商周时期圈足铜器的三角形加强筋技术浅析

A Preliminary Study of the Triangle Stiffener Technique Used on Ring-foot Bronze Wares of the Shang and Zhou Dynasties

商周时期青铜器上的三角形加强筋技术主要用于觚、尊、簋、卣、壶、瓿、盘等圈足器的底部与圈足连接处,纵向延伸,上端较粗,承接铜器外底,下端向下延伸逐渐变细,多为等距或对称分布。加强筋的大小、数量多少的设置,根据器形因器而异,铜觚器体修长,圈足较高,加强筋多为2条或4条,纵向延伸较长,而铜簋、方彝等,底部面积较大,圈足粗矮,加强筋数量相对较多,纵向延伸较短。三角形加强筋技术起源于商代早期郑州商城陶鼎、铜鼎鼎耳与口沿连接处采用的加强筋技术,商代晚期至西周早期比较盛行,延用至春秋早期。商代晚期圈足铜器上使用较多,但又不仅限于圈足器,部分带鋬器,如爵、斝等,鋬的两端与鋬下腹壁连接处也有发现。其功能在于防止铸件连接处因凝固收缩的应力作用而出现裂纹,强化圈足器器底与圈足之间连接。

The triangle stiffener technique played an important role in the casting process of bronze ritual vessels of Shang and Zhou dynasties.The recognition of it began in the 1980 s,but only limited to scholars who are specialized in the research of bronze ware or have the academic background of metallurgy and casting.Many bronze wares were unearthed with residues of mold clay at the connection between the ring foot and the bottom,where is often the location of the triangular stiffeners.Archaeologists tend to keep the original state while cleaning the bronze wares,which leads to the ignorance of such important information relating to the casting process and restricted the in-depth research to a great extent.The triangle stiffener technique of Shang and Zhou dynasties was mainly used at the junction of the bottom and the ring foot of bronze wares such as Gu,Zun,Gui,You,Hu,Bu and Pan,extending longitudinally with a thick upper end to support the exterior bottom,and a tapering lower end stretching downward,mostly distributed in a equidistant or symmetrical order.The size and number of stiffeners vary according to the shape of vessels.As for bronze Gu which has a slender body and high ring foot,there are usually two or four longer stiffeners extending length wise,while for bronze Gui or square Yi which has a large bottom area and short and thick ring foot,there is a relatively large number of stiffeners with short longitudinal extension.Originated from the early Shang dynasty stiffener technique used at the junction of ears and mouths of pottery and bronze Ding discovered at Zhengzhou Shangcheng,the triangular stiffener technique prevailed during the late Shang and early Western Zhou dynasties and existed to the early Spring and Autumn Period.The technique is widely seen on ring-foot bronze wares of the late Shang dynasty,and is also found at the junction of the handle and lower body of some bronze wares such as Jue and Jia.It helps to prevent cracking at the junction resulting from solidification contraction and strengthen the connection of the bottom and ring foot.