bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Investigation of the Elastic Stress-Strain Behavior of a Banded Sandstone and a Sandstone-Like Material
Authors: Talesnick ML , Katz A , Ringel M 
Published: February 2009

Abstract
A complete methodology has been presented and implemented that enables the independent determination of the five mechanical parameters required to describe the elastic behavior of a transverse isotropic rock. The uniqueness of the methodology is that only one specimen is required. A single hollow specimen is subjected to a series of specific stress conditions. From each stress condition a different parameter or parameters may be determined. The most important advantage of the methodology is that the difficulty of material variability between specimens is to a large extent eliminated. Testing of multiple specimens allows for a better formulation of the nature of the material isotropy and the variability in material parameters.
Results of the methodology compare favorably to other more conventional frameworks such as uniaxial testing and Brazilian compression. The bulk of the testing was carried out on a natural anisotropic banded sandstone; however, a set of control specimens of sand concrete were tested in order to consider the credibility of the methodology.
The methodology has been implemented to consider possible differences in the response of both materials to compressive and tensile stress regimes. Over the range of stresses considered, the differences between the compressive and tensile stiffnesses are surprisingly small.
Instrumentation of Bored Concrete Piles for Horizontal Load Tests
Authors: de Sousa Coutinho AGF , Toco Emilio F , de Almeida Garrett JL , Tavares Cardoso E 
Published: February 2009

Abstract
This paper contains the fundamental outline of an experimental work developed over a period of several years covering the instrumentation and execution of horizontal load tests on bored reinforced concrete piles and pile groups. The instrumentation used is described, with particular emphasis on a system that is a completely original concept in strain measurement in piles of this kind. Hints are also given on system assemblage, insertion into the pile borehole, and preparation for automatic data acquisition. The paper also contains a description of the loading systems for piles and pile groups, giving special emphasis to the new aspects introduced. Finally, some references are made to the execution of the tests and some critical observations given on the results of the instrumentation equipment used.
Lateral Load Behavior of Jetted Piles
Authors: Hameed RA , Gunaratne M , Putcha S , Kuo C , Johnson S 
Published: February 2009

Abstract
Water jetting can be utilized as an effective aid to impact pile driving when hard strata are encountered above the designated tip elevation. When jetting, the immediate neighborhood of the pile is first liquefied due to high pore pressure induced by the water jet and subsequently densified with its dissipation. In addition, the percolating water also creates a filtration zone further away from the pile. Hence, jetting invariably causes substantial disturbance to the surrounding soil that results in a noticeable change in the lateral deformation behavior. Currently, no definitive criteria are available to quantify the possible reduction in the lateral strength of driven piles when jetting is employed. This paper presents the results of an experimental study performed with model piles installed using (1) impact driving and (2) jetting in a sandy soil (with 10% clay) compacted to different unit weights under unsaturated as well as saturated conditions. The beam theory and polynomial approximations are used to convert measured load-strain data to conventional lateral pressure-deformation characteristics (p-y curves). Then, the effect of jetting on the lateral load behavior of piles is presented in terms of non-dimensional empirical curves. An example is also provided to illustrate how the results can be utilized to synthesize p-y curves for jetted piles based on available p-y curves for impact-driven piles in the same soil.
Model for Capillary-Induced Radial Flow in Cohesionless Soils
Authors: Sivakumar Babu GL , Fox PJ 
Published: February 2009

Abstract
Capillary phenomena in cohesionless soils play an important role in the migration of liquids through the unsaturated zone above and close to groundwater sources. The purpose of this paper is to present the results of a theoretical and experimental study of capillary flow in the radial direction. A closed-form solution for the time-dependent advance of wetting front radius is derived as a function of porosity, degree of saturation, hydraulic conductivity, and capillary head. A laboratory test called the “radial horizontal capillarity test” was developed to measure the radial movement of the wetting front as a function of time and experiments were conducted. Values of capillary-induced hydraulic conductivity and capillary head from the theory and experiments on sands and silt are close to those obtained from linear horizontal capillarity tests.
Tomographic Evaluation of Air and Water Flow Patterns in Soil Column
Authors: Wong RCK , Wibowo R 
Published: February 2009

Abstract
This paper describes the use of computerized tomography (CT) as a nondestructive method to estimate the three-dimensional spatial distributions of porosity, air, and water saturations during air-water displacement tests in a soil column. Local porosity was found to be a critical factor in controlling the air and water flow patterns. In nonhomogeneous soil, high local porosity promotes early development of isolated air channel breakthrough that maintains a high average water retention saturation. In homogenous soil, micro air channels are established uniformly, resulting in a low water saturation. Interpretation of data based on overall porosity could lead to unreliable flow analysis for water and/or air movement in unsaturated soil. In addition, this paper investigates the use of gas exsolution to enhance the delivery of air within soil media.
Miniature Cone Penetration Tests in Soft and Stiff Clays
Authors: Titi HH , Mohammad LN , Tumay MT 
Published: February 2009

