bluuebunny/crossref_metadata_2025_split huggingface dataset:
Automated Measurement of Slurry Surface Settlement
Authors: Tan S-A , Tan T-S , Liang KM 
Published: February 2009

Abstract
An automated float method for measuring slurry surface settlement is described. The system consists of a Perspex float which is denser than water but lighter than the slurry into which it penetrates slightly and floats on the slurry/water interface. Settlement of this float is then automatically tracked using an LVDT. Comparison with direct cathetometer measurement demonstrates that except for the initial penetration the float's depth of embedment into the slurry surface is unchanged as settlement progresses. Hence it is able to follow the settlement of the slurry surface. This method is then used to measure quickly and accurately the surface settlement of kaolin during self-weight consolidation tests under single drainage condition. The initial rate of settlement is then used to determine the permeability of the slurry, which is not an easy property to measure using other methods.
Using an Automated Rowe Cell for Constant Rate of Strain Consolidation Testing
Authors: Sheahan TC , Watters PJ 
Published: February 2009

Abstract
The paper describes the automation and calibration of a hydraulic Rowe consolidation cell that tests 151-mm-diameter by 60-mm-high specimens. The associated measurement instrumentation for the cell and specimen preparation procedures are also described. The cell was used to perform a set of one-dimensional constant rate of strain (CRS) tests at two vertical strain rates, 0.1 and 1%/h. The nonlinear CRS theory of Wissa et al. (1971) is presented, including methods for interpreting test results at higher strain rates. The results from the Rowe cell tests conducted on resedimented Boston Blue Clay are compared to those from more conventional incremental loading (IL) oedometer tests (63.5-mm-diameter by 23-mm-high specimens). For both the 0.1%/h tests (in which negligible excess pore pressure was generated at the undrained specimen base) and the 1%/h tests, the compression curves compare well with the baseline IL oedometer test curves. Values of preconsolidation pressure, σ′p, averaged 94.0 kPa in the Rowe tests and 94.5 kPa in the IL oedometer tests. The compression ratios, CR = Δεv/Δ log σ′v, in the virgin compression range were slightly lower in the Rowe cell tests (average 0.156 versus an average CR = 0.173 in the IL oedometer tests), which may be due to different testing conditions (e.g., back pressure in the Rowe cell) or the larger Rowe cell specimen. The coefficient of consolidation and hydraulic conductivity values computed from the Rowe cell tests are essentially identical with regard to stress level to the IL oedometer tests. The automated Rowe cell data indicate that the device offers a reliable and potentially rapid method for determining consolidation parameters, including hydraulic conductivity.
Measurements of Soluble Salt Content of Soils from Arid and Semi-Arid Regions
Authors: Karakouzian M , Pitchford A , Leonard M , Johnson B 
Published: February 2009

Abstract
Soils with soluble salts occur in arid regions worldwide. Depending on the amount of soluble salts present, treatment of these soils may be needed before construction. In engineering, the amount present is usually determined gravimetrically by finding the weight loss for a soil diluted with a fixed quantity of water. However, if the soluble salt content is evaluated with an insufficient amount of water, some of the salt present may not dissolve. This condition, termed “salt saturation,” may cause the amount of soluble salts present to be underestimated. To identify the correct dilution, this paper proposes checking successive dilutions until an unsaturated solution is obtained. This can be accomplished using either gravimetric or electrical conductivity measurements to detect salt saturation. The volume of water used to determine percent soluble salts can then be adjusted accordingly. This paper describes how to find the most suitable dilution using either method and how to determine the percent of soluble salts. Using this approach, five different soils from Las Vegas, Nevada, were evaluated. Unsaturated water-soil dilution ratios ranged from 2:1 to 100:1. In two cases, the 2:1 dilution was adequate, but for the other three it was not. Soil “M” exemplified this best: percent soluble salts increased from 1% measured at a 5:1 dilution (indicating a leave-in-place/no-action recommendation) to 7% at a 100:1 dilution (indicating a removal recommendation). This result illustrates the importance of using an unsaturated dilution for determining percent soluble soil.
Measuring Anisotropic Elastic Properties of Sand Using a Large Triaxial Specimen
Authors: Hoque E , Tatsuoka F , Sato T 
Published: February 2009

Abstract
An advanced automated triaxial testing system developed to characterize elastic behavior of soils is described. Small axial and lateral strains of a large rectangular prismatic specimen were measured locally at various stress states along a specified stress path, which was achieved by automatically controlling axial load and confining pressure. Elastic deformation was measured by applying very small cycles of axial or lateral stress at each given neutral stress state. Typical test data for air-dried sand are presented. It is observed that the elastic Young's modulus is a rather unique function of the normal stress in the direction of the major principal strain increment, and therefore elastic deformation characteristics of sand become anisotropic under anisotropic stress conditions.
A Flow Pump System for Assessing Clay Barrier-Permeant Compatibility
Authors: Kashir M , Yanful EK 
Published: February 2009

