【摘要】 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^-18～4.3×10¹³m²)组成（有效压力40 MPa）,其中新鲜断层泥具有最低的渗透率.断层泥和两侧原岩由于渗透率低,阻碍流体跨断层带流通,断层带内的流体活动局限在高渗的破碎带中,这一结果与断层岩显微结构和粒度分布特征能很好的吻合.对汶川地震同震热压作用发生的条件进行了探讨,结果显示,约2 km以下汶川地震主滑动带具有发生热压作用所要求的低渗透率特征.更多还原

【Abstract】 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.更多还原