Uncertainty of One-Dimensional Consolidation of Multi-Layered Soft Clay Soils

2011 ◽  
Vol 250-253 ◽  
pp. 1838-1841
Author(s):  
Xiao Yong Li
Keyword(s):  
Soft Clay ◽  
Compression Modulus ◽  
Probability Characteristic ◽  
Coefficient Of Consolidation ◽  
One Dimensional ◽  
The Monte Carlo Method ◽  
Consolidation Coefficient ◽  
Characteristic Values ◽  
Consolidation Degree ◽  
Substantial Degree

The measured coefficient of consolidation can have a substantial degree of variation even in a uniform clay layer. The probability characteristic values for such parameters as consolidation coefficient and compression modulus are analyzed from local engineering data. This paper, through a probabilistic analysis, examines the variability of one-dimensional consolidation solutions. The multilayer models are evaluated. Then the Monte Carlo method is used to develop solutions for one dimensional consolidation. It identified the influence of the parameter uncertainty on the probability characteristic of the consolidation degree. The uncertainty of consolidation coefficient has a great impact on the probabilistic characteristics of the consolidation degree, but for compression modulus it is opposite true. It proposed a simplification analysis method that considers only the uncertainty of consolidation coefficient without consideration of the uncertainty of compression modulus, and its erroneous precision can meet the engineering requirements.

Probabilistic Analysis of One-Dimensional Consolidation with Monte Carlo Simulations

2011 ◽  
Vol 55-57 ◽  
pp. 907-912
Author(s):  
Xiao Yong Li ◽  
Liao Qi Hu
Keyword(s):  
Probabilistic Analysis ◽  
Clay Soil ◽  
Probabilistic Method ◽  
Distribution Model ◽  
Considerable Influence ◽  
Coefficient Of Consolidation ◽  
One Dimensional ◽  
Degree Of Consolidation ◽  
Distribution Type ◽  
Substantial Degree

Themeasured coefficient of consolidation can have a substantial degreeof variation even in a uniform clay layer. This paper examines the variability of one-dimensional consolidationsolutions through a probabilistic analysis. The spatial probabilistic characteristics for the coefficient of vertical consolidation are studied. The influence of a spatially random coefficient of consolidation on one-dimensional consolidation has been studied using the probabilistic method. In the probabilistic analysis, the adequacy of distribution model for coefficient of consolidation is tested using experimental data. A sensitivity analysis of the degree of consolidation to uncertain parameters is presented for clay soil. It is the analysis result that probability distribution type of vertical consolidation has a considerable influence on degree of consolidation. Theresults are discussed in terms of confidence level.

Calculation of Consolidation Coefficient and Percent Consolidation from Measured Pore Water Pressure of Soft Clay

2011 ◽  
Vol 250-253 ◽  
pp. 1889-1892
Author(s):  
Yong Mou Zhang ◽  
Jian Chang Zhao
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Soft Soil ◽  
Soft Clay ◽  
Coefficient Of Consolidation ◽  
Consolidation Process ◽  
Consolidation Coefficient

Consolidation coefficient and percent consolidation of soft clay were calculated according to the measured pore water pressure of a project in Pudong Shanghai. Calculated coefficient of consolidation was one magnitude larger than the experimental one. This was in conformity with the actual consolidation process of dynamically-consolidated soft soil.

scholarly journals One-Dimensional Nonlinear Consolidation Analysis Using Hansbo’s Flow Model and Rebound-Recompression Characteristics of Soil under Cyclic Loading

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Banghua Zhu ◽  
Gang Shi ◽  
Zihe Wei
Keyword(s):  
Cyclic Loading ◽  
Effective Stress ◽  
Void Ratio ◽  
Flow Model ◽  
Soft Clay ◽  
Real Life ◽  
Excess Pore Pressure ◽  
One Dimensional ◽  
Consolidation Degree ◽  
Consolidation Analysis

