bluuebunny/crossref_metadata_2025_split huggingface dataset:
New Sample Holder for the Preparation of Undisturbed Fine-Grained Soil Specimens for Laboratory Element Testing
Authors: Wijewickreme D , Sanin MV 
Published: March 2009

Abstract
The paper describes a new soil sample holding device, the undisturbed soil sample holder (USSH), which has the ability to minimize potential sample disturbance during the preparation of relatively soft fine-grained cylindrical soil specimens. The USSH is capable of providing suitable external, uniform lateral confinement to a sample of soil extruded from a field sampling tube. The device comprises a split hollow cylindrical aluminum housing that is internally lined with a flexible synthetic foam material. The foam lining allows the diameter of the cylindrical cavity of the USSH to be variable, while maintaining the shape of the cavity cylindrical. The device has the ability to essentially eliminate the sample freestanding period that is commonly associated with conventional preparation methods and to reduce potentially significant soil deformations that occur due to the self-weight of the sample. The effectiveness of the USSH in minimizing sample disturbance is demonstrated using comparative laboratory tests conducted on relatively soft soil specimens prepared with and without the USSH. The observed axial strains during specimen preparation, volumetric strains during consolidation, and stress-strain-pore water pressure response during undrained triaxial shear testing show that the USSH contributes to the preparation of undisturbed soil specimens for element testing.
Viscous Effects on the Stress-Strain Behavior of Gravelly Soil in Drained Triaxial Compression
Authors: AnhDan L , Tatsuoka F , Koseki J 
Published: March 2009

Abstract
A series of special drained triaxial compression tests using a large-scale triaxial apparatus was carried out to study the viscous properties of gravelly soil. To evaluate loading rate effects on the stress-strain behavior, the axial strain rate was changed stepwise during otherwise monotonic loading (ML) at a constant strain, which resulted in a sharp increase or decrease in the deviator stress. Drained creep loading tests were also performed at several deviator stresses during otherwise monotonic loading and unloading along different stress paths. The amount of creep strain increased with an increase in the deviator stresses. The stress-strain behavior was nearly elastic for some stress range immediately after ML was restarted at a constant strain rate following each creep stage. The viscous properties of partially and fully saturated specimens were essentially the same.
Monitoring the Hydraulic Conductivity of Crushing Sands
Authors: Valdes JR , Caban B 
Published: March 2009

Abstract
Crushing occurs when particles are subjected to sufficiently high external stresses. The crushing process leads to the production of fragments and to ensuring changes in void ratio, pore sizes, specific surface, and hydraulic conductivity. This paper presents a study of the changes in hydraulic conductivity that take place during particle crushing in sand specimens. A new one-dimensional compression cell modified for double-ring permeametry was used to measure the hydraulic conductivity of various sands during crushing and is described in detail in this paper. The device, procedures, and data analyses incorporate arching and localized crushing effects, and are presented as a development towards a new testing standard for determining hydraulic conductivity degradation curves that result from crushing of sands subjected to large stresses. Results show that the hydraulic conductivity degradation curve is dependent on sand type, in particular the particle shapes and mineral composition. The role of arching on the compression behavior and the associated post-crushing grain size distribution curves is also addressed.
The Use of Filter-Paper and Suction-Plate Methods for Determining the Soil-Water Characteristic Curve of Undisturbed Colluvium Soils
Authors: Feuerharmel C , Gehling WYY , Bica AVD 
Published: March 2009

Abstract
The relationship between matric or total suction and gravimetric water content, volumetric water content, or degree of saturation is denoted as the soil-water characteristic curve. This relationship has been widely used for predicting the engineering behavior of unsaturated soils. Residual and colluvium soils from tropical and subtropical regions often show bimodal-shaped soil-water characteristic curves, indicating that both micropores and macropores present in these soils govern the inflow and outflow of water. The objective of this paper is to discuss testing methods adequate for obtaining soil-water characteristic curves of bimodal shape, particularly by the combined use of the suction-plate method (suction &lt; 10 kPa) and the filter-paper method (5 kPa &lt; suction &lt; 30 000 kPa). The soil-water characteristic curves of two undisturbed colluvium soils from Southern Brazil are then presented to highlight the application of those methods.
Twin-Cell Stress Path Apparatus for Testing Unsaturated Soils
Authors: Sivakumar R , Sivakumar V , Blatz J , Vimalan J 
Published: March 2009

