摘要
多道面波分析勘探法在工程场地安全评价中应用广泛,主要有人工源和天然源两种方法,但人工源法具有勘探深度相对较小的缺陷;天然源法其数据采集周期长现场操作便捷性差.文章通过引入伪随机震源作为面波勘探震源,希望能够在较短的采样周期内获取质量较高的频散能量谱.对获得的面波数据记录分别使用适合主动源法的F-K法以及适用于被动源法的SPAC法获取相应频散谱,并将伪随机震源的频散谱与同场地、同排列条件下人工源和天然源面波数据结果对比,认为:(1)运用SPAC法进行伪随机震源面波法频散分析所得到的频散谱收敛性较高;(2)伪随机震源面波法能够弥补人工源面波法勘探深度较小的缺点,相对于天然源面波法能够兼顾浅层高频区域,且现场操作简单、工作效率更高,适宜于不同地质条件的场地应用评价.
MASW is widely used in engineering site safety evaluation. it contained two methods: active surface waves and passive surface waves,but the active surface waves method has the defects of relatively small depth of exploration. The passive surface waves method has a time consuming and poor convenience. In this paper,the F-K method and the SPAC method are used to process the surface wave data,and the frequency spectrum of the vibroseisrandom source is compared with that of the same field and the artificial environment. Compared with the results of the surface waves data,it is concluded that the SPAC method is better used to analyze the dispersion spectrum of the vibroseis-random source surface wave method. The vibroseis-random source surface wave method can compensate for the low depth of the artificial surface wave method shortcomings,compared with the passive surface waves method can take into account the shallow high-frequency region,and the field operation is simple, more efficient, suitable for different geological conditions of the site application evaluation.
引文
Aki K.1957.Space and Time Spectra of Stationary Stochastic Waves,with Special Reference to Microtremors[J].Bull.earthquake Res.inst.tokyo Univ,35:415-456.
Li N,He Z Q,Ye T L,et al.2015.Test for comparison of array layout in natural source surface wave exploration[J].Acta Seismologica Sinica(in Chinese),(2):323-334.
Liu K H,Wei S M.2001.The instantaneous surface wave exploration and its application[J].Design Of Water Resources&Hydroelectric Engineering(in Chinese),20(2):31-33.
Luo Y,Xia J,Miller R.D,et al.2008.Rayleigh-wave dispersive energy imaging by high-resolution linear Radon transform[J]Pure and Applied Geophysics,165,903-922.
Park C B,Miller R D,Xia J.1999.Multichannel analysis of surface waves(MASW)[J].Geophysics,64(3):800-808.
Park C B,Miller R D,Xia J,et al.2007.Multichannel analysis of surface waves(MASW)-active and passive methods[J].The Leading Edge,26(1):60-64.
Park,C B,R D Miller,Xia J.1998.Imaging dispersion curves of surface waves on multi-channel record:Technical Program with Biographies,the 68th Annual Meeting of the Society of Exploration Geophysicists,New Orleans,Louisiana,1377-1380.
Wang W,He Z Q,Hu G,et al.2012.Detect the velocity structure of shallow crust with artificial and nature source Rayleigh wave technology[J].Technology for Earthquake Disaster Prevention,07(1):26-36.
Wang Z D.2006.Essentials and recent advances of the surface wave exploration technique[J].Geophysical And Geochemical Exploration(in Chinese),30(1):1-6.
Wang Z R,Chai Z Y.2007.Seismic response to pseudorandom coded vibrator signal[J].Progress In Geophysics(in Chinese),22(6):1736-1739.
Xia J,Miller R.D.,Park C.B.1999.Estimation of near-surface shear-wave velocity by inversion of Rayleigh wave[J]Geophysics,64,691-700.
Xia J,Xu Y.,Miller R.D.2007.Generation image of dispersive energy by frequency decomposition and slant stacking[J]Pure and Applied Geophysics,164:941-956.
Yilmaz,.1987,Seismic Data Processing:Society of Exploration Geophysicists,Tulsa,OK,USA.
Zhao D.2010.Passive surface waves:methods and applications[J].Geophysical And Geochemical Exploration(in Chinese),34(6):759-764.
李娜,何正勤,叶太兰,等.2015.天然源面波勘探台阵对比试验[J].地震学报,(2):323-334.
刘康和,魏树满.2001.瞬态面波勘探及应用[J].水利水电工程设计,20(2):31-33.
王振东.2006.面波勘探技术要点与最新进展[J].物探与化探,30(1):1-6.
王忠仁,柴治媛.2007.伪随机编码震源信号的地震响应[J].地球物理学进展,22(6):1736-1739.
张维,何正勤,胡刚,等.2012.用人工源和天然源面波联合探测浅层速度结构[J].震灾防御技术,07(1):26-36.
赵东.2010.被动源面波勘探方法与应用[J].物探与化探,34(6):759-764.