<rss version="2.0" xmlns:atom="https://www.w3.org/2005/Atom">
  <channel>
    <title>Transport Research International Documentation (TRID)</title>
    <link>https://trid.trb.org/</link>
    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
    <description></description>
    <language>en-us</language>
    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <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>
    </image>
    <item>
      <title>THERMAL SPALLING EXPERIMENTAL DRILLS USE HEAT, ELECTRICITY, MICROWAVES, CHEMICALS</title>
      <link>https://trid.trb.org/View/121392</link>
      <description><![CDATA[DIFFERENTIAL THERMAL EXPANSION OF CONSTITUENT CRYSTALS AND GRAINS OF ROCKS IS PRODUCED BY SEVERAL DIFFERENT MECHANISMS: HIGH THERMAL GRADIENTS, PHASE CHANGES IN THE MINERALS, DIFFERENCES IN THERMAL EXPANSION COEFFICIENTS OF CONSTITUENT MINERALS, REMOVAL OF WATER OF CRYSTALLIZATION, HEATING OF LIQUID AND GASEOUS INCLUSIONS, AND CHEMICAL BREAKDOWN OF THE MINERALS. THE VOLUMETRIC EXPANSION WHICH QUARTZ UNDERGOES DURING ITS ALPHA-TO-BETA TRANSITION IS ONE OF THE MOST IMPORTANT MECHANISMS IN SPALLING. HIGH THERMAL GRADIENTS ARE ALSO IMPORTANT IN THERMAL SPALLING. MANY ROCKS WILL NOT SPALL BECAUSE THE INDUCED THERMAL STRESSES ARE TOO LOW. IN MANY OF THESE ROCKS, HEATING WILL PRODUCE THERMAL STRESSES SUFFICIENTLY HIGH TO WEAKEN OR BREAK THE BONDS BETWEEN CRYSTALS AND GRAINS. THIS PROCESS IS CALLED THERMAL DEGRADATION, WHICH CAN REDUCE ROCK STRENGTH BY AS MUCH AS 50% TO 75%. DIAGRAMS AND DISCUSSIONS ARE PRESENTED OF THE FOLLOWING TYPES OF THERMAL SPALLING EXPERIMENTAL DRILLS: JET PIERCING DRILLS, FORCED FLAME DRILLS, ELECTRIC DISINTEGRATION DRILL, HIGH-FREQUENCY ELECTRIC DRILLS, MICROWAVE DRILLS, INDUCTION DRILLS, AND CHEMICAL DRILLS.]]></description>
      <pubDate>Sun, 15 Aug 2004 02:39:11 GMT</pubDate>
      <guid>https://trid.trb.org/View/121392</guid>
    </item>
    <item>
      <title>SOIL - ROCK DRILLING AND ROCK LOCATING BY ROCK INDICATOR</title>
      <link>https://trid.trb.org/View/121027</link>
      <description><![CDATA[A NEW METHOD IS PRESENTED OF DETERMINING THE LEVEL OF BEDROCK SURFACE, WHEN IT IS COVERED BY SOIL. THE METHOD COMPRISES DRILLING THROUGH SOIL INTO ROCK /SOIL-ROCK DRILLING/, IN COMBINATION WITH MONITORING THE DRILLING SOUND FROM THE WORKING OF THE DRILL BIT IN THE ROCK. FOR SOUND MEASUREMENT A MICROPHONE IS PLACED IN A BOREHOLE INTO SOLID ROCK. THE SOUND IS LISTENED TO BY HEAD-PHONES AND READ ON A METER, AND CAN BE RECORDED. THE SOUND MEASUREMENT CAN DISTINGUISH BETWEEN BOULDERS AND ROCK EVEN WHEN LARGE BOULDERS LIE CLOSE TO THE ROCK SURFACE. WITH ONE LISTENING POINT AN AREA ABOUT 100 METERS IN RADIUS CAN BE COVERED. THE REACH IS DEPENDENT ON THE SIZE OF THE ROCK DRILL AND QUALITY OF THE ROCK. GOOD RESULTS HAVE BEEN ACHIEVED IN BOTH ERUPTIVE /GRANITE AND GNEISS/ AND SEDIMENTARY /LIMESTONE AND SANDSTONE/ ROCKS. /AUTHOR/]]></description>
      <pubDate>Sun, 15 Aug 2004 02:37:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/121027</guid>
    </item>
    <item>
      <title>RATIONALIZE SOIL INVESTIGATION</title>
      <link>https://trid.trb.org/View/121009</link>
      <description><![CDATA[DESCRIPTIONS ARE PRESENTED ON THE FOLLOWING TYPES OF BORING EQUIPMENT' AUTOMATIC SOUNDING, PENETRATION SOUNDING, VANE BORES, STANDARD PISTON SAMPLER AND ROCK DRILLER. MOST OF THE EQUIPMENT IS DEVELOPED ESPECIALLY FOR SCANDINAVIAN CONDITIONS E.G. SOFT CLAYS. A NEW STANDARDIZED PRESENTATION OF BORE-HOLES IS SHOWN.]]></description>
