Soil Testing Articles

  • How To Complete A Soil Test The Right Way

    A soil test should be one of the first steps you take in your landscape plan. Many of us never take this important first step, which contributes, to wasted resources and wasted time. The U.S. Department of Agriculture says soil testing is an “essential” tool that provides information on fertility and pH. Testing also indicates ...


    By Jain Irrigation, Inc

  • Biodegradation of fenpropathrin by a novel Rhodopseudomonas sp. strain PSB07-8

    The aim of our study was to isolate a fenpropathrin-degrading bacterial strain and to determine its effectiveness in bioremediating fenpropathrin-contaminated soil in the laboratory. We isolated a bacterial strain from soils and named it as PSB07-8, and showed that this organism was able to degrade pyrethroid pesticide fenpropathrin. The organism was identified as a strain of Rhodopseudomonas ...


    By Inderscience Publishers

  • Case Study: Highland Elementary School

    Prior to constructing new classroom buildings on newly acquired property adjacent to Highland Elementary School, the California Department of Toxic Substance Control (DTSC) requires that soil testing be conducted as part of a 'Preliminary Endangerment Assessment' (PEA). Ellis is administering testing of soils near existing buildings (lead), and beneath the location of a former hydraulic elevator ...

  • Response of corn and cotton to starter phosphorus on soils testing very high in phosphorus

    Phosphorus from agricultural lands poses a problem in water resources. In 2003, more than 48% of soil samples submitted to the North Carolina Department of Agriculture and Consumer Services (NCDA&CS) soil testing laboratory tested very high in soil P (>120 mg dm–3 P). As soil test P increases, off-site P loss increases, through erosion, soluble P runoff, or leaching. On soils testing above high ...

  • Consolidation Apparatus for Testing Unsaturated Soils

    An apparatus for performing consolidation tests under K0 conditions was designed and constructed for testing unsaturated soils. Three types of consolidation tests are of interest in unsaturated soils. These are: (1) constant water content loading tests, (2) consolidation under a net total stress, and (3) consolidation under a matric suction. The apparatus had been used for simultaneous and ...


    By ASTM International

  • A Flexible Strain Gage for Soil Testing

    A novel strain gage for the measurement of soil deformation is introduced. The gage is based on the principle that the change in the length of a coil is linearly related to the change in its inductance. The gage measures a wide range of strains and can be easily installed on a soil specimen in any direction; therefore, it is particularly suitable for the measurement of deformations of in situ ...


    By ASTM International

  • A New Technique for Diffusion Testing of Unsaturated Soil

    A technique is proposed for determining the coefficients of diffusion and adsorption for ions in unsaturated soils. The method integrates the single reservoir diffusion testing of saturated soil with the axis-translation technique for the control of matric suction. The procedure allows for the application of a net total stress and matric suction to the soil during the diffusion test. The use of ...


    By ASTM International

  • Alternative Test Method for Resilient Modulus of Fine-Grained Subgrades

    The mechanistic design of flexible pavement systems requires the specification of mechanical properties for asphaltic concrete, base course, and soil subgrade. The stiffness of the soil subgrade is represented by the resilient modulus, Mr, which is determined in the laboratory from cyclic triaxial tests and is usually a function of the level of applied stress. For a typical pavement project where ...


    By ASTM International

  • Air Volume Change Measurement in Unsaturated Soil Testing Using a Digital Pressure-Volume Controller

    One of the challenges associated with the testing of unsaturated soils is the measurement of air volume change induced by stress changes. This paper reports the results of an evaluation of a digital pressure-volume controller as an air volume change indicator. Effects of temperature, confined volume, and precompression of the measurement medium on the p-V characteristics and the device response ...


    By ASTM International

  • Model Study on the Failure Mechanism of Soil-Nailed Structure Under Surcharge Loading

    To investigate the effects of surcharge loading on the failure mechanism of soil-nailed structures, reduced scale-model tests were performed. The main variables for this study were the bending stiffness and tension resistance of nails and applied surcharge loading levels. In addition, two different testing sequences were used to simulate, respectively, the application of soil nailing in both new ...


