24m全自动液压仰拱栈桥的研发与应用

隧道施工过程中,往往存在仰拱施作与前方工作面作业相互干扰的情形,一定程度上影响了施工进度和安全。为此,通过广泛调研和实践研改,设计完成了24m全自动液压仰拱栈桥,并进行了推广应用。与传统仰拱栈桥相比,该栈桥具有安全可靠、跨度大和移动灵活等优点,有效解决了工序间相互干扰进而影响施工进度和安全的难题,取得了良好的工程应用效果,适用于长大隧道的快速施工。     

隧道仰拱施工工艺研究及大跨度仰拱栈桥研制

以钻爆法施工为研究目标,深入研究隧道仰拱施工工艺,结合施工工艺对仰拱栈桥进行研究,通过分析现有栈桥优缺点,提出一种安全性更好,劳动强度更低,效率更高的仰拱施工解决方案。通过详细的设计计算,研制了一种大跨度仰拱栈桥,有效跨度达36 m,可满足3个仰拱施工面的开展,在多个工地现场应用效果良好,为后续仰拱施工及栈桥设计提供了思路和方法。     

隧道仰拱与中心水沟机械化高效施工技术探讨

介绍了一种带固定式全环弧形模板及中心水沟模板的液压移动栈桥,该设备可以将传统的隧道仰拱施工由一个作业面变成两个作业区间,进行流水施工,实现隧道仰拱与中心水沟的高效施工,有效提高施工效率,同时可成功解决仰拱质量难以保证的难题。     

公路隧道仰拱填充模板与移动栈桥工装优化

目前大多数隧道仰拱填充施工采用简易型钢栈桥,施工时栈桥、中心沟模板、仰拱弧形模分别进行吊装,工人劳动强度大、机械配合量大、效率低,也难以满足机械化配套施工需求,文章结合芜黄高速项目雾岭头隧道仰拱填充施工工装的优化,介绍了利用移动栈桥跨度大、自行行走特点,将双中心沟模板、仰拱弧形模与栈桥优化组合成整体,栈桥前移时将模板同步前移、就位,达到了快速移位、安装,提高施工质量和效率、降低劳动强度的目的,为类似工程提供参考。     

宜万铁路堡镇隧道仰拱施工技术

在宜万铁路堡镇隧道工程中,采用了防干扰栈桥式仰拱施工技术,成功解决了不允许纵向分幅施工、仰拱紧跟掘进施工的问题,又避免了与隧道开挖支护之间的干扰,既保证了质量,又加快了速度。     

仰拱移动模架快速施工工艺在隧道中的应用

以成渝铁路客运专线缙云山隧道为工程背景,介绍仰拱快速施工技术和配套施工设备在隧道施工中的应用,分别对仰拱快速施工设备的构造和功能进行了阐述,并详细说明了仰拱快速施工工艺及注意事项,以促进仰拱快速施工设备在隧道中的应用。     

单线铁路隧道仰拱栈桥与仰拱模板一体化研制与应用

为解决单线铁路隧道断面小,空间狭窄,仰拱栈桥与仰拱模板配套应用的难度较大问题,开展了单线铁路隧道机械化配套专项研究,提出了一种单线铁路隧道仰拱栈桥与仰拱模板一体化方案。采用Auto CAD、MIDAS、Solidworks软件辅助设计与分析作为理论支撑,并经过试制、试验,成功应用于丽香铁路项目。     

履带式仰拱移动模架研发应用技术

目前铁路隧道仰拱施工处于设备更新阶段,如何采用超长移动栈桥及拖动模架进行仰拱施工是隧道工程师潜心研究的课题。文章根据现场实际情况,介绍了仰拱移动模架的工作原理、安装方法及防护措施,对配套施工步序、方法进行分析、研发及应用,可供参考。     

长仰拱栈桥在隧道施工中的应用分析

清凉山隧道在工期紧、断面大且要求步距达标的条件下,利用现有资源对仰拱栈桥进行自行设计,通过机构建模计算确定栈桥安全系数,按照已确定的加工尺寸自行加工。通过普通栈桥与长栈桥在人员配置、施工时间、施工效益等对比,确定长栈桥施工的可行性,并通过实践证明长栈桥在隧道施工中能成功应用的实例。     