      <pubDate>Sun, 15 Aug 2004 02:37:41 GMT</pubDate>
      <guid>https://trid.trb.org/View/121009</guid>
    </item>
    <item>
      <title>ROCK DRILLING: THE RIGHT STUFF</title>
      <link>https://trid.trb.org/View/476348</link>
      <description><![CDATA[This article examines proper tool selection, which is the key to successful rock drilling. Topics discussed include: drill bit selection, matching a mud motor to the rig's capacity, adding enough power to a rig.]]></description>
      <pubDate>Wed, 18 Mar 1998 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/476348</guid>
    </item>
    <item>
      <title>RESEARCH SPECIALIST EVALUATES POTENTIAL OF 25 NOVEL ROCK DRILL TYPES</title>
      <link>https://trid.trb.org/View/110999</link>
      <description><![CDATA[DRILLING RATES OF NOVEL DRILLS ARE PROPORTIONAL TO POWER TRANSMITTED TO THE ROCK DIVIDED BY THE SPECIFIC ENERGY REQUIRED TO REMOVE ROCK.  TORARY DRILLS ARE EFFICIENT IN TERMS OF ENERGY REQUIRED TO REMOVE ROCK, BUT THEY ARE LIMITED BY LOW POWER OUTPUT.  POWER TRANSMITTED TO THE ROCK BY NOVEL DRILLS IS LIMITED BY: (1) THE AMOUNT OF POWER THAT CAN BE TRANSMITTED DOWN THE DRILLPIPE, (2) POWER OUTPUT OF THE DRILL, OR (3) AMOUNT OF POWER THAT THE ROCK WILL ACCEPT FROM THE DRILL.  THE FOLLOWING NOVEL DRILLS ARE LIMITED PRIMARILY BY THE AMOUNT OF POWER THAT CAN BE DELIVERED DOWN THE DRILLSTEM: (1) CHEMICAL, (2) EROSION, (3) EXPLOSION, (4) IMPLOSION, (5) PELLET, AND (6) TURBINE.  ESTIMATES ARE PRESENTED OF MAXIMUM DRILLING RATES FOR 8-IN. DIAMETER NOVEL DRILLS IN MEDIUM STRENGTH ROCK.  LABORATORY AND FIELD TESTS HAVE DEMONSTRATED THAT SOME NOVEL DRILLS HAVE POTENTIAL FOR DRILLING OIL WELLS FASTER AND CHEAPER THAN ROTARY DRILLS. RESEARCH IS NEEDED ON THESE NOVEL DRILLS TO DELIVER MORE POWER TO THE DRILL AND REDUCE THE ENERGY REQUIREMENT FOR REMOVING ROCK.]]></description>
      <pubDate>Thu, 04 Aug 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/110999</guid>
    </item>
    <item>
      <title>NOVEL MECHANICAL TYPES INVOLVE TURBINES, PELLETS, IMPLOSION, ULTRASONICS, SPARKS</title>
      <link>https://trid.trb.org/View/107481</link>
      <description><![CDATA[MECHANICAL NOVEL DRILLS ARE DEFINED IN THIS STUDY AS THOSE WHICH REMOVE ROCK BY MECHANICALLY INDUCED STRESSES. ENERGY SOURCES FOR THESE DRILLS ARE NOT NECESSARILY MECHANICAL AS EVIDENCED BY THE PRESENCE OF EXPLOSIVE, EROSION, AND SPARK DRILLS IN THIS CLASSIFICATION.  THESE DRILLS INDUCE MECHANICAL STRESSES IN THE ROCK BY IMPACT, EROSION, AND ABRASION.  THE FOLLOWING TYPES OF DRILLS ARE REVIEWED:  TURBINE DRILLS, PELLET DRILLS, CONTINOUS PENETRATORS, IMPLOSION DRILLS, ULTRASONIC DRILLS, SPARK DRILLS, EXPLOSIVE DRILLS, AND EROSION DRILLS.  MAJOR IMPROVEMENTS NEED TO BE MADE IN THE EFFICIENCY OF THE SINGLE-STAGE TURBINE OR IN THE ROCK-REMOVAL MECHANISM BEFORE SINGLE-STAGE TURBINE DRILLS CAN COMPETE WITH ROTARY DRILLS.  PELLET DRILLS DEMONSTRATED THEY CAN DRILL EVEN THE HARDEST ROCKS, BUT THE DRILLING RATES WERE LOW DUE TO LOW POWER OUTPUT.  THE NECESSARY HIGH THRUST MAKES THE CONTINUOUS PENETRATOR IMPRACTICAL EXCEPT FOR DRILLING VERY WEAK ROCKS.  IMPLOSION DRILLS SEEM TO HAVE LITTLE POTENTIAL FOR DRILLING OIL WELLS BECAUSE OF THEIR LOW POWER OUTPUT AND HIGH CAPSULE REQUIREMENT.  BECAUSE OF THEIR LOW DRILLING RATES, ULTRASONIC DRILLS APPEAR TO HAVE LITTLE POTENTIAL UNLESS MAJOR IMPROVEMENTS CAN BE MADE IN THE ROCK REMOVAL MECHANISM.  LOW POWER OUTPUT AND LOW EFFICIENCY LIMIT APPLICATION OF THESE DRILLS.  SPARK DRILLS, BECAUSE OF THEIR HIGH/POWER OUTPUT AND HIGH-POTENTIAL DRILLING RATE, APPEAR TO HAVE MORE POTENTIAL THAN MANY OF THE OTHER NOVEL DRILLS.  TESTS INDICATE THAT EXPLOSIVE DRILLS WOULD BE MOST EFFECTIVE FOR DRILLING DEEP OIL WELLS WHERE ROTARY DRILLING RATES ARE LOW AND COSTS ARE HIGH.  EROSION DRILLS APPEAR TO BE ONE OF THE MORE PROMISING NOVEL DRILLING METHODS BECAUSE OF THEIR HIGH POWER OUTPUT AND HIGH DRILLING RATE.]]></description>
