Guidelines for the design of tunnels ita working group on general approaches to the design of tunnels abstractthis second report by the ita working group on general approaches to the design of tunnels presents international design procedures or tunnels. Past and present soft ground natm for tunnel and shaft. Rapid and consistent support of freshly excavated ground, easier construction of complex intersections and lower capital cost of. Thus, the total width of the tunnel is about 12 m and the height is about 7 m. Load sharing in twopass lining systems for natm tunnels. Sem, as commonly known as the new austrian tunneling method natm. Geology is very important while designing a tunnel. Challenges of design and construction of a highway tunnel. Designbuild framework and the team with the members sato kogyo s ltd.
Realtime use of all this cumulative information gathered requires for a high level of competence mainly for the following staff. Technical manual for design and construction of road tunnels. The natm has often been referred to as a design as you go approach, by providing an. The work explored in particular the cost savings and the increased security that natm brings during construction. Tunnels are safer to the earthquake from the other on ground structures. The term natm can be misleading in relation to softground tunnels. Systematic presupport systematic shotcrete initial lining support with early ring closure top heading excavation with temporary invert, bench and invert excavation example. Tunnels have played a vital role in the evolution and sustenance of mankind. Discover the new austrian tunnelling method and the role of shotcrete.
Construction of tunnels, by new austrian tunneling method natm. Nchrp project 2068a scan 0905 best practices for roadway. The fhwa technical manual for design and construction of road tunnels. General ilfs technical knowhow in the field of railway lines and tunnelling has been used for the benefit of clients all over the world germany, austria, switzerland, poland, danmark, usa, italy, france, uk, greece, hungary etc. The new austrian tunnelling method was first employed in the uk within the within the mining field in 1964 karakus and fowell 2004. In practice, natm involves a combination of several tunnelling aspects from ground characterization via rock mechanics and tunnel design to construction. Natm new austrian tunnelling method one of the most well known methods using some elements of an observational approach is the new austrian tunnelling method, or natm. The basic aim of natm is for getting stable and economic tunnel support systems.
Not emerged in the years 1957 to 1965 1 and was entitled in this way to be distinguished from the old austrian tunnelling method. It was the first time in austria that full sets of tender documents for two design alternatives have been provided by the client. Systematic presupport systematic shotcrete initial lining support with early ring closure. The criteria for rock tunnels are to be determined on a project specific basis, subject to wssc approval. Erik eberhardt tunnel excavation in soft ground conditions. Barchips macro synthetic fiber concrete reinforcement has been used to successfully reinforce over 5000 kms of underground structures. The practical application of the loadsharing design approach in a natm tunnel project, the caldecott fourth bore, is also presented. The surrounding rock is transformed from a complex load system to a selfsupporting structure together with the installed support elements, provided that the detrimental loosening, resulting in a substantial loss of strength, is avoided. Objectives the objective of this workshop is to update the knowledge of. Tunnels have played a vital role in the evolution and sustenance of mankind through the ages. This lesson illustrates the use of plaxis for the analysis of the construction of a natm tunnel. Application of the natm and its successes laid the ground work for the methods increased use on urban soft ground tunnels, recently the beacon hill station in seattle.
A combination of nmt and natm principles applying the qbased support design system was proposed for a major tunnel in partly soft and partly hard rock. Introduction to tunnel design and construction seminar instructor david g. Excavation and support categories in soft ground description soft ground shallow cover. Natm is based on a concept whereby the rock surrounding an. In the last 20 years the sequential excavation method sem or the new austrian tunneling. Design guidelines for sequential excavations method sem. Support patterns by natm in japan are designed by experienced experts regarding an overall evaluation based on the condition of a cutting face, the condition of an underground surface, compressive strength, weathering, condition of joints, joins set. New austrian tunneling method used for design of softground. The design involved two vertically stacked tunnels along cambie st. 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. This paper discusses the basic mechanism of load sharing in twopass lining systems and proposes a rational approach for design.
Experience has always played an important role, and will continue to do so. The work described in this document was conducted as part of nchrp project 2068a, the u. New austrian tunneling method used for design of soft. Dec 21, 2011 realtime use of all this cumulative information gathered requires for a high level of competence mainly for the following staff. Fiber reinforcement for tunnelling natm shotcrete lining. Comparison of tunnelling methods natm and adecors linda cerna vydrova 1, 1. Pdf an insight into the new austrian tunnelling method natm. Fort canning tunnel is a 180m 590ft long, threelane highway tunnel, and has a cross section area of 5m2 1440ft2. Pas 8810 is a publicly accessible standard published by the british standards institution that documents recommendations and codes of practice for the design of concrete segmental tunnel linings. History has seen the evolution of tunneling starting with cave formation, for water management, under ground transportation, mineral extraction and for. Tunnels 8e deep space softground natm tunnel designs for the washington, d. The new austrian tunneling method natm, also known as the sequential excavation method. The tunnel has been designed using the natm concept.
