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    <title>Transport Research International Documentation (TRID)</title>
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    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
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    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
    <image>
      <title>Transport Research International Documentation (TRID)</title>
      <url>https://trid.trb.org/Images/PageHeader-wTitle.jpg</url>
      <link>https://trid.trb.org/</link>
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    <item>
      <title>CONCRETE FREEZING TECHNIQUE</title>
      <link>https://trid.trb.org/View/1051195</link>
      <description><![CDATA[DETAILS ARE GIVEN OF THE EFFECT OF THE RAPID FREEZING ON CONCRETE: CRYSTALLIZATION IN THE SHAPE OF ICE NEEDLES AND OF THE TECHNIQUE DEVELOPED BY TARDIEU WHO TOOK OUT A PATENT IN 1972.  THIS NEW TECHNIQUE PERMITS A QUICKER  RELEASE FROM THE MOULD THAN STEAM CURING.  DIRECTIONS OF FUTURE RESEARCH  TO IMPROVE AND ENLARGE THE TECHNIQUE ARE PROPOSED.]]></description>
      <pubDate>Sun, 21 Nov 2010 02:02:24 GMT</pubDate>
      <guid>https://trid.trb.org/View/1051195</guid>
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    <item>
      <title>A CRITICAL AND COMPARATIVE SURVEY OF FROST RESISTANCE TESTING IN ACCORDANCE WITH AUSTRIAN STANDARD B3303 (AUSTRIAN CODE) AND THE GUIDELINES OF THE RILEM COMMISSION 4 CDC</title>
      <link>https://trid.trb.org/View/1049810</link>
      <description><![CDATA[IN COUNTRIES WITH MODERATE AND COLD CLIMATES FROST RESISTANCE IS OF DECISIVE SIGNIFICANCE FOR THE DURABILITY AND SERVICEABILITY OF STRUCTURES.  ALTHOUGH THE IMPORTANCE OF THIS PROPERTY IS KNOWN, THE TESTING AND EVALUATION  OF FROST RESISTANCE IS CARRIED OUT IN VARYING WAYS AND GENERALLY THE NUMERICAL EVALUATION OF IT RESULTS IN THE GREATEST PROBLEMS.  FOR ESTIMATING THE BEHAVIOUR OF CONCRETE UNDER THE EFFECTS OF FROST, TWO METHODS ARE CURRENTLY ADOPTED - THE INDIRECT AND DIRECT METHOD.  THE OBJECT OF THIS INVESTIGATION WAS TO ESTABLISH WHETHER THERE ARE SIGNIFICANT DIFFERENCES BETWEEN  THE FROST TEST ACCORDING TO THE NEW RILEM GUIDELINES AND ACCORDING TO AUSTRIAN STANDARD B3303 WITH RESPECT TO THE EVALUATION OF FROST RESISTANCE.    FROM THE INVESTIGATIONS IT CAN BE CONCLUDED THAT IN THE RILEM GUIDELINES CONSIDERABLY MORE DEFINITE DATA CAN BE GIVEN WITH RESPECT TO THE TEST PREREQUISITES AND THE DEFINITION OF THE TEST CONDITIONS COMPARED WITH THE AUSTRIAN STANDARD REQUIREMENTS.  WITH ALTERATION IN THE DYNAMIC ELASTICITY MODULUS OF EACH RESPECTIVE CONCRETE SAMPLE NO SIGNIFICANT DIFFERENCE COULD BE FOUND BETWEEN THE TESTING METHODS.  WITH RESPECT TO A CRITERION FOR JUDGEMENT OF THE FROST RESISTANCE OF CONCRETE THE RILEM GUIDELINES DO NOT SHOW SIGNIFICANT IMPROVEMENT COMPARED WITH AUSTRIAN STANDARD B3303.  THE CONCLUSION CAN BE DRAWN THAT NONE OF THE TRADITIONALLY APPLIED DIRECT FROST TESTING METHODS PROVIDES AN ABSOLUTE AND QUANTITATIVE ANSWER.  THE RESULTS OF SUCH TESTS ARE DETERMINED TO A LARGE EXTENT FROM THE CONDITION, PROPERTIES, PRE-TREATMENT AND STORAGE OF THE TEST CUBES BEFORE THE START OF THE TEST AND FROM THE TYPE OF TEST.  IF THE FROST RESISTANCE OF CONCRETE IS REQUIRED QUALITATIVELY AND IN RELATION TO ITS PRACTICAL USE, THEN NEW TEST METHODS MUST BE ADOPTED WHICH ARE ALSO BASED ON COMPLETELY DIFFERENT BASIC DATA.]]></description>
      <pubDate>Sun, 21 Nov 2010 01:25:18 GMT</pubDate>
      <guid>https://trid.trb.org/View/1049810</guid>
    </item>
    <item>
      <title>METHODS OF IMPROVING THE ENGINEERING PROPERTIES OF SOFT CLAY. STATE OF THE ART</title>
      <link>https://trid.trb.org/View/1049470</link>
      <description><![CDATA[THIS PAPER WAS PRESENTED AT THE INTERNATIONAL SYMPOSIUM ON SOFT CLAY, BANGKOK, THAILAND, 5-6 JULY 1977.  THEME: METHODS OF IMPROVING THE GEOTECHNICAL PROPERTIES OF SOFT CLAY.  AT THE DESIGN AND CONSTRUCTION STAGE OF STRUCTURES ON SOFT SOIL OR WHEN ENCOUNTERING DISORDERS ON SITE, IT IS IMPORTANT  TO KNOW WHETHER IT IS POSSIBLE TO IMPROVE THE PROPERTIES OF THIS TYPE OF  SOIL, AND IF SO HOW AND HOW MUCH.  THIS REPORT REVIEWS THE SOLUTIONS TO THESE PROBLEMS AND EXAMINES EXISTING METHODS: PRECOMPRESSION LOADING, VERTICAL DRAINS, INTENSIVE TAMPING, STONE COLUMNS, ELECTRO-OSMOSIS, THERMAL TREATMENT, CHEMICAL TREATMENT. FOR EACH METHOD POSSIBLE IMPROVEMENTS ARE MENTIONED TOGETHER WITH CONSTRUCTION METHODS AND DESIGN METHODS.  CASE HISTORIES ARE APPENDED AS ILLUSTRATIONS.  FOR THE COVERING ABSTRACT, SEE IRRD ABSTRACT NO 107555; SEE ALSO IRRD 243851.]]></description>
