对兴建渤海海峡跨海通道有关问题的思考

Reflections on Construction of Bohai Bay Crossing Corridor

从我国长城关内外交通运输量增长的需求,交通运输便捷性,通道建成后的区域受益等方面讨论了建设渤海海峡跨海通道的必要性和迫切性。关于兴建渤海海峡跨海通道的时机,认为只要国家经济形势许可,条件基本具备,就应抓紧进行各项前期工作,促使工程早日开工建设。而对于沿渤海湾海边陆域另外新建沿海快速国道/高铁的建议,则提出了不同的观点。在施工风险方面,认为渤海海峡跨海通道的建设在地质问题处理上难度巨大,应进行严格、详尽的风险评估,并采取有效的安全避险、减险措施。简述渤海海峡跨海通道选用建隧方案的技术优势,并对建隧方案中若干有疑议的观点进行简要说明。重点对渤海海峡跨海通道的施工方案和工期估计进行详述。认为渤海海峡跨海通道施工应采用隧道硬岩掘进机(TBM)与钻爆法相配合,加建中间服务隧道,并给出4种横断面布设方案。以方案2,即:采用高铁,单线、双洞,主洞φ8. 0 m,服务隧道φ5. 5 m的方案为例,给出方案实施建议,并对工期进行预估。将该方案分为2种子方案(第1子方案:中间服务隧道(φ5. 5 m)先行,主洞大口径TBM(φ8 m)和后面拖车部分先拆卸成块后从服务隧道和平洞进入主隧道内,经洞内组装后再开挖掘进;第2子方案(备选):主洞起始段(约180 m)先用φ5. 5 m TBM开挖(经横洞时需拆卸,待进入主隧道后再在洞内重新组装),主洞先形成φ5. 5 m小洞,随后钻爆法扩挖成型,以容得φ8 m TBM掘进,也可改用先将横洞扩挖成弧形大空间,使φ5. 5 m的TBM在打弯进主洞时不需要先拆解),作比选后择优实施。以第1子方案为例,对长约125 km的跨海通道施工工期进行粗略估计,得出"完全成洞"的施工总工期约为19年(含海上详勘的5年)。

The author discusses the necessity and urgency of constructing the Bohai Bay Crossing Corridor from the following aspects such as the increasing traffic volume,the convenience of the transportation after the corridor is constructed,and the regional benefit brought by the corridor.As for the timing of the construction of the sea-crossing corridor,the author thinks that as long as the national economic situation permits and relevant conditions are basically available,the preliminary work should be carried out as soon as possible so as to promote the early commencement of the construction.Regarding the proposal of building another coastal national highway/high-speed railway along the Bohai Bay coast,the author puts forward his viewpoints.In the aspect of construction risks,the author thinks that the geological risks in the construction of the Bohai Bay Crossing Corridor are very difficult to be dealt with;therefore,strict and detailed risk assessment should be carried out,and effective safety measures should be taken to mitigate the risks.The author also briefly describes the technological advantages of the tunnel proposal selected for the Bohai Bay Crossing Corridor,and briefly analyzes some key technological issues in the tunnel construction.The author describes the construction scheme and construction period estimation for the sea-crossing corridor in details.The author makes the following proposal are given:(1)the hard rock tunnel boring machine(TBM)assisted by the drilling and blasting method should be used for the construction of the long sea-crossing tunnel of Bohai Bay Crossing Corridor;(2)a parallel service tunnel shall be arranged between the twin main tunnel tubes;(3)in Proposal 2,the diameters of the twin main tunnel tubes and the service tunnel should be 8.0 m and 5.5 m,respectively.The proposal has two optional solutions:Solution 1:The service tunnel(Φ5.5 m)located between the main tunnel tubes will be constructed first;for the main tunnel tubes,the disassembled TBMs(Φ8 m)and the backup gantries are assembled for tunneling after arriving at the main tunnel tubes through the service tunnel and the cross passage;Solution 2(alternative):Tunneling withΦ5.5 m TBM is carried out;theΦ5.5 m TBM will be dismantled to pass through the cross passage,and then be re-assembled after arriving at the main tunnel;the start section(180 m)of main tunnel tube will be formed byΦ5.5 m TBM before it is enlarged toΦ8 m by drilling and blasting method;or the cross passage is enlarged to a large curved space to allow theΦ5.5 m TBM passing throught without disassembly.Comparison and contrast will be made and the preferred solution will be adopted.According to the rough estimation on the construction period of the 125 km long sea-crossing tunnel,the total construction period of"completed tunnel"will be about 19 years(including 5 years of detailed offshore investigation)in Solution 1.