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111.
112.
开敞式TBM隧道仰拱衬砌同步施工关键技术 总被引:1,自引:0,他引:1
为实现TBM掘进与仰拱衬砌同步施工,缩短工程关键线路工期,提高隧道施工效率,设计出双通道仰拱同步衬砌台车。台车断面为非对称结构形式,以满足TBM掘进施工及其相关配套设施的布置及运行。台车采取"前斜坡段+前道岔段+4个标准段+后道岔段+后斜坡段"的布置方式,台车下方划分成多个作业面,具备仰拱混凝土浇筑准备、浇筑、养护等的功能;根据施工支洞距离长、坡度大以及TBM掘进段交通条件受限的特点,采用支洞轮式运输和主洞有轨运输的联合运输方式,保障物料运输快捷有序;台车前后采用升降坡轨道搭接装置,实现TBM配套标准轨道竖向搭接的平顺过渡。工程实践表明:仰拱同步衬砌台车应用效果较好,施工进度最大可达到648 m/月,在不影响TBM正常掘进的前提下可有效缩短关键线路工期。 相似文献
113.
宁波野猪山公路隧道右线出口段埋深浅、围岩差,采用岩土控制变形工法施工。该工法在我国公路隧道施工中几乎未有使用。本文通过数值模拟和现场监测数据对比分析,得出:1)隧道地表沉降的开挖空间效应约为0.6倍跨径,并据敏感程度划分为沉降敏感区、敏感过渡区、稳定区3个区域;2)隧道拱顶沉降约60%发生在掌子面到达监测断面前,开挖空间效应稍大于单倍跨径;3)隧道掌子面挤出变形呈外凸抛物面形态,建议施工中纤维锚杆的搭接长度设为6 m,并据挤出变形发展速率划分为快速发展、稳定发展、基本稳定3个阶段。 相似文献
114.
为确定在冻土冻结过程中冻结影响范围与冻结时间的关系,将人工冻土冻结过程拆分为土体表面的热散失和冻结管的冻结2个过程,并以热势能及热势能耗散过程中的平衡方程分析上述关系。为确定冻结管间距的合理取值,引入热势能理论并计算当量热阻,建立在多个冻结管影响下微元体的冻结时间方程,提出一种在多个冻结管作用下冻结影响范围与冻结时间的关系的计算方法及冻结管布置间距的确定方法。通过实例分析了人工冻土厚度的计算方法,以数值模拟方法比较了不同冻结管布置对冻结时间的影响。上述研究成果深化了人工冻土理论研究与实际应用之间的关系。 相似文献
115.
为了改善异种钢环焊较易产生未熔合等缺陷,提高焊接接头的焊缝质量,针对出口孟买地铁车辆底架的较为关键的环焊接头形式、焊接手法及要点进行分析,提出了一系列预防及解决措施,以获取符合生产需求的环焊接头。 相似文献
116.
The cross sea channel for the Qiongzhou Strait not only provides a solution for transportation, but also plays an important role in the political and economic development of the region. In addition, the project has an extensive impact on many fields, such as energy, national defense, science and technology, opening up and reform, comprehensive utilization and so on. It is a significant project to enhance China′s comprehensive national strength, defend the country′s territorial integrity and promote regional economic development. The geological conditions across the Qiongzhou Strait are complex. A large amount of existing engineering geological information and hydrogeological data are collected, based on which the seismic impact on subsea tunnels and the main geological conditions including tectonic structures are analyzed. Different options crossing the Qiongzhou Strait have been considered and compared in terms of engineering geology, environmental condition, as well as the construction feasibility. The analystical results indicate that a subsea tunnel has more advantages over a bridge. Because more complicated technical difficulties have to be solved for a highway tunnel which would potentially increase construction and operation costs, a railway tunnel scheme is recommended. Vehicles can be carried by trains through the Qiongzhou Strait railway tunnel. Based on the seabed topography and geological conditions, four preliminary railway tunnel routes are proposed. After a comprehensive comparative analysis, the railway tunnel route Ⅱ is identified to be superior to other alternatives and should be the basis for determining the final tunnel layout. The proposed tunnel cross section includes two railway tunnels and one service tunnel. All the three tunnels have the same structural form and dimension and will be constructed by shield. 相似文献
117.
<正>你的心尖叫要买二手奥迪。你的脑子说要买一辆新的斯柯达。那么在3万英镑的预算下,哪一辆更适合你?vRS喜欢被推到极限,特别是在乡村小路上这是奥迪的完胜,不是吗?在大众高尔夫平台上制造的前轮驱动的四缸斯柯达如何能够跟奥迪操控最好的核心性能车RS4进行对阵?即便是这款顶级的OctaviavRS245,有着180kW和限滑差速器。而对 相似文献
118.
Challenges and Countermeasures in Construction of Gaoligongshan Tunnel of Dali Ruili Railway(大瑞铁路高黎贡山隧道施工挑战与对策)
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In order to resolve the challenges encountered in the construction of Gaoligongshan Tunnel such as soft rock deformation of inclined shafts, water drainage and protection of vertical shafts, TBM jam in crossing areas with adverse geology, solutions and key construction techniques are developed through theoretical analysis, field test, scheme optimization and staged review and summary. The performance results of field practice show that: (1)the goal of no damages and no replacement of the primary support can be achieved by adopting the comprehensive deformation prevention technique of "ring support early formation and quick closure", setting of proper excavation line curvature, and reinforcing of support; (2)the risk of vertical shaft flooding during construction in water rich weak granite can be greatly reduced by adopting the water control principle of "exploration for any excavation, plugging as the main method, and supplemented with drainage method" and the key pre grouting technique of S shaped deep boreholes; (3)the open type TBM can quickly and safely pass through the unfavorable mylonitic granite stratum by adopting the small pilot tunnel construction method, thus the fast and high efficiency construction performance of TBM can be fully utilized. 相似文献
119.
In order to guarantee the stability of surrounding rock and support structure of super large span tunnel and realize quantification of support structure design, the optimal excavation contour line shape is obtained based on study of influence of initial ground stress on bearing arch of surrounding rock; a new quantitative design method, in which the surrounding rock is regarded as an arch structure, bolts, cables, shotcrete and lining are designed to satisfy the intensity, rigidity and stability of the arch structure, is presented to design the support structure system. The method has been successfully applied to super large span tunnel of Badaling Great Wall Station on Beijing Zhangjiajie High speed Railway; and the applicable results show that the maximum accumulative settlement of crown top of large span section is only 17.3 mm, and the relative subsidence of crown top is only 0.09%, which can meet safety requirements. 相似文献
120.
为研究偏压荷载对箱型明洞结构受力影响,为该类明洞结构的设计提供理论依据,以某道路开孔箱型明洞工程为例,采用ANSYS有限元数值模拟方法进行计算分析,综合研究结果表明: 1)偏压回填箱型明洞靠山侧墙底部和外侧墙顶部受力较大,设计配筋时需要加强; 2)靠山侧墙背回填土侧压力对明洞结构受力影响较大,改善回填材料内摩擦角大小可以有效降低明洞结构内力,当内摩擦角增大到47°时最为经济; 3)可以通过在明洞洞顶回填EPE的方式减轻洞顶冲击荷载,降低明洞内力,最优回填厚度为0.9 m。 相似文献