Hansbo’s flow model for one-dimensional consolidation analysis of saturated clay has been widely recognized as being the most representative for soft soils. Many studies have used the model to examine the characteristics of soil under various conditions. However, very few studies have considered soil under cyclic loading. In this study, using a Hansbo’s flow model and assuming known characteristics for soft clay deformation and rebound and recompression of soil, the one-dimensional consolidation model of soft clay under cyclic loading is established. A FlexPDE solution scheme with excess pore pressure u and void ratio e as variables is also given. The reliability of the proposed method is verified by comparing the obtained results with existing results. On this basis, the consolidation characteristics of soft clay foundations under unilateral drainage and cyclic loading are studied. The effects of soil rebound and recompression characteristics, Hansbo’s flow parameters, cyclic loading period, and cyclic loading form on the consolidation characteristics of soft clay foundation are analyzed. The results show that under cyclic loading, the effective stress, void ratio, and average consolidation degree of the foundation all present a cyclic state and gradually enter a stable cyclic state with the increase in cycles. The peak of effective stress lags behind the peak of cyclic load. The rebound and recompression characteristics of soil have little effect on the effective stress of soil but a great effect on the void ratio. In contrast to its characteristic under linear loading, the average consolidation degree of the foundation under cyclic loading finally enters a stable cyclic state. The results of the analysis can be used as a reference in the analysis of real life highways, railways, subway tunnels built on soft soil foundations subjected to periodic cyclic loading.

scholarly journals Effects of temperature on consolidation and consistency of clayey soils

2020 ◽  
Vol 205 ◽  
pp. 09010
Author(s):  
Atsushi Ogawa ◽  
Atsushi Takai ◽  
Takumi Shimizu ◽  
Takeshi Katsumi
Keyword(s):  
Temperature Effect ◽  
Soft Clay ◽  
Clay Soils ◽  
Clayey Soils ◽  
One Dimensional ◽  
Thermal Improvement ◽  
Different Temperatures ◽  
Consolidation Coefficient ◽  
Effects Of Temperature ◽  
Clay Ground

This study focuses on the effects of temperature on the consolidation property and consistency of clay for thermal improvement of soft clay ground. Although it is already known that an increase in temperature can accelerate consolidation of clay, the degree of the temperature effect has not yet been generalized between various clays. In this study, a series of one-dimensional consolidation tests at different temperatures (17, 23, 35, 50, and 65°C) using 2 processed clays and 3 natural clayey soils dredged at ports are presented. To evaluate the temperature effect on soil consistency, which might affect the consolidation behavior, atterberg limits of the clays were also evaluated at different temperatures. As a result, it was confirmed that, although the temperature effect on consistency limits varies depending on the type of clay, the consolidation coefficient increases with increase in temperature in all the clay soils tested.

Line-by-Line Random-Number Database for Monte Carlo Simulations of Radiation in Combustion System

2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Tao Ren ◽  
Michael F. Modest
Keyword(s):  
Heat Transfer ◽  
Monte Carlo ◽  
Monte Carlo Method ◽  
Radiative Heat ◽  
Random Number ◽  
Test Cases ◽  
Combustion System ◽  
Absorption Coefficients ◽  
One Dimensional ◽  
The Monte Carlo Method

With today's computational capabilities, it has become possible to conduct line-by-line (LBL) accurate radiative heat transfer calculations in spectrally highly nongray combustion systems using the Monte Carlo method. In these calculations, wavenumbers carried by photon bundles must be determined in a statistically meaningful way. The wavenumbers for the emitting photons are found from a database, which tabulates wavenumber–random number relations for each species. In order to cover most conditions found in industrial practices, a database tabulating these relations for CO2, H2O, CO, CH4, C2H4, and soot is constructed to determine emission wavenumbers and absorption coefficients for mixtures at temperatures up to 3000 K and total pressures up to 80 bar. The accuracy of the database is tested by reconstructing absorption coefficient spectra from the tabulated database. One-dimensional test cases are used to validate the database against analytical LBL solutions. Sample calculations are also conducted for a luminous flame and a gas turbine combustion burner. The database is available from the author's website upon request.