Abstract
An electric continuous intrusion miniature cone penetration test system was recently developed for roadway design and construction control of embankments. The system continuously advances a 2 cm2 electric miniature cone penetrometer by uncoiling a stainless steel push rod. Field and laboratory testing programs were conducted on overconsolidated, normally consolidated, and compacted Louisiana clays. The field testing program consisted of cone penetration tests using both 2 and 15 cm2 electric cone penetrometers in conjunction with soil sampling, while laboratory tests included physical properties and strength characteristics of the investigated soils. Analyses of cone penetration tests were conducted to assess the repeatability and reliability, as well as confirming that the electric miniature friction cone output is in compliance with output of the 15 cm2 cone.
Calibration of Testing Equipment for Reliable Small-Strain Deformation Measurements Using Synthetic Specimens
Authors: Kim D-S , Kweon G-C 
Published: February 2009

Abstract
For reliable deformation measurements at small strains, calibration of the entire testing system in addition to routine transducer calibrations are very important. Seven synthetic specimens of varying stiffness (4.3 to 1500 MPa) were constructed and tested to measure the compliance of testing equipment and to improve the measurement setups. Testing equipment used in this study included resonant column device (RC), torsional shear device (TS), free-free resonant column device (FF-RC), cyclic resilient modulus testing device (MR) and the static compression testing device. Moduli of synthetic specimens determined by various testing equipment after improvement were almost identical if considered the effect of loading frequency, indicating that all of the testing devices were well calibrated over a wide stiffness range. To verify the effectiveness of calibration on soil testing, two subgrade soils were tested, and moduli determined by various tests compared well. Use of synthetic calibration specimens shows potential for calibrating testing equipment and determining its capability and limitation of small-strain deformation measurements.
Interfacial Parameters and Work of Adhesion in Soil-Liquid Systems
Authors: Kaya A , Lloyd TB , Fang H-Y 
Published: February 2009

Abstract
The surface/interfacial properties and soil-liquid interaction are studied to serve as a preliminary study to interpret engineering behavior of soils. To fully understand the nature of fine-grained soil-pore fluid interaction, the work of adhesion of liquids on kaolinite and bentonite is determined by means of measuring soil-liquid contact angle by the Wilhelmy Plate technique and horizontal capillarity. The results reveal that work of adhesion of soils with organic liquids varies considerably depending on the surface tension of the organic liquids (cohesive forces) as well as the liquid-soil adhesive forces. Further, surface parameters of the soils, γSLW, γS#x002B;, and γS− are determined and compared with the values reported in the literature. The results reported in this study are compared with the previous ones in the literature. The agreement between the results of this study and reported results in the literature is good. Results also revealed that when the soil particles are wetted with water, organic liquids couldn't displace water molecules and change the soil microstructure. Based on the obtained results, it is concluded that studying the work of adhesion is a very useful way of understanding soil-liquid interaction and predicting engineering behavior of soils.
Laboratory Evaluation of Cemented Backfill Materials for Mines
Authors: Unal E , Cakmakci G 
Published: February 2009

Abstract
A brief state-of-the-art review is given on backfill materials and laboratory tests. A new system developed for testing backfill material in the laboratory is described. In this system, most of the limitations of previously applied techniques have been eliminated. In performing unconfined-deformability tests (UDT) and confined-deformability tests (CDT), large cylindrical specimens having a diameter of 600 mm are used. The specimens were prepared from riverbed sand and gravel mixed with cement. A total of 135 UDT and 127 CDT specimens were tested in order to investigate the strength and deformability characteristics of 40 different combinations of backfill mixture. Calculation methods are evaluated in terms of stress-strain plots and are illustrated with examples. Typical results are presented. Two sets of deformation data can be obtained during testing: one from between the top and bottom plates, and the other from between the rings peripherally fixed onto the specimen. It is shown in this study that ring-to-ring readings provide more reliable modulus results.
Evaluation of Gravel Stiffness by Pulse Wave Transmission Tests
Authors: Modoni G , Flora A , Mancuso C , Viggiani C , Tatsuoka F 
Published: February 2009