AbstractDetermination of specific volume changes of unsaturated soils remains a challenging issue in soil testing for a number of reasons. Various attempts have been made over the years to improve the techniques of sample volume change measurement. This technical note reports the benefit of using a fully automated twin-cell stress path apparatus for measuring sample volume change and hence determining the specific volume. The system requires calibration for apparent volume change due to expansion of plastic tubes and connections. The results have shown excellent repeatability of the apparent volume change during the loading and unloading process.
Identification of Collapsible Soil Using the Fall Cone Apparatus
Authors: Ayadat Tahar , Hanna Adel 
Published: March 2009

Abstract
Soils that go through a great loss of volume upon wetting with or without additional loads are identified as collapsible. In recent years, there has been an increasing awareness of this type of soil due to the expansion of urban developments to arid regions. Also man-made earth structures often exhibit collapsing behavior when compacted at water content less than the optimum moisture content.
In the literature, methods can be found to predict this behavior based on field and laboratories test results. These methods, however, are time consuming and developed for the type of soils tested.
This paper presents the results of an experimental investigation on collapsible soils using the fall cone and the oedometer apparatuses. The fall cone method, originally developed to determine liquid and plastic limits of soils, was adopted in this investigation to identify its collapse potential. A cone penetration limit (Plim) is introduced to identify collapsible soil and a correlation between the collapse potential, CP, and the cone penetration, P, was developed and validated with the present experimental results and those available in the literature. Furthermore, a simple procedure is introduced to determine the optimum Proctor Moisture Content for collapsible soils from the results of the cone test. The proposed procedure is simple and fast to evaluate soil collapsibility by a single reading of the cone penetration.
An Improved Experimental Test Set-up to Study the Performance of Granular Columns
Authors: Black J , Sivakumar V , Madhav MR , McCabe B 
Published: March 2009

Abstract
This paper describes an innovative design of a newly developed large test setup for testing the performance of footings supported on soft clay reinforced with granular columns. This advanced testing method is used to examine the settlement of footings supported on granular columns. Two important features of the equipment are (a) the axial loading system which allows samples to be consolidated under Ko condition while the load is applied onto a small foundation area of the sample, and (b) a relatively large sample size of 300-mm diameter and 400-mm high. The system is also equipped with pressure cells located beneath the footing and top cap to measure the pressure distribution with respect to foundation displacement and a lateral strain gage to monitor boundary effects. This paper reports on some of the early findings from the preliminary tests carried out using this equipment. Samples for testing were prepared by consolidating kaolin slurry in a large one-dimensional consolidation chamber. The granular columns were installed using the replacement method by compacting crushed basalt (uniformly graded with 90 % between 1.5–2-mm particle sizes) into a preformed hole. The preliminary tests have yielded promising results, validating the functionality of the equipment and support the prospect of increasing the knowledge with respect to settlement response and design of a footing supported on granular columns.
Centrifuge Modeling of Solid Waste Landfill Systems—Part 2: Centrifuge Testing of Model Waste
Authors: Indrasenan Thusyanthan N , Gopal Madabhushi SP , Singh S 
Published: March 2009

