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    <title>Transport Research International Documentation (TRID)</title>
    <link>https://trid.trb.org/</link>
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    <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>
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    <item>
      <title>ROCK PROPERTIES COMPUTED FROM RANDOM PORE SIZE DISTRIBUTION</title>
      <link>https://trid.trb.org/View/121081</link>
      <description><![CDATA[A MATHEMATICAL PROCEDURE HAS BEEN USED TO CALCULATE THE POROSITY AND PERMEABILITY OF A POROUS MATRIX. THE TECHNIQUE INVOLVES A SOLUTION OF POISSEUILLES AND DARCYS EQUATIONS ACROSS EACH PORE AND OPENING. THE PROCEDURE USES A DIGITAL COMPUTER, RANDOM NUMBER GENERATOR, AND AN APPROXIMATE RANGE OF PORE DIAMETERS. THE EFFECT OF USING SMALL SAMPLES IN DETERMINING ROCK PROPERTIES IS ALSO DISCUSSED. /AUTHOR/]]></description>
      <pubDate>Sun, 15 Aug 2004 02:37:58 GMT</pubDate>
      <guid>https://trid.trb.org/View/121081</guid>
    </item>
    <item>
      <title>FACTORS INFLUENCING THE EARLY STAGES OF COMPACTION OF CLAYS AND SANDS - REVIEW</title>
      <link>https://trid.trb.org/View/120139</link>
      <description><![CDATA[PETROLOGIC AND GEOCHEMICAL FACTORS STRONGLY INFLUENCE THE COMPACTION OF CLAYS AND SANDS UNDER PRESSURES BETWEEN 0 AND 100 KG PER CM SQ. PARTICLE SIZE IS THE MOST PERVASIVE OF THESE, BOTH IN ITS CONSISTENTLY INVERSE RELATION TO POROSITY AND ITS CONTROL OF THE INFLUENCE EXERTED BY THE OTHER FACTORS. THE WATER CONTENT OF SATURATED CLAYS IS A COMPLEX FUNCTION OF THE PHYSICO-CHEMICAL INFLUENCES ON THE SORPTION OF WATER ON CLAY-MINERAL SURFACES. IT SEEMS TO BE DIRECTLY RELATED TO SPECIFIC SURFACE INCREASE, EXCHANGEABLE CATION VALENCE, AND THE CONCENTRATION OF INTERSTITIAL ELECTROLYTES IN MOST CLAYS. PREFERRED ORIENTATION OF CLAY-MINERAL PARTICLES SEEMS TO DEVELOP AT A VERY EARLY STAGE OF COMPACTION, AT PRESSURES NEAR 1 KG PER CM SQ. ITS DEVELOPMENT IS ENHANCED BY GREATER INITIAL WATER CONTENTS, GREATER AMOUNTS OF CARBONACEOUS ORGANIC MATTER, AND PERHAPS BY LESSER CONCENTRATIONS OF INTERSTITIAL ELECTROLYTES. A TENDENCY TO BE COMPRESSED INTO DOMAINS OR SUBMICROSCOPIC ORIENTED AGGREGATES MAY BE TYPICAL OF FINE-GRAINED CLAYS MIXED WITH CONCENTRATED NA SOLUTIONS OR SOLUTIONS OF OTHER CATIONS. WELL SORTED SANDS HAVE GREATER POROSITIES THAN POORLY SORTED SANDS. ANGULAR SANDS HAVE GREATER INITIAL POROSITIES AND ARE MORE COMPRESSIBLE THAN ROUNDED SANDS OF THE SAME SIZE. ADMIXTURES OF PLATY MICA PARTICLES INCREASE THE POROSITY, COMPRESSIBILITY, AND ELASTICITY OF SANDS. /AUTHOR/]]></description>
      <pubDate>Sun, 15 Aug 2004 02:34:15 GMT</pubDate>
      <guid>https://trid.trb.org/View/120139</guid>
    </item>
    <item>
      <title>A NEW APPARATUS FOR RECORDING PARTICLE SIZE DISTRIBUTION</title>
      <link>https://trid.trb.org/View/121227</link>
      <description><![CDATA[A MANOMETER AND SENSITIVE CAPACITANCE TRANSDUCER FOLLOW THE DROP IN HYDROSTATIC PRESSURE AT A POINT NEAR THE BOTTOM OF A COLUMN OF SOIL SUSPENSION, DURING SEDIMENTATION. CURRENT FROM THE TRANSDUCER IS FED TO A RECORDER, WHICH TRACES AN ACCUMULATION CURVE. THE FIRST DERIVATIVE (SLOPE OF THE CURVE) GIVES A SUMMATION CURVE OF THE PARTICLE SIZE DISTRIBUTION. RESULTS ON FOUR SOILS WITH DIFFERENT PARTICLE SIZE DISTRIBUTIONS AGREE WITH THOSE OBTAINED BY A STANDARD PIPETTE-SAMPLING/SIEVING PROCEDURE OVER THE RANGE 20-200 MICRONS (MU) EFFECTIVE SETTLING DIAMETER. /LCPC/A/RRL/]]></description>
