采动区地表异常形变SBAS识别与损害原因揭示

SBAS identification of surface abnormal deformation in mining area and revealing of damage causes

随着地下煤炭资源的大规模开采,异于常规沉陷规律的地表变形现象不断出现,开展地表异常形变识别提取与损害原因揭示的研究工作,对于沉陷控制理论的发展完善和沉陷区异常损害防护措施的制定具有重要的理论与现实意义。以河北省某城镇的异常损害为研究对象,基于短基线集差分干涉测量技术(SBAS-InSAR),利用25景Sentinel-1A雷达影像,反演了目标区2019-07-14—2020-04-27期间地表形变的空间分布形态和时间演变过程。通过与相近时期48个水准点位监测数据的对比得到,两者平均差值约为5.32 mm。最后结合研究区地质资料,对异常损害的原因进行了揭示。通过研究,得出结论如下:①异常损害区自2019-09-24开始出现变形现象,随工作面推进地表异常变形持续发育,其终止位置近似呈一直线状。②从地表变形的动态发育过程看,异常形变初始发育位置与常规沉陷盆地在空间上相对独立,而后随地下开采范围的不断扩展,两者逐渐发育为一体。③地表异常损害为F15断层“活化”的结果,且地表变形存在跨断层传递现象。研究表明,SBAS技术能够实现对采动地表异常形变的有效识别和提取,可为异常损害规律研究和原因揭示提供数据支撑,相关结论对于后续沉陷控制理论的发展完善亦具有借鉴意义。

With the large-scale mining of underground coal resources,the surface deformation phenomenon different from the conventional law of subsidence continues to appear.It is of great theoretical and practical significance for the development and improvement of subsid⁃ence control theory and the formulation of protection measures against abnormal damage in subsidence areas to carry out the research work of identifying and extracting abnormal surface deformation and revealing of damage causes.In this paper,the abnormal damage of a town in Hebei Province was studied as the research object.Based on short baseline set differential interferometry(SBAS-InSAR),the spatial distribution and temporal evolution of surface deformation in the target area from 2019-07-14 to 2020-04-27 were obtained by using 25 sen⁃tinel-1A radar images.Compared with the monitoring data of 48 benchmarks in the same period,the mean error between InSAR and level⁃ing is 5.32 mm.Finally,combined with the geological data in the study area,the causes of abnormal damage were revealed.Through the study,the main conclusions are as follows:①The abnormal damage area have been deformed since September 24,2019,and the abnormal surface deformation continued to develop with the advance of the working face,and its termination position was approximately linear.②From the perspective of the dynamic development process of surface deformation,the initial development position of abnormal deforma⁃tion was relatively independent of the conventional subsidence basin in space,and then gradually developed into one with the continuous expansion of the underground mining range.③The surface abnormal damage was the result of“activation”of fault F15,and surface de⁃formation was transmitted across faults.The research results shows that SBAS technology can effectively identify and extract the surface ab⁃normal deformation,and provide data support for the study of abnormal damage law and the disclosure of causes.The relevant conclusions also have reference significance for the development and improvement of the subsequent subsidence control theory.