ITA study of non-destructive methods of inspecting and testing tunnel linings

The International Tunneling Association's Working Group on Maintenance and Repair of Underground Structures is preparing a report dealing with non-destructive methods of inspecting and testing tunnel linings. This request for information details the scope of the group's work and the types of information the group is seeking at this time.     

Risk Budget management in progressing underground works: International Society for Trenchless Technology (ISTT) and International Tunnelling Association (ITA) Joint Working Group Report

There is a mass of detailed data concerning technical risk assessment methods and practices for underground work. But there is very little advice or guidance on the broad apportionment of the total risk between the various phases of an underground project or general advice on how risk might be managed. The Working Group has produced a generic Risk Budget covering five typical phases of an underground works project, which illustrates the heavy bias of risk towards the early phases. Using a practical example the report illustrates how project risk can be managed in a structured manner.     

Access way to underground space: Present status of access ways to underground space with examples of spatial requirements ITA Working Group 4 “subsurface planning”

This report presents the results and output from a questionnaire undertaken by the ITA Working Group No. 4 regarding “Design Criteria for Access ways” to different types of underground structures. This theme was considered an important issue as the design and layout of access ways and installed mechanical equipment have great influence on construct ability and construction costs, maintenance and operation of the underground structures.

The questions raised were basically dealing with the theme of access ways, but as well with the wider scope of design criteria for underground structures, such as: road (transport) tunnels; underground (metro) railway stations; underground parking areas and underground shopping malls and other facilities.

Foreword

The theme of this report, design criteria for access ways to underground structures, was proposed by the representatives of Japan and Spain during the ITA Working Group No. 4 meeting, held in Sao Paulo in 1998. Around the globe an increased application of underground space has been experienced and the design of access ways is an important aspect of underground structures. The participants in the meeting in Sao Paolo, representing their member nations, supported the theme. Following the Working Group meetings in Oslo (1999) and Durban (2000) a questionnaire was prepared by Japan and Spain and distributed amongst the ITA member nations. The questions raised were basically dealing with the theme of access ways, but dealt as well with the wider scope of design criteria for underground structures, such as: road (transport) tunnels; underground (metro) railway stations; underground parking areas and underground shopping malls and other facilities.

The main intention of the Working Group No. 4 Subsurface Planning was that the findings of the questions raised could be of great help in the field of assisting, developing and harmonizing subsurface planning.

Not surprisingly, the member nations who replied to the questionnaires addressed the various aspects of this topic in different ways. Nevertheless, the diverse views clearly show differences in opinions and details by which various countries approach these issues. The report is intended to aid subsurface planners who wish to gain a broad view on how matters are dealt with in other countries or seek guidance in comparable situations – and also for the benefit and understanding of owners and operators of such facilities.

The fire and life safety issues in road and railway tunnels are of course of great importance for public confidence in such structures. These issues have been specifically dealt with in a previous report by Working Group No. 4; “Fire and Life Safety for Underground Facilities” published in the journal “Tunneling and Underground Space Technology” (TUST), volume 13/3 July/September 1998.

The ITA expresses the appreciation to the member nations who made contributions and especially to Japan who assembled and presented the material. The ITA also wish to thank Norway and the Netherlands for assisting in finalizing the report, which was completed under remaining Working Group 4 responsibilities.     

隧道工程无损检测技术理论与方法研究

本文介绍了隧道工程中锚杆、喷射混凝土和衬砌质量无损检测技术,为既有工程的加固改造质量评估和新建工程施工过程质量控制、验收、质量事故处理和后期维护使用,提供检测技术理论与方法。     

隧道工程无损检测技术理论与方法研究

本文介绍了隧道工程中锚杆、喷射混凝土和衬砌质量无损检测技术,为既有工程的加固改造质量评估和新建工程施工过程质量控制、验收、质量事故处理和后期维护使用,提供检测技术理论与方法.     

