The smallstrain shear modulus depends on stress in uncemented soils. Conclusion in this study, the determination of shear wave velocity for peat was used multichannel analysis of surface wave masw method and meanwhile shear modulus value was by using empirical formula. Dependencies of shear wave velocity and shear modulus of soil. Relationship between shearwave velocity and geotechnical. Pdf shear wave velocity by support vector machine based. Relationship between shearwave velocity and geotechnical parameters for norwegian clays jeansebastien lheureux, ph. Soil velocity profile is often used as subsurface characterization by using seismicbased. Pdf the shear wave velocity v s is directly related to the elastic shear modulus and. For site characterization, it is important to determine shear wave velocity directly using an empirical. Shear wave velocity, v s, is a soil mechanical property that can be advantageously measured in both the field and laboratory under real and controlled conditions. Unified correlation between sptn and shear wave velocity for all soil types c. The shear wave velocity vs of sediments plays a key role in seismic wave and is amplification required in site response analysis. Estimation of shear wave velocity from soil indices. In effect, the shearwave velocity, which is often used to calculate shear stiffness, follows a power equation with the mean effective stress in the polarization plane v s.
Tool for analysis of masw field data and evaluation of shear. Shear wave velocity v s in geomaterials is strongly dependent on factors such as stress state, void ratio, and soil structure. The seismic surface wave method masw is the simplest and a very efficient way of measuring the shear wave velocity in the field. It is useful and often necessary to determine the numerical values of these properties as they exist in nature through the use of in soil testing. Estimation of engineering properties of soils from field.
The shear wave velocity v s propagation in the compacted specimens was evaluated using bender elements. Study on the correlation between strength parameters and. Review of geotechnical provisions in indian seismic code is. The geologic maps, along with measurements of the soils properties, are used to classify the various soils as to how much they would amplify earthquake ground. Correlation of densities with shear wave velocities and spt n. Guidelines for estimation of shear wave velocity profiles. Standard test method for determination of shear wave. Using shear wave velocity measurements from this test, the. Determination of shear wave velocity using multichannel. Dependencies of shear wave velocity and shear modulus of. Rock properties that affect seismic velocity 1 porosity. Shear wave velocity vs is a basic engineering property implemented in evaluating the soil shear modulus. Shear wave velocity v s and smallstrain shear modulus g 0 are the key parameters in defining material response to various dynamic loadings.
Guidelines for estimation of shear wave velocity profiles pacific. Jadi, determination of dynamic soil properties using geophysical methods, proceedings of the first international conference on the application of geophysical and ndt methodologies to transportation facilities and infrastructure, st. The spt n value has been linked with many properties like the relative density, the consistency, youngs modulus, the shear wave velocity, the shear modulus, the over consolidation ratio and the california bearing ratio cbr. However, this test is expensive, requiring two closely spaced boreholes, special recording equipment and skill in identifying shear wave arrivals. A polarized shear wave is generated in one borehole or at the surface and the time is measured for the shear wave to travel a known distance to the geophone in the borehole. However, a similar study of the deltaic sediments from the fluvial, marsh, and swamp depositional environments found throughout the louisiana coastal zone figure 1 do not exist. Using shear wave velocity measurements from this test, the composite stiffness of the soil combined stiffness of the soil and ground improvement can be determined.
Swaves dont penetrate the outer core, so theyre shadowed everywhere more than 104. For the model waste and the saturated sand, shear wave velocity vs is obtained using a miniature air hammer which. Mar 29, 20 information on shear wave velocities vs of soil deposits is required for solution of design earthquake motions, soil structure interaction and wave amplification. Correlation between shear wave velocity and porosity in. The shear wave velocity can be measured insitu by using several different geophysical techniques, such as the uphole, downhole, or crosshole methods. The determination of v s profiles using surface wave thus appears as a most promising avenue for non intrusive geotechnical investigations. Numerous researchers and practitioners have examined the viability of correlations between. Test, cone penetration test and shear wave velocity measurements. Pdf shear wave velocity vs is a basic engineering property implemented in evaluating the soil shear modulus. Canadian geotechnical journal canadian science publishing.
