Support design criteria coupling analysis, modelling and in. Tunnel life cycle cost analysis lcca is a datadriven tool that provides a detailed account of the total costs of the project over its expected life. The specific purposes of support systems, however, depend greatly on the purposes of the tunnel. An acceptable design involves the selection of ground support schemes which have sufficient energy dissipation and displacement capacity to exceed the energy and displacement demand imposed by an ejecting mass. Therefore, in this research, we try to build expert systems on design of support patterns in tunnel construction using support vector machines svm which is a kind of statistical machine learning. Sep 25, 2019 however, current decision methods on support patterns require expertise, and moreover, there often exists discrepancy in judgements. Engineering geological evaluation and preliminary support design for the metro extension tunnel, ankara, turkey. It should be noted that the application of these systems at the design stage is strongly dependant on the quality of the site investigation data available. Rockbolt is the most widely used support element in support systems in underground mines and civil tunnels. Insitu monitoring can be applied only after the tunnelling.
Tunnel support ribs and lagging timber rock boltsdowels shotcrete straps. Tunnels constructed in bcm grounds are rare still, and there is a big gap between the design and construction of tunnels. The contractual aspects also include risk sharing and risk responsibilities. Ground support design for sudden and violent failures in hard. Design for support patterns of natm tunnel using machine.
This work resulted from close collaboration between industry and university in the fields of precompetitive research. High tunnel selection and construction considerations by. Rock support interaction analysis for tunnels in weak rock masses introduction tunnelling in weak rock presents some special challenges to the geotechnical engineer since misjudgements in the design of support systems can lead to very costly failures. For constructing underground structures, we need to provide rock supports, which support the mass of the rocks under which construction is to follow. Tunnel support design by comparison of empirical and.
Structural documents for the final design of the tunnel project, including the detailing. The importance of additional support in soil tunneling is due to instability of tunnel face, unsupported. In tunnel designing books or design standards, it can be found the load that need to be considered for the lining design depending on the rock type. Tunnels that are not adequately planned, designed, and constructed usually require more costly and extensive repairs. Tunnel support design by comparison of empirical and finite. Tunnel life cycle cost analysis lcca is a datadriven tool that provides a detailed account of the total costs of the project. Engineering classification of rock masses for the design. Background utility tunnel is a utilidor for mechanical and electrical services, installed by drilling andor tunneling. High tunnel selection and construction considerations. Methodology for tunnel and portal support design in mixed. Analysis, design, and construction of tunnels and underground. The survival rate of tunnel instruments is generally as low as 30 percent. Geotechnical engineering design of a tunnel support system. A level ii reliability approach to tunnel support design.
Pdf despite the success of new austrian tunneling method natm in many weak ground tunnels, a newer concept, the norwegian method. Types of rock supports in design of underground structures. Q system was also utilized to define the support requirements. New construction technology of a shallow tunnel in boulder. Ground support design for sudden and violent failures in. Engineering classification of rock masses for the design of tunnel support. Part 3 history, design, and detailing course satisfies five 5 hours of professional. The criteria for rock tunnels are to be determined on a project specific basis, subject to wssc approval.
As a typical granular bulk medium, problems are common in bouldercobble mixed grounds, such as easy collapse and instability and difficult effective support for largesection tunnel excavation. Lining design is done considering the type of the rock. A twodimensional approach for designing tunnel support in. Drovera a western australian school of minescurtin university of technology, crc mining, locked bag 30, kalgoorlie, wa, 6430 australia. Initially formulated for application in rock tunneling in the early 1960s, natm has. Types and functions of tunnel support systems the basic functions of a tunnel support system are to keep the tunnel stable and to make the opening usable. Pdf an empirical approach for tunnel support design through q. Erik eberhardt w during construction of a tunnel, some. Different methods of tunnel construction and their details. Instability of the rock mass surrounding tunnels can be divided into two categories. An empirical approach for tunnel support design through q. This thesis is a continuation of a project assignment carried out in 20 and analyses stability and support design of joberget soil tunnel, based on empirical and numerical methods. Geotechnicalgeological studies and tunnel support design.
In the current study 1989 form called rmr 89 is used, although a new version of the system has been introduce called rmr. Tunnel support measures are selected based on rmr and q classification systems. A comparison is made between the tunnel support design based on the classical teraghi rcak load method and the support selection based on the rsr concept, the geomechanic classification. Many tunnel kits require outside purchase of base board and end wall materials cost of the tunnel and availability of funds for purchase.
The design of support for tunnels in weak rock is an iterative process. This chapter presents the construction methodology and excavation support systems for cutandcover road tunnels and describes the structural design in accordance with the aashto lrfd bridge design specifications aashto, 2008. An analysis of some 200 tunnel case records has revealed a useful correlation between the amount and type of permanent support and the rock mass qualityq, with respect to tunnel stability. Practical considerations for tunnels used in mining applications marco d. Tunnel support design by comparison of empirical and finite element.
