台湾公路隧道工程之展望

Prospect of Highway Tunnel in Taiwan

台湾之地形多山,山地面积几占三分之二,中央山脉纵贯南北,将有限之平地分隔于东西。西部平原纵深较大,土地利用强度较高,而呈高度开发之状况;东部则呈狭窄之纵谷地形,难以有效利用,东西部之产业发展悬殊。为因应交通之需要铁公路之兴筑势必穿越山区,因此自清朝之狮球岭铁路隧道、40年代之东西横贯公路、70年代之北回铁路、80年代之南回铁路、90年代之第二高速公路等岛内重要之交通建设均施筑有相当数量之隧道。近年来由于经济的快速成长及为促进东部地区发展需要,交通建设之需求更形殷切。除西部地区加速兴建第二高速公路外,12条东西向之快速道路亦积极兴建中,并开始推动环岛高(快)速公路网。另高速铁路亦已开始兴建。该等工程多须经过山区,隧道工程自为其重要之施工项目。而未来东部地区之铁路、横贯本岛之公路设施将因穿越海岸山脉、中央山脉等山区而须面对高覆盖层、高地温、地层构造复杂、地下水丰沛、大断面、长距离等高难度之技术挑战。本文拟就台湾近年来公路隧道工程之规划、设计与施工作一汇整回顾,并推论未来之隧道工程技术之发展趋势,以供相关工程同侪参考。

Taiwan is a mountainous district with the mountain area occupying two thirds of iis total area. The limited plain is separated in two parts by the Central Mountains developing northwards and southwards. The western part is highly cultivated due to the large area of plain while the eastern part is difficult to he developed due to the narrow valley, therefore a sharp contrast is formed between them. With the development of traffic, many mountain crossing railways and highways as well as tunnels have been built, such as Shiqiulin railway tunnel, the highway spreading in eastwards and westwards, northward railway, southward railway and the no. 2 expressway. Recently in order to stimulate (he development in eastern part, twelve westward expressways are already in full swing and the expressway net around the island is promoted and the high - speed railways are under construction. Most of these projects cross through mountains and the tunneling is one of the most important. It is estimated that deep overburden, high ground temperature, complex ground structure, rich ground water, large cross section and long distance will probably be encountered during the construction of highway and railway. In this paper, a review of tunnel design and construction is taken and the development tendency is presented which can be taken as a reference for the similar projects in the future.