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    <title>Transport Research International Documentation (TRID)</title>
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    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
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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>
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      <title>Transport Research International Documentation (TRID)</title>
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      <link>https://trid.trb.org/</link>
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    <item>
      <title>THE CORRUGATED METAL CONDUIT AS A COMPRESSION RING</title>
      <link>https://trid.trb.org/View/110176</link>
      <description><![CDATA[BRIEF DISCUSSIONS OF THE TYPES OF LOADINGS ON A CORRUGATED METAL STRUCTURE ARE GIVEN. THE LOADS CONSIDERED ARE THOSE ACTING IN A PLANE PERPENDICULAR TO THE LONGITUDINAL AXIS OF THE STRUCTURE WHICH TEND TO CHANGE ITS CROSS-SECTIONAL SHAPE. TWO TYPES OF STRENGTH IN THE STRUCTURE ARE CONSIDERED - RING COMPRESSION STRENGTH AND RING BENDING STRENGTH. A DISCUSSION OF REQUIREMENTS FOR RING COMPRESSION STRENGTH INCLUDES THE APPLICABLE FEATURES OF A RING COMPRESSION THEORY AND SHOWS HOW A CORRUGATED METAL CONDUIT CARRIES FILL LOAD BY MEANS OF ITS RING STRENGTH AND ITS ABILITY TO UTILIZE SUPPORT FROM SURROUNDING EARTH. A METHOD OF APPLYING LINEAR ARCH THEORY TO THE STRUCTURE IS GIVEN WHICH WILL ENABLE A DESIGNER TO APPROXIMATE THESE COMPRESSION REQUIREMENTS IN THE PERIPHERY OF THE STRUCTURE AND PRESSURE REQUIREMENTS IN THE SOIL SURROUNDING IT. THE REQUIREMENTS FOR BENDING STRENGTH ARE PRESENTED IN THREE PARTS DEALING WITH STRENGTH FOR RESISTING COLUMN BUCKLING IN THE STRUCTURE'S WALLS AND FOR BRIDGING INCONSISTENCIES IN THE BACKFILL, STRENGTH FOR MINIMUM COVER INSTALLATIONS, AND STRENGTH FOR HANDLING, TRANSPORTING, ERECTING AND INSTALLATION OF THE STRUCTURE. A DISCUSSION OF INSTALLATION FEATURES SUCH AS FOUNDATION CONDITIONS, BEDDING, IMPERFECT TRENCH METHODS OF CONSTRUCTION IS GIVEN, INCLUDING WHAT CONSTITUTES ADEQUATE BACKFILL AND COMPACTION AROUND A STRUCTURE. A SUMMARY INCLUDES STEP-BY-STEP PROCEDURES FOR THE VARIOUS METHODS OF DESIGN AND INSTALLATION OF CORRUGATED METAL STRUCTURES AS LOAD-CARRING CONDUITS. /AUTHOR/]]></description>
      <pubDate>Fri, 09 Dec 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/110176</guid>
    </item>
    <item>
      <title>DESIGN FEATURES OF AN 18.5-FOOT DIAMETER CULVERT INSTALLATION IN MONTANA AND DATA ON SUBSEQUENT FAILURE</title>
      <link>https://trid.trb.org/View/103837</link>
      <description><![CDATA[A PROFILE REQUIRING A 100-FT HIGH FILL DICTATED THE SELECTION OF AN ENCLOSED PIPE CONDUIT TO CONVEY A CANYON STREAM ACROSS INTERSTATE HIGHWAY 115 IN WEST CENTRAL MONTANA. AN 18.5-FT DIAMETER STRUCTURAL PLATE CIRCULAR PIPE DESIGNED BY THE RING COMPRESSION THEORY WAS INSTALLED FOR 2.3 MILES. AFTER COMPLETION OF THE EMBANKMENT OVER THE PIPE, MAJOR RUPTURES IN THE PIPE REQUIRED REMOVAL AND RECONSTRUCTION OF A LARGE PORTION. DATA IS PRESENTED COVERING PHYSICAL FEATURES OF THE PROJECT SITE IN THEIR RELATIONSHIP TO THE SELECTION OF A PIPE, BASIC DESIGN DATA AND FEATURES OF THE FAILED PIPE. A PAPER BY ARMCO STEEL CORPORATION DEALS WITH THE EXAMINATION OF FAILED BOLTS TAKEN FROM THE CULVERT AND SPECIAL TESTS OF THE TYPE OF HIGH STRENGTH BOLTS USED.]]></description>
      <pubDate>Fri, 02 Dec 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/103837</guid>
    </item>
    <item>
      <title>FIELD VERIFICATION OF RING COMPRESSION CONDUIT DESIGN</title>
      <link>https://trid.trb.org/View/103831</link>