长大隧道自行式移动仰拱栈桥研制及施工技术

为确保重载铁路永久运营安全,研究解决隧底仰拱及填充施工质量通病,研制开发了长大自行式移动仰拱栈桥,对该工装设备技术参数做了详细介绍,并配备了下挂式仰拱模板,仰拱及填充一次性浇筑24m,形成了专项施工技术方案。通过在长大隧道施工中采用带有行走装置的仰拱栈桥跨越仰拱作业区段,解决了隧道施工通道,工人施工环境得到了很大改善,减少了工序干扰,减少了施工缝,降低了仰拱施工工艺对不均匀沉降的影响,极大地提高了工效。     

铁路隧道仰拱施工控制

针对仰拱是隧道结构的主要组成部分之一,它是隧道结构的基础,结合太中银铁路兴旺峁隧道仰拱施工的实例,着重说明了铁路隧道仰拱施工的主要注意事项及相应的处理措施,从而确保该隧道仰拱施工质量。     

三台阶临时仰拱法在单线铁路隧道中的应用

以具体工程为例,介绍了三台阶临时仰拱法在单线铁路隧道中的应用,分别阐述了CRD法与三台阶临时抑拱法的优缺点,并对开挖方案进行了优化,实践证明采用三台阶临时仰拱法施工既可保证隧道安全又能提高施工工效。     

隧道仰拱及基底能量桩热致应力与换热效率现场试验

依托黄土塬区银川—西安高铁驿马一号隧道工程,在隧道仰拱和基底桩基内埋设换热管,搭建能源隧道仰拱-基底能量桩联合热泵系统,实测不同进口温度作用下换热管的进出口水温、隧道仰拱结构和基底桩基的温度、热致应力,探讨黄土塬区隧道仰拱结构及基底桩基的换热效率、热力响应特性与变化规律。结果表明:在现场特定条件下,进口温度与初始地温差值分别为4.7 ℃和14.7 ℃时,隧道仰拱结构温度升幅分别约为3.8 ℃和11.4 ℃,热致轴向应力分别为3.13 MPa和13.86 MPa,热致环向应力分别为2.85 MPa和9.93 MPa,隧道仰拱换热效率分别约为7.86 W?m^-1和24.15 W?m^-1; 单位温升条件下热致轴向应力和热致环向应力分别为0.44 MPa?℃^-1和0.35 MPa?℃^-1; 恒功率运行下仰拱基底能量桩换热效率随进口温度与初始地温差值的变化近乎为一条斜率k=4.1过原点的直线,换热效率维持在50～70 W?m^-1之间,与常规能量桩的换热效率规律基本一致; 桩基周围土体的力学性质受能量桩运行影响有限。     

Roughness evaluation in shotcrete-lined water tunnels with invert concrete based on cases from Nepal

Most of the existing roughness estimation methods for water tunnels are related to either unlined or concrete/steel-lined tunnels. With the improvement in shotcrete technology, advancement in tunneling equipment and cost and time effectiveness, future water tunnels built for hydropower projects will consist of rock support with the extensive use of shotcrete lining in combination with systematic bolting and concrete lining in the tunnel invert. However, very little research has been performed to find out tunnel surface roughness for shotcrete-lined tunnels with invert concrete, which is important in calculating overall head loss along the waterway system to achieve an optimum and economic hydropower plant design. Hence, the main aim of this article is to review prevailing methods available to calculate tunnel wall roughness, and to use existing methods of head loss calculation to back-calculate roughness of the shotcrete-lined tunnels with invert concrete by exploiting measured head loss and actual cross-sectional profiles of two headrace tunnels from Nepal. Furthermore, the article aims to establish a link between the Manning coefficient and the physical roughness of the shotcrete-lined tunnel with invert concrete and to establish a link between over-break thickness and physical roughness. Attempts are also made to find a correlation between over-break thickness and rock mass quality described by Q-system and discussions are conducted on the potential cost savings that can be made if concrete lining is replaced by shotcrete lining with invert concrete.     