      <pubDate>Sun, 21 Nov 2010 01:15:04 GMT</pubDate>
      <guid>https://trid.trb.org/View/1049470</guid>
    </item>
    <item>
      <title>Artificial ground freezing</title>
      <link>https://trid.trb.org/View/804062</link>
      <description><![CDATA[Poor ventilation of the London Underground in the UK is a major problem, particularly on the deep tube lines. Heat sources include electrical cables, train motors, platform lighting and signage, escalator motors, and the passengers and staff. Heat build up has caused temperatures to rise up to 40 C. The only significant means by which the deep tube railway network is ventilated and cooled is by the piston effects of the trains on the line. The deep tube network has 120 tunnel cooling fans to remove heat from the tunnels when trains are not running at night. A draught relief system is also present. A solution based on Artificial Ground Freezing (AGF) has been proposed. This operates as a closed loop that delivers an injection of cold air into the tunnel ahead of an oncoming train. The AGF would be installed entirely from underground openings constructed in the London Clay off-line from the live railway. The ground freeze would take place mainly in the Upper Chalk aquifer. The principles of AGF are outlined. The ways in which cooling load requirements would be met and the delivery of cold air to the underground network are discussed. (A)]]></description>
      <pubDate>Tue, 06 Mar 2007 09:03:27 GMT</pubDate>
      <guid>https://trid.trb.org/View/804062</guid>
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    <item>
      <title>Enlargement of the Marienplatz metro station - a complex tunnel project beneath Munich City Hall</title>
      <link>https://trid.trb.org/View/781979</link>
      <description><![CDATA[Due to expected capacity requirements for public transport during the 2006 Football World Cup, it was decided to enlarge the metro station Marienplatz, situated right beneath Munich city hall. The project concept finally approved provides for two extra tubes running in parallel to the existing ones. By connecting the new and old tubes with 11 cross cuts each approximately 3.10m wide, an intended doubling of the platform passenger capacity is achieved. The close vicinity of the new tunnel tubes to existing buildings - in particular the historic city hall 'Neues Rathaus' that was erected from 1867 to 1909 - puts a high demand on control and limitation of the soil movements to be expected during the construction process. While the original bid invitation proposed a lowering of the groundwater level, the solution finally chosen uses an innovative brine freezing technique, a specific proposal made by the executing consortium. As the analysis covers numerous non-linear construction stages involving parametric studies, it was essential to have a fast solution technique. On the other hand, simulation of the cross cutting process is a complex non-linear three-dimensional problem. Aiming at the best compromise between efficiency and required accuracy, a novel concept was adopted. It started with a classical two-dimensional finite element analysis of representative cross-sections using standard and approved techniques but was extended to account for the three-dimensional stress redistribution effects occurring during tunnel excavation. A special combined mesh generation and mapping technique is applied to create a three-dimensional model that inherits the load history induced by the tunnelling process and thus allows for simulation of the cross cut installation process. This combined approach enables the complex analysis task to be performed within a reasonable timeframe. (A)]]></description>
      <pubDate>Thu, 18 May 2006 08:32:07 GMT</pubDate>
      <guid>https://trid.trb.org/View/781979</guid>
    </item>
    <item>
      <title>The water margin</title>
      <link>https://trid.trb.org/View/770538</link>