      <description><![CDATA[A LOADING-TO-FAILURE TEST WAS CONDUCTED BY ARMCO-THYSSEN TO PROVIDE SCIENTIFIC DATA ON THE BEHAVIOR OF CORRUGATED STEEL STRUCTURES UNDER LOADING CONDITIONS, ESPECIALLY TO DETERMINE UNDER WHAT LOAD THE STRUCTURE WOULD FINALLY COLLAPSE AND HOW THIS COLLAPSE DEVELOPED. THE LIVE-LOAD TEST WAS CONDUCTED TO PROVE TO THE GERMAN FEDERAL RAILWAY THAT LARGE CORRUGATED STEEL STRUCTURES ARE SAFE FOR USE AS CONDUITS AND UNDERPASSES IN RAILWAY EMBANKMENTS. THE TEST STRUCTURE WAS A 7-GAGE MULTI-PLATE PIPE ARCH OF 20-FT 7-IN. SPAN AND 13-FT 2-IN. RISE, ARMCOS LARGEST STRUCTURE OF THIS SHAPE. THE COVER HEIGHT AND THE POSITIONING OF THE LOAD WERE VARIED ACCORDING TO DIFFERENT TEST PURPOSES. SINCE THE COVER WAS LOW AND THE LIVE LOAD WAS FAIRLY SMALL, THE WALL THICKNESS WAS NOT DETERMINED BY RING-COMPRESSION METHODS BUT BY EMPIRICAL DATA APPLYING TO THE STRUCTURE DURING BACKFILLING. THUS THE WALL THICKNESS WAS DESIGNED BY THE FLEXIBILITY FACTOR. STRAIN MEASUREMENTS WERE TAKEN WITH STRAIN GAGE STRIPS INSTALLED AT EACH OF SIX MEASURING POINTS IN TWO SECTIONAL PLANES. THREE HEIERLI PRESSURE CELLS WERE INSTALLED IN BACKFILL IN A HORIZONTAL PLACE ABOVE THE PIPE ARCH. UNDER A LOAD OF 850 TONS, TWO INWARD BULGES BEGAN TO DEVELOP ON EACH SIDE OF THE CREST. THE LARGE INCREASE IN DEFORMATIONS CAME TO A STANDSTILL IN THE COURSE OF THE NIGHT. THE NEXT MORNING, IT WAS NOTED THAT THE FIRST LAYER OF SLABS WAS RESTING FIRMLY AGAINST THE SOIL AS A RESULT OF SETTLING OF THE TIES AND SAGGING OF THE SLABS. WALL PRESSURE MEASUREMENTS WERE MADE AND AVERAGE DISTRIBUTION OF WALL PRESSURES COMPUTED.]]></description>
      <pubDate>Fri, 18 Nov 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/103831</guid>
    </item>
    <item>
      <title>PIPELINE ECONOMY THROUGH THE DESIGN OF BACKFILL</title>
      <link>https://trid.trb.org/View/106602</link>
      <description><![CDATA[SOME METHODS FOR THE STRUCTURAL DESIGN OF SOIL-PIPE INTERACTION SYSTEMS ARE REVIEWED AND CORRELATED. THESE METHODS INCLUDE WALL CRIPPLING FOR WHICH RING COMPRESSION IS AN ADEQUATE MEANS OF ANALYSIS UNDER MANY CONDITIONS, AND RING DEFLECTION. BECAUSE PRECISE ANALYSIS IS NOT USUALLY JUSTIFIED, PRACTICAL RULES OF THUMB ARE PROPOSED FOR AVERAGE DESIGN BASED EITHER ON WALL CRIPPLING OR RING DEFLECTION. MAXIMUM PRESSURE CONCENTRATIONS ARE EVALUATED AS A WORST CONDITION FOR DESIGN WHEN WALL CRIPPLING CONTROLS. CONTROL OF RING DEFLECTION BY COMPACTION OF THE BACKFILL NEAR THE PIPE IS DESCRIBED. REDUCTION OF SOIL PRESSURES ON THE PIPE BY CONTROL OF SOIL COMPACTION NEAR THE PIPE IS PROPOSED. THE TECHNIQUE MAY RESULT IN A SIGNIFICANT INCREASE IN THE ALLOWABLE HEIGHT OF FILL ON THE PIPE WITH CONSEQUENT ECONOMY. /AUTHOR/]]></description>
      <pubDate>Sun, 16 Jan 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/106602</guid>
    </item>
    <item>
      <title>STRUCTURAL DESIGN OF BURIED CORRUGATED POLYETHYLENE PIPES</title>
      <link>https://trid.trb.org/View/282943</link>
      <description><![CDATA[Test sections of corrugated polyethylene pipe (CPEP) were buried, as in typical drainage installation, in competent, compacted, granular backfill.  Both dead load (soil cover) and surface live load (truck dual wheels) were applied.  The objectives of the tests were to (a) observe performance of the pipes under load, (b) identify performance limits, (c) resolve some of the questions unanswered by present design methods, and (d) propose improved methods for the structural design of buried CPEP.  The objectives were achieved. Experimenters agreed that tests confirmed the complementary interaction of pipe and backfill.  Minimum soil cover was investigated under multiple passes of live loads. Conditions for structural stability of the pipe were identified.  