Abstract
Laboratory techniques for the measurements of very small strain stiffness parameters of coarse-grained materials include: (a) static tests using local strain transducers like LDTs and (b) wave propagation measurements performed using bender elements, shear plates, and so on. The former method has been employed for most kinds of soil, while the use of wave propagation methods has been restricted to small specimens of sand and clay. At the University of Naples Federico II (DIG), a simple device to generate and monitor compressional and shear waves has been designed to be used in large-scale triaxial apparatuses. The testing device was first used on densely compacted gravel specimens in a large triaxial apparatus in Naples and, after some further improvements, also in another large triaxial cell in Tokyo. In the tests carried out in Tokyo, dynamic and static measurements were performed simultaneously on the single gravel specimens. In this paper, the details of the new system are presented and the results are discussed. The comparison between stiffness moduli evaluated by dynamic and static measurements shows that density, stress state, and strain history effects are similar, but that the dynamically measured stiffness values are consistently larger, about two times, than the statistically determined ones. Since the stiffness of gravels has proven to be strain rate independent, possible reasons for this difference are addressed.
Variations in Membrane Contact Patterns of Reconstituted Sand Specimens
Authors: Saussus DR , Frost D , Ashmawy AK 
Published: February 2009

Abstract
The penetration of the latex membrane into the peripheral voids of a sand specimen during application of confining stress can cause significant errors in subsequent triaxial test results. Analytical solutions are commonly used to account for this source of error by predicting the shape of the deflected membrane based on a sand particle-membrane contact pattern assumed to be represented by four spheres of diameter D50 whose centers form a square of length D50 on a plane parallel to the undeflected membrane. This paper presents the findings of a study that used image analysis to study actual contact patterns and compare these with the generally assumed configuration. The results show that the generally assumed constant configuration does not reflect the variability of actual patterns, which are a function of the specimen relative density and preparation method and may therefore grossly underestimate the amount of membrane penetration. The study shows that an increase in relative density results in a decrease in inter-contact distance, regardless of the specimen preparation method, and that the inter-contact distance at the sand-membrane interface is larger and more variable for moist tamped than air-pluviated specimens at any given density. These observations suggest that the sand-membrane contact patterns assumed by future analytical solutions, as a minimum, will need to take specimen relative density and preparation method into account if the amount of membrane penetration is to be more accurately predicted.
A Triaxial and Oedometer Apparatus for Testing Unsaturated Soils
Authors: Aversa S , Nicotera MV 
Published: February 2009

AbstractThe paper describes a new system for testing unsaturated soils designed at the University of Naples Federico II. The system is modular and can be configured either as an oedometer or a triaxial cell. Triaxial specimens are 68 mm in diameter and 140 mm in height, and oedometer specimens have a diameter of 56 mm and a height of 20 mm. The suction control is based on the axis translation technique. Radial strains are determined by an accurate measurement of the difference in pressures between the water filling an inner cell coaxial to the sample and that filling a reference double-walled burette, submitted to the same pressure. The water content variations are determined by measuring the difference in pressure in two double-walled burettes, one of which being connected to the drainage circuit, the other one operating as a reference. The calibration of all the devices, as well as their precision and accuracy, is widely discussed in the paper. Finally, the results of tests performed on an unsaturated pyroclastic soil are presented in order to highlight the features of both apparatuses.
A Miniature Soil Inclusion for Measuring Axial Force and Radial Stress
Authors: Standing JR , Burland JB 
Published: February 2009

Abstract
This paper describes the design, development, and manufacture of a miniature soil inclusion 175 mm long and 8 mm in diameter for measuring axial force and radial stress at three points along its length. The individual devices rely on strain gages for their operation and were found to be stable in a laboratory environment. The axial force and radial stress measurements can be resolved to less than 1 N and 1 kPa, respectively. The model inclusion has been used in a study to investigate the development of shear stress along a soil nail. The instrumentation allowed the influence of arching to be positively identified. The paper includes discussion of factors such as calibrating for cross-effects, converting the electrical outputs to engineering units, and cell-action effects. These factors along with the soil stiffness govern the accuracy of measurement.
Mechanical Properties of Shredded Tires
Authors: Yang S , Lohnes RA , Kjartanson BH 
Published: February 2009

Abstract
The use of scrap tires as construction materials in civil engineering applications is one of the most promising ways of recycling this troublesome waste material. Design of scrap tire structures, however, requires data on engineering characteristics of tire-derived materials. Confined compression, direct shear, and triaxial tests were carried out to evaluate the mechanical characteristics of tire chips approximately 2 to 10 mm in size. These test results were synthesized with data from previous shredded tire studies to generate empirical relationships between normal stress and direct shear strength and between confining pressure and initial tangent modulus from triaxial testing. It was found that the shear strength of shredded tires is independent of the particle size of the material, and the strength envelope is a power function for normal stresses from 0 to 90 kPa. The initial tangent modulus relates to confining pressure through a quadratic equation, and the lateral strain ratio is independent of confining stress.
Effects of Small Cement Content on Consolidation Behavior of a Lacustrine Clay
Authors: Feng T-W 
Published: February 2009