Pdf engineering geological evaluation and preliminary. Different methods of tunnel construction and their details are discussed. Information affecting mine tunnel design and performance depth of cover tunnel size min 7 ft. Rocksupport interaction analysis for tunnels in weak rock masses introduction tunnelling in weak rock presents some special challenges to the geotechnical engineer since misjudgements in the design of support systems can lead to very costly failures. Tunnel support system design university of cape town. A tunnel construction is an underground passage provided beneath earth surface or water. Structural integrity of the tunnel structure and design as related to weather extremes. The tunnel is feasible at this location with proper support measures. The changes included the ratings added for ground water, joint condition and joint spacing. During and after the excavation, reports on the field. A reliability approach to tunnel support design is presented in this paper. The intent of this chapter is to provide guidance in the interpretation of. Twodimensional methodology for practical tunnel support design the paper proposes a simple, yet practical, 5stage methodology for designing realistic tunnel support using any twodimensional numerical method such as the finite element or finite difference methods.
Ground classification systems in tunnel construction. It allows ground deformation and stress redistribution, to optimise the support applied to the rock, by taking the rocksupport interaction into account. Backanalysis methods for optimal tunnel design sotirios vardakos abstract a fundamental element of the observational method in geotechnical engineering practice is the utilization of a carefully laid out performance monitoring system which provides rapid insight of critical behavioral trends of the work. These will likely add cost many tunnel kits require outside purchase of base board and end wall materials cost of the tunnel and availability of funds for purchase. Tunnel life cycle design and cost analysis railway age. The tunnel ground is classified and divided by the empisical classification systems like rock mass rating rmr, q system q, and geological strength index gsi. Engineering classification of rock masses for the design of. Part 3 design and detailing ezekiel enterprises, llc. Empirical studies of joberget soil tunnel include a study of experiences with soil tunneling.
Support of underground excavations in hard rock is the most complete and uptodate manual for use in the design of excavations and support mechanisms for underground mines. Rock support interaction analysis for tunnels in weak rock masses. Tunnelling in rocks present technology and future challenges zhao jian. Empirical systems for the classification of rock mass are used primarily for preliminary support design in tunneling. Design guide utility tunnels and trenches basis of design this section applies to reinforced concrete utility tunnels and trenches. Types of rock supports in design of underground structures free download as powerpoint presentation. Rock tunnel support system selectionsoft ground slurry tunneling soft ground tunneling using epb systems methods settlementalignment noise etc.
The aim of the work is the incorporation of classical level ii techniques to the current design method based on the study of the groundsupport interaction diagram. This report discusses tunnel design procedures based on various rock mass classification systems. Therefore, the rock mass properties of the site were determined by using the rock mass classification systems. Engineering classification of rock masses for the design of tunnel support an analysis of some 200 tunnel case records has revealed a useful correlation between the amount and type of permanent support and the rock mass qualityq, with respect to tunnel stability. Rockbolting design is indeed mainly based on experience and it appears that rockbolting design is simply a business of selection of rockbolt types and the determination of bolt length and spacing, but, one essentially uses, either explicitly or implicitly. Practical considerations for tunnels used in mining. Rock tunnel support are divided into two categories. A high energy dissipation ground support strategy for extremely high demand rock mass conditions is also presented. The purpose of this study is to present a methodology for tunnel and support design in mixed limestone, schist and phyllite conditions through investigating two highway tunnel case studies that are located along the antalyaalanya highway in southern turkey. Tunnelling instrumentation support design, optimization and. The design support pressure in the affected length of tunnel may be taken as 1. Tunnel lighting professionals need to consider disability glare.
Tunnels in general represent a significant financial investment with challenging design, construction, and operational issues. Computer based finite element analysis fem has given yet another dimension to design approach. The preferred alternative has two overarching components. If the inline pdf is not rendering correctly, you can download the pdf file here. The worst combinations of joints for wedge analysis are of bedding, joint 1 and joint 2 and bedding, joint 2 and joint 3. Tunnel support, use of lattice girders in sedimentary rock.
Based on the nianggaicun highway tunnel crossing the bcm grounds. Rock excavation and support systems refer to handout factors unique to tunnelling uncertainty in the nature and variability of ground conditions rock quality, ground water, gas, etc need for adequate site investigations prior to and vigilance during tunnelling onfined space of tunnel environment limited access, escape, air quality. Practical considerations for tunnels used in mining applications. However, current decision methods on support patterns require expertise, and moreover, there often exists discrepancy in judgements. Approved continuing education for licensed professional engineers design and construction of road tunnels. Other shield types for soft ground compressed air tunneling tunnel lining selection and design for soft ground sheet pilessoft ground tunneling ground support system selection. Rock excavation and support systems faculty of civil. For analyzing the stability of the tunnel and for deter. Empirical studies of joberget soil tunnel include a study of experiences with soil tunneling and a rock mass classification based on the q and rmrsystem. Rock support interaction analysis for tunnels in weak rock.
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