Study on the correlation between strength parameters and. Shear wave propagation in soil is a physical phenomenon and has been used widely for monitoring and seismic property assessment in geotechnical engineering. The shear wave travel time is measured, which over a known travel distance yields the shear wave velocity. The velocity of the shear wave is about half of the velocity of the compression wave. For the model waste and the saturated sand, shear wave velocity vs is obtained using a miniature air hammer which. The swave 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. It is, however, an expensive parameter to determine in situ and in the laboratory. Therefore, the shear modulus obtained from shear wave velocity data is considered to be the smallstrain shear modulus gmax. One probe acts as an emitter of the shear waves, the other as the receiver of the waves generated in the first probe. Correlation of densities with shear wave velocities and spt n. Use of shear wave velocity is an alternative method to describe dynamic properties of soil.
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. Shear waves are generated by striking the push rods attached to the probes in the ground with hammers. The shear wave velocity vs is theoretically related to the shear modulus and thereforeis a direct measurement of the small strain shear modulus gmax. Evaluation of shear modulus and damping in dynamic centrifuge. Testing procedure in total, seven types of soil were tested. The measured v s values are customarily used in conjunction with other in situ e. Firm soil indented only by strong finger pressure 50100 kpa stiff soil indented by thumb pressure 100200 kpa very stiff soil indented by thumb nail 200400 kpa. The shearwave velocity v s is one of the most important parameters for determining dynamic soil properties and groundresponse analyses. In seismic hazard analysis, sitespecific shear wave velocity is an indication.
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. The shear wave velocity in a crystal varies according to the direction of propagation and the plane of polarization i. A very rough rule due to wyllie is the so called time average relationship. Results from field testing at two pavement sites and two soil sites indicate that the spectral analysis of surface waves. Shear wave velocity v s in geomaterials is strongly dependent on factors such as stress state, void ratio, and soil structure. Prediction of axial capacity of piles driven in noncohesive soils based on. Compressive and shear wave velocity profiles using seismic. Evaluation of shear modulus and damping in dynamic. Investigation of shear wave velocity and predominant. The shear wave velocity can be measured insitu by using several different geophysical techniques, such as the uphole, downhole, or crosshole methods.
Dependencies of shear wave velocity and shear modulus of. Manual on estimating soil properties for foundation design. Test, cone penetration test and shear wave velocity measurements. Guidelines for estimation of shear wave velocity profiles pacific. 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. Examination of existing shear wave velocity and shear modulus. The soil profiles of compressive and shear wave velocities were verified using the borehole data and showed good agreement with the borehole data.
Correlation of densities with shear wave velocities and. Tool for analysis of masw field data and evaluation of. Using shear wave velocity measurements from this test, the. The shear wave velocity v s propagation in the compacted specimens was evaluated using bender elements. 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. A pair of bender elements adapted in a bishopwesley standard triaxial cell setup was able to generate and detect shear waves through the unsaturated compacted soil specimens. The determination of soil properties is an essential step to proper foundation design. The estimation of seismic velocities, modulus of elasticity and structural properties of soils is not enough in the design of engineering projects. Pdf shear wave velocity in geotechnical engineering. 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. Similarly for predicted spt n value standard penetration test for the best correlation is found for clay having soils. It assesses soil properties that are not determined from cone penetration testing. Elastic theory relates the shear modulus, g, soil density, p, and shear wave velocity, v, as follows, go v, 1.
Pdf shear wave velocity by support vector machine based. Critical friction angle and dilation increase with increasing nonplastic. 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. Pdf the shear wave velocity v s is directly related to the elastic shear modulus and. Rayleigh wave velocities from which shear wave velocities were calculated. 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. Guidelines for estimation of shear wave velocity profiles. 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. Shear modulus shear strain strain amplitude void ratio shear wave velocity. Shear wave velocity is an important parameter with respect to geophysical investigation, site classification and microzonation studies. The seismic surface wave method masw is the simplest and a very efficient way of measuring the shearwave velocity in the field.
Shear wave velocity relations for silty and gravely soils. The shear wave velocity v s is one of the most important parameters for determining dynamic soil properties and groundresponse analyses. Pdf shear wave velocity, vs is a mechanical property of soil that advantageously can be measured directly in both the field and laboratory. This report presents guidelines for evaluating liquefaction resistance using shear wave velocity measurements.
Estimation of engineering properties of soils from field. By using three kinds of subgrade soil and controlling dry density and moisture content,the correlation between strength parameters of pavement subgrade soil, california bearing ratiocbr and resilience modulus e, and their shear wave velocity are studied through cbr penetration test, lever pressure meter test and shear wave velocity test. 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. Miller kansas geological survey university of kansas 1930 constant avenue, campus west lawrence, kansas 660473726 final report to richard w. The determination of v s profiles using surface wave thus appears as a most promising avenue for non intrusive geotechnical investigations. For site characterization, it is important to determine shear wave velocity directly using an empirical. Unified correlation between sptn and shear wave velocity for.
Other methods that can be used to determine the insitu shear wave velocity include the seismic cone. Several studies were conducted in order to relate the spt n value and shear wave velocity to various soil properties. Determination of in situ shear wave velocities from spectral. The significance of the shear wave velocity to the analysis of small amplitude soil vibration problems has. Investigation of shear wave velocity and predominant period. Stressdependency and voidratio dependency can be represented by the equations and v s ae b where. 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. Pdf statistical correlations of shear wave velocity and. Shear waves travel at about half the speed of compressional waves e. Relationship between shearwave velocity and geotechnical parameters for norwegian clays jeansebastien lheureux, ph. 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.
