浅埋偏压双连拱隧道施工技术探讨

文章结合工程实例,重点介绍了双连拱隧道进口段"偏压、大跨、浅埋"等施工技术难题,阐述了半明洞施工的施工方案、工艺流程以及明洞"人工山体"的形成等关键施工技术,并总结了监控量测数据所取得的效果。     

隧道盖挖法施工在下穿公路中的应用

随着社会发展,建设领域的安全意识逐渐加强,建筑市场安全风险等级也逐渐提高,因此也面临着许多新的挑战,在传统隧道施工工艺的基础上,更加严格的安全风险管控体系下,对如何改进隧道下穿施工工艺进行探讨。隧道进口明洞段采用盖挖法进行施工,在明洞上方S102省道施作钢便桥后再进行隧道施工,隧道采用明洞暗做。待明洞衬砌强度满足要求后,进行明洞回填,将S102省道按照要求进行改移,该方案大幅提高了施工安全系数,使安全从技术角度得到有效保障。     

隧道洞口明洞段防排水技术的探讨

针对隧道洞门及明洞防排水的重要性，通过对鹰嘴岩隧道洞门及明洞防排水的总体要求、洞门防排水、明洞防排水等方面的探讨，详细介绍了隧道工程防排水技术及施工工艺，以达到防水可靠、经济合理的目的。     

逆作法改造施工步序对人防隧道安全影响分析

重庆市核心城区下防空地下室众多,为了解决地面交通的拥堵问题,需对既有人防隧道进行扩建改造,以满足设计要求。本文以重庆解放碑地下停车系统工程K0+550~+635段利用原人防隧道扩挖明洞为工程背景,提出采用逆作法从现状人防隧道路面向下扩挖明洞的设计方案,利用有限元数值技术模拟改造扩挖施工过程,分析明洞施工引起的既有人防隧道的结构内力、安全系数和围岩的变形情况,验证了设计方案中的逆作法施工步序对既有人防隧道结构安全性的影响。结果表明:在采用逆作法向下扩挖明洞的施工过程中,既有人防隧道衬砌结构处于安全状态,该改造扩挖明洞设计方案可行。     

浅谈铁路隧道洞口及明洞段边坡防护

为确保隧道施工安全和隧道结构稳定,对铁路隧道洞口及明洞段边坡防护进行了探讨,提出了具体的处理措施,指出在实际设计和施工中应针对性的进行隧道洞口及明洞边坡防护,以保证隧道设计“经济”“合理”“安全”“环保”。     

浅谈隧道洞口、明洞施工控制要点

通过隧道洞口、明洞工程常见的施工质量问题,指出隧道洞口、明洞工程施工质量控制措施的控制要点。     

善庆峪隧道明洞施工技术

介绍了善庆峪隧道明洞施工技术,结合该隧道实际情况,采用明洞暗作的施工方法,着重阐述了控制初支下沉、保持开挖仰拱时的稳定、洞顶防水三个关键工序及施工要点,为今后同类隧道工程积累了宝贵经验。     

浅埋隧道盖挖法与地表注浆固结暗挖法施工方案比选

浅埋隧道一般采用明挖法施工,但根据地形及施工环境限制,亦有采用明洞暗挖的施工方法。明洞暗挖的主要方法一般有地表固结法、盖挖法和冷冻法等,各类方法因地制宜,合理选用。某客专凤凰山隧道浅埋偏压段,采取了明洞暗挖形式过渡,经过对两种明洞暗挖措施工工艺、施工安全、组织安排、设备投入、工程费用的比选,将原设计的反压回填地表注浆固结暗挖法优化为盖挖法施工,加快了施工进度,缩短了施工工期。实践表明盖挖法施工该类型隧道明洞暗挖段切实可行、经济高效,对今后类似工程具有一定的借鉴价值。     

某隧道出口洞口段施工的要点和风险预防

以某隧道施工为例,从明洞施工、洞口超前支护施工、明洞衬砌施工等方面,阐述了隧道洞口段的施工要点,并分析了洞口段的施工风险,提出了针对性的防治措施,从而确保洞口施工安全。     

论隧道洞口工程的施工技术与方法

以五指山隧道工程为例,对洞口开挖施工及明洞施工的要点进行了归纳总结,通过隧道实践施工证明,对于斜交、偏压、浅埋隧道,在进行洞口边坡以及仰坡开挖时,使用长管棚和长护拱形成半明洞是十分有效的施工方法。     

Deformation and mechanical characteristics of tunnel lining in tunnel intersection between subway station tunnel and construction tunnel