Erik eberhardt tunnelling in weak rock sequential excavation sequential excavation ground reaction ground reaction convergenceconvergence in practice, it may not be possible to establish the exact form of the. Dec 25, 2018 scmaglev central japan railway company this is the official website of the superconducting maglev system by jr central. The surrounding rock is transformed from a complex load system to a selfsupporting structure together with the installed support elements, provided that the detrimental loosening, resulting in a. The design methodology, in brief, and construction problems being faced so far on the basis of. Czech technical university in prague, faculty of civil engineering, department of geotechnics, thakurova 7, 166 29, prague 6, czech republic.
Definition of natm the new austrian tunnelling method is a support method to stabilize the tunnel perimeter by means of sprayed concrete,anchors and other support and uses monitoring too control stability. The philosophy looks to use the strength of the surrounding soil to the greatest. Heflin abstractthe stateoltheart new austrian tunneling method na tm design alternatives developed or three contract sections on the washington, d. The method, has often been mentioned as a value engineeredvalue engineered version of tunnelling due toversion of tunnelling due to its use of light, informal support. The paper discusses the way in which wma ta, assisted by its. Risk control at the design of a km long railway tunnel in. The natm accomplishes tunnel stabilization by controlled stress release. Where expanded segmental linings are used for the main tunnel, it is common practice to used bolted segmental rings within a distance of about two tunnel tunnel lining design guide. It covers design considerations from project inception through to the end of the service life of the tunnel. Softground natm tunnel designs for the washington, d.
Simulation and measurement analysis of natm tunnel. The new austrian tunnelling method natm, in german. Scmaglev central japan railway company this is the official website of the superconducting maglev system by jr central. Safety of new austrian tunnelling method natm tunnels. Pdf an insight into the new austrian tunnelling method. Erik eberhardt tunnelling in weak rock sequential excavation sequential excavation ground reaction ground reaction convergenceconvergence in practice. Support patterns by natm in japan are designed by experienced experts regarding an overall evaluation based on the condition of a cutting face, the condition of an underground surface, compressive strength, weathering, condition of joints, joins set, joint spacing. Its main idea is to head the tunnel conventionally, to apply. Selection of shield method depends on ground conditions, surface conditions, dimensions of the tunnel section, boring distance, tunnel alignment and construction period. It was given its name in salzburg in 1962 to distinguish it from old austrian tunnelling approach. In its final buildout it is configured as an emergency egress structure.
Design for support patterns of natm tunnel using machine. Natm new austrian tunneling method known as sequential excavation method, is a construction method of mountain tunnels. Natm is the association that represents manufacturers that produce light and mediumduty trailers and suppliers of products and services to these manufacturers. Road development authority rda guideline for design of road tunnel japan international cooperation agency jica i technical assistance for improvement of capacity for planning of road tunnels.
Natm tunneling is currently being employed in a designbuild framework for the extension of. New austrian tunneling method natm the new austrian tunneling method natm was developed between 1957 and 1965 in austria. The strength of the ground around a tunnel is deliberately mobilized to the maximum extent possible. The first use of natm in soft ground tunnel in frankfurt europe metro in 1969. In order to avoid any disorders in traffic flow of modares highway the surface vertical displacements have been restricted to 1 inch in design. Tunnel design shall follow the above dimensions and clearance in height for the traffic is determined as 5. Design guidelines for sequential excavations method sem practices for road tunnels in the united states vojtech gall gall zeidler consultants, ashburn, virginia nasri munfah parsons brinckerhoff, new york, new york abstract. First published 1996 isbn 978 0 7176 1068 6, reissued as pdf 2014. This program was requested by the american association of state. Thomas telford, london, 2004 87 diameters of the portals, to safeguard against di. The twinbore tunnel section, approximately 1,000 ft. The method adopted for tunneling is based on the type of rock and geological conditions. As noted by emit brown, natm can refer both to a design philosophy and a construction method.
New austrian tunneling method an overview sciencedirect. Simulation and measurement analysis of natm tunnel construction method fig working week 2012 knowing to manage the territory, protect the environment, evaluate the cultural heritage rome, italy, 610 may 2012 shallow tunnel excavation. Apr 03, 2017 geology is very important while designing a tunnel. All other tunnel structures of the western part and the double track tunnel of the eastern section of the project will be carried out by conventional tunneling method. Many aspects of tunnel design influencing whether a tunnel is constructed safely, like tunnelling in rock or soft ground, are decided in the concept design stage.
Engineer and gall zeidler consultants natm designer has been awarded the contract. New austrian tunneling method history of natm the term new austrian tunneling method popularly known as natm got its name from salzburg austria. The natm is a technique in which ground exposed by excavation is stabilized with shotcrete to form a temporary lining. National association of trailer manufacturers topeka, ks natm. Safety of new austrian tunnelling method natm tunnels page 4 of 7 part 6. The stateoltheart new austrian tunneling method na tm design alternatives developed or three contract sections on the washington, d. Predicated upon the observational method, it works by mixing construction with settlingin periods during which the rock mass is observed, to adapt the tunnel support design to the geological requirements. Natm is both a construction method and a design philosophy. Design and construction of tunnel through such a complex and varying geology with a rock cover of more than m is a difficult and challenging taks.