      <pubDate>Mon, 03 Nov 2003 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/121227</guid>
    </item>
    <item>
      <title>A TECHNIQUE FOR THE RAPID DETERMINATION OF THE LIGHT MINERALS OF DETRITAL SANDS</title>
      <link>https://trid.trb.org/View/107138</link>
      <description><![CDATA[DETERMINATION OF LIGHT MINERALS OF DETRITAL SANDS BY ETCHING AND STAINING PROCEDURES IS GREATLY FACILITATED WITH THE USE OF A BLACK ROOFING TAR MOUNTING MEDIUM. THIS MEDIUM IS UNAFFECTED BY HYDROFLUORIC ACID ETCHING AND PROVIDES A CONVENIENT DARK BACKGROUND FOR COUNTING STAINED GRAINS WITH REFLECTED LIGHT. THE TECHNIQUE IS PARTICULARLY SUITED FOR THE DETERMINATION OF QUARTZ, CHERT, AND FELDSPAR PERCENTAGES OF LARGE NUMBERS OF SAMPLES. /AUTHOR/]]></description>
      <pubDate>Tue, 09 Sep 2003 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/107138</guid>
    </item>
    <item>
      <title>A SIMPLE PEEL TECHNIQUE FOR SILTS AND CLAYS</title>
      <link>https://trid.trb.org/View/60738</link>
      <description><![CDATA[A simple peel technique is described for fine silts and clays.  The method is equally successful in the laboratory and under even the most difficult of field conditions.  The peels are easily portable since they can be rolled up and stored in small containers, provide good color representations, are durable, do not destroy the section, and require very little equipment and even less section preparation.  /Author/]]></description>
      <pubDate>Fri, 13 Jan 1978 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/60738</guid>
    </item>
    <item>
      <title>AN ELECTRO-OSMOTIC KNIFE FOR SLICING LARGE BOX CORES</title>
      <link>https://trid.trb.org/View/53698</link>
      <description><![CDATA[Large box cores can be sliced vertically or horizontally on board ship with a knife that has an electrified metal blade. The knife operates on the principle of electro-osmosis, which reduces drag along the blade during slicing and minimizes distortion of the sediment.  The slices are useful for subsampling the core and for studying physical and biogenic sedimentary structures.  Making slices helps solve the problems of handling, storing, and shipping the large volumes of sediment recovered in box cores. /Author/]]></description>
      <pubDate>Tue, 20 Sep 1977 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/53698</guid>
    </item>
    <item>
      <title>A COMPARISON OF ELECTRONIC PARTICLE COUNTING AND PIPETTE TECHNIQUES IN ROUTINE MUD ANALYSIS</title>
      <link>https://trid.trb.org/View/51976</link>