Results from field testing at two pavement sites and two soil sites indicate that the spectral analysis of surface waves. Dynamic soil stiffness, as indicated by either shear modulus or shear wave velocity, is a prerequisite parameter for dynamic analysis of earthen structures, foundations for superstructures, and freefield seismic response. The seismic surface wave method masw is the simplest and a very efficient way of measuring the shearwave velocity in the field. Oct 10, 2014 the smallstrain shear modulus depends on stress in uncemented soils.
The velocity of the shear wave is about half of the velocity of the compression wave. The s wave is a transverse wave, meaning that, in the simplest situation, the oscillations of the particles of the medium is perpendicular to the direction of wave propagation, and the main restoring force comes from shear stress. Review of geotechnical provisions in indian seismic code. Pdf shear wave velocity as a geotechnical parameter. Unified correlation between sptn and shear wave velocity. In deepsoil, a soil column can be broken up into individual layers, each of which is characterized using the corresponding soil properties shear wave velocity. Shear wave velocity an overview sciencedirect topics. For example, shear wave velocity is linked to the dynamic shear modulus and also to density section 2. A very rough rule due to wyllie is the so called time average relationship. Smallstrain shear wave velocity measurements provide a promising supplement and in some cases, where only geophysical measurements are possible, may be the only alternative to the penetrationbased approach. Furthermore, the shear wave velocity is vital in assessments of both liquefaction potential and soil amplification and for seismic site classification kramer 1996.
The shearwave velocity in a crystal varies according to the direction of propagation and the plane of polarization i. Testing procedure in total, seven types of soil were tested. From this shear wave velocity and the density of the soil specimen the initial shear modulus g max can be determined, which is the result of primary interest from bender element tests. When a seismic design for an earthquakeprone area is required, dynamic soil properties including shear wave velocity, shear modulus, and. Elastic theory relates the shear modulus, g, soil density, p, and shear wave velocity, v, as follows, go v, 1. Soil properties for shear wave propagation springerlink. Guidelines for evaluating liquefaction resistance using. Use of shear wave velocity is an alternative method to describe dynamic properties of soil. The shear wave velocity vs is theoretically related to the shear modulus and thereforeis a direct measurement of the small strain shear modulus gmax. Pdf shear wave velocity, vs is a mechanical property of soil that advantageously can be measured directly in both the field and laboratory.
Correlations between shear wave velocity and geotechnical. Correlation of densities with shear wave velocities and. This is not based on any convincing theory but is roughly right when the effective pressure is high and the rock is fully saturated. Determination of in situ shear wave velocities from. For design of foundation, engineering properties like strength and deformability characteristics of soils are very important parameters. From this shear wave velocity and the density of the soil specimen the initial shear modulus g max can be determined, which is the. Investigation of shear wave velocity and predominant period properties of bornova plain izmir doi. Furthermore, the shear wave velocity is vital in assessments of both liquefaction potential and soil amplification and.
Evaluation of shear modulus and damping in dynamic centrifuge. Standard test method for determination of shear wave velocity. This report presents guidelines for estimating the shear wave velocity profiles in. Examination of existing shear wave velocity and shear. The paper presents a description of the dynamic properties of cohesive material, namely. Unified correlation between sptn and shear wave velocity for. The shear wave velocity v s is directly related to the elastic shear modulus and constitutes an important characterization parameter in terms of engineering properties. These soils were chosen to represent a wide range of soil type, from sandy to silty, and clayey. The shear wave travel time is measured, which over a known travel distance yields the shear wave velocity. Determination of in situ shear wave velocities from spectral. A shear wave is generated at one boundary of a soil specimen and then received at an opposite boundary. Crosshole logging technique gives reliable measure of in situ shear wave velocity. A database of shearwavevelocity v s measurements using a variety of techniques and soil properties measured on highquality samples for 28 norwegian sites has been established. Mechanical parameters and bearing capacity of soils.
Shear wave velocity relations for silty and gravely soils. Shear modulus shear strain strain amplitude void ratio shear wave velocity. Table 1 lists the classifications and basic properties of the soils. Elastic moduli shear moduli and youngs moduli were then calculated from the shear wave velocities. Manual on estimating soil properties for foundation design. Shear wave velocity vs, dynamic shear modulus g,, and damping characteristics of soils are important parameters required for dynamic site response analysis as well as for design and performance evaluation of earth structures and foundations.