AbstractThis paper presents the performance, reliability, and features of a hydraulic conductivity, k, testing equipment specially designed and fabricated for clay barrier-permeant compatibility studies. The key component of the equipment is a flow or infusion/withdrawal pump that is used to deliver a constant and continuous flow of permeant at some prescribed rate through two stainless steel syringes to a soil specimen. The pump has a switch that allows the motor direction to be changed to allow one syringe to empty while the other is filling. This provides an uninterrupted flow of permeant to the specimen, unlike most traditional testing equipment that requires complete stoppage of permeation in order to provide a fresh supply of permeant. In some cases, re-establishment of flow pressures can take a long time and therefore affect the attainment of chemical equilibrium and specimen volume changes during compatibility testing. A Plexiglas cell containing an inflatable rubber diaphragm is used in the present equipment as a permeant supply tank to prevent the exposure of the permeant to air, therefore making the equipment particularly suited for testing with volatile organic liquids and redox-sensitive permeants such as acid mine drainage. Furthermore, this cell is connected to a back pressure supply to decrease the time required for the pressure to return to its original value after switching gears. The advantage of the equipment includes a graphic-based data acquisition system that allows test parameters such as hydraulic gradient, hydraulic conductivity, volume change, and room temperature to be continuously monitored and displayed on a computer monitor screen. The performance and features of the equipment are demonstrated with a series of k-tests on clayey soil specimens permeated with water and then with acid mine drainage (AMD). The data indicated that, while AMD did not change k, it may have dissolved some primary soil minerals such as calcite and dolomite, which in turn buffered the pH of the effluent from a specimen permeated with more than ten pore volumes of AMD.
Friction Angle Between Expanded Shale Aggregate and Construction Materials
Authors: Valsangkar AJ , Holm TA 
Published: February 2009

Abstract
Results of an experimental program are presented for the interface friction mobilized between expanded shale lightweight aggregate and commonly used structural materials: formed concrete, steel, and wood. A large-size direct shear device is used to perform tests. The mobilized friction between lightweight aggregate and solid surfaces of construction materials are compared with interface angles of friction associated with coarse normal-weight aggregates. The results provide useful design information on the appropriate mobilized angle of friction to be used while designing retaining structures with lightweight aggregate as backfill. The data are also useful in estimation of skin friction for piles driven through lightweight aggregate fills.
Evaluation of True Cν and Instantaneous Cν, and Isolation of Secondary Consolidation
Authors: Tewatia SK 
Published: February 2009

Abstract
It is shown that the presence of a distinct straight line in the initial portion of settlement versus the square root of time plot indicates that soil follows theoretical behavior and that there is no initial and secondary compression in the straight line portion. If the coefficient of consolidation, cν, is determined using the data of only this portion, it can be regarded as the true cν. Secondary consolidation essentially starts after 60% consolidation and runs superposed over the primary consolidation. Its effect is to gradually decrease cν so that at every instant of time it is a new Terzaghian soil with a new cν and other consolidation parameters. Characteristics of linear and semi-log plots of U versus U, where U is the degree of consolidation and U is the theoretical velocity, are used for determining true cν and instantaneous cν, and for isolation of secondary consolidation from the experimental consolidation curve.
A Simplified Method for Assessment of Volume Change Behavior of Rockfill Material
Authors: Thallak SG , Nagaraj TS , Yaligar P 
Published: February 2009

Abstract
In this paper an attempt was made to generalize the results of laboratory tests on modeled rockfill materials so as to evolve a simplified method for assessment of their bulk mechanical properties from minimum test data with an acceptable degree of confidence. Examination of the experimental data of the modeled rockfill materials from different sites revealed that the plots of logarithm of strain at failure against logarithm of confining pressure are linear. A trend of increase in failure strain with increase in confining pressure and maximum size of particle is also observed. The simplified approach high-lights prediction of volume change properties of rockfill materials during isotropic consolidation and triaxial state of stress over a range of confining pressures and particle sizes. This approach is based on the results of only two tests carried out at two different confining pressures for a selected maximum particle size on modeled rockfill material with the use of the parallel gradation technique. The two-test approach and its application in engineering design of rockfill materials is illustrated by means of selected experimental data available in the literature.
Plummet Balance—A Potential Tool for Subsieve Particle Size Analysis
Authors: Nagaraj TS , Sivapullaiah PV 
Published: February 2009