隧道及地下工程岩体模型材料研究现状分析

归纳了当今国内外地质力学模型相似材料的研究现状,指出了常用相似材料的优缺点,并对测试相似材料力学特性的方法作了介绍,最终选取相似程度最好的模型材料,以更好的模拟实际条件。     

Development of methods for the protection of buildings, structures, and underground utilities

Methods of protecting an urban setting during underground construction and underworking of lands are analyzed in an example of the development of domestic regulatory-recommendatory documents. Attention is focused on methods used to protect underground utilities. The urgency of accumulated experience is assessed for modern conditions of underground construction. The paper is based on results of analysis of the problem’s status, which was conducted for the development of Standard [1]. __________ Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 3, pp. 18–22, May–June, 2008.     

Design and construction of a segmental lining for a machine-bored tunnel: Delivery tunnel North, Lesotho highlands water project

The 21-km-long Delivery Tunnel North for the Lesotho Highlands Water Project is split into two main tunnel drives of 8 km and 11 km lengths. The tunnel is located in the sedimentary rocks of the upper Karoo series with cover of up to 350 m. The rock units comprise claystones, siltstones and sandstones. In the poorer geology, early support of the tunnel periphery is essential. The method of tunnel construction involves excavation by a TBM and the simultaneous erection of a precast concrete segmental lining that provides both rock support and a final tunnel lining. The segmental lining is designed and constructed as part of an integrated excavation/support/lining system. There are three types of segments, differentiated by the amount of steel reinforcement. The distribution of the different segment types along the tunnel, relative to the geological conditions and depth of cover, will be optimized by monitoring of the performance of the lining during the construction period.     

A holistic numerical approach to simulating the thermal and mechanical behaviour of a tunnel lining subject to fire

Conventional heat transfer analysis for the prediction of fire-induced damage in a tunnel is performed without consideration of the spalling and dehydration of concrete, meaning that the fire-induced damage of concrete may be underestimated. This study proposes a new model that is able to simulate structural loss during a fire by eliminating the elements exceeding a pre-determined critical temperature in a finite element analysis. The important parameters for the application of the proposed element elimination model include the critical temperature chosen as the element elimination criterion and the changes of the combined heat transfer coefficients, which are dependent on element size and the time–temperature history during a fire, respectively. These parameters are derived from a series of parametric studies based on real fire experiments using a high-temperature furnace. In order to verify the applicability of thermo-mechanical coupling analysis using the proposed model, the fire-induced damage of an unreinforced concrete tunnel lining was estimated with a focus on the spalling depth, temperature distribution, and equivalent stress in the remaining part of the concrete lining under RABT and RWS fire scenarios.     

西南某水电站地下厂房顶拱衬砌裂损机理探讨

通过对水电站地下厂房顶拱衬砌裂损进行分析探讨,揭示了衬砌裂损的机理,并指出开挖过程中,顺层岩体的顺层滑移产生偏压是主要原因,提出了初步的修复措施,以提高地下厂房围岩岩层的抗弯刚度及强度。     

高层建筑施工对邻近地下隧道影响的监测分析

针对高层建筑对临近建筑的不利影响,结合具体工程实例,以此次安全监控的实施情况为依据,系统地说明了量测方法、数据处理以及数据的应用,并论述了对类似工程的指导意义.     

深埋长大隧道交叉段衬砌裂缝成因分析与处治

通过对某高速公路深埋隧道主、横洞交叉段开洞侧主洞衬砌裂缝的现场检测及性状分析，研究对比了可能引起衬砌开裂的各种因素，得出了开裂的主要原因，认为隧道交叉段地层工程地质情况复杂，构造应力在应力场构成中占有很大比例，水平应力要比竖向应力大，且在横洞开挖后。主洞开洞侧截面承载能力一定程度上有所削弱，衬砌受力不均匀，出现应力集中现象，从而导致混凝土开裂；基于现场地质参数及裂缝成因初步分析，利用有限元分析软件对衬砌开裂段的应力场及位移场进行了模拟，模拟结果验证了现场成因分析所得结论的正确性；基于现场裂缝实际情况，提出了详细的裂缝处治措施，可为今后解决类似隧道衬砌开裂问题提供参考。     

