引言

The Romans, who once controlled areas of Europe, North Africa and Asia Minor, adopted the construction techniques of other civilizations to build tunnels in their territories.

第1段

The Persians, who lived in present-day Iran, were one of the first civilizations to build tunnels that provided a reliable supply of water to human settlements in dry areas. In the early first millennium BCE, they introduced the  method of tunnel construction, which consisted of placing posts over a hill in a straight line, to ensure that the tunnel kept to its route, and then digging vertical shafts down into the ground at regular intervals. Underground, workers removed the earth from between the ends of the shafts, creating a tunnel. The excavated soil was taken up to the surface using the shafts, which also provided ventilation during the work. Once the tunnel was completed, it allowed water to flow from the top of a hillside down towards a canal, which supplied water for human use. Remarkably, some  built by the Persians 2,700 years ago are still in use today.

第2段

They later passed on their knowledge to the Romans, who also used the  method to construct water-supply tunnels for agriculture. Roman tunnels were constructed with vertical shafts dug at intervals of between 30 and 60 meters. The shafts were equipped with handholds and footholds to help those climbing in and out of them and were covered with a wooden or stone lid. To ensure that the shafts were vertical, Romans hung a plumb line from a rod placed across the top of each shaft and made sure that the weight at the end of it hung in the center of the shaft. Plumb lines were also used to measure the depth of the shaft and to determine the slope of the tunnel. The 5.6-kilometer-long Claudius tunnel, built in 41 CE to drain the Fucine Lake in central Italy, had shafts that were up to 122 meters deep, took 11 years to build and involved approximately 30,000 workers.

第3段

By the 6th century BCE, a second method of tunnel construction appeared called the counter- excavation method, in which the tunnel was constructed from both ends. It was used to cut through high mountains when the  method was not a practical alternative. This method required greater planning and advanced knowledge of surveying, mathematics and geometry as both ends of a tunnel had to meet correctly at the center of the mountain. Adjustments to the direction of the tunnel also had to be made whenever builders encountered geological problems or when it deviated from its set path. They constantly checked the tunnel’s advancing direction, for example, by looking back at the light that penetrated through the tunnel mouth, and made corrections whenever necessary. Large deviations could happen, and they could result in one end of the tunnel not being usable. An inscription written on the side of a 428-meter tunnel, built by the Romans as part of the Saldae aqueduct system in modern-day Algeria, describes how the two teams of builders missed each other in the mountain and how the later construction of a lateral link between both corridors corrected the initial error.

第4段

The Romans dug tunnels for their roads using the counter-excavation method, whenever they encountered obstacles such as hills or mountains that were too high for roads to pass over. An example is the 37-meter-long, 6-meter-high, Furlo Pass Tunnel built in Italy in 69-79 CE. Remarkably, a modern road still uses this tunnel today. Tunnels were also built for mineral extraction. Miners would locate a mineral vein and then pursue it with shafts and tunnels underground. Traces of such tunnels used to mine gold can still be found at the Dolaucothi mines in Wales. When the sole purpose of a tunnel was mineral extraction, construction required less planning, as the tunnel route was determined by the mineral vein.

第5段

Roman tunnel projects were carefully planned and carried out. The length of time it took to construct a tunnel depended on the method being used and the type of rock being excavated. The construction method was usually faster than the counter-excavation method as it was more straightforward. This was because the mountain could be excavated not only from the tunnel mouths but also from shafts. The type of rock could also influence construction times. When the rock was hard, the Romans employed a technique called fire quenching which consisted of healing the rock with fire, and then suddenly cooling it with cold water so that it would crack. Progress through hard rock could be very slow, and it was not uncommon for tunnels to take years, if not decades, to be built. Construction marks left on a Roman tunnel in Bologna show that the rate of advance through solid rock was 30 centimeters per day. In contrast, the rate of advance of the Claudius tunnel can be calculated at 1.4 meters per day. Most tunnels had inscriptions showing the names of patrons who ordered construction and sometimes the name of the architect. For example, the 1.4-kilometer Cevlik tunnel in Turkey, built to divert the floodwater threatening the harbor of the ancient city of Seleuceia Pieria, had inscriptions on the entrance, still visible today, that also indicate that the tunnel was started in 69 CE and was completed in 81 CE.