Abstract
Natural soft clays are frequently encountered in civil engineering projects. Such soils possess large compression potential that needs to be alleviated by means of effective ground improvement techniques. Current knowledge on mixing soft clay with small cement content to improve its consolidation properties is limited. This study looks into the consolidation behavior of undisturbed lacustrine soft clay treated with small cement contents. Based on the pH values of soft clay and cement mixtures, small cement contents of 3 and 6% were chosen to prepare soft clay-cement oedometer specimens. The oedometer test results show that the preconsolidation pressure may be decreased or increased, depending on the cement content added. The secondary compression index is reduced and the ratio of secondary compression index to compression index is also reduced, indicating a change in grain size characteristics. The coefficient of consolidation is reduced for consolidation pressures near the effective overburden pressure and is about equal or slightly increased for consolidation pressures higher than the preconsolidation pressure. These data indicate that treating natural soft clay with cement at small cement contents can be effective in reducing both primary and secondary settlements.
An Improved Statistically Based Technique for Evaluating the CPT Friction Ratio
Authors: Jaksa MB , Kaggwa WS , Brooker PI 
Published: February 2009

Abstract
This paper examines a statistical technique known as the cross-correlation function (CCF) for determining the shift distance associated with the cone penetration test (CPT). When evaluating the friction ratio, FR ( = fr/qc), for soil classification purposes, it is essential that the measured values of ), for soil classification purposes, it is essential that the measured values of qc and fs are shifted relative to one another because of the physical offset between the cone and the friction sleeve. Generally, the shift distance is estimated by means of empirical and subjective methods, a value of 75 to 100 mm is adopted, or it is ignored all together. Using a series of case studies, this paper demonstrates that the CCF is a useful and objective technique for estimating the shift distance. In addition, a phenomenon associated with sleeve friction measurements related to elastic rebound of clay soils is discussed.
Determination of Water Saturation Using Miniature Resistivity Probes During Intermediate Scale and Centrifuge Multiphase Flow Laboratory Experiments
Authors: Kechavarzi C , Soga K 
Published: February 2009

Abstract
Physical modeling is essential to the conceptual understanding of the mechanisms governing multiphase flow in porous media. However, the need for accurate data is hampered by the limited amount of appropriate instrumentation designed to measure fluid saturation in three-fluid phase flow experiments. In centrifuge testing, this is accentuated by the fact that the instruments must be small and resistant to the effects of increased gravity. Miniature resistivity probes, developed at Cambridge University Engineering Department (CUED), were used to determine water saturation variations during a centrifuge test and a 1 g two-dimensional multiphase flow experiment. These experiments were conducted to study the migration of light non-aqueous phase liquids (LNAPL) in unsaturated sands. Prior to the tests, the resistivity probes were calibrated against the water saturation of unsaturated sand samples. The calibration relationship was compared to Archie's law. The miniature probes proved to be a valuable tool for monitoring water saturation variations during three-fluid phase flow under 1 g conditions, as well as under the accelerated gravity field of 20 g.
Development of a Multiple-Purpose Borehole Testing Device for Soft Rock
Authors: Huang A-B , Fang C-K , Liao J-J , Pan Y-W 
Published: February 2009

Abstract
The authors developed a versatile in situ testing device specifically for soft rock. The main purpose of this device was to provide design parameters for shallow or deep foundations in soft rock. The new device, referred to as the Borehole Testing Device (BTD) consisted of four radial curved platens at the top and a circular steel plate at the bottom. The BTD was designed to be used in a 200-mm-diameter borehole. Driven by a high stress pressuremeter and a hydraulic piston, the BTD can be used to perform a borehole jacking test, plate-loading test, and borehole shear test in the same borehole. A multistage testing procedure was proposed to perform the BTD test. This paper describes the design and operation of the BTD and presents a set of test data to demonstrate the capabilities of the BTD.
Interpretation of Seismic Piezocone Results for the Estimation of Hydraulic Conductivity in Clays
Authors: Burns SE , Mayne PW 
Published: February 2009

Abstract
Seismic piezocone penetration tests with dissipation phases provide sufficient data for outlining the geostratigraphy, soil strength, stiffness, and flow characteristics in fine-grained soils. The dissipation of excess pore water pressures with time can be monitored at regular intervals (e.g., at 1-m rod breaks) and provides information on the coefficient of consolidation (ch). Monotonic and/or dilatory responses of Δu decay can be accommodated. The shear wave velocity (Vs) provides a measure of the small-strain stiffness (G0), or surrogate evaluation of the constrained modulus (D′). A sampling of data from ten clay sites was used to assess the derived magnitude of hydraulic conductivity, as determined from k = chγw/D′.