古人利用节理面开凿遂昌唐代金矿巷道的发现及论证

在对遂昌金矿唐代古金矿4号古洞的考察中，发现分布在矿中的巷道两侧的围岩都是坚硬的变质岩。通过现场研究，作者有4点发现：（1）发现发育于围岩中的节理面具有密度大、倾角陡和间距小的特点；（2）古巷道轴线的走向与节理面的走向基本一致；（3）古巷道的横截面被古人设计成高宽比很大的洞形；（4）巷道的走向都被设计成某种弧形。据此，可以作出以下判断：在一千多年前的唐代，古人很可能已发现这些发育于围岩中的陡倾角节理面之间的结合力很低，使用铁凿就可撬下来，并据此来开挖古巷道的。这也表明唐代的古人已经掌握了相当多的地质知识，并能够将之成功地应用于工程实践中。

USE OF JOINT PLANES FOR ROADWAY EXCAVATION OF SUICHANG GOLD MINE AT ONE THOUSAND YEAR AGO

This paper investigated the Cavern No.4 in Tang Dynasty Gold Cavern of Suichang Gold Mine. The surrounding rock of ancient passages is found to be hard metamorphic rock. Its Protodyakonov coefficient is as high as 14～19. From field research, four interesting phenomena are founded. Firstly, the joint planes in ancient passages have the feather of high density, high dip angel and small spacing. Secondly, the strike between axis in ancient passages and joint plane are basically consistent. Thirdly, the ratio of height to width in cross-section of ancient passages has the values ranging from 4 to 6,which is large. Fourthly, most of ancient passage axes are arc shape. As it is known, tensile strength and cohesion on joint planes are low. More than a thousand years ago, the ancients understood the above feather of joint planes with high dip angle and could make good use of them to excavate the passages. In order to take full advantage of the above feather, the ancients adjusted the direction of axis in ancient passages according to the strike of joint planes, and made them be consistent. Because the strikes of joint planes can change, the shape of ancient passages axis become arc. This shows that the ancients at the Tang Dynasty had mastered a considerable amount of geological knowledge, which was successfully applied in their engineering practice.