      <description><![CDATA[Hong Kong's new rail line to the Chinese border is being built across environmentally sensitive wetlands. The 7.4km route between Sheung Shui and Lok Ma Chau crosses the Long Valley area of the Mai Po wetlands, home to 60,000 migratory birds. Following pressure from green groups, the line is to be built underground beneath the wetlands. The project will consist of four sections: modernisation of the existing Sheung Shui station, the Sheung Shui to Chau Tau twin tunnels, a western viaduct and Lok Ma Chau station. A footbridge will link the station to China across the Shenzhen river. The tunnels have been driven using an earth pressure balance tunnel boring machine for 3. km under the Long Valley. Cut and cover construction has been used for the 700m of tunnel adjacent to the viaduct. Kowloon-Canton Railway Corporation has reclaimed land to extend the wetlands area to compensate for land lost to the new Lok Ma Chau station. Due to environmental constraints a full site investigation of the Long Valley area was not possible. The engineering team relied on old borehole logs and geological maps, which revealed decomposed volcanic soil with hard rock above and soft ground below. Stringent thresholds were imposed on settlement during construction. Ground freezing was used in the construction of cross passages between the two tunnels in waterlogged ground.]]></description>
      <pubDate>Thu, 22 Dec 2005 11:24:54 GMT</pubDate>
      <guid>https://trid.trb.org/View/770538</guid>
    </item>
    <item>
      <title>BOSTON'S MASSIVE JACKED TUNNELS SET NEW BENCHMARK</title>
      <link>https://trid.trb.org/View/705826</link>
      <description><![CDATA[The Boston Central Artery/Tunnel project, known as 'The Big Dig', is a US$15 billion project that involves replacing a 1950s flyover carrying Interstate 93 through Boston with a new underground highway and building a new highway tunnel eastwards from I-93 to Logan International Airport. The tunnelling involved the largest, most complex tunnel-jacking project in the world. The original design concept focused on cut-and-cover construction, which required five phased relocations of the railway tracks and infrastructure. This was eliminated by the introduction of tunnel jacking. The contracting process for the project is outlined. The challenges faced by the contractors included ground freezing to stabilise the clay deposits, obtaining acceptance of the tunnel jacking process, tunnelling through obstructions such as contaminated fill and buried structures, the construction of thrust pits, and the huge scale of the project. The key benefits from using the tunnel jacking process included time and cost, traffic relief, a safe working environment, and enhanced quality of the completed works.]]></description>
      <pubDate>Fri, 03 Sep 2004 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/705826</guid>
    </item>
    <item>
      <title>HOW TO CONTROL GROUNDWATER IN TUNNELLING PROJECTS</title>
      <link>https://trid.trb.org/View/271562</link>
      <description><![CDATA[Inadequate control and management of groundwater can affect the construction progress of a tunnel considerably.  Large unexpected quantities of water may endanger lives and machinery and bring work to a halt.  Small flows can decrease productivity, result in soil loss and subsequent surface settlements, or face instability.  From the initial design, through construction to the maintenance of the finished tunnel, a variety of methods are used.  Some of these need a large inventory of specialised plant and equipment, as reviewed in the paper, to carry out such remedial measures as grouting, freezing and dewatering. (TRRL)]]></description>
      <pubDate>Fri, 27 Aug 2004 22:01:40 GMT</pubDate>
      <guid>https://trid.trb.org/View/271562</guid>
    </item>
    <item>
      <title>MEASUREMENTS AND RESULTS OF APPLYING THE GROUND FREEZING METHOD IN TUNNELLING</title>
      <link>https://trid.trb.org/View/268572</link>
      <description><![CDATA[The 1310m long Milchbuck Tunnel takes the SN 1 expressway under a heavily built up area in the town of Zurich. Problem conditions included non-cohesive silty-sandy material and the presence of water under an artesian pressure of up to 3 bar.  This paper describes the constructin method used, which included ground freezing prior to full face excavation; and the lowering and pressure relief of the ground water by means of small bore filter wells.  (TRRL)]]></description>
      <pubDate>Fri, 27 Aug 2004 21:41:58 GMT</pubDate>
      <guid>https://trid.trb.org/View/268572</guid>
    </item>
    <item>