An analytical procedure was developed for predicting the minimum height of soil cover to assure ring stability under multiple passes of live loads.  Maximum soil cover tests confirmed the ring compression analysis as the primary basis for design but also revealed a need to include the effects of ring deflection.  An observable performance limit was identified, and a method of design was developed that combined the effect of ring deflection and ring compression on the performance limits of CPEP buried under maximum height of soil cover.]]></description>
      <pubDate>Sun, 31 Jul 1988 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/282943</guid>
    </item>
    <item>
      <title>DESIGN OF BURIED CULVERTS WITH STRESS-RELIEVING JOINTS</title>
      <link>https://trid.trb.org/View/282946</link>
      <description><![CDATA[Circumferentially slotted bolt hole connections, a new concept for corrugated metal culverts, have proven to be effective in reducing thrust stress (ring compression) in deep embankment installations.  Pragmatically, this means that slotted-joint culverts can be buried deeper than standard-joint culverts, or lighter-gauge metal can be used. However, because of the present lack of design tables and guidelines, this economical innovation has far from reached its full application potential.  In an attempt to fill this need, a complete design methodology employing an experimentally verified culvert-joint-soil system model with analytical solutions along with a set of realistic design criteria is offered in this paper.  The design methodology is used to generate a sequence of design tables for 6-in. x 2-in. corrugated steel pipes with slotted joints, in which the tables specify the maximum allowable fill height cover as a function of pipe diameter, wall thickness (gauge), and soil stiffness.  Even though the design methodology is conservative, the slotted-joint pipes can, in some cases, sustain fill heights more than twice those of standard pipes if good-structural-quality soil is used.  On the other hand, when poor-quality soil is used, the slotted-joint pipes do not provide a gain in allowable fill height.]]></description>
      <pubDate>Sun, 31 Jul 1988 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/282946</guid>
    </item>
    <item>
      <title>ANALYSIS AND BEHAVIOR OF BURIED CULVERTS WITH SLOTTED JOINTS</title>
      <link>https://trid.trb.org/View/276734</link>
      <description><![CDATA[Corrugated metal culverts with circumferentially slotted bolt-hole-connections, a new concept in culvert technology, have the potential to significantly reduce thrust stress (ring compression) in deep embankment installations. From a design viewpoint, this means that deeper burial depths can be achieved or lighter-gauge metal can be used or both. The results of a comprehensive investigation on the structural behavior, analysis, and design of slotted-joint culvert installations are summarized. The scope includes data gathering, experimental testing, analytical model development, verification with field data, and guidelines for design. Based on laboratory load-deformation tests, slotted-joint behavior is simulated with a five-parameter model and incorporated into the CANDE computer program with two methods for solving the culvert-soil boundary value problem: a modified elastic solution and a finite-element procedure. The latter method, which offers sophisticated modeling capabilities (e.g., incremental construction, nonlinear soil models, and frictional interfaces), is shown to correlate well with experimental field data. The former method, although more idealized, provides a keen insight into fundamental behavioral aspects of slotted-joint culverts and is an extremely useful design aid. Both analytical and experimental findings demonstrate that the slotted bolt-hole concept is extraordinarily successful in reducing ring compression. In many cases allowable fill height may be increased 40 ft or more.]]></description>