      <description><![CDATA[Electronic particle counting and pipette size-analysis technqieus are compared for their relative effectiveness in large-scale routine mud analysis.  Optimum laboratory procedures for conducting electronic analyses with a Model TA Coulter Counter are presented.  Comparative electronic and pipette analyses conducted on the same samples resulted in equivalent precision for both techniques.  Results of electronic analyses consistently showed size distributions significantly coarser than those obtained by pipette analyses.  The laboratory efficiency of the relatively rapid electronic technique is far superior to that of the pipette technique, although more extensive precautionary measures are required to maintain a high level of analytical accuracy and precision.  The quality of electronic analyses largely depends upon the effectiveness of standardized operational procedures established within the laboratory.  /Author/]]></description>
      <pubDate>Wed, 22 Jun 1977 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/51976</guid>
    </item>
    <item>
      <title>COMPETENCE OF FINE-GRAINED DEBRIS FLOWS</title>
      <link>https://trid.trb.org/View/36373</link>
      <description><![CDATA[Debris flow is the gravity-propelled movement of sediment- water mixtues, in which grains are supported above the non-moving bed by the strength and buoyancy of a  clay-water matrix.  The competence (largest supported grain size) of a debris flow is thereby determined by the magnitudes of matrix strength and density, which vary primarily and directly with matrix clay content.  Strength also varies with the type of clay mineral and with the cation content of the water.  Experiments reported here indicate that as little as 1.5 to 4 wt. % clay mixed into water is sufficient to support finest sand.  The experiments also show that competence is less in flowing debris than in static debris, and that competence decreases with flow duration for durations less than about one hour but remains essentially constant for durations greater than one hour. Competence apparently is independent of flow velocity or velocity gradient, although low velocities and gradients were not examined here.  Calculations based on the experimental data reveal that marine sediments with finest sand as their coarsest material and with bulk clay contents as low as 2 wt. %, or less, can move as debris flows. Sediments with coarsest sand can move as debris flows if they contain as little as 19% clay, or less.  Considering that these values are high estimates, many fine-grained marine sediments have clay contents great enough in order to move as debris flows.  Zones of various competences should exist within a debris flow because of the nature of the velocity profile and the dependence of competence on shear and flow duration.  These zones are preserved during deposition and therefore, debris-flow deposits expectably should have layers of various grain sizes, and perhaps be normally and/or inversely graded.  Debris flow is discussed in this paper as an idealized concept, where grain support is wholly by strength and buoyancy.  In real flows, support also may be provided by grain-interaction dispersive pressure and by turbulence, increasing the competence of the flows.  Debris-flow mobility, in terms of the forces required to keep the flow moving, was not considered here but is equally significant to competence in evaluating the occurrence of real debris flows. /Authors/]]></description>
      <pubDate>Wed, 10 Mar 1976 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/36373</guid>
    </item>
    <item>
      <title>MEASURING VOLUMES OF SEDIMENTARY GRAINS</title>
      <link>https://trid.trb.org/View/126497</link>
