城市复杂条件下双跨连拱隧道施工力学效应研究

发布时间：2018-04-15 10:10

本文选题：城市双连拱隧道 + 松动围岩荷载　；参考：《中国铁道科学研究院》2014年硕士论文

【摘要】：修建城市隧道,合理利用地下空间,是解决越来越严重的城市交通拥挤、行车缓慢等问题的重要方法。城市隧道由于其所处的特殊位置,经常会受到规划用地、已有建筑等因素的影响,导致其线路难以展开,在这种情况下双连拱隧道是一种十分理想的解决方案。双连拱隧道具有方便洞口洞身的选择、避免桥隧线分幅、使线路流畅、节约城市用地等优点。但是双连拱隧道往往跨度大、埋深浅、工序繁多、受力复杂,在施工和设计上还有许多未解决的问题。研究如何在城市中安全、经济、合理地修建双连拱隧道是十分必要的。本文以某城市浅埋山岭双连拱隧道为背景,借鉴了国内外学者的相关研究成果,从施工方法、设计理论、数值模拟、现场量测等方面对城市双连拱隧道施工和设计中的一些关键问题进行了研究,主要得到如下结论： (1)城市双连拱隧道往往埋深浅、跨度大、水位高、结构受力复杂、施工难度大,综合考虑地质条件、周围环境、施工技术、工期、经济投入等因素正确选择施工方法及配套辅助施工措施至关重要。 (2)采用荷载—结构模型计算双连拱隧道松动荷载时,其塌落拱高度介于结构全跨度和半跨度之间,塌落拱高度可采用普氏理论计算,附加荷载在全跨度上分布。 (3)浅埋情况下采用三导洞法施工比中导洞法更有利于控制沉降,也更有利于中隔墙的受力情况,左右洞室先开挖的一侧会受到更大的影响。 (4)在双连拱隧道开挖过程中,中隔墙会受到各个方向上的偏压弯曲作用,对中隔墙两侧进行回填处理能够显著降低中隔墙的最大受力和偏压程度,但是由于回填土的自重会对土体沉降产生一定影响。 (5)各导洞开挖会对周围已挖导洞的拱顶沉降、洞周收敛以及上方地表沉降造成影响。 (6)本次数值模拟得到的结果对比现场实测值低,但是仍然可以定性地反映双连拱隧道开挖过程中的各种力学效应,是研究双连拱隧道施工力学效应的有力工具。 (7)在施工过程中引入信息化设计施工可以随时了解围岩与支护受力状态,验证并调整支护参数,发生异常时立即采取应对措施,控制施工对周边环境影响,确保工程的安全性、可靠性和经济性。
[Abstract]:It is an important method to build urban tunnels and make rational use of underground space to solve the problems of more and more serious urban traffic congestion and slow driving.Due to its special position, urban tunnel is often affected by planning land, existing buildings and other factors, which leads to its line difficult to expand. In this case, double-arch tunnel is a very ideal solution.The double-arch tunnel has the advantages of convenient choice of hole body, avoiding the separation of bridge and tunnel line, making the line smooth, saving urban land and so on.However, double arch tunnels often have large span, shallow buried depth, various working procedures and complicated forces, so there are still many unsolved problems in construction and design.It is necessary to study how to build double arch tunnel safely, economically and reasonably in the city.In this paper, based on the shallow buried mountain double-arch tunnel in a certain city, and referring to the related research results of domestic and foreign scholars, from the construction method, design theory, numerical simulation,Some key problems in the construction and design of urban double-arch tunnel are studied in the field measurement and other aspects. The main conclusions are as follows:Urban double-arch tunnels are often buried in shallow depth, with large span, high water level, complicated structure, difficult construction, comprehensive consideration of geological conditions, surrounding environment, construction technology, construction period,It is very important to select construction methods and auxiliary construction measures correctly for economic input.2) when the load-structure model is used to calculate the loose load of double-arch tunnel, the height of collapse arch is between the whole span and half span of the structure. The height of collapsing arch can be calculated by using Plancey theory, and the additional load is distributed on the whole span.3) under shallow burying condition, it is more favorable to control settlement and force condition of middle partition wall by using three guide tunnel method than middle guide tunnel method, and the side of left and right cavern excavation will be more affected.4) in the course of double arch tunnel excavation, the middle partition wall will be subjected to the deflection bending action in all directions, and the backfill treatment on both sides of the middle partition wall can significantly reduce the maximum force and the degree of bias of the middle partition wall.However, the self-weight of backfill will have a certain effect on soil settlement.5) the excavation of each guide tunnel will have an effect on the settlement of the arch top, the convergence around the hole and the surface subsidence above the tunnel.6) the results obtained by this numerical simulation are lower than the field measured values, but they can still reflect qualitatively all kinds of mechanical effects in the excavation process of double-arch tunnels, which is a powerful tool for studying the construction mechanical effects of double-arch tunnels.Introduction of information design and construction in the construction process can know the state of surrounding rock and support force at any time, verify and adjust the supporting parameters, take immediate measures to control the impact of construction on the surrounding environment, and ensure the safety of the project.Reliability and economy.
【学位授予单位】：中国铁道科学研究院
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U455.4

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