扁作梁用料浅识

Timber Beams with Less With in Section

摘要:

中国建筑向以木架负重，营造以立大木为先，故如何确定木架尺寸最为首要。古籍中关于用扁方料之扁作梁的做法却不尽完备。且现在旧的量木计价制度早已废止，木材供应渠道、方法与旧时代截然不同，故用定围径为先来确定梁的尺寸已不适用。扁作梁的形式与宋式月梁颇为相似。根据《营造法原》和对苏南一带的调查，梁的高跨比为1/10～1/12。经过结构验算，这样比例的大梁，它的弯曲强度与挠度均在容许范围内，抗剪强度也不成问题，梁下的梁垫及斗拱的作用尚未计算在内，安全系数是足够的。

Abstract:

Chinese architecture all along to bear the weight of wooden framework, set up frame as the first step in the construction, so how to determine the size of the wooden frame is the most important. In ancient books, the method of using flat square materials as beams is not complete. And now the old wood pricing system by Measurement valuation has long been abolished, and the wood supply channels and methods are completely different from the old times, so it is no longer applicable the circumference to determine the size of the beam. The form of the flat beam is quite similar to the Song style moon beam. According to the 'Ying Zao Fa Yuan' and the survey of the southern Jiangsu region, the height-span ratio of the beam is 1/10 to 1/12. After structural calculation, the bending strength and deflection of such a proportion of girders are within the allowable range, and the shear strength is not a problem. The role of the beam pad and the bucket arch under the beam has not been taken into account, and the safety factor is sufficient.