基于地基动力测试模型基础垫层的影响分析  

Analysis of Influence of Foundation Cushion Based on Ground Dynamic Test

作　　者：张开伟 李志勇[1] 齐松松 韩文永 聂庆科 Zhang Kaiwei;Li Zhiyong;Qi Songsong;Han Wenyong;Nie Qingke(Hebei Shuangcheng Construction Engineering Testing Co.Ltd., Shijiazhuang Hebei 050031, China;Hebei Research Institute of Construction & Geotechnical Investigation Co. Ltd., Shijiazhuang Hebei050031, China)

机构地区：[1]河北双诚建筑工程检测有限公司,河北石家庄050031 [2]河北建设勘察研究院有限公司,河北石家庄050031

出　　处：《工程地球物理学报》2020年第5期636-642,共7页Chinese Journal of Engineering Geophysics

基　　金：河北省建设科技计划项目(编号:2014-014号)。

摘　　要：进行地基动力测试时垫层与下覆岩石地基粘连会对测试结果产生影响,不同垫层影响程度也不同。结合实际项目,首先设计建立素混凝土垫层、砂垫层与岩石地基不同粘连状态的地基动力测试模型基础,同时对素混凝土垫层、砂垫层与岩石地基未粘连状态进行竖向及水平向振动测试试验、对素混凝土垫层与岩石地基粘连状态模型基础进行竖向振动测试试验。其次通过实测试验结果,对垫层和岩石地基共同作用结果进行总结分析,分析各垫层模型基础不同粘连状态对岩石地基动力基础设计参数的影响。最后通过总结得到,在岩石地基动力基础设计时,如果采用素混凝土垫层,下覆岩石地基要与其保持未粘连状态,垫层强度与岩石地基强度基本相当,基础的振动可通过垫层无损耗地传递给地基,地基动力参数由岩石地基本身决定;当素混凝土垫层与岩石地基完全处于粘连状态时,地基动力测试幅频响应曲线无明显共振幅,基础参振总质量巨大,无法获取有效测试参数。如果采用砂垫层,由于砂垫层强度远低于岩石地基,岩石地基与模型基础之间形成阻抗软垫,测试结果不再是岩石地基本身的动力参数,而是砂垫层软垫和岩石地基共同作用的结果,岩石地基本身的刚度以及砂垫层的软硬、厚薄决定最终的测试结果。When a ground-based power test is carried out,the adhesion of the mat and the sub-rock foundation affects the test results,and the effect of different cusions varies greatly.Based on the actual projects,a foundation dynamic test model for establishing different adhesion states of concrete cusion,sand cusion layer and rock foundation is first proposed,and vertical and horizontal vibration test is carried out on the non-adhesive state of concrete cusion,sand cusion and rock foundation.Experiments are carried out on the vertical vibration test of the solid concrete cusion and rock foundation adhesion state,followed by a summary and analysis of the results of the joint action of the mat layer and rock foundation,and an analysis of the different adhesion states of each mating model base.The influence on the design parameters of rock foundation power base is discussed,finally,by summing up that the rock foundation should be unadhesive with the solid concrete cusion when the rock foundation power machine base design is adopted,the pad strength is basically equivalent to the rock foundation strength,the base vibration can be passed to the foundation without loss,and the ground base power parameter is determined by the rock ground base.The total mass of the base vibration is so huge that is not possible to obtain effective test parameters,because the sand mat layer strength is much lower than the rock foundation,the rock foundation and the model foundation form an impedance cushion,the test results are no longer the power parameters of the rock floor base,but the results of the joint action of the sand mat layer upsole and the rock foundation,the stiffness of the rock base and the soft and thin sand mat layer determine the final test results.

关 键 词：地基动力测试 垫层 岩石地基 模型基础 幅频响应曲线 

分 类 号：P631.4[天文地球—地质矿产勘探]