城市活断层探测中的浅层地震勘探方法

对大量地震灾害的研究表明,地震发生时,位于地表活动断层上的房屋或构筑物的破坏最严重,尤其是20世纪90年代后期美国北岭地震,日本阪神地震和中国台湾集集大地震等的发生后,世界许多国家的政府和地震科学家都清楚地认识到城市活断层探测与研究的重要性和急迫性,城市活断层的探测对于城市规划,抗震设防,减轻地震对城市设施的破坏都具有重要的现实意义,浅层高分辨地震勘探是城市活断层探测手段中最有效,最可靠的方法之一,可以在地表探测到地下活断层的位置,埋深,产状和空间展布情况,但由于城市环境的强干扰背景和场地条件的复杂性,必须针对实际情况,在观测系统,震源,数据采集环境的强干扰背景和场地条件的复杂性,必须针对实际 情况,在观测系统,震源,数据采集和处理方法等环节中,采用一系列提高分辨率, 提高信噪比的有效方法,才能取得可靠的探测成果,本文对城市活断层探测中的浅层地震勘探方法的技术难点和相应的解决方法进行了讨论,并结合我们近几年来在城市开展浅层地震勘探的一些经验,介绍一些实用性的浅层地震勘探工作方法。

The Application of Shallow Seismic Prospecting Methods to Active Fault Dectection in Cities

Through research on an amount of earthquake disasters,it shows that when an earthquake occurrs,houses or buildings located on active faults of surface will suffer the most serious damage from earthquake,especially after the occurrence of the Northridge earthquake,USA,Hanshin earthquake,Japan and Taiwan Chi Chi earthquake,China in the latter of the 1990s, governments and seismologists of many countries in the world have clearly recognized that it is important and urgent to make active fault detection and research in cities.Urban active fault detection has important actual significance for urban planning,earthquake resistance,reducing damages of urban facilities from earthquakes.The seismic prospecting of shallow high resolution is one of the effective and reliable methods in urban active fault detection,and may survey the location of active faults underground,buried depth,attitude and space distribution.Because strong interference background of urban environments and the complexity of field conditions,we must, in view of actual situation,adopt a series of effective methods with raising resolution rate and signal noise ratio in the links of observational systems,seismic focus, data collection and proccessing methods etc,so as to obtain reliable detection results.This paper discusses difficult points in technology and relative resolving ways of shallow seismic prospecting methods in urban active fault detection,and introduces some methods with practicality in combining with some experiences which we have gained in shallow seismic prospecting in urban areas in recent years.