Abstract
Particle size distribution analysis as an inferential soil parameter plays a dominant role in geotechnical engineering. This investigation encompasses laboratory study of subsieve particle size analysis by hydrometer, pipet, and plummet balance methods to assess their relative performances and also to examine the critical factors that influence the results obtained by the plummet method. The results of this investigation indicate that for a plummet immersion of 20 cm the particle size distribution would be similar to that obtained by hydrometer and pipet methods. The marginal differences would in no way affect either the classification of the soil or the inferred properties of soils.
Statistical Estimation of Compression Index
Authors: Koppula SD 
Published: February 2009

Abstract
The amount of compression a soil will experience depends, among other factors, on its compression index Cc which may be determined through consolidation tests on undisturbed or remolded soil samples. Alternatively empirical relationships between Cc and other physical properties such as liquid limit or void ratio may be used.
It has been postulated that empirical relationships between Cc and other readily determined soil properties are of much practical importance especially during planning stages, because these relationships permit computations of approximate settlements of structures founded on cohesive soils without the benefit of conducting consolidation tests. These empirical relationships form the basis on which rational decisions can be made as to the suitability of a foundation site.
The data from more than 130 consolidation tests performed on cohesive soils are statistically examined. Ordinary least squares and ridge regression techniques are used to obtain linear models for the variable Cc and the results are compared with published results. It is concluded that a simple linear relationship between the compression index and the initial water content yields highly significant results.
Incremental Loading Device for Stress Path and Strength Testing of Soils
Authors: Nagaraj TS , Murthy MK , Sridharan A 
Published: February 2009

Abstract
A new incremental loading device has been designed and fabricated to hydraulically control the axial stresses in triaxial compression and extension. Several different types of stress paths may be used during shear testing without the problems associated with conventional stress-controlled tests using dead weights. The versatility of the loading device is demonstrated by presenting the results of typical tests. Other potential uses of this test apparatus are also cited.
A Mechanistic Model for Strength and Fatigue of Cement-Treated Soils
Authors: Raad L 
Published: February 2009

Abstract
A mechanistic model for strength and fatigue of cement-treated soils is developed using the Griffith failure theory for the purpose of understanding the structural behavior of cement-treated bases in pavements. Failure under static loads is assumed to occur when the tensile stress at the tip of the most critically oriented flaw reaches a value characteristic of the material. This static failure model is used to study fatigue behavior under repeated stresses. Results of repeatedload triaxial tests on a clayey gravel soil cement are used to define fatigue failure criteria for cement-treated soils. The analytical fatigue model developed is used to derive a cumulative damage hypothesis. According to this hypothesis, fatigue behavior under compound loading depends on the sequence and magnitude of applied loads and the curing age of the cement-treated material. The hypothesis also suggests that Miner's rule could lead to unconservative predictions of fatigue life under random loading conditions.
A Ring Torsion Apparatus for Evaluating Friction Between Soil and Metal Surfaces
Authors: Yoshimi Y , Kishida T 
Published: February 2009

Abstract
A ring torsion apparatus was used to evaluate friction between-dry sand and a steel surface over wide ranges of surface roughness and sand density. The deformation of sand near the steel surface was observed by X-radiography. The apparatus is suitable for evaluating skin friction under well-defined test conditions. The test results show that frictional resistance is primarily governed by the roughness of the steel surface, irrespective of the density of the sand.
An Electropneumatic Cyclic Loading System
Authors: Chan CK 
Published: February 2009

Abstract
This paper reviews some of the current systems in use for the application of cyclic loads to soil specimens. Their main features and principles of operation are described. A relatively low-cost electropneumatic system recently developed at the University of California at Berkeley is described in detail. This system provides sinusoidal and other shape load traces using normal compressed air controlled electronically and is an assembly of commercially available components.
New Sampler for Drilling in Noncohesive Soils
Authors: Johansson HG , Söderström T 
Published: February 2009

Abstract
Taking representative and sufficient samples of noncohesive soils, for example, gravel, sand, and different types of till from boreholes has always been a problem. In Sweden some samplers with very heavy supplementary equipment were used during the 1950s and 1960s. During the last three years a sampler for noncohesive soils has been developed in Sweden. The sampler has been tested in different soils over the whole country.
The sampler provides samples especially for physical and chemical property tests. The sampled soils, especially the tills, have shown very small disturbances. It has been easy to locate and determine different strata. The visual determination in the field of the grain size distribution has correlated well with laboratory analysis. The large quantities of the samples have resulted in a reliable determination of the soil characteristics. Boulders and stones have been drilled through. Samples of soils below the groundwater level as well as samples of underlying bedrock have been obtained.
Temperature Controlled Microwave Drying of Soils
Authors: Charlie WA , Von Gunten MW , Doehring DO 
Published: February 2009

