周期气压波对地壳应变场观测影响的若干因素分析

英文篇名：Analysis on several factors of periodic air pressure wave affecting crustal strain field
中文刊名：地震学报
英文刊名：Acta Seismologica Sinica
作者：张凌空 ; 王广才 ; 牛安福
英文作者：Zhang Lingkong1)Wang Guangcai2)Niu Anfu1)1)China Earthquake Networks Center ; Beijing 100045 ; China 2)School of Water Resources and Environment ; China University of Geosciences ; Beijing 100083 ; China
中文关键词：体应变 ; 气压 ; 岩石弹性参数 ; 周期 ; 耦合系数
英文关键词：volume strain ; air pressure ; elastic modulus of rock ; period ; coupling coefficient
出版日期：2011-05-15
机构：中国地震台网中心;中国地质大学水资源与环境学院;
年：2011
期：03
出版单位：地震学报

摘要

地壳应变场常用钻孔体应变仪进行测量,而周期为几分钟到几小时的短周期气压波是影响体应变仪工作的一种长期因素.本文以Evertson等人推导的体应变短周期气压干扰模型为基础,从理论上进一步探讨了体应变气压影响系数与气压周期、岩石弹性参数和井孔深度的关系及变化规律.由于体应变观测井孔存在耦合效应,又建立了大气压垂直载荷作用下观测井孔耦合系数计算方程,比较了在多重因素作用下体应变气压影响系数理论观测值与无孔岩石真实值之间的差异,并与涞水、顺义、东三旗和昌平台的Sacks体应变实际观测资料进行了比对分析.这对地震前兆微动态信息背景场的探索具有实际意义.
Crustal strain field is usually measured by borehole volumetric strainmeters.It is a long-term influence that short-period air pressure waves with period of a few minutes to several hours affect the work of volumetric strainmeters.Evertson and others derived a model that volume strain was disturbed by short-period air pressure.Based on their work this paper made a theoretical study on the relation between the influence coefficient of air pressure on volume strain and the air pressure cycle,rock elastic modulus and borehole depth.Since there is a coupling effect between strainmeter and borehole,we established the equation for calculating the borehole coupling coefficient under the vertical atmosphere loads.The difference between the theoretical air pressure coefficient and the true value of non-porous rock under the action of multiple factors was examined,and compared with the Sacks volume strain observed data at Laishui,Shunyi,Dong Sanqi and Changping station.The study result is of practical significance for exploring basic micro-dynamic variation of possible earthquake precursors.

引文

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