【摘要】 应用地震物理模拟技术对孔洞型地层进行地震响应特征研究时,会遇到孔洞模型的尺度和洞内填充物较难满足模拟条件等问题,通过在实验室合理调整孔洞与模型的比例关系,分析确定合适的填充材料和制作工艺,制作了4种孔洞形态的物理模型,针对每一种形态的洞设计了5种尺寸,并分别进行了二维观测。在二维叠加剖面上,洞的三维形态各不相同,绕射特征有较大的差异,水平棍形洞的绕射能量远强于其它形态的洞,形态和尺度相近的球形和柱形洞的绕射能量相近,当洞的垂向尺度小于1/2围岩波长时,绕射能量随洞的横向尺度增大而增强。偏移剖面上的串珠状特征主要由洞底绕射引起,当水平洞的长度增加时,串珠状特征更加明显,因此可以利用这些特征对孔洞形态进行识别。更多还原

【Abstract】 The scale and filling of cavern model usually don’t meet the simulation conditions during the research on seismic response char- acteristics by applying seismic physical modeling technology in cav- ern formations.In laboratory,the proportions of cavern to model were reasonably adjusted;the favorable material and manufactur- ing process were found out and four cavern physical models were manufactured.Meanwhile,every form has five holes with different scales,and 2-D observation was carried out to every cavern physi- cal model.On 2-D stacking profiles,the 3-D shape of holes is dif- ferent,resulting in a great deviation in diffraction characteristics. The diffraction energy of horizon stick hole is far stronger than that of other kind of holes,the diffraction energy of globular hole and column aspect hole is close,the two holes has a similar shape and scale.When the vertical scale of hole is smaller than half wave- length of surrounding rock,the diffraction energy becomes stron- ger as the horizontal scale of the holes increases.On the migration profiles,the diffraction from the cavern floor is one of the reasons causing a moniliform characteristic.When the length of horizontal cavern increases,the moniliform characteristic becomes more obvi- ous.These characteristics can be applied in the recognition of cav- ern shapes.更多还原