Albert Yeung - Academia.edu (original) (raw)
Papers by Albert Yeung
Géotechnique, 2012
The cavity expansion theory is being applied to describe many geotechnical engineering processes.... more The cavity expansion theory is being applied to describe many geotechnical engineering processes. Many of these processes are controlled by the cavity volumetric expansion rate in practice. As soil is not an elastic material, the injection pressure is a non-linear function of the cavity volume, rendering it very difficult to produce the appropriate time history of injection pressure so that the controlled cavity volumetric expansion rate can be simulated. In this technical note, an algorithm to develop the time history of injection pressure using appropriate soil properties to generate the required cavity volumetric expansion rate in clay is presented. The simulation and experimental results of a series of laboratory-scale compaction grouting experiments are presented as an example to demonstrate the validity of the approach.
The Hong Kong Tunnelling Conference, Hong Kong, 20-21 November 2009. In Conference Proceedings, 2... more The Hong Kong Tunnelling Conference, Hong Kong, 20-21 November 2009. In Conference Proceedings, 2009, p. 229-235
Proceedings of the Institution of Civil Engineers - Management, Procurement and Law
The design of a handheld mobile system for biometric authentication originally designed for the H... more The design of a handheld mobile system for biometric authentication originally designed for the Hong Kong construction industry is presented. The system can read the registration smart card of a registered construction worker and any standard Mifare contactless smart cards. It uses a radio-frequency imaging sensor to capture the fingerprint on the dermal skin layer of the construction worker, eliminating the problems of sweat, minor cuts or dirt on that individual’s fingers, so as to verify the identity of the cardholder efficiently and accurately. The system is also equipped with a global positioning system receiver. Practically, it can identify the position of a particular person at a particular time. Current applications of the innovative system in construction management, illustrated by application case histories, are presented in this paper. Potential applications are also discussed.
Underground Construction and Ground Movement, 2006
Electrokinetic extraction is an emerging technology that can be used to remove contaminants from ... more Electrokinetic extraction is an emerging technology that can be used to remove contaminants from heterogeneous fine-grained soils in situ. Contaminants in the subsurface are removed by the application of a direct-current electric field across the contaminated soil. The primary contaminant transport and removal mechanisms are electroosmotic advection and ionic migration. However, there are many complex physicochemical reactions occurring simultaneously during the process that may enhance or retard the cleanup process. Nonetheless, the viability of the technology has been established by results obtained from many bench-scale and large-scale laboratory and pilot-scale field experiments performed on various soils. This paper will review the fundamental concepts of the technology and discuss some important practical aspects and design criteria of the technology for field implementations. An example on cost analysis of the technology is also presented to demonstrate the use of various equ...
Chelating Agents for Land Decontamination Technologies, 2012
Soil contamination is a worldwide problem of increasing concern. Many sites are contaminated by d... more Soil contamination is a worldwide problem of increasing concern. Many sites are contaminated by different hazardous contaminants, both inorganic and organic. The problem is serious and fast growing, in particular in industrially developed or developing economies. The problem is persistent and long lasting, impacting public health and the ecology adversely in the long term. In fact, the long-term impacts of soil contamination are not fully understood or delineated. The nature and properties of the contaminated soil may change from site to site. However, soil can be broadly classified into two categories in accordance with its particle size distribution: (1) coarse-grained soil; and (2) fine-grained soil. Depending on: (1) the nature and properties of the contaminated soil; (2) the type, chemical state, and concentration of the contaminant; and (3) the specific environmental conditions of the contaminated site; there are many available in-situ or ex-situ remediation technologies that can achieve varying degrees of remediation (Yeung, 2009a). However, remediation of contaminated fine-grained soil is particularly difficult due to its extremely low hydraulic conductivity and very large specific area (Yeung, 2008).
Environmental Engineering Science, 2006
Environmental Toxicology and Risk Assessment: Biomarkers and Risk Assessment: Fifth Volume
Soil vapor extraction (SVE) is a proven technology that can remove volatile organic compounds (VO... more Soil vapor extraction (SVE) is a proven technology that can remove volatile organic compounds (VOCs) from the subsurface effectively if the conditions are favorable. However, most systems are designed by empirical methods or engineering judgment based on results of pilot tests. An attempt is made to develop a mathematical model for the technology so that optimal operating parameters can be obtained. The pressure distributions induced by multiple-well extractions are obtained by superimposing an existing analytical solution. Concentrations of VOCs as a function of time and space are obtained by numerical simulation of the migration and fate of VOC. The effectiveness of SVE systems using different operating parameters is evaluated on the basis of the quantity of contaminant removed. The developed mathematical model provides the necessary engineering design tools to evaluate different operation scenarios.
When a direct-current (dc) electric field is applied to a dilute clay suspension, negatively char... more When a direct-current (dc) electric field is applied to a dilute clay suspension, negatively charged clay particles are moved toward the anode (Positive electrode). This electrokinetic phenomenon is used to reseal leaking geomembrane liners while they are in service. The basis of this innovative environmental protection technology and the results obtained from full-scale evaluation of the feasibility of the technology are presented in the paper. The significant reduction in leakage rate from a geomembrane lined surface impoundment caused by the formation clay cake at the leak indicates the technology is feasible.
