Monitoring and interpretation of hydrologically induced deformations at the KTB location

这项研究项目旨在量化孔压变化与KTB现场大规模泄洪试验引起的流体状态和地表凹陷的变化之间的关系。阿斯卡尼亚钻孔倾斜仪将在五个位置记录上大陆地壳的变形。主要的三维数值模拟(孔弹性有限元方法)表明，可以预期有很大的倾斜幅度，特别是在受控流体注入过程中。观测到的变形将根据流体流动行为和诱发的地球动力学效应进行研究，并使用耦合水文-地质力学有限元模型(ABAQUS)进行建模。利用该数值模式，可以量化上地壳形变(倾斜测量)和KTB地区物质参数的变化。这一拟议项目的主要目的是增进对地质力学-水力耦合过程的了解，并量化重要的过程参数。这将加深对断裂控制水文地质参数变化过程的认识，量化地质力学参数变化和参数场的非均质性，解释诱发应力场变化，认为这是局部地震活动增加的主要原因。

This research project is intended to quantify the relationship between changes in pore pressure and modifications of the fluid state and depressions of the surface induced by a large scale discharge experiment at the KTB site. Deformation of the upper continental crust will be recorded by ASKANIA borehole tiltmeters at five locations. Principal 3D numerical modelling (poro-elastic Finite-Element-Method, FEM) of the poro-elastic behaviour showed, that significant tilt amplitudes, particulary during controlled fluid injection, can be expected. The observed deformations will be investigated regarding the fluid flow behaviour and the induced geodynamic effect and modelled using a coupled hydro-geomechanical finite-element model (ABAQUS). With the numerical model both effects can be quantified: a) the deformation of the upper crust (tilt measurements) and b) the changes of material parameters in the KTB area. The main aim of this proposed project is to improve the knowledge of the coupled geomechanic-hydraulic processes and to quantify important process parameters. Thus, the understanding of processes of fracture dominated changes of the hydrogeological parameters will be enhanced, geomechanic parameter changes and the heterogeneity of the parameter field quantified, and the induced stress field variation explained, which is believed to be mainly responsible for the increase of local seismic activity.