      <title>FREEZING OF AQUEOUS SOLUTIONS IN A POROUS MEDIUM. PART I FREEZING OF AIR-ENTRAINING AGENT SOLUTIONS</title>
      <link>https://trid.trb.org/View/217895</link>
      <description><![CDATA[In this investigation, a pre-formed, autoclaved porous material, of stable pore characteristic, was used to study the freezing characteristics of wet porous materials.  Prior to freezing, prisms made from this material were filled with solutions of air-entraining agents.  The results show that (I) a major part of a solution could be frozen without any dilation of the matrix, (II) the dilation, when it occurs, is connected with the later stages of the freezing process when only a limited amount of ice forms, (III) initially, ice forms on the surfaces of large air-filled pores, (IV) ice formation strengthens the matrix.  It is proposed that the initially formed ice-layers on the pore surfaces seal in the remainder of the solutions.  Continued ice formation generates a bursting pressure within the unfrozen solution. When this bursting pressure exceeds the tensile strength of the ice-strengthened matrix, it fails. Attention has been drawn to the relevance of the above observations and the hypothesis to freezing of cement paste.  (TRRL)]]></description>
      <pubDate>Wed, 25 Aug 2004 02:39:26 GMT</pubDate>
      <guid>https://trid.trb.org/View/217895</guid>
    </item>
    <item>
      <title>BIG PRICE TAG FOR SMALL SUBWAY</title>
      <link>https://trid.trb.org/View/683296</link>
      <description><![CDATA[The cost of constructing a 50m long pedestrian underpass in Copenhagen, linking a railway terminus with a new underground metro station, is likely to be about 15M. To be located beneath the basement slab of a railway station and above twin metro tunnels, the 5m high subway is to be hand-dug through saturated sands and gravel. To ensure that the close-boarded face remains dry, the whole area is surrounded by a computer-controlled ground-freezing system requiring 200 vertical, horizontal and inclined freeze pipes. Even with -24 degrees C ground-freezing in operation, constant monitoring was necessary to record movement of the station's concrete roof, caused by heave and settlement which had been set at only 5mm.]]></description>
      <pubDate>Thu, 03 May 2001 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/683296</guid>
    </item>
    <item>
      <title>OSLOFJORD CHALLENGE</title>
      <link>https://trid.trb.org/View/650234</link>
      <description><![CDATA[This article describes the unexpected ground conditions faced during excavation of the 7.2km long Oslofjord subsea road tunnel in Norway; it includes a route map. The Oslofjord crossing will include 26.5km of new highway and open in Summer 2000. Because of its hilly topography, the road will have seven bridges and six tunnels, several of which are specified mainly for environmental reasons. As part of the site investigation, acoustic measurements and reflective and refractive seismic studies were conducted, mainly in 1979-80 and 1985-86. As a result, the present tunnel alignment was designed, which follows a rock threshold in the fjord for about 2.1km. Due to the sensitive environment along the fjord, the rest of the tunnel crosses to portals well away from the shore areas on both sides.  Seismic investigations showed three wide channels in the rock, eroded by glaciation; in each channel, major weaknesses were confirmed. The worst problems occurred in the Hurum weakness zone, which consisted of crushed rock and clay, like that found when excavating many other Norwegian subsea tunnels. A working group, representing the client, the contractor, and specialist external experts, was formed to advise on investigating and treating this zone. It decided to apply a stabilisation method, using a freezing operation.]]></description>
      <pubDate>Fri, 03 Mar 2000 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/650234</guid>
    </item>
    <item>
      <title>MANY PRESSURES ON GROUND IMPROVEMENT</title>
      <link>https://trid.trb.org/View/638605</link>
