姑咱台钻孔应变观测值年变化的数值模拟解释

发布时间：2017-12-27 12:14

本文关键词：姑咱台钻孔应变观测值年变化的数值模拟解释　出处：《地震地质》2016年04期 　论文类型：期刊论文

【摘要】：中国是最早开始以地震预测为目标的钻孔应变观测的国家之一。YRY-4四分量应变仪等中国自行研制的应变仪已达到世界先进水平,其分辨率可达10-10量级,且可以稳定工作。为了捕捉构造应力变化的信号以及探讨它们与地震活动的联系,首先需要识别并排除降雨、气压变化、地下水位变化、河流涨落、抽注水等非构造因素引起的地应变。在某些台站(如大渡河谷旁的姑咱台),YRY-4型应变仪观测到年周期变化的应变信号。截至目前,没有相关文献解释产生这种信号的物理机制。文中试图解释该信号的成因。考虑地形因素,建立了三维有限元热-弹性耦合模型,模拟了地表温度年变化引起的热应变,说明了春季和秋季达到波峰和波谷的年周期变化的信号是地表温度年变化引起的热应变信号。建议高分辨应变仪(例如YRY-4型应变仪)地应变台站选址时应尽量选择开阔的区域而避免地形起伏较大的区域。
[Abstract]:China is one of the first countries to begin the observation of borehole strain with the target of earthquake prediction. The YRY-4 four component strain gauge, such as the strain gauge developed by China, has reached the world's advanced level, its resolution can reach 10-10, and it can work steadily. In order to capture the signals of tectonic stress change and explore their relationship with seismicity, we first need to identify and exclude the ground strain induced by non structural factors such as rainfall, air pressure change, groundwater level change, river fluctuation, pumping and water injection. In some stations (such as the Dadu River valley near Guza), YRY-4 type strain gauge strain signal observed annual change. Up to now, there is no relevant literature to explain the physical mechanism that produces this signal. The article tries to explain the cause of the signal. Considering the terrain factors, a three-dimensional finite element thermo elastic coupling model is established. The thermal strain induced by annual variation of land surface temperature is simulated. It shows that the annual variation of peak and trough in spring and autumn is the thermal strain signal caused by annual variation of land surface temperature. It is suggested that high resolution strain gauge (such as YRY-4 strain gauge) should choose open area and avoid terrain undulating area when the ground strain station is located.
【作者单位】：中国地质科学院地质研究所大地构造与动力学重点实验室;中国科学院大学计算地球动力学重点实验室;中国地震局地震研究所地震大地测量重点实验室;
【基金】：国家自然科学基金(41604080,41590860) 国土资源部深部探测技术与实验研究专项(201511028,201311187)共同资助
【分类号】：P315.727
【正文快照】： 0引言自从美国启动了“板块边界观测”(PBO)项目(http:∥pboweb.unavco.org)以来,钻孔应变观测受到了空前的重视。受到重视的根本原因是,与其他应变观测手段相比,在数秒至数年的不同时间尺度上钻孔应变观测都具有高分辨率,甚至具有不可替代性(Gladwin,1984;Gladwinet al.,1985

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