断裂对地下水力扩散的影响及其与诱发地震关系的讨论

本文重点讨论了断裂规模、断裂相交网络和断裂力学的性质对地下水力扩散的影响,及其与诱发地震的关系。指出断裂密集成带的地方,水力扩散大。根据流体流动规律,水力扩散沿断裂方向流体流速大,断裂越长越深,沿断裂方向水力扩散距离就越大。而水力扩散随深度的变化,由于不同深度上岩性变化和应力状态的不同,有的深度上的岩类可能出现扩容而增大水力扩散。因此它并不是随围压的增大而单值地减少。 文章指出断裂的末端和断裂的交汇处是地下水富集的地方,在水富集地方的四周,水力扩散比其它地方要大。另外现代活动的张性和张扭性断裂比压性和压扭性断裂的水力扩散大。文章还提出水沿断裂扩散是水库诱发地震的直接原因。水力扩散大的断裂,水库诱发地震的可能性大,规模大而活的断裂诱发地震的震级可能大。

DISCUSSION OF THE FORCE DIFFUSION OF GROUND WATERUNDER THE INFLUENCE OF FAULT SYSTEMS AND ITSCORRELATION WITH THE INDUCED EARTHQUAKES

This paper focuses on I he force diffusion of ground water under the influence ol nets formed by fault junctures and the property of the fracturing mechanies. If is pointed out that in areas where the faults cluster into zones, the force of ground water would have greater diffusions. In the light of the regularity ol the fluid flow, the diffused force of the ground water would show greater flow rate along the strikes of the faultings. The force diffusion of ground water also show depth-dependent changes. Owing to the changes in rock properties and in the stress conditions at respective depths, rocks at certain depth ranges might he associated with increased ground water force diffusions because of the emergence of the dilatancy planes. Therefore, the water force diffusion does not necessarily show single-value decreases along with the increase of the confining pressure.The paper also points out that both the ends and the junctures of the fault-ings are localities where ground water is abundant. In the neighborhood of such water-logging localities, there may exist greater water force diffusions. In addition, the presently-active tensional and tension-Lorsional faultings would cause far greater water force diffusions compared with that caused by compres-sional and compression-torsional faultings.