相关特性。明确了4项对脱空的强关联性参数、1项对脱空无关联参数、6项对脱空大小的关联性参数,并得出所述8项参数无法识别35 cm厚及以上厚衬砌脱空的大小等信息。本次隧道衬砌脱空模型叩击信号特征分析的成果,能有效指导叩击法对衬砌脱空病害的识别。

Analysis of Percussion Signal Characteristics Based on Tunnel Lining Void Model

In order to analyze the signal characteristics of percussion method in the tunnel lining void, and obtain the correlation parameters of percussion signal to the void disease, the analysis of the tunnel lining void disease has been carried out, and the model of various conditions has been established to analyze the percussion signal. There were 27 conditions of the model, included the thickness form 5 cm to 45 cm, increasing by 5 cm, and it was divided into three types: 5 mm Void, 20 mm Void and complete lining. Based on the statistical analysis of 8 parameters of percussion signal, such as time-domain response length, frequency width, frequency peak number, etc., the type of source hammer needed to obtain stable wave field signal was determined, and the relevant characteristics of 8 parameters were analyzed on the situation and size of void. There were four parameters that were strongly correlated with the void, and one parameter was irrelevant. There were 6 parameters associated with void size. We obtained the information that 8 parameters can not identify of the void size of 35 cm thick and above lining. The results of the percussion signal characteristic analysis of the tunnel lining void model can effectively guide the percussion method to identify the lining void disease.