      <pubDate>Sun, 30 Nov 1986 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/276734</guid>
    </item>
    <item>
      <title>PROOFTESTING OF A STRUCTURAL PLATE PIPE WITH VARYING BEDDING AND BACKFILL PARAMETERS: SECTION VI: ANALYSIS OF SETTLEMENTS</title>
      <link>https://trid.trb.org/View/179297</link>
      <description><![CDATA[Settlement data obtained from 64 fluid settlement platforms, plate and rod platforms, and leveling at four zones of the BD Culvert, 120-in. (3048-mm), structural plate pipe, under 188 ft. (57m) of overfill are employed in calculation of quasi-theoretical crown loads, using methods developed by Marston and Spangler. Soil stresses measured by stressmeters near the soil-pipe interface and in the embankment are compared with quasi-theoretical stresses assessed with calculated settlement ratios. Some very encourageing correlations were observed between quasi-theoretical and measured soil stresses; however, on the average, the quasi-theoretical stresses tended to be significantly larger than measured ones. This approach is probably more valuable for structural plate than for rigid pipes, when used in conjunction with Ring Compression Theory. (FHWA)]]></description>
      <pubDate>Mon, 30 Aug 1982 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/179297</guid>
    </item>
    <item>
      <title>CENTRIFUGE TESTS OF FLEXIBLE CIRCULAR PIPES SUBJECTED TO SURFACE LOADING</title>
      <link>https://trid.trb.org/View/156064</link>
      <description><![CDATA[The report covers work carried out in the Cambridge university engineering department under a transport and Road Research Laboratory research contract to study the behaviour of buried flexible pipes.  The work consists of a series of centrifuge experiments conducted on very flexible model pipes buried at shallow depth in uniform dense sand, to examine the validity of ring compression theory under the combined action of self weight of the backfill and surface loading.  Tests were carried out on model pipes made from steel and plastic having different effective stiffness to study the influence of this factor on the reductions in load which takes place due to arching.  A comparison is given of the calculated pressures and measured pipe stresses from which load reduction factors are derived.  The ring compression theory is shown to be valid for model pipes in wide trenches or under embankments when subjected to combined surface and backfill loadings.  The results illustrate that the load reduction factor is influenced by the intensity of surface loading and by the depth of embedment and is greatly dependent on the effective stiffness of the pipe.(a) (TRRL)]]></description>
      <pubDate>Fri, 06 Feb 1981 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/156064</guid>
    </item>
    <item>
      <title>THE VALIDITY OF RING COMPRESSION THEORY IN THE DESIGN OF FLEXIBLE BURIED PIPES</title>
      <link>https://trid.trb.org/View/84123</link>