Abstract
The use of temperature controlled microwave drying for the rapid determination of the moisture content of clay soils was investigated. Six soils having plasticity indexes ranging from five to fifty were tested. Temperature controlled microwave drying correlated greatly with water contents obtained from conventional temperature controlled drying. Drying at full microwave power without temperature control indicated higher water contents than drying by conventional means. Compared to the conventional oven method, drying times were approximately 13 times faster when full power microwave techniques were used and two to seven times faster when temperature controlled microwave operations were used.
Sensitivity Study of a Ground Probing Radar System
Authors: Bowders JJ , Lord AE , Koerner RM 
Published: February 2009

Abstract
A study was undertaken to determine the sensitivity of a ground probing radar (GPR) system. A review of the literature showed that an interface caused by a small contrast in densities resulted in a minimum amount of power from a transmitted signal being reflected. The following laboratory study revealed that the minimum amount of this power reflected is capable of causing a printable signal. It is these signals that cause difficulty in distinguishing the desired target in a GPR survey. Thus, the GPR system is often too sensitive for many applications, and it is suggested that some type of signal enhancement be considered for the system.
Electrical Analogy of Hydraulic Flow Through Rock Fractures
Authors: Sundaram PN , Frink D 
Published: February 2009

Abstract
Electrical analogy is used to study the influence of contact areas on the hydraulic flow through rock fractures. The investigation has shown that in the case of radial flow the location of contact zones, as well as the total contact area, influences the flow rate. It is also demonstrated that when injection tests are conducted in boreholes, where the fracture close to the borehole is partially plugged by loose particles or other debris, the flow rate may be substantially underestimated.
A Multi-Purpose Rock Core Testing Device
Authors: Swan G , Olofsson T 
Published: February 2009

Abstract
The need for a multi-purpose rock tester that incorporates a microcomputer for logging and evaluation purposes is identified. A number of semistandard test methods adaptable to such a tester are examined and found suitable from the point of view of simplicity, cheapness, and accuracy of determination. Some design aspects of this tester in its present state of development are considered.
Cyclic Triaxial Tests with Continuous Measurement of Dissipated Energy
Authors: Simcock KJ , Davis RO , Berrill JB , Mullenger G 
Published: February 2009

Abstract
This article describes conventional cyclic triaxial tests on a uniform sand in which the amount of energy dissipated by the specimen was continuously monitored. Energy monitoring was achieved by means of a digital circuit that automatically integrated the force-displacement signals as the test progressed. The resulting energy trace was plotted against the pore pressure buildup within the specimen. From a total of 21 tests, it appears that pore pressure generation and dissipated energy are functionally related, but this relationship appears to depend strongly on the level of cyclic deviator stress.
Suggested Test Method for Determination of the Soluble Salt Content of Soils by Refractometer
Authors: Chaney RC , Slonim SM , Slonim SS 
Published: February 2009

Abstract
A method suitable for laboratory or field application is proposed to extract pore water from a soil and determine its salinity. The pore water is extracted from the soil using a soil press originally developed by Kriukov and Komarova. Once the pore water has been extracted its salinity is determined using a hand-held refractometer with either a parts per thousand (ppt) or refreaction index scale. Using this method it is possible to measure salinity to an accuracy of ±1 ppt. Notes on sample storage and handling are included.
Burst Tester for Geotextile Bidirectional Strength
Authors: Costa JMA , Raymond GP 
Published: February 2009

Abstract
A burst tester for assessing the bidirectional strength of geotextiles has been developed and is presented herein. The tester was used to determine the properties of a number of differently manufactured geotextiles, and these results are described. The results are analyzed using the theory for membranes subject to a uniform pressure.
Having established the usefulness of the tester for bidirectional strength testing the apparatus was used to assess the resistance of geotextiles to abrasion produced with the standard double-head rotary test in accordance with ASTM Tests for Abrasion Resistance of Textile Fabrics (Oscillatory Cylinder and Uniform Abrasion Method) (D 1175). The effects using different stones are reported on, and the results using an H-18 stone are compared with the field performance of some geotextiles recovered from a railroad track environment. Conclusions are presented favorable to the use of the developed appratus.
Direct Shear Strength of Appalachian Coal
Authors: Peng SS , Patrick CW , Khair AW 
Published: February 2009

Abstract
A total of 142 prismatic specimens were prepared from five different Appalachian coal seams for direct shear-strength tests. Two types of specimen fracture were observed. The shear stress versus shear displacement and normal displacement for each specimen were recorded and analyzed. Two linear regressions were derived to best fit the shear failure of the coal.
Use of a Chain Saw for Obtaining Undisturbed Block Samples
Authors: Tiedemann DA , Sorensen RD 
Published: February 2009

Abstract
High quality undisturbed soil samples can be obtained by hand cutting methods. However, the procedures currently used are tedious, time consuming, and may not yield acceptable results in certain soil types. A procedure using a chain saw with a specially fabricated chain has been developed and field tested. The procedure has been shown to provide quality samples of a variety of materials in much less time than would be required using coventional methods.