Correlations between shear wave velocity and geotechnical. Mechanical parameters and bearing capacity of soils. Guidelines for evaluating liquefaction resistance using shear. The small strain shear modulus of individual soil layers is directly proportional to the square of their characteristic shear wave velocity. 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. 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. From this shear wave velocity and the density of the soil specimen the initial shear modulus g max can be determined, which is the. The dynamic response of a soil mass subjected to excitation is the focus of much attention among engineers both in research studies and in application of stateoftheart technology to practical problems.
The shear wave velocity vs of sediments plays a key role in seismic wave and is amplification required in site response analysis. These soils were chosen to represent a wide range of soil type, from sandy to silty, and clayey. The database allowed the development of several empirical correlations between in situ vs and basic soil properties, cone penetration parameters, undrained. In many instances it may be preferable to determine vs indirectly by common insitu tests. Soil properties for shear wave propagation springerlink. The predicted of indian standards, new delhi, india. 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. For example, shear wave velocity is linked to the dynamic shear modulus and also to density section 2. 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. Crosshole logging technique gives reliable measure of in situ shear wave velocity. 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. Table 1 lists the classifications and basic properties of the soils.
Shear wave velocity vs is a basic engineering property implemented in evaluating the soil shear modulus. Pdf shear wave velocity vs is a basic engineering property implemented in evaluating the soil shear modulus. The shear wave velocity, depends on the following material properties. Test data shown in section 4 is normalised by a gmax obtained from equation 7, where vs is shear wave velocity and. Shear wave velocity tests are increasingly being used to assess a wider range of soil properties including strength. Statistical correlations of shear wave velocity and penetration resistance for soils. The shear modulus is related to shear wave velocity as 2 max. The seismic velocity profile was obtained at a depth of 20 m. Canadian geotechnical journal canadian science publishing. 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. Correlation between shear wave velocity and porosity in.
The shearwave velocity in a crystal varies according to the direction of propagation and the plane of polarization i. The shear wave velocity of the soil can also be used to determine the soil profile type. Furthermore, the shear wave velocity is vital in assessments of both liquefaction potential and soil amplification and. Study of resistivity and shear wave velocity as a predictive.
Shear wave velocity, vs, is a soil mechanical property that can be. 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. Determination of shear wave velocity using multichannel. This report presents guidelines for estimating the shear wave velocity profiles in. In this study three methods of they are 1 the menard pressuremeter, situ soil testing are examined. Characterization of shear wave velocity profiles for south carolina. 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.
Pdf shear wave velocity by support vector machine based on. Soil properties like cohesion, angle of friction, shear wave velocity, poissons ratio etc. However, the attenuation of surface waves based on frequency section 2. Examination of existing shear wave velocity and shear. Standard test method for determination of shear wave.
Tool for analysis of masw field data and evaluation of shear. A shear wave is generated at one boundary of a soil specimen and then received at an opposite boundary. In seismic hazard analysis, sitespecific shear wave velocity is an indication of the expected ground shaking, in response. Review of geotechnical provisions in indian seismic code. Numerous researchers and practitioners have examined the viability of correlations between. This is not based on any convincing theory but is roughly right when the effective pressure is high and the rock is fully saturated. Smallstrain stiffness, shearwave velocity, and soil.
The smallstrain shear modulus depends on stress in uncemented soils. Shear wave velocity v s and smallstrain shear modulus g 0 are the key parameters in defining material response to various dynamic loadings. Standard test method for determination of shear wave velocity. Determination of in situ shear wave velocities from. Soil velocity profile is often used as subsurface characterization by using seismicbased. Rock properties that affect seismic velocity 1 porosity. Shear wave velocity an overview sciencedirect topics. Furthermore, the shear wave velocity is vital in assessments of both liquefaction potential and soil amplification and for seismic site classification kramer 1996. After that the received signal filtered offthenoiseandthenrecordedanddisplayeditontheoscilloscope. The paper presents a description of the dynamic properties of cohesive material, namely. 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.
Unified correlation between sptn and shear wave velocity. Elastic moduli shear moduli and youngs moduli were then calculated from the shear wave velocities. 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. Review of geotechnical provisions in indian seismic code is.
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. Unified correlation between sptn and shear wave velocity for all soil types c. Estimation of shear wave velocity from soil indices. Dependencies of shear wave velocity and shear modulus of soil. G v s 3 where gmax is smallstrain shear modulus in pa. The seismic surface wave method masw is the simplest and a very efficient way of measuring the shear wave velocity in the field. Investigation of shear wave velocity and predominant period properties of bornova plain izmir doi. When a seismic design for an earthquakeprone area is required, dynamic soil properties including shear wave velocity, shear modulus, and. Oct 10, 2014 the smallstrain shear modulus depends on stress in uncemented soils.
For design of foundation, engineering properties like strength and deformability characteristics of soils are very important parameters. Pdf shear wave velocity as a geotechnical parameter. Relationship between shearwave velocity and geotechnical. However, this test is expensive, requiring two closely spaced boreholes, special recording equipment and skill in identifying shear wave arrivals. 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.