      <description><![CDATA[The report covers work carried out in the Cambridge University Engineering Department under a Transport and Road Research Laboratory sponsored research contract to study the behaviour of buried pipes.  The work consists of a series of experiments conducted on model flexible pipes embedded in uniform dense sand, to examine the validity of ring compression theory and the load reductions which take place due to arching.  Conventional laboratory floor tests with surface overpressure as well as centrifuge tests to simulate gravity loading have been carried out to study the influence of a range of boundary conditions.  The ring compression theory is shown to be valid in the cases of model pipes placed in wide trenches or under embankments, while for pipes placed in narrow vertical or battered trenches relatively large bending moments are developed and the line of thrust may lie outside the wall thickness.  The results from the tests are also presented in terms of arching factors for different trench geometries and these are compared with the assumptions of present design practice.(a) /TRRL/]]></description>
      <pubDate>Wed, 15 Aug 1979 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/84123</guid>
    </item>
    <item>
      <title>BEHAVIOR AND DESIGN OF LONG-SPAN METAL CULVERTS</title>
      <link>https://trid.trb.org/View/86632</link>
      <description><![CDATA[The interaction between flexible metal culverts and the surrounding backfill is examined by means of finite element analyses that simulate the placement of backfilling and subsequent application of live loads.  Although metal culverts are flexible in bending, they are stiff in ring compression, and the ring compression forces are therefore greater than those corresponding to the weight of backfill above the structure.  The bending moments in metal culverts are dependent on the relative flexibility of the culvert and the backfill, which can be expressed in terms of a dimensionless flexibility number.  Comparisons between finite element results and field measurements show the suitability of the method as a basis for design.  A simplified rational design procedure is described that considers both bending and ring compression. /Author/]]></description>
      <pubDate>Sat, 30 Jun 1979 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/86632</guid>
    </item>
    <item>
      <title>EFFECTS OF METHODS A AND B BACKFILL ON FLEXIBLE CULVERTS UNDER HIGH FILLS</title>
      <link>https://trid.trb.org/View/25673</link>
      <description><![CDATA[Two large-diameter; structural steel plate pipes embedded in deep embankments were instrumented and tested to assess circumferential soil stress distributions, deformations, and internal strains.  Construction techniques included the "imperfect trench" method (method B backfill) and positive projection (method A backfill).  Method B uses layers of baled straw over a 114-in. (290-cm) pipe under 89 ft (27 m) of overfill.  Method A consists of ordinary embankment materials surrounding twin, 108-in. (274-cm) pipes under 160 feet (49 m) of overfill.  Method B soil stress-fill height functions were nonlinear; strains and strain gradients in the pipe walls were larger than those observed for the method A installation.  Radial displacements were smaller than those observed for the method A installation.  Method A soil stress-fill height functions were essentially linear.  Observed deformations and stresses were compared with theoretical values obtained from Marston's theory, the Iowa deflection formula, and the ring compression method.  The ring compression method provided correlations that were sufficient for design purposes.  Internal strains were correlated with external, measured pressures by nautral point and finite element methods.  Baled straw inclusions are not recommended for future designs of flexible pipe culverts.  Design can be based on ring compression with a safety factor of 4, but a 70 percent increase in soil densities may be anticipated over a period of time after fill completion.]]></description>
