意大利Sparvo隧道超大断面盾构施工关键技术

意大利Sparvo隧道采用直径为1555 m、开挖断面达到15615 m的土压平衡盾构进行掘进施工,是当时世界上最大直径的盾构法隧道工程之一,其施工风险高、技术难度大为业界所公认。扼要介绍意大利Sparvo隧道工程所采用的一些关键技术： 1）盾构装备的选型; 2）衬砌管片的设计与生产,包括混凝土配合比设计、配筋设计与调整、管片接头、管片止水带以及管片预制厂情况; 3）超大断面盾构隧道掘进施工关键技术,包括土体改良、易燃易爆混合气体的对策和盾构原地掉头。这些技术较好地解决了该隧道施工中出现的诸多难题,可为今后同类工程提供借鉴与参考。     

特大断面小净距隧道爆破振动控制技术

为解决大帽山新建隧道爆破对既有隧道结构的影响,采用分步钻爆开挖、楔型掏槽、炮孔堵塞等一系列技术措施,控制了爆破振动速度,同时还确定了大断面小净距隧道不同围岩中的爆破振动控制标准,此标准比类似隧道的标准大有提高。     

Intelligent optimization of the structure of the large section highway tunnel based on improved immune genetic algorithm

As in the building of deep buried long tunnels, there are complicated conditions such as great deformation, high stress, multi-variables, high non-linearity and so on, the algorithm for structure optimization and its application in tunnel engineering are still in the starting stage. Along with the rapid development of highways across the country, It has become a very urgent task to be tackled to carry out the optimization design of the structure of the section of the tunnel to lessen excavation workload and to reinforce the support. Artificial intelligence demonstrates an extremely strong capability of identifying, expressing and disposing such kind of multiple variables and complicated non- linear relations. In this paper, a comprehensive consideration of the strategy of the selection and updating of the concentration and adaptability of the immune algorithm is made to replace the selection mode in the original genetic algorithm which depends simply on the adaptability value. Such an algorithm has the advantages of both the immune algorithm and the genetic algorithm, thus serving the purpose of not only enhancing the individual adaptability but maintaining the individual diversity as well. By use of the identifying function of the antigen memory, the global search capability of the immune genetic algorithm is raised, thereby avoiding the occurrence of the premature phenomenon. By optimizing the structure of the section of the Huayuan tunnel, the current excavation area and support design are adjusted. A conclusion with applicable value is arrived at. At a higher computational speed and a higher efficiency, the current method is verified to have advantages in the optimization computation of the tunnel project. This also suggests that the application of the immune genetic algorithm has a practical significance to the stability assessment and informationlzation design of the wall rock of the tunnel.     

考虑脆性围岩张拉破坏的终南山超大直径深竖井稳定性分析

脆性围岩中常常发生张拉破坏,有必要对检验脆性围岩的抗张拉承载能力的判据进行研究。在此基础上对张拉破坏判据如何在工程应用进行了研究。采用数值分析对比分析了常见断面形式的较大张应变区域,为断面的合理选型提供了参考。提出了基于张应变破坏区的锚杆设计方法,认为锚杆的设计长度应略长于最终的张应变破坏区的厚度。最后将张拉破坏判据应用于终南山2号超大直径深竖井工程稳定性分析中。通过三维有限元模拟分析表明:按照张拉破坏判据,秦岭终南山2号竖井I级围岩在开挖后,仅进行喷射混凝土支护,便可保持稳定;Ⅲ级围岩在施加按张应变破坏区设计的锚杆后,围岩也可以保持稳定。     

特大断面地下洞库开挖技术研究

国内300万m3及以上的地下洞库高度在24~30 m,断面超过300 m2,必须分层开挖,且设置几条进入各层开挖的横向通道。以某地下洞库为依托,对特大型洞室的分层高度、对称爆破成井技术及层间施工方法进行了研究。研究表明:层间采取对称爆破一次成井技术、实施梯段预裂爆破,特大型断面开挖是完全可以减少一个临时通道的设置,既做到安全有保障,又有利于快速施工、节约工程施工成本。     

超大直径泥水盾构隧道综合施工技术控制

针对南京长江隧道复杂的地质条件,结合已施工地段的特点,对超大直径泥水盾构的掘进参数设定、掘进姿态控制、泥水管理、同步注浆、管片拼装、同步施工等综合施工技术进行较系统的阐述。     

地铁与上盖超大地下室共建基坑围护设计研究

随着国内经济与文化的发展，轨道交通与区域商业、文化功能设施融合的需求愈加强烈，出现了许多地铁上盖大型建筑综合体。以杭州地铁4号线勾阳路站～金家渡站区间与余政储出【2019】35号地块共建项目为例，对地铁与上盖建筑地下室共建的围护设计方案进行探讨和研究，并从设计和施工的角度分析其中的关键性问题，可为将来类似工程提供参考。