      <pubDate>Thu, 04 Aug 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/107481</guid>
    </item>
    <item>
      <title>ELECTRIC DRILL MELTS WAY THROUGH ROCK</title>
      <link>https://trid.trb.org/View/107451</link>
      <description><![CDATA[A DRILL HAS BEEN DEVELOPED AT LOS ALAMOS SCIENTIFIC LABORATORY THAT USES HEAT TO MELT ITS WAY THROUGH ROCK. THE DEVICE HOLDS THE PROMISE OF DRILLING HOLES TO DEPTHS UNATTAINABLE WITH ROTARY DRILLS. IT COMPRISES A STEAL TUBE TIPPED BY A FLAT SHOE THAT CONTAINS THE HEATING ELEMENT. USING A TWO INCH DIAMETER BIT HEATED ELECTRICALLY TO 2192 F BY A 5 KW GENERATOR, THE DRILL WENT THROUGH BASALT AT THE RATE OF 50 FT/DAY. SOME OF ITS ADVANTAGES ARE /1/ OPERATIONALLY UNAFFECTED BY DEPTH, /2/ PERFORMS AS WELL IN HARD ROCK AS IN SOFT, /3/ NO MOVING PARTS TO WEAR OUT, AND /4/ USAGE IN SPECIAL APPLICATIONS SUCH AS HORIZONTAL OR UPWARD DRILLING. THE HEAT MELTS THE ROCK. DOWNWARD PRESSURE ON THE DRILL FORCES THE MOLTEN ROCK THROUGH A TUBE IN THE CENTER OF THE BIT.]]></description>
      <pubDate>Thu, 09 Jun 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/107451</guid>
    </item>
    <item>
      <title>14 NEW DRILL CONCEPTS</title>
      <link>https://trid.trb.org/View/107458</link>
      <description><![CDATA[APPLICATIONS OF A LASER ACTIVATED DRILL TO ROCK DRILLING ARE DISCUSSED. SOME OF THESE APPLICATIONS ARE: (1) BLAST- HOLE DRILLING, (2) BIG-HOLE DRILLING, (3) BUILDING STONE MINING, (4) PRE-SHEARING, AND (5) KERF CUTTING. METHODS USING ELECTRICAL ENERGY FOR BORE-HOLE DRILLING DISCUSSED ARE: (1) CARBON-ARC, (2) COVERED METAL (ELECTRODE) -ARC, (3) OXYGEN OR AIR CARBON-ARC, (4) GAS SHIELDED METAL OR TUNGSTEN-ARC AND (5) PLASMA ARC. THE TERRA-JETTER DRILL UTILIZES SUPERHEATED STEAM AND LIQUID NITROGEN TO RIP AND TEAR ITS WAY THROUGH ROCK. OTHER SUGGESTED APPLICATIONS ARE: DRILLING FOR FOUNDATIONS, WATER WELLS AND TUNNELS. THE RUSSIANS USE A SHOCK-WAVE DRILL TO DELIVER CRUSHING LOADS TO ROCK BY SHOCK-WAVES WHICH TRAVEL THROUGH LIQUID. THE PRINCIPAL OF THE VIBRATORY DRILL IS TO DELIVER MORE BLOWS PER UNIT OF TIME FOR PENETRATION OF ROCK. A DRILL CAPABLE OF FREQUENCIES UP TO 1,400 PER SECOND HAS BEEN REPORTED IN ONE CASE. THE FORCE MAY BE USED DIRECTLY TO FRACTURE THE ROCK OR IT MAY VIBRATE A RESONANT LENGTH OF DRILL STEEL ATTACHED TO THE BIT. PLASMA IS SUGGESTED AS A POTENTIAL ENERGY SOURCE FOR DRILLING. ADVANTAGES OF THE HYDROGEN-PLASMA TORCH FOR THERMAL ROCK REMOVAL LISTED ARE: (1) THE TEMPERATURE AND HEAT TRANSFER COULD BE OBTAINED TO SPALL OR MELT ROCKS OR POSSIBLY VAPORIZE THEM, (2) ELECTRICAL REQUIREMENTS WOULD NOT CREATE A SAFETY HAZARD, AND (3) GASES PRODUCED, MOSTLY WATER VAPOR, PROBABLY WOULD PRESENT NO UNUSUAL VENT PROBLEMS. THERMAL DRILLING IS DISCUSSED FOR APPLICATIONS IN OIL WELL DRILLING. THE THERMAL BIT CONSISTS ESSENTIALLY OF A TUNGSTEN OR MOLYBDENUM FACE, AN INNER BASE OF A BORON- NITRIDE ELECTRICAL INSULATOR AND HEAT CONDUCTOR, A TUNGSTEN HEATING ELEMENT, AND A BORON-NITRIDE BACKING PLATE. PERCUSSION DRILLING IS DISCUSSED WITH THE PREDICTION THAT THE USE OF MORE AIR PRESSURE AVAILABLE FROM NEW COMPRESSORS, WILL INCREASE PENETRATION OF PERCUSSION DRILLS.]]></description>
