汶川地震断层带结构及渗透率

对汶川地震断层带进行了跨断层的渗透率测量.结果显示汶川地震断层由低渗的核部(2.4×10-19～3.8×10-16m2)、高渗的破碎带(3.7×10-16～3.0×10-15m2)以及含裂隙原岩(6.0×10-18～4.3×10-13 m2)组成(有效压力40 MPa),其中新鲜断层泥具有最低的渗透率.断层泥和两侧原岩...

Internal structure and permeability of Wenchuan earthquake fault

Cross-fault permeability measurement was conducted on the Wenchuan earthquake fault. The results showed that this earthquake fault consists of fault core with low permeability (2.4×10^-19 -3.8×10^-16 m²), highly permeable damaged zone (3.7×10^-16 -3.0×10^-15 m²) and the fractured protolith (6.0×10^-18 -4.3×10^-13 m²) (40 MPa effective pressure), among which fresh gouges on the main slip surface are the most impermeable. Impeded by the impermeable protolith and fault gouge, cross-fault fluid flow was inhibited and fluid activity was confined within the damaged zone. This recognition is consistent with microstructure and grain size distribution of fault rocks. Condition of co-seismic thermal pressurization was calculated and the results showed that at depth greater than 2 km, the main slip zone of Wenchuan earthquake has the characteristics of low permeability for thermal pressurization to occur.