Fire and life safety for underground facilities: present status of fire and life safety principles related to underground facilities : ITA working group 4, “subsurface planning”

This study on the present status of fire and life safety principles for underground facilities is based on contributions by eight member nations of the International Tunnelling Association: Australia, Canada, China, Germany, Italy, Japan, Sweden and the U.SA This document may serve as a tentative guideline for future development in this field Findings are divided into three major category areas of underground works: road tunnels, railway tunnels, and underground parking facilities. Tables and explanatory information for each category are provided.     

基于结构材质状况的分层综合评定法在桥梁检测中的应用

以山东省枣庄市S343北留线漷河大桥为例,通过对桥面系及上、下部结构的病害进行了外观调查,分析了病害产生的原因,并通过混凝土强度、钢筋保护层厚度、混凝土碳化深度的检测对桥梁结构材质参数进行了测定,给出了各检测项的评定标度值,采用分层综合评定法确定了旧桥的技术状况等级,对桥梁的使用状态给出了科学评价,提出了后期维修养护建议,为桥梁后期养护、维修和加固提供了决策依据。     

Application of the comprehensive forecast system for water-bearing structures in a karst tunnel: a case study

Bulletin of Engineering Geology and the Environment - While tunneling in karst terrains, engineers may encounter unpredictable well-developed karst conduits, which frequently lead to water inrush...     

水下浅埋软岩隧道施作拱墙二衬力学效应的现场实测与分析

以一座用矿山法施工的水下浅埋软岩公路隧道为工程背景,基于现场实测数据,分析了施作拱墙二衬对初期支护受力性状的影响以及拱墙二衬本身的受力特性.研究结果表明:与浇注拱墙二衬混凝土的前一天相比,浇注完拱墙二衬混凝土后第20d,初期支护的局部锚杆轴力和局部型钢拱架应力明显减小,说明施作拱墙二衬能分担初期支护承受的部分围岩荷载;...     

关于既有建筑评估和改造的目标可靠指标确定方法的探讨

采用拟建建筑设计的目标可靠指标直接对既有建筑进行评估往往是不合理的。介绍了确定既有建筑评估和改造的目标可靠指标方法,包括可接受风险准则、生命安全准则、成本优化准则和可靠度“校准法”,提出了既有建筑评估和改造的目标可靠指标的最优决策方法。研究表明：可接受风险准则与生命安全准则决定了既有建筑评估的目标可靠指标的下限值;基于贝叶斯方法、验证荷载方法和“等失效概率原则”的“校准法”可以获得符合既有建筑实际的可靠指标;成本优化准则可以使业主以最经济的方案对既有建筑的改造升级做出决策。综合以上四种方法进行决策,可以使既有建筑的安全与成本之间达到最佳的平衡。     

导水裂缝带高度研究方法探讨——以陈家沟煤矿为例

导水裂缝带高度是采煤安全性评估、矿井涌水量预测及防水煤(岩)柱设计等工作的重要参考指标,在顶板水害事故预防、瓦斯灾害防治及煤层气资源开发等方面也有重要的意义。以陈家沟煤矿为例,运用实测法、公式法、数值模拟法、物探法、类比法和理论分析法等方法对其导水裂缝带高度进行了研究,并对其成果进行了优劣性及适用性对比分析,结果表明不同方法得出的陈家沟煤矿导水裂缝带高度值有一定差异。实际应用中,应尽量采取实测法,辅以物探法、数值模拟法或公式法等,由点扩展到面;当实测法在某些地区不能取得可靠的数据时,应根据实际情况选取其他适合的多种方法综合分析,相互补充、反复论证,以使研究成果趋近实际值。