Predicting the Hydraulic Conductivity of Makassar Marine Clay Using Field Penetration Test (Cptu) Results (original) (raw)
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INVESTIGATION ON THE VALUE OF PERMEABILITY OF MARINE CLAY BASED ON CPTu VALUE
Recently, the Cone Penetration testing (CPTu) is a rapid method for determining the mechanical and transport properties of soils. The CPTu provides continuous profiles of soil characteristics that are reliable, fast, and economical. In recent years, the CPTu has been used for site exploration, construction control, assessment of ground improvement effectiveness, assessment of contaminant transport, and direct application to deep foundations. Moreover, the estimation of the permeability from the CPTu is traditionally made from the pore water pressure dissipation test data. The main objective of this research is to interpret the correlation between CPTu field test data and value of permeability (k). From the result of CPTu’s data can be evaluated and interpreted as correlation of value the soil permeability. Taking over the data was done in continuously automatic record with velocity 2 cm/sec. Sum of point tests were three points with distance point 30 m each. Profile interpretation in soil layer can be interpreted using the data value of cone resistance (qc), soil friction along a side sleeve (fs), and pore water pressure (u2). Those values were firstly calculated to obtain 3 derived units as total cone resistance (qt), friction ratio (FR), pore pressure parameter (Bq). The ground water level is found at 1.4 – 1.5 m from surface, while the dissipation test is found 13.86 - 16.84 m in depth. The value of permeability (k) determined in this research is found in the range of 1,5 x 10-4 – 5 x 10-8 cm/sec.
Correlation of hydraulic conductivity of clay–sand compacted specimens with clay properties
Applied Clay Science, 2004
Hydraulic conductivity of compacted specimens consisting of 1 of 16 clay samples and siliceous sand/natural soils was measured using permeameters with flexible wall cells. Clay samples studied were eight natural bentonites, one purified montmorillonite, five standard clay samples, one synthetic hectorite, and two cation-exchanged bentonites. The clay content to whole solid was fixed at 11.5% w/w, and the mixtures were rammed in a mold to form disk compactions. A higher hydraulic conductivity was observed with increase in the Ca/Na ratio of clay. Hydraulic conductivity was also affected by bentonite content of the clays and the mineral content. A relation between the hydraulic conductivity and the characteristic index properties of the clays such as chemical concentration, methylene blue adsorption capacity (MB), and so on were elucidated, and then a polynomial expression was derived to reproduce measured hydraulic conductivity data. This relation was then utilized to estimate hydraulic conductivity of blended bentonites from characteristic properties of the component bentonites. D
The hydraulic conductivity of Singapore marine clay at Changi
Quarterly Journal of Engineering Geology and Hydrogeology
The hydraulic conductivity of Singapore Marine Clay at Changi was studied by both in situ and laboratory methods. In situ tests, such as the Cone Penetration Test (CPT), Dilatometer Test (DMT), Self-boring Pressuremeter Test (SBPT) and BAT permeameter test were carried out. Rowe Cells and oedometers were used to determine the horizontal hydraulic conductivity and vertical hydraulic conductivity respectively. Hydraulic conductivity values were found to range between 10-10 m/s and 10-9m/s. Hydraulic conductivity values in the horizontal direction measured from laboratory Rowe Cell tests were found to be about twice the vertical hydraulic conductivity from oedometer tests. Horizontal hydraulic conductivity values measured from Rowe Cell tests were also higher than those measured from BAT and SBPT but about the same order as values obtained from CPTU and DMT. Most hydraulic conductivity values evaluated indirectly from in situ dissipation tests were higher than direct measured values from BAT permeameter tests. DMT and CPTU gave the highest horizontal hydraulic conductivity values and SBPT yielded values in between. However CPTU, DMT and SBPT dissipation tests were found to be suitable alternative methods for estimating the hydraulic conductivity of clay. The variation of vertical hydraulic conductivity was characterized by the relationship between void ratio and hydraulic conductivity change index which, based on oedometer results, is only Ckv=0.3e0 .
Estimation of Soil Hydraulic Conductivity on Clay Content, Determined from Resistivity Data
Symposium on the Application of Geophysics to Engineering and Environmental Problems 2006, 2006
We considered clay content in loose soil as the factor mostly influencing on hydraulic conductivity (filtration coefficient). We collected and analyzed some published experimental data about hydraulic conductivity relation with soil lithology and clay content in the form of grain size. Also we performed some theoretical modeling modifying well-known formulas to include clay content in them. Experimental and calculated data showed quite good coincidence. Correlation between hydraulic conductivity and clay content seemed better, than correlation between hydraulic conductivity and resistivity. We created some approximation formulas relating filtration coefficient with clay content. Clay content in soil can be estimated on soil resistivity obtained from VES data interpretation and from groundwater salinity found from its resistivity. Then filtration coefficient is determined on clay content. Some examples of this method practical application at clean and oil contaminated areas are presented. We considered anomalies of decreasing filtration coefficient in contaminated zones not as a real effect, but as a good indicator of contamination, though in several publications there were some indications of hydro geological changes in soil properties due to oil contamination.