Abstract
This paper presents the use of the model waste developed in the companion paper, “Centrifuge modeling of solid waste landfill systems—Part 1: Development of a model municipal solid waste,” in centrifuge testing. Two centrifuge tests were performed using the model waste to understand the static and dynamic behavior of municipal solid waste (MSW) landfills. First centrifuge test demonstrates the use of model waste to study the settlement profile in a landfill. In the second centrifuge test model earthquake loadings were applied to the model waste to investigate its dynamic behavior. The results were used to obtain shear modulus reduction and damping curves of the model waste. These curves were shown to match with those reported for MSW validating the use of model waste to study the seismic behavior of MSW landfills.
Development of TDR Penetrometer through Theoretical and Laboratory Investigations: 2. Measurement of Soil Electrical Conductivity
Authors: Lin CP , Chung CC , Tang SH 
Published: March 2009

Abstract
A TDR penetrometer was introduced to allow simultaneous measurements of dielectric permittivity and electrical conductivity during cone penetration. This study focused on the theoretical development and experimental evaluation of electrical conductivity measurement using the TDR penetrometer. Theoretical development takes into account the cable resistance and nonconducting cone shaft, leading to a new data reduction equation and calibration procedure. Measurement sensitivity and spatial sampling bias were experimentally evaluated for various probe configurations. The results show that the measurement sensitivity of interest may be controlled by the geometric factor of the probe. The complication and implications of the spatial weighting bias are discussed. A prototype TDR penetrometer was calibrated and used to perform simulated penetration tests in a soil. Experimental results do not show significant errors in electrical conductivity due to the penetration disturbance, verifying the effectiveness of the TDR penetrometer for electrical conductivity measurement.
Mechanical and Microstructural Properties Characterization of Heat-Treated, Beta-Extruded Ti-6A1-6V-2Sn
Authors: Ulitchny MG , Rack HJ , Dawson DB 
Published: March 2009

The mechanical behavior of β-extruded Ti-6A1-6V-2Sn has been examined after a variety of subtransus heat treatments. Increasing strength has been found to result in a gradual decrease in fracture toughness. The fracture toughness that may be achieved at any given strength level is also a function of prior solution treatment. Optimum toughness at intermediate strength levels (yield strength of approximately 1035 MPa) is associated with lower solution treatment temperatures, while at high strength levels (yield strength of approximately 1200 MPa), the use of higher solution temperatures appears to enhance the maximum achievable toughness. Comparison of the present results with those previously obtained for α-β processed Ti-6A1-6V-2Sn also indicates that, at any given strength level, β processing will result in a higher fracture toughness and a somewhat lower tensile ductility.
Finally, microscopic evidence suggests that the ordering in the primary α phase which occurs after high temperature aging does not play a predominant role in limiting the fracture toughness of high strength α-β titanium alloys; indeed, the deformation limiting characteristics of the interface α phase may be the principal factor controlling the toughness of these alloys.
Influence of Composition, Annealing Treatment, and Texture on the Fracture Toughness of Ti-5A1-2.5Sn Plate at Cryogenic Temperatures
Authors: Van Stone RH , Shannon JL , Pierce WS , Low JR 
Published: March 2009

The plane strain fracture toughness (KIc) and conventional tensile properties of two commercially produced 25.4-mm (1-in.) thick Ti-5A1-2.5Sn plates were determined at cryogenic temperatures. One plate was extra-low interstitial (ELI) grade, the other, normal interstitial. Portions of each plate were mill annealed at 1088 K (1500°F) followed by either air or furnace cooling. The tensile properties, flow curves, and KIc of these plates were determined at 295 K (room temperature), 77 K (liquid nitrogen temperature), and 20 K (liquid hydrogen temperature).
The air-cooled ELI plate was the toughest material evaluated. The KIc of the furnace-cooled ELI plate was about 25 percent below that of the air-cooled ELI material. Cooling rate from the annealing temperature had no influence on the toughness of the normal interstitial plates, both of which had a KIc approximately half that of the air cooled ELI plate. The 20 K fracture toughness of the normal interstitial plates varied only slightly with specimen orientation. The LS toughness of both ELI plates was approximately 20 percent greater than the LT toughness.
Based on these results and a study of the microstructural fracture mechanism, it is recommended that Ti-5A1-2.5Sn, which is to be used in applications requiring high fracture toughness, should have the lowest possible interstitial level and be air-cooled from the annealing treatment so as to prevent ordering.
Effect of Stacking Sequence on the Notched Strength of Laminated Composites
Authors: Whitney JM , Kim RY 
Published: March 2009