      <description><![CDATA[THE HYDROSTATIC WEIGHING METHOD BASED ON ARCHIMEDES' PRINCIPLE IS THE SIMPLEST, AND PROBABLY THE MOST ACCURATE METHOD OF DETERMINING THE VOLUMES OF INDIVIDUAL SEDIMENT GRAINS OR FOSSILS.  A SIMPLE WEIGHING INSTRUMENT CAN BE USED WITHOUT CONSTRUCTING SPECIAL DEVICES.  THE SEDIMENT GRAIN OR FOSSIL IS FIRST WEIGHED IN DEVICE, AND SUSPENDED BY A VERY THIN WIRE IN A SMALL CONTAINER FILLED WITH DISTILLED WATER (OR OTHER LIQUID OF KNOWN DENSITY).  IT IS WEIGHED WHILE IMMERSED COMPLETELY IN LIQUID.  THE BALANCES THAT MAY BE USED FOR THE DETERMINATION ARE DESCRIBED.  THE ADVANTAGES OF THIS METHOD ARE OUTLINED, AND FACTORS WHICH MAY AFFECT THE ACCURACY OF THIS METHOD ARE DISCUSSED.]]></description>
      <pubDate>Fri, 15 Mar 1974 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/126497</guid>
    </item>
    <item>
      <title>GELATIN COATED MICROSCOPE SLIDES IN SEDIMENTARY SIZE ANALYSIS</title>
      <link>https://trid.trb.org/View/126500</link>
      <description><![CDATA[DETAILS ARE GIVEN OF THE METHOD OF MAKING GELATIN COATED MICROSCOPE SLIDES AND OF MOUNTING DISPERSED GRAINS.  SUCH SLIDES WHEN USED FOR THE SUPPORT OF CLAY SIZED PARTICLES PREVENTS MOVEMENTS IN THE MOUNTING MEDIUM LEADING TO FLOCCULATION OR CLUMPING WHICH MAY AFFECT THE ACCURACY OF PARTICLE SIZE ANALYSIS WITH AN IMAGE ANALYZING COMPUTER. THIS TECHNIQUE ENABLES THE MEASUREMENT OF SIZE DISTRIBUTION WITHIN VERY CLOSELY SPACED UNITS IN FINELY LAMINATED SEDIMENTS, AND HAS PERMITTED THE RESOLUTION OF VARIATION WITHIN THE DIFFERENT PHASES OF SINGLE UNITS OF VARIED GLACIAL DEPOSITS.  IT IS ALSO THE SIMPLEST WAY TO OBTAIN CONSISTENT DISPERSION (OF SUCH MATERIALS AS THE FINER GRADES OF MINE MILL PRODUCTS, AND OF INDUSTRIAL CHIMNEY SMOKE AND FLY ASH PARTICLES) FOR EVALUATION OF SIZE DISTRIBUTION.]]></description>
      <pubDate>Fri, 15 Mar 1974 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/126500</guid>
    </item>
    <item>
      <title>AUTOMATIC GRAIN SIZE ANALYSES BY MEANS OF ELECTRO-MAGNETIC SURFACE MEASUREMENTS</title>
      <link>https://trid.trb.org/View/120252</link>
      <description><![CDATA[AUTOMATION OF THE TIME-CONSUMING CONVENTIONAL METHODS OF OPTICAL OR MECHANICAL IDENTIFICATION OF GRAIN SIZE IS POSSIBLE BY THE ELECTRO-MAGNETIC READ-OUT OF THE SURFACE ROUGHNESS OF THE SAMPLE. THE INSTRUMENT USED IS KNOWN AS A SURFACE MEASURING INSTRUMENT. ITS BASIC PRINCIPLE IS THE SAME AS THAT USED IN SELF-INDUCTANCE HEADS OF PICK-UP ELEMENTS. THE ADVANTAGES OF THIS METHOD ARE ITS EXTREMELY HIGH SPEED IN COMPARISON TO CONVENTIONAL METHODS AND THE POSSIBILITY OF COMPUTERIZING THE PROCEDURE, LEADING TO AUTOMATIC ANALYSES AND INSTANT READ-OUT OF GRAIN-SIZE, ORIENTATION OF THE GRAINS, AND DISTRIBUTION OF SPECIFIC MINERALS. /AUTHOR/]]></description>
      <pubDate>Tue, 17 Apr 1973 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/120252</guid>
    </item>
    <item>
      <title>THE DESCRIPTION AND MEASUREMENT OF SEDIMENTARY PARTICLES AND THE CONCEPT OF FORM</title>
      <link>https://trid.trb.org/View/120260</link>
