以贵州独山变电站内地层为研究对象,将主动源面波多道分析法(multichannel analysis of surface waves,MASW)和被动源面波空间自相关法(spatial auto correlation,SPAC)频散能量叠加,得到一条复合频散曲线。该曲线频带更宽,既能保证表...以贵州独山变电站内地层为研究对象,将主动源面波多道分析法(multichannel analysis of surface waves,MASW)和被动源面波空间自相关法(spatial auto correlation,SPAC)频散能量叠加,得到一条复合频散曲线。该曲线频带更宽,既能保证表层的分辨能力,避免形成较大的勘探盲区,又可以有效提高反演深度,获得更加精细化的横波速度模型。结合钻探资料对比标定,可赋予该模型地质意义。研究结果表明,采用MASW和SPAC相结合的分析方法,有利于从表层到深层对地层进行精细成像,了解地层的岩性结构特征。与钻探相比,该方法成本低、效率高,可为复杂城区不良地质体的探测提供重要参考依据。展开更多
In recent years,karst construction projects in the built-up area of Wuhan(capital of Hubei Province,China)are increasing,and the karst geological disasters have aroused social concerns.The actual engineering projects ...In recent years,karst construction projects in the built-up area of Wuhan(capital of Hubei Province,China)are increasing,and the karst geological disasters have aroused social concerns.The actual engineering projects usually use shallow geophysical exploration methods to explore karst.This paper uses Spatial Auto-Correlation Method(SPAC)and electromagnetic Computerized Tomography(CT)to detect karst in urban built-up areas.Depending on the different physical properties of rock and soil,the SPAC method can better reveal the interface between soil and rock strata and the interface between soil layers.The electromagnetic CT method can identify strata according to the apparent absorption coefficient,which can better reveal the interface between soil and rock,the interface between the more intact and weathered rock.The SPAC method is mainly qualitative to measure the low-speed area,namely,the wrong geological body i.e.,karst cave,but also can detect the fracture zone or filling mode of karst cave,and at the same time,cannot use exploration holes or logging observation.The electromagnetic CT method can accurately detect the location and scale of the karst caves and has a higher accuracy detecting karst bands.In addition,exploration holes or well logging observations are also expected to be conducted,and their detection effect is greatly affected by lithology.展开更多
文摘以贵州独山变电站内地层为研究对象,将主动源面波多道分析法(multichannel analysis of surface waves,MASW)和被动源面波空间自相关法(spatial auto correlation,SPAC)频散能量叠加,得到一条复合频散曲线。该曲线频带更宽,既能保证表层的分辨能力,避免形成较大的勘探盲区,又可以有效提高反演深度,获得更加精细化的横波速度模型。结合钻探资料对比标定,可赋予该模型地质意义。研究结果表明,采用MASW和SPAC相结合的分析方法,有利于从表层到深层对地层进行精细成像,了解地层的岩性结构特征。与钻探相比,该方法成本低、效率高,可为复杂城区不良地质体的探测提供重要参考依据。
文摘In recent years,karst construction projects in the built-up area of Wuhan(capital of Hubei Province,China)are increasing,and the karst geological disasters have aroused social concerns.The actual engineering projects usually use shallow geophysical exploration methods to explore karst.This paper uses Spatial Auto-Correlation Method(SPAC)and electromagnetic Computerized Tomography(CT)to detect karst in urban built-up areas.Depending on the different physical properties of rock and soil,the SPAC method can better reveal the interface between soil and rock strata and the interface between soil layers.The electromagnetic CT method can identify strata according to the apparent absorption coefficient,which can better reveal the interface between soil and rock,the interface between the more intact and weathered rock.The SPAC method is mainly qualitative to measure the low-speed area,namely,the wrong geological body i.e.,karst cave,but also can detect the fracture zone or filling mode of karst cave,and at the same time,cannot use exploration holes or logging observation.The electromagnetic CT method can accurately detect the location and scale of the karst caves and has a higher accuracy detecting karst bands.In addition,exploration holes or well logging observations are also expected to be conducted,and their detection effect is greatly affected by lithology.
