盾构隧道管片接头嵌入式密封垫防水性能探究

为解决传统密封垫易于与混凝土管片胶结处发生渗漏水的问题,对新型嵌入式密封垫的防水性能进行研究。与传统的现场粘贴防水橡胶密封垫的工艺不同,嵌入式密封垫是将密封垫与混凝土管片整浇预制。采用模型试验和有限元数值模拟方法,对隧道接头中嵌入式密封垫的防水能力进行分析和论述。研究结果表明： 文中所涉截面形式的嵌入式密封垫在控制工况,即张开量7 mm、错缝量10 mm的情况下,满足上海深层排水调蓄隧道0.6 MPa的耐水压力要求,且弥补了传统密封垫易从密封垫与混凝土接触面渗漏水的缺陷。此外,通过在密封条两侧设置凹槽,可有效减小密封垫脚部与混凝土间接触应力,减少局部应力集中,保证混凝土管片的完整性,提高接头防水能力。     

地下叠合墙接触面形式的设计研究

为解决地下工程中叠合结构接触面采用常规凿毛等方式进行预处理时存在的施工难度大、剪力槽设置参差不齐等难题,提出一种便于施工的预制叠合结构形式,然后运用ANSYS有限元软件对波浪形、三角形以及梯形波纹结构面进行受力对比分析,结果表明梯形结构面在结构应力、接触面压力以及接触面滑移方面更有优势,并确定梯形结构面作为静力荷载试验方案。通过静力荷载试验对比分析整体现浇梁和梯形结构面叠合梁在各级荷载作用下的挠度、水平位移以及裂缝开展形态,结合实测数据表明： 在受到相同荷载作用下,叠合梁的挠度增量小于整体现浇梁,同时叠合梁在裂缝开展阶段存在停滞现象,能够减缓裂缝穿过叠合面,从而提高结构的整体承载力。     

砂卵石地层台阶法施工隧道围岩-支护结构应力应变特性三维离散元分析

为了解砂卵石地层隧道围岩和支护结构的应力应变特性，以青海循隆高速公伯峡隧道为依托，借助PFC3D离散元软件对公伯峡隧道穿越砂卵石地层进行三维模拟，重点研究以密排短管棚预支护为根本前提，以三台阶预留核心土为施工方法的砂卵石地层围岩和支护结构的应力应变特性，并与现场实测进行对比分析。研究结果表明： 隧道台阶开挖时，围岩应力集中范围逐渐从拱顶过渡到拱腰，直到拱脚，对应的塑性区范围不断扩大，且密排短管棚对塑性区的发展有一定的“遮拦效应”； 围岩横纵向变形规律一致，主要是向隧道临空面产生收敛变形，且密排短管棚形成的梁拱效应限制了掌子面前方位移发展； 2种方法得到的初期支护变形规律一致，均呈阶段性变化，拱顶下沉累计值大于周边收敛累计值，且两者的最终变形量均满足规范限值要求。     

Main Construction Technical Difficulties and Solutions of  Shenzhen Chunfeng Tunnel（深圳春风隧道主要施工技术难题与解决方案）

Shenzhen Chunfeng Tunnel is one of the shield tunnels under construction with the largest diameter in mainland of China. The whole tunnel passes through the coastal composite stratum, with rock from broken to integral, and the strength of some sections reaches 173 MPa. The tunnel under crosses the railway, subway, bridge and multiple buildings closely in a complex and sensitive environment. Combining the stratum situation and characteristics of large diameter shield machine, the problems that will be faced during the construction process, including low rock breaking efficiency of shield machine, discharge stagnation and jamming of the chamber, settlement control in sensitive environment, and impact of large diameter shield segment floating, cracking and construction on urban traffic, are analyzed. Based on the engineering experience, the following solutions are proposed: a shield rock breaking efficiency solution for the complete extremely hard rock section, settlement control measures for adjacent buildings and structures of shield driven tunnels, solutions for jamming and discharge stagnation of large diameter slurry shield, comprehensive measures for prevention and control of shield segment floating and cracking, and a slag treatment plan for downtown areas. Chunfeng Tunnel tests the wisdom of Chinese builders with its tremendous volume and strict construction standards, and it also has certain reference significance for other similar projects.     

