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Correlation between SPT and CPT tests in liquefiable deposits
Published in Guido Gottardi, Laura Tonni, Cone Penetration Testing 2022, 2022
Rashid Shahgholian, Cristiana Ferreira, António Viana da Fonseca
Comparison between the results of different geotechnical tests in a site is essential for a correct estimate of the geotechnical parameters of the soil profile. The Standard Penetration Test (SPT) and the Cone Penetration Test (CPT) are two of the most common site characterization techniques, which have advantages and weaknesses over each other. Besides, the literature shows that these tests have different libraries of formulas and relations behind. Correlation of these two tests has a history over seventy years and extensive research indicates there is not a unique relation between them, which may result from the fact that these penetration tests are differently influenced by various factors, including geological conditions, available machinery and tools, operator skills, etc. The application of the empirical equations and charts available in the literature needs to be performed with great care; a certain level of similarity should be assured between the site and the region from which the empirical correlations were developed.
Geotechnical Considerations
Published in Paul W. McMullin, Jonathan S. Price, Sarah Simchuk, Special Structural Topics, 2018
The Standard Penetration Test (SPT; ASTM D1586)8 uses a split-barrel sampler to collect a disturbed soil sample and to measure the standard penetration resistance, or N-value. This N-value is determined by the sampler being hit multiple times with a 140-lb hammer dropped from a height of 30 in. The geologist or investigator watches the sampler and counts how many “blow counts” it takes for the sampler to drop 6 in; this is done three times (in one continuous set of hammer drops, for a total of 18 in). The blow count for the first 6 in is generally thrown out (as there may be disturbed soil in this area owing to the drilling operation), and the last two are added together to determine the N-value, which has as units “blows per foot.” Table 6.4 correlates N-value to soil compactness.
Nature of soil and rock
Published in Hsai-Yang Fang, John L. Daniels, Introductory Geotechnical Engineering, 2017
Hsai-Yang Fang, John L. Daniels
The Standard Penetration Test (SPT) method: The SPT is an in situ testing technique, as noted in Chapter 1, and is frequently used in geotechnical engineering for soil classification, estimation of shear strength and bearing capacity. A brief description of this method is presented as follows. The test is standardized by ASTM as D1586. It is performed by driving a specified split spoon sampler (I.D. = 3.5 cm; 1.375 in.) into the ground soil with a hammer of certain weight (63.5 kg; 140 lb) dropped freely from a given height (76 cm; 30 in.). The number of hammer blows (N) required to drive the sampler a fixed distance (46 cm; 18 in.; three 15.2 cm; 6 in. increments) is counted and recorded. The SPT provides some indication of the relative density of the soil. The denser the soil, the more difficult it is to penetrate and therefore more blows are required to drive the sampler. The SPT blow count, or N value, is obtained by adding the number of blows for the second and third 6 in. increments and discarding the value for the first increment. If the number of counted blows for three increments were 8, 9, and 11, the N value would be reported as (9 + 11 = 20). The N value has units of blows per foot. N values have many uses such as prediction of liquefaction potentials (Sec. 11.4), and estimation of bearing capacity of ground soil (Sec. 12.7) and pile capacity (Sec. 15.12). This technique has the added advantage of producing a sample, albeit disturbed (Ch. 1) that can be used for classification purposes.
Assessment of variability in soil properties from various field and laboratory tests
Published in Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards, 2019
Ömer Bilgin, Kevin Arens, Alexander Dettloff
The Standard Penetration Test (SPT) is the most commonly used in-situ test around the world. In general, almost all subsurface investigations conducted include SPT tests, providing both test data and soil samples that can be used for basic testing and soil classification. The SPT is a simple and rugged test. Many engineers have experience using SPT data for analysis and design of foundations, and many structure foundations around the world were designed solely based on SPT results. The Cone Penetration Test (CPT) is increasingly popular in transportation projects, because it is not only conducted relatively quickly but it also provides continuous data through the depth of investigation. While the data have to be interpreted between the discrete test depths in SPT, data are commonly obtained at every 20 mm during CPT testing.
A new approach to constructing SPT-CPT correlation for sandy soils
Published in Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards, 2023
Yu-Chen Lu, Li-Wei Liu, Sara Khoshnevisan, Chih-Sheng Ku, C. Hsein Juang, Shi-Hao Xiao
The Standard Penetration Test (SPT) and Cone Penetration Test (CPT) are two commonly used in situ tests in a geotechnical site investigation (Rogers 2006). In practice, these in situ tests are often used to derive geotechnical parameters such as relative density and shear strength parameters (e.g. Jamiolkowski, Presti, and Manassero 2001; Mayne 2006). In addition, they are often chosen, based on preference or out of necessity, to evaluate the performance of a geotechnical system, such as the liquefaction potential of soils (e.g. Seed et al. 1985; Youd et al. 2001) or the load-carrying capacity of piles (e.g. Mayne et al. 2009; Haque and Steward 2020).
GPR analysis to detect subsidence: a case study on a loaded reinforced concrete pavement
Published in International Journal of Pavement Engineering, 2022
Mercedes Solla, Norberto Fernández
A standard penetration test (SPT) was also carried out, which is an in situ dynamic penetration test designed to provide information on the geotechnical properties of the soil. Table 3 presents the initial and final heights for sampling, as well as the depth and the results obtained (number of blows, NSPT).