      <description><![CDATA[This article describes some of the main current options for ground stabilisation for underground excavation. Better methods are needed today to improve the ground and ensure minimal effects of tunnelling on adjacent structures. Ground consolidation enables larger, more complex new excavations in urban areas, in soft ground, and in severely faulted regions. Extra problems are caused by environmental concerns, especially the chemical interaction of materials with the natural environment. One simple way to protect shallower underground works temporarily is to dewater the ground by a series of well points; it can be used only in ground of suitable permeability. Injection grouting can now be done in stages from the same holes, so that a cured grout wall can be built gradually with different materials. Permeation grouting, which fills voids by grout injection, is the simplest underground improvement technique. Compensation grouting uses a comprehensive geotechnical monitoring system to compensate precisely for settlement caused by excavation. Jet grouting has been developed in the last two decades for soft ground, and replaces the existing soil structure. Ground freezing and later thawing can now be controlled very accurately. The article includes some information about grouting companies and their products.]]></description>
      <pubDate>Mon, 07 Feb 2000 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/638605</guid>
    </item>
    <item>
      <title>MAIDENHEAD'S BIG FREEZE</title>
      <link>https://trid.trb.org/View/513683</link>
      <description><![CDATA[The towns of Maidenhead, Windsor, and Eton in Berkshire, England are liable to major floods twice a century and lesser floods every five to seven years. This article discusses the #6.7M Dorney Bridge project on the outskirts of Maidenhead, which is part of an Environmental Agency (EA) scheme to divert water from the River Thames along an 11.6km long artificial but natural-looking channel which will rejoin the river just east of Eton. Work on the scheme began in 1996 and is due to finish in Winter 2000. At Dorney Bridge, where site work began in September 1997, a huge box culvert had to be jacked through an embankment under the main line of the Great Western Railway. The culvert is 50m long, 23m wide, and 9.5m high. The project was designed by consultant Scott Wilson Rail for main contractor Edmund Nuttall, and it was decided to use freezing to stabilise the embankment during the jacking. The northern side of the 10m high embankment is made of clay fill, and the southern half has a mixture of clay and gravel. Gravels, sands and chalk lie under the embankment, and the water table is very high, a minimum of 1.5m below ground level. As it was vital to minimise movement in the embankment and its four railway lines, settlement was carefully monitored.  Jacking is complete, and final preparations are being made to thaw the ground.]]></description>
      <pubDate>Fri, 07 Jan 2000 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/513683</guid>
    </item>
    <item>
      <title>PREPARING FOR THE BIG PUSH</title>
      <link>https://trid.trb.org/View/507315</link>
      <description><![CDATA[This article describes preparation for the first of three huge tunnel jacking operations in the Central Artery in Boston, USA; it includes a map of its locality. The operations are occurring at the South Bay Interchange between the I-90 and I-93 highways. As it approaches the centre of Boston, a new elevated section of the I-93 will be linked to the I-90 and its new extension east to Logan Airport. The extension will be built in cut-and-cover, jacked tunnels, and immersed tube tunnels under the Fort Point Channel. At the South Bay Interchange, the tunnel jacking operations will take the I-90 from an exit ramp in the immersed tunnel under eight railway lines with heavy traffic, and on towards the I-93 in the downtown area. The site is 200m by 300m, bounded by existing roads and buildings, and by the Fort Point Channel. Previous reclamation and construction works have left variable sand, silt, and gravel fill with a variety of construction material, including concrete, steel and timber, and granite blocks. Under the fill, there are layers of sands, silts, and peats overlying Boston Blue Clay. There will be full-size tunnel jacking for building the tunnels under the tracks, and the tunnel sections are being built in three jacking pits. 1800 steel freeze pipes have been installed in and around the tracks.]]></description>
      <pubDate>Thu, 07 Oct 1999 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/507315</guid>
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