Monitoring and interpretation of hydrologically induced deformations at the KTB location

该研究项目旨在量化孔隙压力变化与KTB现场大规模放电实验引起的流体状态和表面凹陷的修改之间的关系。ASKANIA钻孔倾斜仪将在五个地点记录上大陆地壳的变形。多孔弹性行为的主要3D数值建模（多孔弹性有限元法，FEM）表明，可以预期显著的倾斜幅度，特别是在受控流体注入期间。将调查所观察到的变形的流体流动行为和诱导的地球动力学效应，并使用耦合的水文地质力学有限元模型（ABAQUS）建模。利用数值模型，可以量化两种效应：a）上地壳的变形（倾斜测量）和B）KTB地区物质参数的变化。该项目的主要目的是提高耦合地质力学-水力过程的知识，并量化重要的过程参数。从而加深对断裂主导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匀性，解释诱发的应力场变化，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.