合肥台定点短水准测量场地改造
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摘要
合肥台跨断层短水准测量场地位于郯庐断裂带南段,1987年后测量资料长期趋势变化主要是西端点(A点)场地受荷载变迁等环境条件改变的干扰造成的。2007年新建支线10-S段,经改造形成跨断层测线B-S段,2008-01-01～2008-12-31试测,试测结果表明:10-S段观测精度优于原线路的10-A段;跨断层B-S段观测资料2008年9月以前变化平稳,9月以后的趋势性变化可能是肥东MS3.5级地震的震前反映。由此认为:跨断层短水准测量测线布设既要有利于断层形变信息提取,又要能有效地分析排除干扰。并要进行多组的观测,增加检核条件。
The across-fault short leveling measuring site of Hefei seismological station is located in the southern section of the Tan-Lu fault zone,and the long-term trend of the measurement data is mainly caused by the interference of environmental condition changes at the western end point(A point),such as the load changes.After the branch line 10-S constructed in 2007 was modified to form the cross-fault line B-S,we find that: the observation accuracy of the 10-S line is higher than the original line through one year tests from January 1 to December 31 in 2008;the observation data of cross-fault section B-S were steady before September 2008,and were changing in trend after that,which may be the precursor reflection of Feidong MS3.5 felt earthquake.Summarizing the reconstruction of short leveling measuring sites at Hefei seismological station,it is concluded that during the transformation and construction of acrossfault short leveling measuring sites,the line layout should be arranged not only in favor of fault deformation information extraction,but also in favor of effective analysis and interference elimination.In addition,extra observations are needed to increase the check conditions.Finally,it is necessary to ensure the steel tube bed rock bench marks be connected completely with fresh and integral bedrock,and the observation should be conducted only after the stabilization of marked stone.
The across-fault short leveling measuring site of Hefei seismological station is located in the southern section of the Tan-Lu fault zone,and the long-term trend of the measurement data is mainly caused by the interference of environmental condition changes at the western end point(A point),such as the load changes.After the branch line 10-S constructed in 2007 was modified to form the cross-fault line B-S,we find that: the observation accuracy of the 10-S line is higher than the original line through one year tests from January 1 to December 31 in 2008;the observation data of cross-fault section B-S were steady before September 2008,and were changing in trend after that,which may be the precursor reflection of Feidong MS3.5 felt earthquake.Summarizing the reconstruction of short leveling measuring sites at Hefei seismological station,it is concluded that during the transformation and construction of acrossfault short leveling measuring sites,the line layout should be arranged not only in favor of fault deformation information extraction,but also in favor of effective analysis and interference elimination.In addition,extra observations are needed to increase the check conditions.Finally,it is necessary to ensure the steel tube bed rock bench marks be connected completely with fresh and integral bedrock,and the observation should be conducted only after the stabilization of marked stone.
引文
[1]周必才,王雪莹,顾乃根,等.合肥形变台跨郯庐断层短水准异常研究[J].地震地磁观测与研究,2007,28(2):65-68.
[2]谢觉民.钢管基岩标在形变台站的应用[J].地震研究,1983,6(4):663-671.
[3]国家地震局科技监测司.大地形变测量规范(短水准测量)[M].北京:中国铁道出版社.1990.11-17.
[2]谢觉民.钢管基岩标在形变台站的应用[J].地震研究,1983,6(4):663-671.
[3]国家地震局科技监测司.大地形变测量规范(短水准测量)[M].北京:中国铁道出版社.1990.11-17.
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