    By ASTM International

  • Rigid Plate Settlements on Soils with Varying Deformation Properties

    The need to reliably predict foundation settlements has led to the use of plate-loading tests as a method of in situ determination of soil-deformation properties. The results of bearing-plate tests, especially when presented in graphical form, serve as a way to estimate allowable pressures and deformation moduli calculations. The magnitudes of plate settlements and the configurations of plate ...


    By ASTM International

  • Compressibility Characteristics of Gypseous Sandy Soils

    Soils containing gypsum as a cementing agent are affected considerably when subjected to changes in water content. Seepage through sandy gypseous soil causes serious damage to foundations built on such soils. A testing program was conducted on undisturbed soil specimens with three different gypsum contents to study the compressibility characteristics of such soils. The testing program included ...


    By ASTM International

  • Use of Fuzzy Control in Automated Soil Testing

    A servo-control algorithm that uses fuzzy logic has been developed for automated soil testing. The algorithm emulates the reasoning process of an experienced operator in controlling the pressure. The amount of pressure adjustment and time delay between adjustments is determined by fuzzy inference matrices. The fuzzy control logic provides a framework for the development of intelligent control ...


    By ASTM International

  • A General Dynamic Model for the Resonant Column/Quasi-Static Torsional Shear Apparatus

    A new model is proposed that allows for more general boundary conditions at both the active and passive ends of resonant column apparatus, especially those incorporated within the resonant column/quasi-static torsional shear devices. The improved three-degree-of-freedom model can be used in order to obtain more accurate measurements of the dynamic properties of tested soils when the base and the ...


    By ASTM International

  • A Multiple Purpose Soil Testing Apparatus

    A relatively compact soil testing system that is capable of performing monotonic/cyclic triaxial and torsional simple shear tests has been developed. A high-torque direct-drive, servo/stepper motor is used to provide the driving force. Under the servo mode, the motor could be controlled to provide a constant torque, which is used in stress-controlled tests. Strain-controlled tests are conducted ...


    By ASTM International

  • Torsional Motion Monitoring System for Small-Strain (10−5 to 10−3%) Soil Testing

    For accurate measurements of stress-strain hysteresis loops at strains below 10-3%, a torsional motion monitoring system was modified to incorporate micro-proximitors. A micro-proximitor system with enlarged target arms resulted in about 50 times higher resolution in motion monitoring than previously possible. The four proximitor signals (instead of two) were measured, compared, and averaged to ...


    By ASTM International

  • Determination of Cation Exchange Capacity of Clayey Soils by the Methylene Blue Test

    The methylene blue adsorption test (MBAT) for determining the cation exchange capacity (CEC) of clays is described. An attempt has been made to respond to previously expressed uncertainties in the MBAT itself and then to apply this test to determine the CEC values of the three geologically different soil types encountered in Ankara (alluvial soils, terrace deposits, and residual ...


    By ASTM International

  • Swell Potential Versus Overburden Pressure

    Data were collected and reviewed pertaining to one-dimensional vertical free-swell tests performed on existing fill soils from various projects located in Southern California. The purpose of reviewing the data was to evaluate the effect of overburden pressure on the swelling potential of expansive soils. The swell tests were performed on relatively undisturbed specimens at the in-place moisture ...


    By ASTM International

  • Dynamic Centrifuge Testing of Soil-Nailed Excavations

    A series of dynamic centrifuge tests was conducted on models of soil-nailed excavations. The models were subjected to various levels of horizontal shaking to investigate the seismic stability of their prototypes. The scaling factor was 50 in all tests, the depth of the prototype excavation was H = 7.6 m, and the length of nails in each test varied between 0.33 H and 1 H. The tests revealed the ...


    By ASTM International

  • Friction at the Cohesionless Soil-Structure Interface: Effect of Various Parameters according to a Classic Study and a New Approach

    A direct shear box, a ring shear apparatus, and a minipressuremeter are used: (1) to study the behavior of the cohesionless soil-structure interface; (2) to evaluate the friction mobilized at this interface. Tests have been carried out with a continual displacement of the structure in contact with the soil. The applied normal stress was kept constant during all tests. The influence of the ...


    By ASTM International

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