      <description><![CDATA[THE DEFINING EQUATIONS FOR INVESTIGATION OF SEDIMENTARY AGGREGATE PROPERTIES AND OF INDIVIDUAL PARTICLES ARE EXAMINED. THE EQUATION FOR INDIVIDUALS IS EXTENDED IN RELATION TO COMPONENTS OF 'FORM,' WHICH IS DEFINED AS 'THE EXPRESSION OF THE EXTERNAL MORPHOLOGY OF AN OBJECT.' THESE COMPONENTS ARE SHAPE, SPHERICITY, ANGULARITY, ROUNDNESS, AND SURFACE TEXTURE. IMPLICATIONS OF THIS DIVISION ARE DISCUSSED WITH REGARD TO MEASUREMENT TECHNIQUE AND THE NEED FOR SUCH A DIVISION OF FORM COMPONENTS. /AUTHOR/]]></description>
      <pubDate>Sun, 08 Apr 1973 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/120260</guid>
    </item>
    <item>
      <title>EXPERIMENTAL ERROR IN PEBBLE ROUNDNESS DETERMINATION BY THE MODIFIED WENTWORTH METHOD</title>
      <link>https://trid.trb.org/View/120261</link>
      <description><![CDATA[TWO QUESTIONS ARE ADDRESSED, ACCURACY OF THE MODIFIED WENTWORTH METHOD IN DETERMINING PEBBLE ROUNDNESS AND THE NATURE OF ROUNDNESS FREQUENCY DISTRIBUTIONS. THIRTY OBSERVERS, RANGING FROM LIBRARIANS THROUGH SEDIMENTOLOGISTS, EMPLOYED THE MODIFIED WENTWORTH METHOD TO MEASURE THE RADIUS OF CURVATURE OF THE SHARPEST CORNER. WHILE THERE WERE SYSTEMATIC ERRORS ARISING FROM SOME OBSERVERS' TENDENCY TO MEASURE CONSISTENTLY HIGH OR LOW, MOST ERRORS AROSE FROM DEFINITION OF 'THE SHARPEST CORNER' AND FROM THE FACT THAT CORNERS MAY APPROACH SEGMENTS OF PARABOLAS OR HYPERBOLAS RATHER THAN A TRUE CIRCLE, SO THAT IT WAS DIFFICULT TO PICK A TEMPLATE CIRCLE. IN ANOTHER EXPERIMENT, DATA FOR RIVER AND BEACH PEBBLES WERE USED TO PLOT ROUNDNESS FREQUENCY DISTRIBUTIONS. THESE WERE FOUND TO BE ARITHMETIC-NORMAL, RATHER THAN LOG-NORMAL AS SUGGESTED BY OTHER AUTHORS. IN CONCLUSION, IT IS RECOMMENDED THAT WHEN TWO OR MORE PERSONS ARE CONDUCTING ROUNDNESS STUDIES, PEBBLES IN ANY ONE LOCALITY OR SIZE CLASS OR LITHOLOGY SHOULD BE MEASURED IN EQUAL AMOUNTS BY ALL OPERATORS.]]></description>
      <pubDate>Sun, 08 Apr 1973 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/120261</guid>
    </item>
    <item>
      <title>A NEW METHOD FOR DETERMINING SPHERICITY</title>
      <link>https://trid.trb.org/View/120262</link>
      <description><![CDATA[A STATISTICAL METHOD FOR DETERMINING THE SPHERICITY OF AN ASSEMBLAGE OF PARTICLES IS PRESENTED. THE PROPOSED METHOD REQUIRES THAT RANDOM PACKED PARTICLES BE CEMENTED WITH A COLORED PLASTIC. THE RESULTING SOLID IS THEN SLABBED INTO SECTIONS WHICH ARE ANALYZED BY MEANS OF A SQUARE GRID. INFORMATION THUS OBTAINED IS USED IN A RAPID AND PRECISE EVALUATION OF PARTICLE SPHERICITY. /AUTHOR/]]></description>
      <pubDate>Sun, 08 Apr 1973 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/120262</guid>
    </item>
    <item>
      <title>A SIMPLE APPARATUS FOR THE RAPID AND ACCURATE DETERMINATION OF BULK DENSITIES OR VOLUMES OF ROCK OR MINERAL FRAGMENTS</title>
      <link>https://trid.trb.org/View/120263</link>
      <description><![CDATA[A MERCURY-IMMERSION METHOD FOR DETERMINING THE BULK DENSITY OR VOLUME OF ANY COHERENT OBJECT, KNOWN SINCE 1926 BUT APPARENTLY NEVER FULLY DESCRIBED, IS PRESENTED. THE METHOD IS VERY RAPID, PRECISE, ACCURATE, AND CONVENIENT. THE APPARATUS, THE MEASURING PROCEDURE, AND THE ANALYTIC CALCULATIONS ARE DESCRIBED BRIEFLY, AND THE RESULTS OF TESTS ARE DISCUSSED.]]></description>
      <pubDate>Sun, 08 Apr 1973 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/120263</guid>
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