Estimation of the compression behaviour of reconstituted clays
Abstract The void index is a relative quantity measuring the position of the current void ratio of a clay against the void ratios of the clay at two specific vertical effective stresses (i.e., σv′ = 100 kPa and σv′ = 1000 kPa). Based on this concept, a simple systematic tool is proposed for estimating the compression behaviour of reconstituted clays over a wide range of stresses and water contents. Following the practice of geotechnical engineering computation, the compression behaviour of clays is idealised as linear segments in the Iv ~ lnp′ (or the void index and the mean effective stress) space. Considering the variation in the available data, there are three related but independent models for describing the compression behaviour of reconstituted clays. The accuracy of estimation increases with the level of available data. The proposed estimation is used to simulate the behaviour of a variety of reconstituted clays over a wide range of stresses and water contents. With different levels of available data, the estimation is evaluated on the basis of these simulations. The proposed estimation can take maximum use of available data and provide a simple yet practical tool for calculating the compression behaviour of reconstituted clays and a basic parameter for geotechnical engineering computations, the compression index. An empirical equation for the initial compression index is also suggested and verified.
Estimating the compression behaviour of metal-rich clays via a Disturbed State Concept (DSC) model
Many studies have been made on the compression behaviour of clay exposed to metal-rich liquids (metal-rich clay) because metal contamination of clay is found worldwide and increasingly poses as an environmental risk. However, the study on predicting the compression behaviour of contaminated clay with various metal concentrations is very limited. In this paper, a general compression model of the metal-rich clays is proposed based on a general Disturbed State Concept (DSC) compression model. A simplified form of the general model is proposed, and validated based on the compression behaviour of metal-rich clays with various metal concentrations in the pore liquid. The following conclusions are obtained in this study: (1) the simplified DSC compression model provides a practical means to estimate the compression behaviour of metal-rich clays, and it can quantify the influence of various metals on the compression behaviour of clay; (2) in the simplified DSC compression model, the influence of metal exposure can be reliably described by one parameter b, which is very useful for geotechnical engineering practice; (3) the ratio of the bulk modulus for metal-rich clays over that of the parent clay (i.e., without metal contamination) is found to be dependent on parameter b only, and that value is usually greater than 1. The highest value for the bulk modulus ratio found in this study is 2.2 for a sea water-exposed clay; and (4) two empirical equations for estimating parameter b are established. Hence the proposed model can be used for engineering estimation.
Luminescence Phenomena Involving Metal Enolates
1 
Introduction 
 
2 
Metal Enolates 
 
3 
Luminescence of Rare-Earth Enolates 
 
4 
Luminescence Involving s, p and d Metal Block Enolates 
 
5 
Applications 
 
6 
Acknowledgments 
 
 
 
Keywords: 
 
luminescence phenomena involving metal enolates; 
chemistry of metal β-diketonate complexes; 
luminescence of rare-earth enolates; 
photoluminescence of rare-earth β-diketonates; 
diketonate ligand–rare-earth ion energy transfer rates; 
luminescence involving s, p and d metal block enolates; 
photoluminescence of d-transition metal enolates; 
applications - time-resolved detection of luminescence for bioassays