The effect of laminate stacking sequence on the notched and unnotched tensile strength of quasi-isotropic graphite/epoxy laminates is investigated. Notch geometry includes circular holes and center cracks. Experimental data are presented for two different stacking sequences of quasi-isotropic graphite/epoxy laminates. One stacking sequence produces large interlaminar tensile stresses along straight free-edges of a tensile coupon, while the second yields compression at the same free-edges. Three different notch sizes are used for the circular hole and center crack in conjunction with both stacking sequences. Each data point is represented by a minimum of 15 replicates so that statistical distributions of notched and unnotched strengths can be obtained. The experimental data indicate that unnotched tensile strength is reduced by the presence of interlaminar tensile stresses at the straight free-edge, while notched strength appears to be independent of stacking sequence for notch sizes which produce tensile failure prior to delamination at the straight free-edge.
Experimental results also are compared against theoretical notch strengths obtained from the average stress criterion and the point stress criterion, two recently developed criteria for predicting notch strength of laminated composites.
Effects of Themal Cycling on the Properties of Graphite-Epoxy Composites
Authors: Mazzio VF , Mehan RL 
Published: March 2009

There is strong evidence that weaker composites, regardless of fiber content, tend to cleave on a single plane, while stronger specimens exhibit extensive fracture zones as a result of cumulative damage. This type of behavior is the same before and after thermal cycling of specimens up to 500 cycles.
Assessment of the mechanical and thermal cycling behavior of engineering composites has been extended to include transverse tensile, compressive, and flexural properties, as well as the longitudinal tensile properties and short-beam shear strength. After cycling, the 55 volume percent 0-deg tensile modulus exhibits a five percent loss. In 25 volume percent specimens, the effect is less because of the greater bulk of the resin. Compressive strength of 25 and 55 volume percent specimens shows a significant decrease for higher fiber content, while the lower fiber content retains about the same strength after thermal cycling. Flexural strength in high-fiber content specimens shows an increase with increased thermal cycling. Similar behavior is noted for 25 volume percent up to 200 cycles; however, there is a drastic reduction after 200 cycles. There was little change in interlaminar strength with the number of cycles.
Tunnel-Gully Erosion and Urban Development: A Case Study
Authors: Crouch RJ 
Published: March 2009

An area of tunnel gully erosion induced by the excavation of a drain through a residential subdivision in Southern New South Wales was examined.
Twelve months after excavation, tunnels extend 7 m from the drain wall and threaten residential blocks only 5 m further away.
A survey of a major tunnel by excavation and probing indicated tunnel formation along soil cracks around large (50 to 100 cm diameter) structural units.
Soil analyses rated the soil as highly dispersible by all the routine tests used by the Soil Conservation Service (SCS) of New South Wales, namely, Emerson's Crumb Test, Ritchie's Dispersal Index, and Floyd's Sticky Point Test, and showed that this dispersibility could be attributed to a high exchangeable sodium percentage (ESP) (mean 10.5). In addition, the soil had a low volume expansion (&lt;5 percent) and was relatively impermeable.
These analyses have been compared with published criteria to show that the soil could have been identified as highly susceptible to tunnel erosion prior to excavation. This would have permitted an improved channel design, with a more gently sloping batter and stressed the need for lime stabilization, topsoiling, and immediate revegetation to minimize the possibility of tunnel development.
An Overview of Magnetic Particle and Liquid Penetrant Methods Documents and Associated Quantitative Measurement Standards Needs
Authors: Borucki JS 
Published: March 2009