      <pubDate>Fri, 06 May 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/107458</guid>
    </item>
    <item>
      <title>APPLICATION OF NEW ROCK DRILLING TECHNOLOGY TO FOREST ROAD CONSTRUCTION IN COASTAL BRITISH COLUMBIA</title>
      <link>https://trid.trb.org/View/359065</link>
      <description><![CDATA[In 1988, the Forest Engineering Research Institute of Canada initiated a series of studies to evaluate the effect of state-of-the-art drills on the techniques and costs of constructing low-volume forest roads in coastal British Columbia.  The fact that rubber-tired units are more mobile than conventional pneumatic tank drills has changed many aspects of constructing coastal logging roads.  Total ownership and operating costs for the rock drills studied varied from $127 to $182 per hour (in Canadan dollars). Average productivity varied from 97 to 128 m drilled per shift, and cost per meter drilled ranged from $9.15 to $14.43.  Rock drill utilization levels ranged from 31 to 46%.  The relatively low utilization levels result from lengthy nonmechanical delays associated with the overall forest road construction process; planning, work procedures, and the organization of crews and equipment can influence these figures.]]></description>
      <pubDate>Sat, 31 Aug 1991 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/359065</guid>
    </item>
    <item>
      <title>FAST HORIZONTAL DRILLING SPEEDS I-70 TUNNEL JOB</title>
      <link>https://trid.trb.org/View/354335</link>
      <description><![CDATA[Rock excavation is running two to three months ahead of schedule at the $67.7 million Hanging Lake tunnel project, which will carry I-70 through the Rockies at Glenwood Canyon, Colorado.  With twin bores 3900 ft long, requiring 290,000 cu yd of hard rock to be drilled and shot, Hanging Lake is one of the world's largest tunneling projects now underway.  The key to the job's rapid progress is the use, for blasthole drilling, of two twin-boomed H245 rock drills made by Atlas Copco Roctec Inc.  This article provides further details of the excavation, which is scheduled for completion in 1992.]]></description>
      <pubDate>Fri, 31 May 1991 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/354335</guid>
    </item>
    <item>
      <title>ROCK DREDGING NOW AND IN THE FUTURE: WHAT ARE THE LIMITS?</title>
      <link>https://trid.trb.org/View/262838</link>
      <description><![CDATA[No abstract provided.]]></description>
      <pubDate>Tue, 28 Feb 1989 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/262838</guid>
    </item>
    <item>
      <title>EICHELBERG TUNNEL IS SUCCESSFUL PROVING GROUND FOR UPDATED JUMBO</title>
      <link>https://trid.trb.org/View/210559</link>
      <description><![CDATA[The first of a new generation of advanced hydraulic drifters from Finland is now in full operational use drilling sandstones in a tunnel on Germany's Hannover-Wurzburg fast intercity railway.  Up to 25% more penetration for the same input of energy is claimed for the drill.  This article discusses the machinery in general and its particular application in the Eichelberg Tunnel construction, including tunneling techniques, drill patterns, mucking, and other aspects of the work.]]></description>