罗马人曾经掌控着欧洲、北非和小亚细亚地区，他们采用了其他文明的建筑技术，在自己的领土上建造了隧道。

第一段
波斯人生活在现今的伊朗，是最早建造供乾旱地区人类定居点提供可靠水源的文明之一。在公元前一千年初，他们引入了隧道建造方法，该方法包括将柱子放在山丘上的一条直线上，以确保隧道保持其路线，然後在规则的间隔下挖掘垂直井。在地下，工人们清除井口之间的土壤，形成一个隧道。挖掘的土壤通过井口带到地表，井口也在工作期间提供通风。一旦隧道完成，它就可以使水从山坡顶部流向一个运河，为人类使用提供水源。令人惊讶的是，一些波斯人在2700年前建造的隧道至今仍在使用。

第二段
他们後来将他们的知识传给了罗马人，他们也使用了这种方法来建造农业用的供水隧道。罗马隧道的建造方式是在间隔30至60米的地方挖掘垂直井。井口上配有扶手和脚手，以帮助爬入和爬出，并用木板或石头盖住。为了确保井口垂直，罗马人在每个井口上方放置了一根横杆，挂上了一根垂线，并确保其末端的重物悬挂在井口的中心。垂线还用於测量井的深度和隧道的坡度。克劳迪乌斯隧道全长5.6公里，建於公元41年至79年，用於排水意大利中部的福奇内湖，其井深可达122米，耗时11年，大约需要3万名工人参与。

第三段
公元前6世纪，出现了第二种隧道建造方法，称为反挖法，即从两端同时建造隧道。当方法不是实际选择时，它被用於穿越高山。这种方法需要更高的规划和对测量、数学和几何的高级知识，因为隧道的两端必须准确地在山的中心相遇。当建造者遇到地质问题或隧道偏离预定路线时，也必须进行隧道方向的调整。他们经常检查隧道的前进方向，例如通过观察穿过隧道口的光线，并在必要时进行修正。可能会发生较大的偏差，这可能导致隧道的一端无法使用。一个由罗马人建造的位於现代阿尔及利亚的Saldae水道系统中的428米隧道的铭文描述了两个建造队在山中错过对方以及後来建造两个走廊之间的横向连接以纠正最初的错误。

第四段
罗马人挖掘隧道用於道路时使用反挖法，每当遇到山或山太高无法通过道路时。一个例子是义大利69-79年间建造的37米长、6米高的Furlo山口隧道。令人惊讶的是，现代道路至今仍在使用这个隧道。隧道也用於矿物提取。矿工会找到矿脉，然後在地下用井和隧道追寻矿脉。在威尔斯的Dolaucothi矿场仍可以找到用於开采黄金的隧道的痕迹。当隧道的唯一目的是矿物提取时，建造需要的规划较少，因为隧道路线由矿脉决定。

第五段
罗马的隧道项目都经过精心计划和执行。建造隧道所需的时间长短取决於使用的方法和挖掘的岩石类型。建造方法通常比反挖法更快，因为山可以从隧道口和井口挖掘。岩石的类型也可能影响建造时间。当岩石很硬时，罗马人使用了一种称为火熄灭的技术，即用火烧热岩石，然後用冷水迅速冷却，使岩石裂开。穿越坚硬岩石可能非常缓慢，隧道建造可能需要数年，甚至数十年。在义大利的博洛尼亚，一个罗马隧道上留下的建造标记显示，在坚硬岩石中的前进速度为每天30厘米。相比之下，克劳迪乌斯隧道的前进速度可以计算为每天1.4米。大多数隧道上都有显示下达建造命令的赞助人的铭文，有时还会显示建筑师的名字。例如，土耳其的Cevlik隧道全长1.4公里，建於公元69年至81年，用於改变威胁古代城市Seleuceia Pieria港口的洪水的方向，入口上仍可见到铭文，表明隧道始於69年，完工於81年。