基于分布式压密传感器的隧道衬砌防脱空主动监测

为解决二次衬砌脱空的问题，实现在浇筑过程中对衬砌脱空的主动监测，结合隧道二次衬砌衬背脱空的成因，研发基于分布式压密传感器的隧道衬砌脱空主动监测系统。该系统由分布式压密传感带、延长线、直显终端及工业电脑组成，具有原理简单、安装便捷等优点。通过在衬砌层间预埋分布式压密传感器，对浇筑过程进行主动监测，结合带模注浆技术，实现对衬砌脱空的精准注浆与快速处治，有效解决隧道衬砌脱空问题。在验证试验中，系统在浇筑过程中共发现2处拱顶空洞，证明该系统对脱空监测的有效性。同时，该系统在国内部分重点铁路线已经取得应用，现场应用情况表明，该系统对二次衬砌拱顶脱空的识别准确率可达到95.5%。     

Innovation and Practice of Parallel Dual mode Slurry/EPB Shield Construction Technology and Freezing Cutterhead Opening Technology（并联式泥水/土压双模式盾构施工技术与冷冻刀盘开舱技术的创新与实践）

Two major concerns have been drawn in the process of shield construction: one is the difficulty in selecting a shield machine; the other is the high risk of opening for cutterhead changing. Based on the existing shield systems, a parallel dual mode shield with freezing cutterhead is developed by optimising internal structure and equipment and carrying the freezing device. The dual mode shield construction technology and freezing cutterhead technology are successfully carried out on project cases including Guangzhou Metro Line 9, Guangzhou Metro Line 21 and 220 kV Shijing Huanxi Electric Tunnel (Xiwan Road Shisha Road Section). The parallel dual mode slurry/EPB shield not only has the functions and advantages of slurry shield and EPB shield but also can switch into slurry/EPB mode for different strata and environments easily. Thus, it can achieve rapid shield tunneling. By combining the shield with the freezing system, the soil around cutterhead can be frozen to provide conditions for chamber opening under atmospheric condition. Meanwhile, it is also compatible with dual mode shield.     

圆形钢筋混凝土桩局部破除后抗弯能力计算及应用

深基坑工程中常常出现围护桩成桩垂直度偏差以致侵入主体结构限界的现象，为保证后续主体结构尺寸符合要求，需要对侵限部位进行凿除，进而导致其抗弯承载能力下降。针对圆截面桩体局部凿除后的抗弯承载能力计算问题，基于二次逼近法，建立圆形钢筋混凝土桩局部破除后正截面抗弯承载能力计算方法，结合实际工程分析围护桩局部破除后对基坑围护结构体系的安全性影响。结果表明： 桩身局部破除后，纵向受力钢筋切断和桩身截面面积的减小将导致桩身正截面抗弯能力快速下降；依托工程中800 mm 的围护桩，凿除18 cm 厚度（含切断6根主筋）后，其正截面抗弯能力下降至原设计值的55%，剩余承载力已不能满足安全支护的要求，需进行加固处理。     

Innovation and Future Application of Mechanized and Intelligentized Construction Technology for High speed Railway Tunnels: A CaseStudy of Hubei Section on Zhengzhou Wanzhou High speed Railway（高速铁路隧道机械化修建技术创新与智能化建造展望——以郑万高速铁路湖北段为例）

To ensure the safe, rapid and high quality construction of Zhengzhou Wanzhou High speed Railway, a series of exploration and innovation of construction technology, structural design and information management under the condition of large scale mechanization is used in the whole construction process. The technology includes: （1）A set of advanced geological prediction, advanced pre reinforcement technology of excavation face, mechanized construction technology of primary support, wide waterproof board trolley operation technology and intelligentized full face lining trolley of large scale mechanized construction technology are formed. （2）A classification method of surrounding rock stability is established based on the mechanized construction technology, and the design parameters of the tunnel support structure are optimized under the guidance of New Austria Tunneling Method. （3）To realize informatized management of tunnel construction, the tunnel construction management system, construction information record system, construction safety management system, quality management system of concrete mixing station and quality credit evaluation system are established. Finally, on the basis of mechanized and informatized construction, exploration and outlook of the tunnel intelligentized construction technology are given from the aspects of the dynamic intelligentized design system of tunnel support system, the intelligentized robot construction technology of tunnel support system and the intelligentized monitoring system of tunnel structure, to promote China′s tunnel construction technology.     

公路隧道运营典型风险辨识

为加强对公路隧道运营风险的辨识、改善和优化公路隧道运营安全，降低重大隧道事故对人员伤亡、隧道结构、设备和经济收益的损失，通过隧道事故调研和大数据技术，收集近些年在全国范围内发生的802起公路隧道事故，对公路隧道自身特性和隧道事故的时间、空间、类型、诱因等特征进行分析。研究结果表明： 1)外界因素对隧道事故影响较大，在高温和车流量较大的环境下，事故发生较多； 2)特长隧道和长隧道的事故数远高于短隧道和中隧道； 3)小型车是隧道内发生事故的主要车型，事故原因多是驾驶员违规驾驶，事故类型多为追尾事故； 4)火灾事故的诱因多为车辆自身故障，其中危化品泄露多为易燃液体泄露。