The magnetic particle and liquid penetrant inspection methods are the most widely used nondestructive testing methods in industry today, as evidenced by the existence of a multitude of worldwide governmental, institutional, and industrial specifications which govern the use of these processes. However, there are some problem areas, that is, inconsistencies, overlaps, omissions, etc., associated with the various documents which control these two recognized test methods.
Of fundamental importance, and in keeping with the theme of this symposium, this presentation will concentrate on the need for and the problems associated with the development of magnetic particle and liquid penetrant physical property standards and physical performance standards. We recognize the need for reproducible, quantitative, physical, and performance measurement standards such as calibrated cracks, artificial defects, magnetic penetrameters, flux density, “black light,” fluorescent brightness, and penetrant removability.
Industry can benefit from the development of such standards. It is our intention, therefore, to discuss this area candidly and seek ways and means of achievement.
Standards for Quantitative Nondestructive Examination
Authors: Tittmann BR , Thompson DO , Thompson RB 
Published: March 2009

In this report, the subject of ultrasonic standards is reappraised in terms of history, philosophy of calibration, and future needs. In answer to the critical need for a procedure to calibrate ultrasonic systems for quantitative nondestructive examination (NDE), a new calibration standard and procedure is proposed.The calibration standard proposed is the far-field sphere (cavity or inclusion embedded in a solid or a ball suspended in a liquid). As a result of recent work, the sphere now is understood well theoretically and experimentally and can be reproduced and fabricated in a solid, for example, by diffusion bonding techniques. A major advantage of the sphere is that it has no preferential orientation, the transducer alignment is not critical, and it allows multipoint checks on a single standard block.The backbone of the calibration procedure is an equation which relates the transmitter signal to the received signal in a quantitative way. With the help of this equation, the scattering parameters, namely, the angular dependence, frequency dependence, and amplitude of the differential scattering cross section may be determined from data obtained on a calibration standard. The results may be compared then with the invariant theoretical solution to verify the proper operation of the ultrasonic system. A key feature of the development is the G-factor which is a proposed figure of merit for a transducer. The discussion includes a technique for its simple determination and its use in the calibration procedure.
Low-Temperature Ductility in Relation to Pavement Performance
Authors: Kandhal PS 
Published: March 2009

The data on changing asphalt properties, especially the low-temperature ductility measured at 39.2 and 60°F (4 and 15.6°C), have been analyzed and related to the performance of ten experimental pavements in Pennsylvania.
It has been observed that aging of the pavement results in progressively lower penetration and higher viscosity. However, the accompanying decrease in low-temperature ductility is an important factor. After the penetration of asphalt drops below 30 due to hardening. the pavements containing asphalt with low ductilities are likely to show poorer service than pavements containing asphalts of the same penetration but with high ductilities. The data also indicate the probable ranges of low-temperature ductility values at which the progressive deterioration of the pavement (such as loss of fines, raveling, cracking, etc.) takes place under Pennsylvania climatic conditions.
At lower temperatures, the ductility values are lower, reproducible, and better defined than the values at higher temperatures determined on long, thin threads of asphalt. Therefore, a specification requirement at a 60°F or lower temperature should provide better criteria.
Development of High-Strength Alloyed Rail Steels Suitable for Heavy Duty Applications
Authors: Marich S , Curcio P 
Published: March 2009

In the first section of the paper, a summary will be given of the various defects which can develop in rails subjected to high axle loads, such as corrugations, gross plastic deformation and abrasive wear of the railhead, checking and spalling, shelling and transverse defects.
The second section of the paper will cover in detail the developmental work on high-strength alloyed rail steels conducted at Broken Hill Proprietary Co. Ltd. Melbourne Research Laboratories. An essential part of the work has been the development of techniques for laboratory simulation of industrial rail production and on-site welding procedures. Various other material properties have also been used in assessing material types.
The major emphasis of the work has been directed to optimizing the mechanical properties of three rail steel types, namely: chromium-columbium-vanadium steels, chromium-vanadium steels, and chromium-molybdenum steels. Fully pearlitic steels exhibiting yield strengths greater than 900 MPa have been developed without adversely influencing other mechanical properties. The steels can be flash butt welded using modified procedures.