Other methods that can be used to determine the insitu shear wave velocity include the seismic cone. In the last 25 years much has been learned about the properties which affect dynamic response and wave propagation and ways to measure those properties. Test data shown in section 4 is normalised by a gmax obtained from equation 7, where vs is shear wave velocity and. Study of resistivity and shear wave velocity as a predictive. The shear wave velocity in a crystal varies according to the direction of propagation and the plane of polarization i. The shear modulus is related to shear wave velocity as 2 max. The soil profiles of compressive and shear wave velocities were verified using the borehole data and showed good agreement with the borehole data.
Characterization of shear wave velocity profiles for south carolina. Therefore, the shear modulus obtained from shear wave velocity data is considered to be the smallstrain shear modulus gmax. In seismic hazard analysis, sitespecific shear wave velocity is an indication of the expected ground shaking, in response. In many instances it may be preferable to determine vs indirectly by common insitu tests.
Shear wave velocity, vs, is a soil mechanical property that can be. Critical friction angle and dilation increase with increasing nonplastic. Soil properties like cohesion, angle of friction, shear wave velocity, poissons ratio etc. Statistical correlations of shear wave velocity and penetration resistance for soils. Shear wave propagation in soil is a physical phenomenon and has been used widely for monitoring and seismic property assessment in geotechnical engineering. Smallstrain stiffness, shearwave velocity, and soil. Pdf shear wave velocity in geotechnical engineering.
The small strain shear modulus of individual soil layers is directly proportional to the square of their characteristic shear wave velocity. Shear waves travel at about half the speed of compressional waves e. The significance of the shear wave velocity to the analysis of small amplitude soil vibration problems has. The predicted of indian standards, new delhi, india. Shear waves are generated by striking the push rods attached to the probes in the ground with hammers. In this study three methods of they are 1 the menard pressuremeter, situ soil testing are examined. Compressive and shear wave velocity profiles using seismic. Prediction of axial capacity of piles driven in noncohesive soils based on. The shear wave velocity, depends on the following material properties. Recently 1, 6 8, in the case of homogeneous isotropic porous materials, modulus of elasticity, shear modulus, and poissons ratio were modelled using power law dependence on porosity on the basis. Similarly for predicted spt n value standard penetration test for the best correlation is found for clay having soils. Tool for analysis of masw field data and evaluation of. Stressdependency and voidratio dependency can be represented by the equations and v s ae b where.
Pdf shear wave velocity by support vector machine based on. The shearwave velocity v s is one of the most important parameters for determining dynamic soil properties and groundresponse analyses. For analysis and design of structures and for interpretation of wave propagation phenomena, the key soilrock properties are shear modulus, material damping and unit weight. Characterization of the smallstrain shear modulus and the shear wave velocity of soils and rocks is an integral component of various seismic analyses, including site classification, hazard analysis, site response analysis, and soilstructure interaction. It assesses soil properties that are not determined from cone penetration testing.
Miller kansas geological survey university of kansas 1930 constant avenue, campus west lawrence, kansas 660473726 final report to richard w. Evaluation of shear modulus and damping in dynamic. However, the attenuation of surface waves based on frequency section 2. Shear wave velocity vs is a valuable indicator of the dynamic properties of soil and rock because of its relationship with gmax, given by equation 1.
Shear wave velocity is an important parameter with respect to geophysical investigation, site classification and microzonation studies. After that the received signal filtered offthenoiseandthenrecordedanddisplayeditontheoscilloscope. The shear wave velocity of the soil can also be used to determine the soil profile type. Rayleigh wave velocities from which shear wave velocities were calculated. Shear wave velocity tests are increasingly being used to assess a wider range of soil properties including strength. Investigation of shear wave velocity and predominant. In seismic hazard analysis, sitespecific shear wave velocity is an indication. Several studies were conducted in order to relate the spt n value and shear wave velocity to various soil properties. The measured v s values are customarily used in conjunction with other in situ e. The shear wave velocity v s is one of the most important parameters for determining dynamic soil properties and groundresponse analyses.
This report presents guidelines for evaluating liquefaction resistance using shear wave velocity measurements. Guidelines for evaluating liquefaction resistance using shear. The seismic velocity profile was obtained at a depth of 20 m. Investigation of shear wave velocity and predominant period. G v s 3 where gmax is smallstrain shear modulus in pa.
690 1350 318 415 301 1070 239 1026 906 939 1535 275 465 1261 1245 1025 1234 119 706 249 2 634 273 562 1277 681 931 669 1277 662 1421