高分辨率轻便可控震源系统实现评价城市地质隐患

THE ASSESSMENT OF CIVIL HIDDEN DAMAGE USING A HIGH-RESOLUTION PORTABLE ELECTROMAGNETIC VIBRATOR SEISMIC SOURCE

浅层地震探测规模小,干扰因素复杂,较常规石油地震勘探更为复杂,因而要求更高的信噪比和分辨率。笔者介绍了轻便可控震源的关键技术,相关与锥化能有效地抑制随机噪声及环境噪声,提高信噪比与分辨率。可控震源信号持续时间较长、幅度相对较炸药震源小,破坏性小。野外应用实例表明可控震源是一种无损、可控、高分辨率的探测工具,具有工作稳定、抗干扰、效率高等一系列优点,可满足勘察精度要求,已广泛用于水文、工程、环境地质调查以及城市地质灾害预测领域。

Shallow seismic reflection survey is more complex than conventional oil exploration because of coherent and random noise, and the most important factors connected with this method are high S/N ratio and high resolution. This paper deals with the key technique of the portable vibrator system, whose correlation and tapper processing can restrain random noise and improve resolution greatly. The vibrator seismic source is of longer duration and generally lower amplitude than dynamite sources, with relatively less damage to ground and nearby structures. Field practice has demonstrated that the portable vibrator system can indeed serve as a nondestructive, controllable and high-resolution technique. This technique has already been applied successfully in the field of hydrology as well as civil and environmental engineering.