纵横波法在华北平原区浅层精细结构探测中的应用

Application of P-S method in the shallow fine structure detection in North China Plain

鉴于城建规划等对城市地下空间探测精度要求越来越高的的形势需求,在华北平原雄安新区附近开展了针对浅层的纵横波勘探试验研究。从方法技术层面详细阐述了野外数据采集的相关参数、数据处理流程和关键技术及其试验效果。研究获得了试验区浅层精细地质结构和速度分布特征,纵横波在深度域具有较好的对比性。纵波法在试验区最大有效探测深度达700 m,最浅探测深度为24 m,整体分辨率可达4 m,横波法最大探测深度约220 m,最浅探测深度为9 m,整体分辨率则高达1 m左右。横波弥补了浅表层纵波盲区和分辨率不足的问题,提高了浅表结构划分和断层上断点定位的精度,而纵波则弥补了横波探测深度小的缺陷。

In view of the situation that urban planning requires more and more precision of urban underground space detection,a pilot study of shallow P-S wave exploration was carried out near the Xiong’an New Area in North China Plain.The parameters of field data acquisition,data processing flow,key techniques and test results are described in detail from the aspect of method and technology.The study has resulted in fine geological structure and velocity distribution of the shallow layer in the test area,and P-wave and S-wave section have good contrast in the depth domain.In the study area,the detective depth of P-wave method is about 700 m,and the lowest detective depth is 24 m,the overall resolution is 4 m;the S-wave detective depth is about 220 m,the shallowest detective depth is 9 m,and the overall resolution is about 1 m.The S-wave makes up for the deficiency of the blind area and insufficient resolution of P-wave in the shallow layer,which improves the accuracy of the shallow structure division and fault location.The P-wave makes up for the defect of shallow detecting depth of S-wave.