118
DOI:10. 7672/sgjs2015150118
施工技术
CONSTRUCTION TECHNOLOGY
浅埋偏压连拱隧道施工工序优化研究
刘建波
（中铁十一局集团第五工程有限公司，重庆400037)
2015年8月上第44卷第15期
［摘要】为了优化浅埋偏压连拱隧道施工工序，依托四川省某浅埋偏压公路连拱隧道工程，利用ANSYS建立了该隧道某代表性浅埋偏压断面的二维平面应变模型，模拟了隧道按照设计的8种中洞法施工工序施工的动态力学效应，结果发现：分台阶法施工的拱顶沉降、围岩最大压力和支护结构最大压应力均小于全断面法施工，并且先开挖较浅埋侧隧道的围岩最大压应力和支护结构最大压应力均较先开挖较深埋侧隧道的小，此外，分台阶法施工在缩短工期和节约成本方面更优于全断面法施工。因此，本隧道工程采用中洞法先进右洞分台阶法施工，取得了较好的施工效果。
【关键词］隧道工程；连拱隧道；浅埋；偏压；施工工序；优化
［中图分类号］U455
【文献标识码］A
【文章编号】1002-8498（201515-0118-05
OptimalResearchon ConstructionProcedureof Double-arched
Tunnel Under Unsymmetrical Pressure
Liu Jianbo
( The 5th Engineering Ld. of the 11th Engineering Bureau of China Raileay, Chongqing400037, China)
Abstract: To optimize the construction procedure of the double-arched tunnel under unsymmetrical pressure, a highway double-arched tunnel under unsymmetrical pressure located in Sichuan of China is referred in this paper. Firstly, the two-dimensional plane strain model is created for a representative section of the double-arched tunnel. Then, eight kinds of construction procedures based on the middle hole excavation method is designed for the tunnel. Finally, the dynamic mechanical behavior of the tunnel excavated in the eight construction procedures is analyzed with the software ANYSYS. It is found that the vault settlement, maximum pressure of the surrounding rock and the supporting structure with the separate steps excavation method are all small than that with the full face excavation method. It is also found that maximum pressure of the surounding rock and the supporting structure are much more small when the tunnel under the more shallow buried is excavated before. In addition, compared with the full face excavation method, the separate steps excavation method is more beneficial to shorten the construction period and save the cost. Therefore, with the separate steps excavation method based on the middle hole excavation method, the right tunnel of this project is excavation firstly and good economic results is achieved.
Key words: tunnels; double-arched tunnel; shallow buried; unsymmetrical pressure; operating procedures; optimize
连拱隧道除了能够保持公路线形流畅和断面美观外，还能减少占地面积和保护生态环境。最重要的是它适用于各种复杂地形条件和便于运营管理。因此，在我国高速公路建设中得到了越来越广泛的应用1]。但是这种特殊结构的隧道由于跨度大、结构复杂和地形条件复杂，造成连拱隧道施工
【作者简介］刘建波，高级工程师，E-mail;565646395@qq-com[收稿日期］2015-04-20
方法复杂，开挖工序较多[2]。不同的连拱隧道施工工序对围岩应力和支护结构荷载变化的影响不同，这直接影响隧道施工的安全进行。因此，优化连拱隧道施工工序对提高隧道施工安全、缩短工期和降低工程造价具有重要的意义。
针对连拱隧道的施工方法和工序的优化，国内已有一些学者进行了研究。丁文其等3通过数值模拟对龙山浅埋大跨度连拱隧道的施工工序进行