拱顶式储罐气顶倒装法施工控制

通过对拱顶罐气顶倒装法施工过程介绍,分析气顶倒装法施工要点和注意事项。     

黄土隧道施工控制要点总结

结合郑西客运专线黄土隧道施工实例，总结了一般黄土隧道施工控制的要点，实践证明：仰拱距掌子面距离不大于30m，二衬距仰拱面距离不大于30m是保证黄土隧道施工安全的强有力措施。     

分离式隧道双洞施工对底鼓及相互影响的数值模拟研究

以某分离式隧道为例,采用有限差分法进行数值模拟,分析了双洞开挖与支护施工对底鼓的影响。分析结果表明:分离式隧道底鼓除了可能与高地应力、水理作用及岩石膨胀性有关外,还可能受到施工的影响,以该隧道为例,左洞的开挖与支护施工使右洞的应力与应变均增大,其中靠近左洞一侧增量尤为明显,右洞底部竖直方向上压应力与水平应力的增大是最终导致底鼓的主要原因之一;此外,由于该隧道所处地段地质与构造条件复杂,按照规范规定的"分离式独立双洞间的最小净距"设计施工仍无法避免双洞施工的影响。     

Experimental investigation on the invert stability of operating railway tunnels with different drainage systems using 3D printing technology

In recent years, the invert anomalies of operating railway tunnels in water-rich areas occur frequently, which greatly affect the transportation capacity of the railway lines. Tunnel drainage system is a crucial factor to ensure the invert stability by regulating the external water pressure (EWP). By means of a three-dimensional (3D) printing model, this paper experimentally investigates the deformation behavior of the invert for the tunnels with the traditional drainage system (TDS) widely used in China and its optimized drainage system (ODS) with bottom drainage function. Six test groups with a total of 110 test conditions were designed to consider the design factors and environmental factors in engineering practice, including layout of the drainage system, blockage of the drainage system and groundwater level fluctuation. It was found that there are significant differences in the water discharge, EWP and invert stability for the tunnels with the two drainage systems. Even with a dense arrangement of the external blind tubes, TDS was still difficult to eliminate the excessive EWP below the invert, which is the main cause for the invert instability. Blockage of drainage system further increased the invert uplift and aggravated the track irregularity, especially when the blockage degree is more than 50%. However, ODS can prevent these invert anomalies by reasonably controlling the EWP at tunnel bottom. Even when the groundwater level reached 60 m and the blind tubes were fully blocked, the invert stability can still be maintained and the railway track experienced a settlement of only 1.8 mm. Meanwhile, the on-site monitoring under several rainstorms further showed that the average EWP of the invert was controlled within 84 kPa, while the maximum settlement of the track slab was only 0.92 mm, which also was in good agreement with the results of model test.     

软弱破碎带不同施工工法隧道围岩变形分析

依托中条山特长公路隧道,采用有限差分软件FLAC3D,对隧道开挖支护过程采用的不同施工工法下的施工过程进行了数值分析,对各工况下围岩变形规律进行了研究,研究结果表明:单侧壁导坑法施工拱底隆起与拱顶沉降的差值较小,可防止因拱底隆起过大而造成的隧道底板的破坏,核心土在维持掌子面稳定方面作用显著,在软弱围岩地层中台阶法与预留核心土法相比优先选用预留核心土法。     

雪峰山隧道进口段仰拱填充结构开裂原因探讨

向莆铁路雪峰山隧道进口段仰拱底板填充结构施作后出现大量未贯通的“V”字型裂缝。通过对衬砌结构受力状态分析发现,若只考虑围岩压力,不会导致仰拱底板填充结构出现裂缝;而考虑围岩压力与水压力共同作用时,最大主应力极值出现在填充结构上部靠近隧道轴线位置,为拉应力,且最大主应力极值会大于素混凝土的极限抗拉强度,会产生拉裂缝。通过现场水压力试验验证了作用在仰拱中心水压力值较大,而两侧水压力值相对较小的结论,作用在仰拱填充结构上的水压力是导致其开裂的主要原因。因此,对于处在地下水位线以下的隧道不但要考虑衬砌背后排水系统畅通,也要考虑设置隧底排水措施,以降低作用在隧底结构上的水压力,从而减少类似隧道病害出现。