Deformability and consolidation characteristics of soft Bangkok clay using screw plate tests

1990 ◽  
Vol 27 (5) ◽  
pp. 531-545 ◽  
Author(s):  
D. T. Bergado ◽  
K. C. Chong ◽  
P. A. M. Daria ◽  
M. C. Alfaro
Keyword(s):  
Graphical Method ◽  
Soft Clay ◽  
Stress Path ◽  
Soil Parameters ◽  
Test Results ◽  
Coefficient Of Consolidation ◽  
Plate Test ◽  
Settlement Time ◽  
Oedometer Tests ◽  
Test Embankment

This study centred on the performance of the screw plate test (SPLT) to determine the deformability and consolidation characteristics of soft Bangkok clay. For comparison, a series of stress-path-controlled triaxial consolidation tests (tri) were carried out on good quality samples of Bangkok clay taken from the same testing sites and imposed with the same loading conditions as the screw plate tests. Undrained and drained moduli and coefficients of consolidation were obtained from the stress-path-controlled triaxial consolidation tests and were compared with the corresponding values of the screw plate test. In addition, the ultimate bearing capacity was derived from the pressure–deformation relationships of the screw plate test results. A graphical method was used to compute the coefficient of consolidation from the screw plate tests and from stress-path-controlled triaxial consolidation test results. The compressibility data were also obtained from conventional oedometer tests (oed). Both cv (SPLT)/cv (tri) and cv (SPLT)/cv(oed) ratios compared favorably with the cv (field)/cv (laboratory) ratio obtained from past investigations. The data from pressure–settlement–time relationships of the screw plate tests were used to successfully predict values that compared favorably with the measured values at each stress level. The pressure–deformation–time relationship from stress-path-controlled triaxial consolidation tests were also evaluated, and they indicated behaviour similar to that of the screw plate test results. Soil parameters obtained from screw plate tests were subsequently used to predict the settlement of two test embankments, giving fairly close agreement with the observed values. Key words: soft clay, settlement, deformation, consolidation, screw plate test, triaxial test, embankment, prediction, stress path.

Test fill on soft plastic marine clay at Onsøy, Norway

2014 ◽  
Vol 51 (1) ◽  
pp. 30-50 ◽  
Author(s):  
Toralv Berre
Keyword(s):  
Soft Clay ◽  
Marine Clay ◽  
Coefficient Of Consolidation ◽  
Geotechnical Parameters ◽  
Second Stage ◽  
Direct Simple Shear ◽  
Rapid Construction ◽  
Loading Case ◽  
The Town

The test fill at Onsøy, close to the town of Fredrikstad in Norway, was built on a very soft marine clay with in situ vane strength as low as 11 kPa and a plasticity index varying from 34 to 50. The dimensions at the bottom of the long fill were 20 m × 60 m and the height 2.3 m. The fill, as placed, had a computed factor of safety against foundation failure of 1.35 based on in situ vane strength. The fill was allowed to sit for about 3 years (from 1972 to 1975) before it, in a second stage, was brought to failure by raising the height. The main purpose of the first stage was to study the stress–strain–time relationships for the soft clay and compare the values of geotechnical parameters determined by careful laboratory tests with those back-calculated from the observed field behaviour. The test fill foundation was heavily instrumented to measure clay deformations and pore pressures with time. Field observations showed that the Onsøy test fill turned out to be more of a drained loading case than an undrained case in spite of the fairly rapid construction of the fill. Actually, subsequent undrained triaxial and direct simple shear tests strongly indicate that the fill might have failed if less drainage had taken place, i.e., if the drainage paths had been longer and (or) if the coefficient of consolidation had been lower.

scholarly journals Drainage Distance and Coefficient of Consolidation in One Dimensional Consolidation

1981 ◽  
Vol 21 (3) ◽  
pp. 132-136
Author(s):  
Masaru Akaishi ◽  
Masuho Inada ◽  
Hiroaki Shirako
Keyword(s):  
Coefficient Of Consolidation ◽  
One Dimensional
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