【作者】 郑光辉；

【导师】 何川；

【作者基本信息】 西南交通大学 ， 桥梁与隧道工程， 2007， 硕士

【摘要】 由于受特殊地质及地形条件、线桥隧衔接方式、总体路线线形和工程造价等原因的限制，双洞隧道间距不能保证达到规范的要求，为获得良好的技术经济效益和环境效益，连拱隧道和小净距隧道方案则成为重要的可选方案，尤其对于中短隧道或长大隧道洞口局部地段。本文通过调查研究，并结合浙江省交通厅科研项目——连拱公路隧道综合修建技术研究和西部交通建设科技项目——双洞小净距隧道设计、施工关键技术研究的相关成果，对公路连拱隧道和小净距隧道的施工力学行为进行了对比研究，得到了以下结论：1、连拱隧道中墙采用混凝土作为两拱的支点和传力点，使其成为连拱隧道结构的重要部分，隧道结构整体受力，人为控制中墙的承载能力，中墙设计符合结构力学的设计思路；而小净距隧道则是通过加固中岩墙和合理安排施工工序，减小两洞开挖对围岩及衬砌结构的影响，充分利用中岩墙围岩的自承能力，中岩墙设计施工符合新奥法理念。2、通过对比连拱隧道和小净距隧道的施工方法可以得出：与连拱隧道相比较，小净距隧道双洞分开施工可以减少10％以上的开挖量，且在相同围岩级别下，小净距隧道施工工序优于连拱隧道。3、在软弱破碎围岩中修建A类小净距隧道，中岩墙需要进行大量加固，施工难度增大，且中岩墙的长期稳定难以保证，而连拱隧道中墙由混凝土构成，其承载能力和稳定性能够得到保证，因此，在软弱破碎围岩中应从结构安全的角度进行比选。4、通过对比数值计算、相似模型试验和现场试验结果，A类小净距隧道初期支护设计强度应大于连拱隧道，B类和C类小净距隧道初期支护设计强度应小于连拱隧道，二次衬砌的设计强度应与连拱隧道相当。5、中墙承受其上覆土荷载和左、右洞初期支护传至中墙顶部荷载，而小净距隧道左右洞独自成环，中岩墙仅承受上覆土荷载，因此在同级别围岩、相同埋深条件下小净距中岩墙所受荷载小于连拱隧道中墙。6、连拱隧道和小净距隧道应根据各自结构形式，结构受力和变形特性，制定现场监控测量的重点、监测项目的组合及监测基准值。更多还原

【Abstract】 Space between left and right of twin-tunnel can’t meet the request of code,oweing to the limit of especial geology, landform condition, join means, collectivity linetype and engineering cost.In the best interest of techno-economy benefit and entironment benefit, multi-arch tunnel and neighborhood tunnel become important choice schemes especially in short or medium length tunnel and the adit of long length tunnel.Besded on the research of key design and construction technology for neighburhood tunnel and the research of synthesis construct technology of multi-arch road tunnel,the result were contrasted Colligating all research,the main contents of this thesis are as follows with the result of the acquisition:(1)The concrete is applied as pivot and trans-force point in the mid-wall of multi-arch tunnel, so the mid-wall becomes the one of the most important parts. It accords with the design way of structure mechanics, which makes the whole tunnel structure suffer load reasonable and controls the support capacity of the mid-wall contrived. The neighborhood tunnel makes full use of the support capacity of the center pillar ground by reinforcing and arranging the steps of construction reasonable, which can eliminate the effection on the ground and the lining structure during the excavation process. This accords with the design method of NATM.(2)Some results can be acquired by the contrast of the construction methods between the multi-arch tunnel and the neighborhood tunnel. The depart construction of the twin-tunnel can reduce the excavation above 10%, and in the same category of ground, the construction steps of the neighborhood tunnel are better than the multi-arch tunnel.(3)The A kind of neighborhood tunnel is constructed in soft and crushed ground. The center pillar need to be reinforced largely, so the difficulty of the construction is also more large and the stability of the center pillar can’t be promised. Whatever, the mid-wall of the multi-arch tunnel is made by the concrete, which can assure the support capacity and the stability. So it should be contrasted and choiced in the view of the structure safety in the soft ground. (4)By the research method of numerical calculation, similitude model test and the in-site test, it gets some results. The design strength of prime support in the A kind neighborhood tunnel should be more than the multi-arch tunnel, but the B and the C kind neighborhood tunnel should be less than the multi-arch tunnel. The design strength of secondary lining should be equal the multi-arch tunnel.(5) The mid-wall of the multi-arch tunnel bears up the overburden load and the top load passed by the prime support of the left and the right tunnels. But in the neighborhood tunnel, the mid-wall only bears up the overburden load. So under the same category of surrounding ground, the load beared by the mid-wall is less in the neighborhood tunnel in the same depth of earth covering.(6)With the structure style and the deformed character of the multi-arch tunnel and the neighborhood tunnel, the important point of in-site measure, the combination of the monitor contents and the benchmark of the monitor should be established更多还原