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Artificial neural networks in the analysis of compressibility of marine clays of Grande Vitória, ES, Brazil
Published in António S. Cardoso, José L. Borges, Pedro A. Costa, António T. Gomes, José C. Marques, Castorina S. Vieira, Numerical Methods in Geotechnical Engineering IX, 2018
A.G. Oliveira Filho, K.V. Bicalho, W.H. Hisatugu, C. Romanel
Projects of civil engineering structures on soil profiles with soft clays may require the determination of parameters of soil compressibility, such as the compression index (CC), which is used to calculate the significance of the consolidation settlement of soft clayey soils. The conventional laboratory oedometer test is utilized to obtain the CC values. However, oedometer test is a test of long duration and requires sufficiently undisturbed soil samples. Thus, several empirical relationships linking the compressibility parameters of clayey soils to their index properties, such as liquid limit (WL), bulk density (GS), plasticity index (PI), natural water content (Wn) and initial void ratio (e0), have been published in the literature for different soft fine-grained soils.
Artificial neural networks in the analysis of compressibility of marine clays of Grande Vitória, ES, Brazil
Published in António S. Cardoso, José L. Borges, Pedro A. Costa, António T. Gomes, José C. Marques, Castorina S. Vieira, Numerical Methods in Geotechnical Engineering IX, 2018
A.G. Oliveira Filho, K.V. Bicalho, W.H. Hisatugu, C. Romanel
Projects of civil engineering structures on soil profiles with soft clays may require the determination of parameters of soil compressibility, such as the compression index (CC), which is used to calculate the significance of the consolidation settlement of soft clayey soils. The conventional laboratory oedometer test is utilized to obtain the CC values. However, oedometer test is a test of long duration and requires sufficiently undisturbed soil samples. Thus, several empirical relationships linking the compressibility parameters of clayey soils to their index properties, such as liquid limit (WL), bulk density (GS), plasticity index (PI), natural water content (Wn) and initial void ratio (e0), have been published in the literature for different soft fine-grained soils.
Laboratory testing of soils
Published in John Atkinson, The Mechanics of Soils and Foundations, 2017
Oedometer tests may be used to investigate compression and swelling of soil (i.e. the relationship between effective stress and volumetric strain) or consolidation (i.e. the relationship between compression and seepage). Remember the distinctions between drained loading, undrained loading and consolidation discussed in Sec. 6.9. One-dimensional compression and swelling of soil is discussed in Sec. 8.5 and one-dimensional consolidation is discussed in Chapter 15.
One-dimensional large-strain model for soft soil consolidation induced by vacuum-assisted prefabricated horizontal drain
Published in European Journal of Environmental and Civil Engineering, 2022
Dingbao Song, Hefu Pu, Dibangar Khoteja, Zhanyi Li, Peng Yang
The dredged sediments with an initial water content of 400% were mixed for 10 min in a bucket by using a mixer, and the mixture was promptly placed in the model tank. The mud layer had an initial height of 39.2 cm, and an initial uniform void ratio of 10.56. After the placement, the mud sample was allowed to deposit and self-consolidate for 48 h, and subsequently, a vacuum pressure of 80 kPa was applied to the bottom through the PHD. The top boundary was freely drained. An oedometer test was conducted to determine the consolidation characteristics of the treated soil sample. The compressibility relationship, shown in Figure 8(a), was derived from the standard consolidation test. The permeability (Figure 8b) was back-calculated indirectly from the values of the coefficient of consolidation obtained from the oedometer test. The constitutive relationships (i.e., compressibility and permeability) for the clay were fitted with the power function equations, and the expressions are shown in Figure 8.
A procedure for determining long-term creep rates of soft clays by triaxial testing
Published in European Journal of Environmental and Civil Engineering, 2022
Hans Petter Jostad, Jorge Yannie
A parallel test was carried out in a standard incremental loading (IL) oedometer apparatus on a material taken from the same block-sample. The results shown in Figure 12 agree very well with the triaxial test. The vertical strain at 100 kPa was only somewhat larger, i.e. around 14.6% (compared to 14.0% in the triaxial test). The secant λ*-value from a vertical effective stress of 84.1 to 100 kPa is λ* =.129 (compared to a tangential value of λ* = .132 in the triaxial test), and μ* = .0033 which is the same as the value at the end of the first creep phase in the triaxial test (as shown in Figure 9). The main purpose of the oedometer test was to measure the creep under the vertical effective stress of 100 kPa for a long period. However, after about 37 days the creep rate started to slow down and almost stopped after about 144 days. Therefore, the last part of this creep phase is disregarded.
Cyclic stress–strain behaviour of soft clay under traffic loading through hollow cylinder apparatus: effect of loading frequency
Published in Road Materials and Pavement Design, 2019
Qi Yang, Yiqun Tang, Bin Yuan, Jie Zhou
The properties of tested soil are shown in Table 1, and the oedometer test results are shown in Figure 1. The maximum shear modulus which is obtained through the resonant column test is 58.76 MPa. The nonlinearity of the shear modulus and damping ratio (%) of studied clay can be described through following fitting function based on Davidenko model (Zhang, Lan, & Cui, 2010): where is the shear strain.