      <pubDate>Wed, 26 Mar 1975 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/25673</guid>
    </item>
    <item>
      <title>MEASUREMENT OF TENSILE STRENGTH BY DIAMETRAL COMPRESSION OF DISCS AND ANNULI</title>
      <link>https://trid.trb.org/View/126151</link>
      <description><![CDATA[IN THE FIRST PART OF THE PAPER, THE VALIDITY OF DIAMETRAL COMPRESSION TESTS FOR THE INDIRECT MEASUREMENT OF TENSILE STRENGTH IS INVESTIGATED THEORETICALLY AND EXPERIMENTALLY. LINEAR ELASTIC THEORY FOR DIAMETRAL COMPRESSION OF DISCS AND ANNULI BY OPOSED STRIP LOADS IS REVIEWED, AND THE SIGNIFICANCE OF FAILURE CRITERIA IN FRACTURE INITIATION AND TEST INTERPRETATION IS CONSIDERED. RESULTS OF TESTS ARE GIVEN FOR THREE TYPES OF ROCK, TWO PLASTICS, GLASS, AND ICE, AND THE EXPERIMENTAL RESULTS ARE COMPARED WITH THEORETICAL EXPECTATIONS. CLOSE CONSIDERATION OF THE CONFLICTS BETWEEN THEORY AND EXPERIMENT LEADS TO THE CONCLUSION THAT, WHILE THERE ARE VERY SERIOUS OBJECTIONS TO THE RING TEST, THE BRAZIL TEST IS CAPABLE OF GIVING A GOOD MEASURE OF UNIAXIAL TENSILE STRENGTH FOR GRIFFITY-TYPE MATERIALS. IN THE SECOND PART OF THE PAPER, PRACTICAL PROBLEMS INVOLVED IN DIAMETRAL COMPRESSION TESTING ARE CONSIDERED IN SOME DETAIL. SPECIAL ATTENTION IS GIVEN TO CONTACT STRESSES UNDER THE APPLIED LOADS, AND A DESIGN IS GIVEN FOR A LOADING JIG THAT REDUCES CONTACT STRESSES. SPECIMEN DIMENSIONS, SIZE EFFECTS, LOADING RATE, FORCE READOUT, AND SPECIMEN PREPARATION ARE DISCUSSED, AND SOME RECOMMENDED PRACTICAL PROCEDURES FOR BRAZIL TESTS ARE OUTLINED. /AUTHOR/]]></description>
      <pubDate>Mon, 23 Apr 1973 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/126151</guid>
    </item>
    <item>
      <title>RESPONSE OF CORRUGATED STEEL PIPE TO EXTERNAL SOIL PRESSURES, WITH DISCUSSION AND CLOSURE</title>
      <link>https://trid.trb.org/View/110431</link>
      <description><![CDATA[FULL-SCALE EXTERNAL LOAD TESTING OF BURIED CORRUGATED STEEL PIPES SHOWS THE STRUCTURAL PERFORMANCE LIMITS OF THE SOIL-PIPE SYSTEM. THE TESTS INDICATE THAT THE 3 MOST IMPORTANT FACTORS INFLUENCING PERFORMANCE ARE THE YIELD POINT STRENGTH OF THE PIPE WALL, THE SOIL COMPRESSIBILITY (DETERMINED PRIMARILY BY SOIL DENSITY), AND THE RING FLEXIBILITY OF THE PIPE. THE EMPIRICAL RELATIONSHIP OF THESE 3 FACTORS IS PLOTTED ON A GRAPH FROM WHICH IT IS POSSIBLE TO DESIGN BURIED CORRUGATED STEEL PIPES. /AUTHOR/]]></description>
      <pubDate>Sun, 23 Apr 1972 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/110431</guid>
    </item>
    <item>
      <title>WORLD'S LARGEST CULVERTS - UP TO 40' DIAMETER</title>
      <link>https://trid.trb.org/View/124078</link>
      <description><![CDATA[CONTROL OF DEFLECTION AND DISTRIBUTION OF CONCENTRATED PRESSURES TO UNIFORM PRESSURES IS MADE POSSIBLE WITH A DESIGN APPROACH PATENTED BY THE AUTHOR. WITH LESS THAN ONE FOOT OF COVER, HEAVY CONSTRUCTION EQUIPMENT WAS PERMITTED OVER A 35 FOOT SPAN CULVERT. IN 1967 THE SERVICE WAS SUCCESSFULLY INSTALLED IN CANADA. A BATTERY OF FIVE HORIZONTAL ELLIPTICAL CULVERTS, 35 FOOT SPANS, 24 FOOT RISE, AND 7 FEET OF COVER CONSTRUCTED IN 1968 NOW SUPPORT LARGE EARTH MOVERS WITH 200,000 LB. SINGLE AXLE LOADING. THESE TWO INSTALLATIONS, PLUS TWELVE OTHERS SINCE 1966, PROVIDE EVIDENCE OF DEFLECTION CONTROL TO THE EXTENT OF PRACTICALLY NO DEFLECTION. COMPACTION OVER THE TOP OF THE STRUCTURE TO CREATE SOIL ARCHES DURING INSTALLATION APPEARS TO BE THE ANSWER. THIS PRESENTATION OUTLINES A METHOD FOR DEFLECTION AND DEFORMATION CONTROL AND SOME OF THE DESIGN CONCEPTS AND POSTULATIONS. /AUTHOR/]]></description>
      <pubDate>Mon, 08 Feb 1971 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/124078</guid>
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