Hardin type resonant column apparatus hrca is a system that allows samples to be tested in resonance while maintaining an anisotropic loading up to 2kn. However, for the purpose of this essay, their resonant frequency equations were considered to be adequate for use in computing the materials young modulus from the flexural resonant column test, if the angular natural frequency is known. Measuring dynamic properties of wind turbine foundation soil in resonant column issues and challenges by zhenzhong wu a thesis submitted in partial fulfillment of the requirements for the degree of. The low strain tests are used to determine the property insitu condition. In this study, the resonant column is modeled as an electromechanical system to. Three type of soils were tested by resonant column rc and two be test methods betd and befd. Details on this theory can be found in richart et al. Astm d401515e1 standard test methods for modulus and. Resonant column combines the features of both resonant column and torsional shear into a single unit including the current driven motor to apply torsional load to sample, a series of transducers with signal conditioning, a cell and back pressure electropneumatic control system and a data logger. Measurements of shear wave velocity by resonant column test, bender element test and miniature accelerometers. The standard magnetcoil driving system in resonant column devices provides the required cyclic excitation. The rct is a material testing method that has been well established in geotechnical engineering. The resonant column test is a commonly used laboratory test for measuring dynamic soil properties at low to medium strains.
The gcts cats resonant column torsional shear module is part of our 32bit windows. The test is performed by vibrating a soil cylinder solid or hollow at one of its natural modes. The objective of the present work is to overview alternative testing and. Shear modulus of a saturated granular soil derived from resonant. The influences of confining pressure, void ratio, water content, sampling method, stress history, confinement duration and. Standard test methods for modulus and damping of soils by.
The resonant column test determines the dynamic soil properties of various soil samples. Resonant column test readings are taken at times similar to that of a consolidation test i. Three type of soils were tested by resonantcolumn rc and two be test methods betd and befd. Resonant column test norges geotekniske institutt ngi. The resonant column method is established as a standard laboratory method for the study of the elastic properties of soils. Resonant column and torsional shear testing can also be followed by a stresspath triaxial test. Nondestructive evaluation of warm mix asphalt through. This paper theoretically analyzes the nonlinear torsional vibration of a granular material specimen in the resonant column test rct. The betd method could be affected by the soil plasticity. The vibration of the specimen may be superposed on a controlled static state of stress in the specimen. The study presents lowamplitude resonant column test results on volcanic sands with intraparticle voids. However, by vibrating the soil sample at resonance in the resonant column test, it was possible to obtain higher shearing strain amplitudes. Shear moduli and damping in frozen and unfrozen clay by. Cyclic triaxial tests were also performed on identical specimens.
Characterization of resilient modulus of compacted. Attachment a7, results of resonant columncyclic torsional. Measurements of shear wave velocity by resonant column test. Srca for many years the resonant column apparatus has been used in research and commercial laboratories to estimate values of the shear modulus, g, and damping ratio, d, for soil specimens across the small to medium strain range pdf view as pdf. Elastic stiffness of volcanic sand through resonant column. Effect of loading frequency on dynamic properties of soils. The resonant column test is used to measure shear modulus g and the. Controls is the global leader in the production of testing equipment for the construction industry with more than 4. Combined resonant column and cyclic triaxial tests for. Resonant column apparatus stokoe type srca gds instruments.
These specimens were tested by resonantcolumn rc and two kind of be. Pdf preloading effects on dynamic sand behavior by resonant. Resonant column torsional shear test equipment geocomp. Characterization of resilient modulus of compacted subgrade.
The resonant column test is a relatively nondestructive test employing wave propagation in cylindrical specimens of soil and rock. The system is capable of displaying the current status of a test and graphically portraying the progress of the test in real time. Laboratory measurement of shear stiffness in resonant. Resonant column test module to automatically perform conventional resonant column tests. Attachment a7 results of resonant columncyclic torsional. Testing equipment for the construction industry controls. Advancements in resonant column testing of soils using. Srca for many years the resonant column apparatus has been used in research and commercial laboratories to estimate values of the shear modulus, g, and damping ratio, d, for soil specimens across the small to medium strain range resonant column tests are also presented. Following each test series, the test system was disassembled and final weights and dimensions obtained for the test specimen. Test results the results of the resonant columncyclic torsional shear tests are presented in the exhibits to the university of texas report. Measurements of shear wave velocity by resonantcolumn test, bender element test and miniature accelerometers javier camachotauta nueva granada military university, bogota, colombia giovanni cascante university of waterloo, waterloo, canada jaime a.
Both solid and hollow specimens can be used with this equipment. In the resonant column test the half power bandwidth method can be used to measure the material damping the bandwidth is the frequency difference between the upper and lower frequencies for which the power has dropped to half of its maximum, the frequencies f1 and f2 at which the amplitude is 0. Tests for measuring undrained shear modulus reduction of sand with plastic fines reference. Advancements in resonant column testing of soils using random. Shear modulus of a saturated granular soil derived from. The resonant column test is used to determine the shear or elastic modulus and damping characteristics of soils based on the theory of wave propagation in prismatic rods. This study presents an evaluation of youngs modulus of a quartzitic sand derived from flexural resonant column tests. Effect of saturation on dynamic soil properties in low. D401515e1 standard test methods for modulus and damping of soils by fixedbase resonant column devices damping properties strain triaxial stress solid cylindrical specimens resonant column method. On this framework, resonant column tests were performed on saturated specimens rubber percentage ranging between 0% and 60% by mixture weight. By changing the length to diameter ratio of these specimens, the resonant frequency was varied between 52. Test results are usually quite accurate, but in some cases insufficient coupling exists between specimen and apparatus or specimens are too stiff for a given apparatus, or both. Evaluation of the freefree resonant frequency method to. Evaluating use of resonant column in flexural mode for dynamic.