Géotechnique, 2012
The cavity expansion theory is being applied to describe many geotechnical engineering processes.... more The cavity expansion theory is being applied to describe many geotechnical engineering processes. Many of these processes are controlled by the cavity volumetric expansion rate in practice. As soil is not an elastic material, the injection pressure is a non-linear function of the cavity volume, rendering it very difficult to produce the appropriate time history of injection pressure so that the controlled cavity volumetric expansion rate can be simulated. In this technical note, an algorithm to develop the time history of injection pressure using appropriate soil properties to generate the required cavity volumetric expansion rate in clay is presented. The simulation and experimental results of a series of laboratory-scale compaction grouting experiments are presented as an example to demonstrate the validity of the approach.
The Hong Kong Tunnelling Conference, Hong Kong, 20-21 November 2009. In Conference Proceedings, 2... more The Hong Kong Tunnelling Conference, Hong Kong, 20-21 November 2009. In Conference Proceedings, 2009, p. 229-235
Proceedings of the Institution of Civil Engineers - Management, Procurement and Law
The design of a handheld mobile system for biometric authentication originally designed for the H... more The design of a handheld mobile system for biometric authentication originally designed for the Hong Kong construction industry is presented. The system can read the registration smart card of a registered construction worker and any standard Mifare contactless smart cards. It uses a radio-frequency imaging sensor to capture the fingerprint on the dermal skin layer of the construction worker, eliminating the problems of sweat, minor cuts or dirt on that individual’s fingers, so as to verify the identity of the cardholder efficiently and accurately. The system is also equipped with a global positioning system receiver. Practically, it can identify the position of a particular person at a particular time. Current applications of the innovative system in construction management, illustrated by application case histories, are presented in this paper. Potential applications are also discussed.
Underground Construction and Ground Movement, 2006
Electrokinetic extraction is an emerging technology that can be used to remove contaminants from ... more Electrokinetic extraction is an emerging technology that can be used to remove contaminants from heterogeneous fine-grained soils in situ. Contaminants in the subsurface are removed by the application of a direct-current electric field across the contaminated soil. The primary contaminant transport and removal mechanisms are electroosmotic advection and ionic migration. However, there are many complex physicochemical reactions occurring simultaneously during the process that may enhance or retard the cleanup process. Nonetheless, the viability of the technology has been established by results obtained from many bench-scale and large-scale laboratory and pilot-scale field experiments performed on various soils. This paper will review the fundamental concepts of the technology and discuss some important practical aspects and design criteria of the technology for field implementations. An example on cost analysis of the technology is also presented to demonstrate the use of various equ...
Chelating Agents for Land Decontamination Technologies, 2012
Soil contamination is a worldwide problem of increasing concern. Many sites are contaminated by d... more Soil contamination is a worldwide problem of increasing concern. Many sites are contaminated by different hazardous contaminants, both inorganic and organic. The problem is serious and fast growing, in particular in industrially developed or developing economies. The problem is persistent and long lasting, impacting public health and the ecology adversely in the long term. In fact, the long-term impacts of soil contamination are not fully understood or delineated. The nature and properties of the contaminated soil may change from site to site. However, soil can be broadly classified into two categories in accordance with its particle size distribution: (1) coarse-grained soil; and (2) fine-grained soil. Depending on: (1) the nature and properties of the contaminated soil; (2) the type, chemical state, and concentration of the contaminant; and (3) the specific environmental conditions of the contaminated site; there are many available in-situ or ex-situ remediation technologies that can achieve varying degrees of remediation (Yeung, 2009a). However, remediation of contaminated fine-grained soil is particularly difficult due to its extremely low hydraulic conductivity and very large specific area (Yeung, 2008).
Environmental Engineering Science, 2006
Environmental Toxicology and Risk Assessment: Biomarkers and Risk Assessment: Fifth Volume
Soil vapor extraction (SVE) is a proven technology that can remove volatile organic compounds (VO... more Soil vapor extraction (SVE) is a proven technology that can remove volatile organic compounds (VOCs) from the subsurface effectively if the conditions are favorable. However, most systems are designed by empirical methods or engineering judgment based on results of pilot tests. An attempt is made to develop a mathematical model for the technology so that optimal operating parameters can be obtained. The pressure distributions induced by multiple-well extractions are obtained by superimposing an existing analytical solution. Concentrations of VOCs as a function of time and space are obtained by numerical simulation of the migration and fate of VOC. The effectiveness of SVE systems using different operating parameters is evaluated on the basis of the quantity of contaminant removed. The developed mathematical model provides the necessary engineering design tools to evaluate different operation scenarios.
When a direct-current (dc) electric field is applied to a dilute clay suspension, negatively char... more When a direct-current (dc) electric field is applied to a dilute clay suspension, negatively charged clay particles are moved toward the anode (Positive electrode). This electrokinetic phenomenon is used to reseal leaking geomembrane liners while they are in service. The basis of this innovative environmental protection technology and the results obtained from full-scale evaluation of the feasibility of the technology are presented in the paper. The significant reduction in leakage rate from a geomembrane lined surface impoundment caused by the formation clay cake at the leak indicates the technology is feasible.