Characterization of Singapore, Bangkok, and Ariake clays

2001 ◽  
Vol 38 (2) ◽  
pp. 378-400 ◽  
Author(s):  
Hiroyuki Tanaka ◽  
Jacques Locat ◽  
Satoru Shibuya ◽  
Tan Thiam Soon ◽  
Dinesh R Shiwakoti
Keyword(s):  
Shear Strength ◽  
Clay Mineral ◽  
Physical And Mechanical Properties ◽  
Site Investigation ◽  
Undrained Shear Strength ◽  
Mechanical Tests ◽  
Mineral Components ◽  
The Difference ◽  
A Site ◽  
Undrained Shear

A soil investigation was carried out at two sites in Singapore and Bangkok, Southeast Asia, and the results were compared with those from a site in Ariake, Japan. Soil samples at all the sites were retrieved using the Japanese sampling method to nullify the effect of sampling on sample quality. From the laboratory tests, consolidation characteristics and undrained shear strength were measured. In addition to the mechanical tests, X-ray diffraction and scanning electron microscope tests were carried out to identify clay minerals and to study their microstructure. Great differences in physical and mechanical properties of these clays were observed, which may be attributed to the difference in their clay mineral components and variation in the sedimentation environment.Key words: site investigation, marine clay, undrained shear strength, anisotropy, consolidation, clay mineral.

Extended multivariate approach for uncertainty reduction in the assessment of undrained shear strength in clays

2014 ◽  
Vol 51 (3) ◽  
pp. 231-245 ◽  
Author(s):  
Rasmus Müller ◽  
Stefan Larsson ◽  
Johan Spross
Keyword(s):  
Shear Strength ◽  
Site Investigation ◽  
Undrained Shear Strength ◽  
Multivariate Approach ◽  
Total Uncertainty ◽  
Investigation Methods ◽  
Measurement Results ◽  
Strength Formula ◽  
A Site ◽  
Undrained Shear

Important features of the multivariate approach are discussed, and an extension to this approach is proposed whereby the total uncertainty in site investigation methods due to spatial averaging is assessed prior to its adoption. Results from a site investigation of spatially averaged values of undrained shear strength ([Formula: see text]) and the corresponding coefficient of variation ([Formula: see text]) in Veda sulphide clay were used as a practical illustration of the extended multivariate approach and provide a basis for discussion. The inherent variability and scales of fluctuation for different methods are presented. The study shows the usefulness of the extended multivariate approach for the evaluation of representative values of [Formula: see text] and [Formula: see text] based on results from different methods. It is also a way of implicitly reducing the transformation errors that arise when a property is derived from measurement results. Nevertheless, considerable care must be taken as a much lower COV for one method will have a significant impact on the results.

scholarly journals CPT-Based Probabilistic Characterization of Undrained Shear Strength of Clay

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Mi Tian ◽  
Xiaotao Sheng
Keyword(s):  
Shear Strength ◽  
Correlation Function ◽  
Random Field ◽  
Site Investigation ◽  
Undrained Shear Strength ◽  
Bayesian Approaches ◽  
Probabilistic Characterization ◽  
Undrained Shear

Applying random field theory involves two important issues: the statistical homogeneity (or stationarity) and determination of random field parameters and correlation function. However, the profiles of soil properties are typically assumed to be statistically homogeneous or stationary without rigorous statistical verification. It is also a challenging task to simultaneously determine random field parameters and the correlation function due to a limited amount of direct test data and various uncertainties (e.g., transformation uncertainties) arising during site investigation. This paper presents Bayesian approaches for probabilistic characterization of undrained shear strength using cone penetration test (CPT) data and prior information. Homogeneous soil units are first identified using CPT data and subsequently assessed for weak stationarity by the modified Bartlett test to reject the null hypothesis of stationarity. Then, Bayesian approaches are developed to determine the random field parameters and simultaneously select the most probable correlation function among a pool of candidate correlation functions within the identified statistically homogeneous layers. The proposed approaches are illustrated using CPT data at a clay site in Shanghai, China. It is shown that Bayesian approaches provide a rational tool for proper determination of random field model for probabilistic characterization of undrained shear strength with consideration of transformation uncertainty.

scholarly journals Undrained shear strength of Lisbon Miocene clay: a reappraisal based on triaxial and pressuremeter test results

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Mafalda Lopes Laranjo ◽  
Manuel Matos Fernandes
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Physical And Mechanical Properties ◽  
Undrained Shear Strength ◽  
Triaxial Tests ◽  
Relevant Parameter ◽  
List Type ◽  
Test Results ◽  
Overconsolidated Clays ◽  
Undrained Shear

Abstract Undrained shear strength plays a fundamental role on the behaviour of clays. In overconsolidated clays, this parameter is largely influenced by test conditions, namely consolidation stress. “Prazeres Clay” is a Miocene overconsolidated formation, that can be found in a significant part of Lisbon area. Over the last decades a number of very relevant constructions have generated a large database for physical and mechanical properties of Miocene clays. Included in a broader study at the Faculty of Engineering of Porto University about Miocene clay’s physical and mechanical properties, existing data was gathered, treated and critically analysed, in order to establish a useful framework for geotechnical designers. This paper presents the results obtained for undrained shear strength, obtained from triaxial tests and Ménard Pressuremeter tests. It addresses the main difficulties associated with test’s interpretation and presents a discussion on how theoretical values relate to experimental ones. The paper proposes a range of variation for Prazeres Clay’ undrained shear strength based on a significant amount of test results, that is considered to be useful for geotechnical design. Article Highlights Undrained Shear strength is a relevant parameter for clays, and is usually derived from triaxial tests For overconsolidated clays, this parameter is highly dependent on preconsolidation stress, and on its relation to in situ stress. Based on a significant set of data, the paper presents a simple methodology for estimating this parameter

scholarly journals Evaluation of Undrained Shear Strength of Miocene Clay from the Weight Sounding Test (WST)

2017 ◽  
Vol 62 (2) ◽  
pp. 367-384
Author(s):  
Sebastian Olesiak
Keyword(s):  
Shear Strength ◽  
Field Testing ◽  
Field Investigation ◽  
Undrained Shear Strength ◽  
Cohesive Soils ◽  
Strength Parameters ◽  
Additional Measurement ◽  
Carpathian Foredeep ◽  
Innovative Solution ◽  
Undrained Shear

Abstract Soil strength parameters needed for the calculation of bearing capacity and stability are increasingly determined from field testing. This paper presents a method to determine the undrained shear strength cuWST of the soil, based on the Weight Sounding Test (WST). The innovative solution which allows for a significant reduction of equipment needed for geotechnical field investigation is presented. The proposed method is based on an additional measurement of the torque during testing. It then becomes possible to estimate the undrained shear strength, cuWST of the soil, using the correlation given in this paper. The research results presented in this paper were carried out on selected cohesive soils, Miocene clays from the Carpathian Foredeep.

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