Nonlinear vibration analysis of the resonant column test of. Resonant column apparatus stokoe type product code. Using timoshenkos beam theory for resonant column testing frequency equation by bruch and mitchell. Dynamic properties of gravel recycled rubber mixtures. Result of the test is a relationship between shear modulus and shear strain and. This paper aims to compare the shear modulus and damping ratio obtained from torsional shear tests and resonant column tests for cement treated clays depending on the associated shear strain.
The gcts cats resonant columntorsional shear module is part of our 32bit windows. This is achieved by a slender, thin walled loading column passing through the drive system to the topcap. Bender elements, originally developed for soft soils, enable transmitting and receiving shear andor compression waves and can be installed virtually in any conventional soil testing device. Contribution to the astm resonant column round robin testing. A series of tests were carried out on the frozen soil specimens in a cold room at 9c. For the resonant column test a torsional drive is used to vibrate the top of the soil specimen at frequencies up to 250 hz in firstmode resonance while the bottom is. Pdf comprehensive characterization of the small strain shear modulus g max of an unsaturated soil specimen during hydraulic hysteresis requires. Effect of sample torsional stiffness on resonant column test. Characterization of resilient modulus of compacted subgrade soils using resonant column and torsional shear tests dongsoo k1m and kenneth h.
A number of resonant column tests were conducted in torsion on aluminium cylindrical bars. The shear modulus torsion test or youngs modulus a exure test are, at that time, obtained from the calculated velocity and the density of the specimen gds instrument 2009. Nonlinear vibration analysis of the resonant column test. Includes automated frequency sweep for forced vibration procedures, least squares calculation of free vibration damping, power ratio damping, and graphing and report generation of. The standard procedure to determine dynamic parameter of soils in the laboratory is the resonant column test astm d4015.
Nondestructive evaluation of warm mix asphalt through resonant. Santos technical university of lisbon, lisbon, portugal antonio viana da fonseca. The experiments were performed on dry samples prepared at variable relative densities and tested in torsional mode of vibration. Pdf resonant column test for unsaturated soils with suction. Pdf measurements of shear wave velocity by resonantcolumn. In the resonant column test the half power bandwidth method can be used to measure the material damping resonant frequency the bandwidth is the frequency difference between the upper and. Therefore to reduce data from the resonant column test, the mass polar moment of inertia of the drive system i 0 is required. Resonant column apparatus hardin type hrca gds instruments.
This software test module has greatly simplified the operation of instruments and conduction of the resonant column test by allowing. Stokoe ii both resonant column rc and torsional shear ts tests were performed at small below 0. Determining the dynamic deformation properties shear modulus and damping ratio of soils. Among various methods for laboratory measurement of shear stiffness, bender elements and resonant column tests are accepted to be most reliable. From the frequency sweep graph the fundamental resonant frequency and modulus of damping can be determined. Dynamic behavior of berlin sand and the preloading effects on shear modulus and damping properties of sand were investigated by resonant column tests in this study, in addition, a new reliable calibration method for the stokoe resonant column apparatus is also presented. Results suggest that in nonplastic soils the stiffness tends to be underestimated compared with the stiffness obtained. The frequencies of loading for the resonant column test are much higher than the frequencies of primary interest for earthquake loading. Frequency dependent dynamic properties from resonant. Cement treatment is one of the widely used ground improvement methods to enhance the strength and compressibility characteristics of soft marine clay deposits. The resonant column was first used by ishimato and iida 1937 1 and iida 1938, 1940 2, 3 to test japanese.
Nov 20, 2015 cement treatment is one of the widely used ground improvement methods to enhance the strength and compressibility characteristics of soft marine clay deposits. The wave propagation velocity and the shear modulus at the tested strain can then be determined from the resonant frequency. The cyclic triaxial test is an astm standard 4 test to evaluate the dynamic properties of soils at frequencies usually below 2 hz and shear strain levels from 0. The resonant column device at penn state was used to determine the modulus and damping of warmmix asphalt prepared with three different warmmix technologies. The resonant column measurements are normally made at constant shear strain level, for example or lower. Advancements in resonant column testing of soils using random vibration techniques. Of 1 small strain tests using a resonant column apparatus and 2 large strain.
Pdf resonant column testing challenges researchgate. Results suggest that in nonplastic soils the stiffness tends to be underestimated compared with the stiffness obtained by the rc test. The resonantcolumn test method was used in this study to determine the dynamic shear moduli and damping ratios of frozen and unfrozen soil samples. Pdf preloading effects on dynamic sand behavior by. Nondestructive testing has been used for decades to characterize engineering properties of hotmix asphalt. Includes automated frequency sweep for forced vibration procedures, least squares calculation of free vibration damping, power ratio damping, and graphing and report generation of test results. Of 1 small strain tests using a resonant column apparatus and 2 large strain tests using a cyclic triaxial apparatus. Naturally frozen soil specimens were obtained insitu during the winter. Resonant columns torsional excitation mechanism youtube. Resonant column and torsional shear gcts testing systems. The gds hardin oscillator contains an electromagnetic drive system incorporating precision wound coils and composite sintered. Measurements of shear wave velocity by resonant column. The standard procedure to determine dynamic parameter of soils in the laboratory is the resonantcolumn test astm d4015.
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