TY  - JOUR
ID  - epos1274
UR  - http://dx.doi.org/10.1007/s11430-012-4470-8
IS  - 12
A1  - Cheng, HuiHong
A1  - Zhang, Huai
A1  - Zhu, BoJing
A1  - Sun, YuJun
A1  - Zheng, Liang
A1  - Yang, ShaoHua
A1  - Shi, YaoLin
N2  - Coulomb failure stress changes (?CFS) are used in the study of reservoir-induced seismicity (RIS) generation. The threshold value of ?CFS that can trigger earthquakes is an important issue that deserves thorough research. The Ms 6.1 earthquake in the Xinfengjiang Reservoir in 1962 is well acknowledged as the largest reservoir-induced earthquake in China. Therefore, it is a logical site for quantitative calculation of ?CFS induced by the filling of the reservoir and for investigating the magnitude of ?CFS that can trigger reservoir seismic activities. To better understand the RIS mechanism, a three-dimensional poroelastic finite element model of the Xinfengjiang Reservoir is proposed here, taking into consideration of the precise topography and dynamic water level. We calculate the instant changes of stress and pore pressure induced by water load, and the time variation of effective stresses due to pore water diffusion. The ?CFS on the seismogenesis faults and the accumulation of strain energy in the reservoir region are also calculated. Primary results suggest that the reservoir impoundment increases both pore pressure and ?CFS on the fault at the focal depth. The diffusion of pore pressure was likely the main factor that triggered the main earthquake, whereas the elastic stress owing to water load was relatively small. The magnitude of ?CFS on seismogenesis fault can reach approximately 10 kPa, and the ?CFS values at the hypocenter can be about 0.7?3.0 kPa, depending on the fault diffusion coefficient. The calculated maximum vertical subsidence caused by the water load in the Xinfengjiang Reservoir is 17.5 mm, which is in good agreement with the observed value of 15 mm. The accumulated strain energy owing to water load was only about 7.3×10^11 J, even less than 1% of the seismic wave energy released by the earthquake. The reservoir impoundment was the only factor that triggered the earthquake.
VL  - 55
TI  - Finite element investigation of the poroelastic effect on the Xinfengjiang Reservoir-triggered earthquake
AV  - none
EP  - 1952
Y1  - 2012///
PB  - Springer Verlag
JF  - Science China Earth Sciences
KW  - Reservoir
KW  -  reservoir triggered seismicity
KW  -  Coulomb failure stress
KW  -  poroelasticity model
KW  -  finite element method
SN  - 1674-7313
SP  - 1942
ER  -