机构地区: 吉林大学建设工程学院
出 处: 《岩石力学与工程学报》 2012年第A01期2745-2750,共6页
摘 要: 隧道的超欠挖对衬砌结构稳定性影响比较大,研究超欠挖规律,对于掌握围岩受力,保证施工安全,具有较为深远的意义。根据小波分析的多尺度功能以及隧道断面轮廓超欠挖序列的统计自相似性特点,对白鹤隧道47个断面轮廓采用小波理论估算分形维数。结合现场调查的节理参数统计数据,分析隧道围岩断面轮廓分形维数与节理参数之间的关系。结果表明:分形维数越大,围岩稳定性越差;洞轴线与节理走向夹角越大,断面轮廓分形维数就越小;节理间距为0.25~0.40 m时,节理间距越大,分形维数越大;超挖百分比越大,分形维数越大。 The stability of lining structure is influenced by under-excavation and over-excavation of tunnels. It is of great significance to understand the surrounding rock stress and ensure construction safety by studying the over-excavation and under-excavation rules of tunnels. Based on the multi-scale function of wavelet analysis and the statistical self-similarity between the over-excavation and under-excavation of tunnel section profile, the fractal dimensions of 47 tunnel section profiles were calculated by the wavelet analysis. According to the statistical data of joint parameters obtained by field investigation, relationship between the fractal dimension of section profile and joint parameters of tunnel surrounding rocks was analyzed. A function for evaluating the stability of tunnel surrounding rocks was established. With the increase of the fractal dimension, the stability of surrounding rocks gets worse. As the angle between the tunnel axis and joint strike and the over-excavation percentage increase, the fractal dimension of section profiles decreases. When the joint space increases from 0.25 to 0.40 m, the fractal dimension of section profile also decreases.