      <pubDate>Wed, 30 Jan 1985 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/210559</guid>
    </item>
    <item>
      <title>THE GENERATION OF BENDING VIBRATIONS IN DRILL RODS</title>
      <link>https://trid.trb.org/View/173443</link>
      <description><![CDATA[One important source of noise from percussive rock drills is bending vibrations of the drill rod.  These vibrations originate from imperfect rotational symmetry in the system. It is possible to improve symmetry at the machine end by means of tight fittings and small tolerances.  It is, however, difficult to improve the conditions at the rock end of the rod.  This paper presents a theoretical investigation of how much of the energy fed into the system that can be expected to be converted to bending energy in the drill rod.  The model considered is simple, an integral steel with the rock response represented by an eccentrically acting viscous damper, but it is believed to give qualitively correct answers.  The results indicate that in a typical situation, one can expect about 10% of the incident stress wave energy to be converted to bending.  For a system with a detachable drill bit the fraction is probably less.  The form of the incident stress wave is not important, although a steep front tends to give more bending.  A heavier piston reduces the bending fraction.  (Author/TRRL)]]></description>
      <pubDate>Wed, 22 Dec 1982 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/173443</guid>
    </item>
    <item>
      <title>DRILLING IN THE EIGHTIES</title>
      <link>https://trid.trb.org/View/180606</link>
      <description><![CDATA[In a discussion of current rock drilling equipment, the paper commences by recalling predictions made in an earlier paper in 1970 concerning the quarrying industry.  Against this background the article examines rock drilling equipment requirements for the 1980s.  Drilling equipment will be required with flexibility of operation (in terms of rock conditions and hole requirements), reliability, speed of penetration and ease of operation.  The fundamental characteristics of pneumatic and hydraulic drilling systems are compared covering production efficiency, economy, ergonomics and serviceability.  The article concludes with factors to be considered when evaluating hydraulic rock drilling equipment. (TRRL)]]></description>
      <pubDate>Fri, 30 Jul 1982 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/180606</guid>
    </item>
    <item>
      <title>DESIGNING ROADHEADER CUTTING HEADS</title>
      <link>https://trid.trb.org/View/174036</link>
      <description><![CDATA[Boom roadheaders are tackling ever harder rocks where the design of their rotary cutting heads is crucial to successful operation.  This paper summarizes early results of research at the Mining Research & Development Establishment into cutting heads and explains the general principles upon which they should be designed.  One of the main conclusions is that the number of tools in a cutting line should not exceed half the number of cutting sequences (or starts), i.e. tools should not cut successively in the same lines.  This is important for effective cutting in harder rocks.  Computer programs have been developed to assist in the design of cutting heads; these are also briefly described.  (Author/TRRL)]]></description>
      <pubDate>Sat, 27 Feb 1982 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/174036</guid>
    </item>
  </channel>
</rss>