However, by vibrating the soil sample at resonance in the resonant column test, it was possible to obtain higher shearing strain amplitudes. Pdf measurements of shear wave velocity by resonantcolumn. Pdf the standard procedure to determine dynamic parameter of soils in the laboratory is the resonantcolumn test astm d4015. Stokoe ii both resonant column rc and torsional shear ts tests were performed at small below 0. Among various methods for laboratory measurement of shear stiffness, bender elements and resonant column tests are accepted to be most reliable. Nondestructive evaluation of warm mix asphalt through resonant. This is achieved by a slender, thin walled loading column passing through the drive system to the topcap. Characterization of resilient modulus of compacted. Pdf comprehensive characterization of the small strain shear modulus g max of an unsaturated soil specimen during hydraulic hysteresis requires. Advancements in resonant column testing of soils using. The study presents lowamplitude resonant column test results on volcanic sands with intraparticle voids. Astm d401515e1 standard test methods for modulus and. The frequencies of loading for the resonant column test are much higher than the frequencies of primary interest for earthquake loading.
Pdf preloading effects on dynamic sand behavior by resonant. Characterization of resilient modulus of compacted subgrade soils using resonant column and torsional shear tests dongsoo k1m and kenneth h. Of 1 small strain tests using a resonant column apparatus and 2 large strain tests using a cyclic triaxial apparatus. Santos technical university of lisbon, lisbon, portugal antonio viana da fonseca. Pdf resonant column test for unsaturated soils with suction.
Resonant column and torsional shear testing can also be followed by a stresspath triaxial test. From the frequency sweep graph the fundamental resonant frequency and modulus of damping can be determined. Evaluation of the freefree resonant frequency method to. 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. Contribution to the astm resonant column round robin testing.
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. The resonant column measurements are normally made at constant shear strain level, for example or lower. Shear moduli and damping in frozen and unfrozen clay by. 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. Characterization of resilient modulus of compacted subgrade. Nonlinear vibration analysis of the resonant column test. 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. The objective of the present work is to overview alternative testing and.
The betd method could be affected by the soil plasticity. 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. The standard magnetcoil driving system in resonant column devices provides the required cyclic excitation. 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 method is established as a standard laboratory method for the study of the elastic properties of soils. 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 resonant column test is a relatively nondestructive test employing wave propagation in cylindrical specimens of soil and rock. The resonant column was first used by ishimato and iida 1937 1 and iida 1938, 1940 2, 3 to test japanese. A number of resonant column tests were conducted in torsion on aluminium cylindrical bars. The resonant column device at penn state was used to determine the modulus and damping of warmmix asphalt prepared with three different warmmix technologies. Measurements of shear wave velocity by resonant column test, bender element test and miniature accelerometers. Advancements in resonant column testing of soils using random. Therefore to reduce data from the resonant column test, the mass polar moment of inertia of the drive system i 0 is required.
Attachment a7 results of resonant columncyclic torsional. Dynamic properties of gravel recycled rubber mixtures. The low strain tests are used to determine the property insitu condition. Evaluating use of resonant column in flexural mode for dynamic.
Elastic stiffness of volcanic sand through resonant column. Resonant column apparatus stokoe type srca gds instruments. Resonant column test norges geotekniske institutt ngi. Naturally frozen soil specimens were obtained insitu during the winter. 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 resonant column test determines the dynamic soil properties of various soil samples. Results suggest that in nonplastic soils the stiffness tends to be underestimated compared with the stiffness obtained. The gds hardin oscillator contains an electromagnetic drive system incorporating precision wound coils and composite sintered. Nonlinear vibration analysis of the resonant column test of. Advancements in resonant column testing of soils using random vibration techniques bing yu iowa state university follow this and additional works at. Includes automated frequency sweep for forced vibration procedures, least squares calculation of free vibration damping, power ratio damping, and graphing and report generation of.
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. On this framework, resonant column tests were performed on saturated specimens rubber percentage ranging between 0% and 60% by mixture weight. Resonant column test module to automatically perform conventional resonant column tests. Pdf resonant column testing challenges researchgate. 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.
Shear modulus of a saturated granular soil derived from. Cyclic triaxial tests were also performed on identical specimens. The vibration of the specimen may be superposed on a controlled static state of stress in the specimen. Effect of sample torsional stiffness on resonant column test. The system is capable of displaying the current status of a test and graphically portraying the progress of the test in real time. 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.
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. Resonant column and torsional shear gcts testing systems. Shear modulus of a saturated granular soil derived from resonant. Effect of saturation on dynamic soil properties in low.
The influences of confining pressure, void ratio, water content, sampling method, stress history, confinement duration and. D401515e1 standard test methods for modulus and damping of soils by fixedbase resonant column devices damping properties strain triaxial stress solid. Test results the results of the resonant columncyclic torsional shear tests are presented in the exhibits to the university of texas report. The experiments were performed on dry samples prepared at variable relative densities and tested in torsional mode of vibration. Attachment a7, results of resonant columncyclic torsional.
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. 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. This paper theoretically analyzes the nonlinear torsional vibration of a granular material specimen in the resonant column test rct. Resonant column test readings are taken at times similar to that of a consolidation test i. Resonant columns torsional excitation mechanism youtube. The resonant column test is used to measure shear modulus g and the. By changing the length to diameter ratio of these specimens, the resonant frequency was varied between 52. 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. Controls is the global leader in the production of testing equipment for the construction industry with more than 4. 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 standard procedure to determine dynamic parameter of soils in the laboratory is the resonantcolumn test astm d4015. Details on this theory can be found in richart et al. 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.
Resonant column apparatus stokoe type product code. Determining the dynamic deformation properties shear modulus and damping ratio of soils. Unlike the resonant column or torsional shear devices, the cyclic loads are axial instead of torsional. Laboratory measurement of shear stiffness in resonant. Standard test methods for modulus and damping of soils by. Nondestructive evaluation of warm mix asphalt through. 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. 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. Nondestructive testing has been used for decades to characterize engineering properties of hotmix asphalt.
Effect of loading frequency on dynamic properties of soils. This software test module has greatly simplified the operation of instruments and conduction of the resonant column test by allowing. Test results the results of the resonant column cyclic torsional shear tests are presented in the exhibits to the university of texas report. Measurements of shear wave velocity by resonant column test. The rct is a material testing method that has been well established in geotechnical engineering. Frequency dependent dynamic properties from resonant. Advancements in resonant column testing of soils using random vibration techniques. Resonant column apparatus hardin type hrca gds instruments. This study presents an evaluation of youngs modulus of a quartzitic sand derived from flexural resonant column tests. Three type of soils were tested by resonantcolumn rc and two be test methods betd and befd.
Three type of soils were tested by resonant column rc and two be test methods betd and befd. Tests for measuring undrained shear modulus reduction of sand with plastic fines reference. Using timoshenkos beam theory for resonant column testing frequency equation by bruch and mitchell. Both solid and hollow specimens can be used with this equipment.
Testing equipment for the construction industry controls. Resonant column torsional shear test equipment geocomp. 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. The resonant column test is a commonly used laboratory test for measuring dynamic soil properties at low to medium strains. 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. 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. Result of the test is a relationship between shear modulus and shear strain and.
The test is performed by vibrating a soil cylinder solid or hollow at one of its natural modes. These specimens were tested by resonantcolumn rc and two kind of be. The gcts cats resonant columntorsional shear module is part of our 32bit windows. Of 1 small strain tests using a resonant column apparatus and 2 large strain.