Ancient Roman engineers used different methods when building the substructure of the seating area (cavea) of theatres and amphitheatres. In the northwestern provinces of the Empire, they often supported the seats by an artificial earth embankment which posed the structural problem of containing the soil infill. Because the curved perimeter wall of the cavea was not able to withstand the lateral earth pressure on its own, Roman engineers started experimenting with reinforcement systems which led to a variety of different cavea substructures. One of the most innovative and intriguing solutions to this problem can be seen in the theatre of Augusta Raurica (present-day Augst, Switzerland) where the retaining walls of the theatre were reinforced by series of semicircular buttresses. In the almost identical theatre of Aventicum (Avenches, Switzerland) the more traditional solution of a system of radial and annular walls were used for the same purpose. To get a better understanding of the structural behaviour of the theatre in Augst, the cavea substructure of both the theatres of Augst and Avenches were analysed with finite element method (FEM). Contrasting the structural properties and the amount of building material needed for each of the two theatres shed light on some of the reasons why the unconventional solution utilized in Augst did not become common. Although it used less building material, it was not as robust as the structural solution used in Avenches. Also, the support for the long, rectangular limestone blocks of the seating were not sufficient in Augst and the seats might have been subject to a considerable uneven sinking as the earth infill under them consolidated and shrank.

中文翻译：

---

罗马剧院的创新建筑技术：奥古斯塔·劳里卡 （Augusta Raurica） 剧院和阿文蒂库姆 （Avenches） 剧院洞穴下部结构的结构分析

古罗马工程师在建造剧院和圆形剧场的座位区 （cavea） 的下部结构时使用了不同的方法。在帝国的西北部省份，他们经常通过人工土堤支撑座椅，这带来了容纳土壤填充物的结构问题。由于洞穴的弯曲围墙无法自行承受横向土压力，罗马工程师开始试验加固系统，这导致了各种不同的洞穴子结构。解决这个问题最具创新性和耐人寻味的解决方案之一可以在 Augusta Raurica 剧院（今瑞士奥格斯特）中看到，剧院的挡土墙由一系列半圆形扶壁加固。在几乎相同的 Aventicum 剧院（瑞士阿旺什）中，更传统的径向和环形墙系统解决方案用于相同的目的。为了更好地了解奥格斯特剧院的结构行为，使用有限元法 （FEM） 分析了奥格斯特剧院和阿旺什剧院的洞穴子结构。对比两个剧院的结构特性和所需的建筑材料数量，可以揭示 Augst 使用的非常规解决方案没有变得普遍的一些原因。虽然它使用的建筑材料较少，但它不如 Avenches 中使用的结构解决方案坚固。此外，在 Augst 对座椅的长矩形石灰石块的支撑不足，并且随着座椅下方的泥土填充物固结和收缩，座椅可能会受到相当大的不均匀下沉。