2021
Overconsolidated (OC) soils may develop a low or negative pore pressure during PCPT. Thus, it is challenging to develop an “on-the-fly” estimation of hydraulic conductivity from PCPT results. This study presents a method to estimate the hydraulic conductivity of OC soils from PCPT results based on a previously developed method for normally consolidated (NC) soils. To apply the existing method, PCPT pore pressure in OC soils is adjusted by using a correction factor. An equation for the correction factor is derived based on the concepts of critical state soil mechanics, cavity expansion, and consolidation theories. Then, it was reformulated so that traditional cone indices could be used as input parameters. It is shown that the correction factor is mainly influenced by the cone tip resistance, pore pressure, and the rigidity index. The comparison of predicted, which is based on corrected pore pressure and measured hydraulic conductivity showed a good match for four well documented dat...
Estimation of hydraulic conductivity on clay content in soil determined from resistivity data
Geofísica …, 2006
El contenido de arcilla en suelos areno-arcillosos influye sobre la permeabilidad hidráulica (coeficiente de filtración). Se presenta una revisión de datos experimentales publicados que relacionan el coeficiente de filtración con el tipo litológico del suelo y el tamaño de las partículas. A partir de cálculos teóricos, se modifican las conocidas fórmulas que relacionan el coeficiente de filtración con el contenido de arcilla. Se estima el contenido de arcilla a partir de los datos interpretados por el método SEV, y se propone un procedimiento para la estimación del coeficiente de filtración: (a) cálculo del contenido de arcilla a partir de la resistividad del suelo y de la salinidad del agua subterránea, (b) estimación del coeficiente de filtración a partir del contenido de arcilla. Se presentan algunos ejemplos de la aplicación de esta metodología.
Predicting the hydraulic conductivity of saturated clays using plasticity-value correlations
Applied Clay Science, 2009
Hydraulic conductivity is one of the important, basic engineering properties of soils. However, as a soil parameter it is difficult to measure and can be highly variable, necessitating the investigation of a large number of samples. For these reasons several researchers have proposed various indirect methods for predicting the hydraulic conductivity of soils from easily measured and routinely obtainable data. As plasticity is the most distinctive and the easiest property of clays to measure, it would be a very convenient basis for predicting the hydraulic conductivity. This paper focuses on an investigation of the relationship between the hydraulic conductivity of clays and their Atterberg limits. For this purpose five samples of expanding and non-expanding clays were used. The results of laboratory tests showed that the hydraulic conductivity of a clay at a selected void ratio could be adequately determined when the external surface area of the clay grains was considered. The finding that there exists an exactly defined relationship between the Atterberg limits of clays and their external specific surfaces helped us to express the hydraulic conductivity in terms of the void ratio and the plasticity value.
Hydraulic Conductivity of Thirteen Compacted Clays
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Hydraulic conductivity tests were conducted on thirteen compacted clayey soils being used for compacted clay liners at landfills throughout the United States. The soils were prepared to various molding water contents and then compacted and permeated in the laboratory. Results of the tests show that for all of the soils, zones exist in the compaction plane (i.e., dry unit weight vs. water content) where the hydraulic conductivity is similar. These zones fall roughly parallel to contours of constant initial saturation (degree ofsaturation at compaction), with lower hydraulic conductivities generally occurring for conditions corresponding to higher initial saturation. Wet of the line of optimums, lower hydraulic conductivity is also attained for soils that are more plastic and have a greater quantity of fines. A regression equation was developed from the data to estimate hydraulic conductivity given the initial saturation, compactive effort, plasticity index, and clay content.
An approach to identify soil types by using hydraulic conductivity values
Sustinere: Journal of Environment and Sustainability
Water treatment in Indonesia still uses coagulant to reduce the contaminant. Therefore, an infiltration gallery is required as the pre-treatment before conventional water treatment conducted. Infiltration gallery is a natural technology for absorbing or filtrating the contaminant. The hydraulic conductivity plays the main role in soil filtration. There are many types of soil with different hydraulic conductivities. In infiltration gallery method it is important to identify the hydraulic conductivity value as the preliminary analysis because it is the important indicator to show the ability of soil to flow the water from one side to other sides when filtrating the contaminant. The slower the conductivity is, the better the quality of the water will be. The method used in this study was the Constant head Permeameter. The result of this study shows that the same type of soil type has different hydraulic conductivities.
Predicting the Saturated Hydraulic Conductivity of Clayey Soils and Clayey or Silty Sands
2020
Predictive models able to provide a reliable estimate of hydraulic conductivity can be useful in various geotechnical applications. Since most of the existing predictive methods for saturated hydraulic conductivity estimation are valid only for a limited range of soils or can be applied under certain restrictive conditions, a new method applicable to clayey soils and clayey or silty sands having a wide range of values of soil index properties is proposed in this study. For this purpose, 329 saturated hydraulic conductivity values, obtained by laboratory tests carried out on different soils, were collected in a database and used to develop five equations using a multiple regression approach. Each equation correlates the hydraulic conductivity with one or more geotechnical parameters. An equation was developed that predicts, within an order of magnitude, the saturated hydraulic conductivity in the range from 1.2 × 10−11 to 3.9 × 10−6 m/s, based on simple geotechnical parameters (i.e.,...