Deformations and stress distributions in tunnel intersection areas are more complicated than those in common tunnels. The literature on deformations and stress distributions in tunnel intersections, in which the intersecting tunnel is in a different section, is limited. The Shangxinjie subway station in Chongqing, China, was selected to investigate the deformation, stress and plastic zone responses of a tunnel intersection using numerical simulations. Based on the numerical results, the scopes of influence with respect to the deformation, stresses and possible failure modes of the tunnel lining were further studied. The numerical results show that the deformation in a section close to the tunnel intersection was larger than the deformations in distant sections. Compared with the common section, the crown settlement reached the maximum value at the tunnel intersection, and the maximum rate of increase was approximately 28%. The range of the plastic zone at the tunnel intersection was much larger than that in the other areas, and it was mainly located in the side wall and tunnel crown. In the longitudinal direction, the lengths of the scopes of influence were 2.4 B and 1.6 B with respect to the deformation and stress, respectively. The magnitudes of the internal forces in the longitudinal and circumferential directions were almost equal. The bending moments of the tunnel lining within 135° and 225° significantly changed, but the axial force decreased dramatically. Tensile and compressive failures may occur at the tunnel intersection and in a section 5 m away. Locally thickening the supporting structures is suggested to improve the stability of the tunnel.     

采用小导坑处理隧道坍方

结合小甸中隧道坍方的实例 ,重点介绍了在坍体中间打设小导坑和采用小导坑处理隧道中间大坍方的新方法。指出该方法能够解决施工中的坍方问题 ,保证了工程质量     

隧道涌水对高速公路隧道施工的影响分析

从某高速公路隧道坍塌事故入手,通过监控量测以及地质雷达探测手段,对坍穴规模进行了评估分析,探讨了隧道涌水产生的原因及危害,并提出了治理建议,以指导实践。     

石头沃隧道下穿引水隧洞施工技术

结合工程概况,介绍了铁路隧道近距离下穿引水隧洞的施工技术及其技术参数,并阐述了其安全措施,实践证明,采用大管棚超前预支护,并辅以行之有效的超前地质预报等先进技术手段,可确保其上部结构物不受影响,同时又能保证隧道本身的安全、质量和工期。     

隧道运营环境检测在某隧道中的应用

根据运营隧道实际情况对其运营环境的几项重要参数进行检测,并根据检测结果对改善隧道运营环境提出了合理化建议,以保证隧道的正常、安全运营。     

公路隧道工程连拱隧道施工技术

为了探讨连拱隧道施工技术在公路隧道工程中的应用效果,以某公路隧道工程实例为研究对象,深入分析连拱隧道施工技术的总体施工工序,并且对施工过程中需要掌握的要点内容进行总结,实践可知,通过连拱隧道施工技术的应用能够确保隧道施工进度、质量和安全性,对提高公路事业的发展有促进作用。     

盾构隧道下穿既有隧道地面变形分析

以郑州地铁工程为背景,研究盾构隧道下穿既有隧道引起的地表变形。基于地层沉降经验公式——Peck公式的预测结果,结合施工现场监测数据分析结果,将两者进行对比,从而得到地表沉降监测断面的累计沉降曲线,与Peck经验公式计算得到的沉降槽曲线变化规律相同,符合地表沉降变形规律,即微小沉降阶段、急剧沉降阶段、缓慢沉降阶段、沉降稳定阶段。可以通过该理论预测更好地控制隧道沉降和收敛变形,保持均衡、连续的盾构推进,减少因盾构停顿造成的地面、隧道沉降。     

公路隧道明洞结构计算方法

简单介绍了公路隧道明洞结构的建模方式和荷载组合工况及截面验算方法,并结合具体工程实例进行了计算和分析,得出了有益的结论,为工程设计提供了一定指导。     

Critical ventilation velocity for tunnel fires occurring near tunnel exits

Ventilation is an effective method for controlling smoke during a tunnel fire. The “critical ventilation velocity” u_cr is generally defined as the minimum velocity at which smoke is prevented from spreading against the longitudinal ventilation flow in tunnel fire situations. This study conducted small-scale experiments to investigate u_cr for situations when tunnel fire occurs near tunnel exits. The model tunnel was 4 m long, 0.6 m wide and 0.6 m tall, and the fires were located at 0.5 m, 1.0 m and 1.5 m from the tunnel exit. 6.3×6.3 cm² and 9.0×9.0 cm² square asoline fuel pans were used as fire source. Results show that u_cr decreases as the fire approaches the tunnel exit.