Engineered nanoparticles have generated significant public and scientific excitement due to their unique physical, chemical and electrical properties, which have led to their application in a wide variety of industries. Among all these, carbon nanoparticles (CNPs) are widely manufactured nanoparticles which are utilised in a significant quantity of consumer products, such as reinforced concrete, plastics

Rainfall plays an important role in affecting the slope stability in a tropical country such as Singapore. The soil in Singapore is mainly residual soil with a deep groundwater table that is commonly found in the unsaturated condition in the presence of matric suction. This paper presents the unsaturated properties of soil with roots of Caesalpinia crista and their effects on slope stability during

This paper presents the results of a comprehensive geotechnical laboratory testing for the assessment and design of a proposed biosolid monofill facility at the As-Samra Waste Water Treatment Plant (WWTP) in Jordan. Previous landfill operations for biosolid materials typically involved co-disposal or lagooning of the dewatered biosolid slurry. However, it is proposed that the solar-dried As-Samra WWTP

Cement-treated soil is widely used in many countries and is sometimes applied in estuary and coastal region civil infrastructures such as embankments and port facilities. In some of these facilities, leachates and deterioration of strength have been detected after 20 years of service and therefore require maintenance work such as chemical injection and reconstruction. The reasons for these failures

Cement-based grout has been used for ground improvement. Owing to environmental issues related to cement, its usage should be reduced. In this study, an inorganic binder is introduced to reduce the use of cement in grout. To evaluate the transient electrical and mechanical properties of the sand–cement admixture samples improved with the addition of inorganic binders, two non-destructive testing methods

This study explored the use of root cross-section dimensions, root distribution, uplifted root/soil volume, greenwood modulus of rupture and soil/greenwood densities in a biomechanical close form model based on past literature to estimate the resistance to uprooting of tree root–soil plates. This study used data obtained from a tree-pulling exercise involving 20 planted Samanea saman, a common species

The effects of climate change including intense rainfalls have resulted in many slope failures. The bioengineering method using vegetation is an environmentally friendly alternative for slope stabilisation. This paper presents the effect of root reinforcement on the stability of vegetated slope under rainfall condition. A transient seepage and slope stability analysis was conducted based on the finite-element

This paper describes a heuristic approach that combines a limited number of experimental measurements with the random finite-element method (RFEM) to accelerate significantly the process of measuring the hydraulic conductivity of unsaturated soils. A microstructure-based RFEM model is established to describe unsaturated soils with distribution of phases based on their respective volumetric contents

The presence of surfactants in the unsaturated zone is one of the scenarios where the flow depends on the solute concentration. The simulation of flow and transport of surfactants requires the coupling of flow and transport, where the surfactant concentration-dependent changes to water retention (i.e. changes in surface tension and/or contact angle) and hydraulic conductivity need to be considered

Drilling-induced tensile fracture under anisotropic stress conditions is investigated numerically with an elasto-viscoplastic constitutive model, in which the plastic strain rate can be decomposed into deviatoric and volumetric components. Both the deviatoric and volumetric invariants of the plastic strain rate are assumed to follow an incremental power-law relationship with an Arrhenius dependence

Thermoactive piles ensure a dual function: they support mechanically the superstructure and at the same time they are used as heat exchanger elements. In comparison to standard design practice, this requires considering the associated thermal loadings from the operation of the heat exchange system. To assess the thermal effects on the mechanical behaviour, different design assumptions and modelling

In engineering practice, energy pile foundations are often designed for the lifetime of the building. Thermal exchange between a pile and the surrounding soil depends on the annual energy needs of the building, as heating mode in winter and cooling mode in summer. Thus, energy pile foundations will undergo a heating–cooling cycle per year. In the present work, an experimental method based on a small-scale

Thermoactive geostructures represent an original and efficient technique for fulfilling the energy demand of buildings and infrastructure, in terms of both cooling and heating. Thermal and mechanical aspects have to be considered to achieve a proper design of such structures. This paper focuses only on thermal aspects and deals with the development of an original approach based on the analysis of thermal

Thermoactive diaphragm walls have proved their efficiency for near-surface geothermal energy use. To get insights into the heat transfer process occurring between the heat exchanger pipes and the surrounding boundaries, an instrumented real case located in northern Italy was taken as reference. Combining on-site monitoring data with computational simulations, the role of the basement space in governing

This study reports on the actual energy and economic performances of a water source heat pump recently installed and operated at a Glasgow Subway station in the UK using subsurface water ingress to provide heating and domestic hot water. This follows from a previous publication that detailed the empirical measurements and design of a heating system designed on the basis of a 15-month monitoring period

Thermoactive geostructures are considered an economically suitable and environment-friendly solution for heating and cooling buildings. Energy tunnels have gained growing interest in recent years because of the large ground volume involved in heat exchange in comparison to building foundations. Heat exchange is obtained by embedding a circuit of pipes into the precast concrete lining, resulting in

Urban settlements, whether single buildings or apartment blocks, influence near-surface ground temperatures. Heat transfer by buildings to the ground must therefore be considered when designing both vertical probes and energy geostructures in urban areas. However, assessment of ground temperature variability in urban areas is still uncommon for shallow geothermal energy purposes, the standard temperature

Shallow geothermal energy is currently adopted in many countries for the heating and cooling of buildings. Interactions between close geothermal plants will become more and more relevant as a result of the widespread dissemination of such systems. This paper describes a preliminary investigation of the interactions at the city scale. The case study of a central district in the city of Turin (Italy)

Permafrost degradation is a major concern in cold regions that are warming because of climate change. To assist in understanding the process, ground temperatures, lateral and vertical deformations and groundwater pressures were measured for 6 years under a road embankment in northern Manitoba, Canada. The road surface requires ongoing maintenance due to irregular settlements. The field data allowed

Mine tailings are one of the main sources of dissolved arsenic (As) in groundwater. In the present study, an investigation was conducted on the efficiency of sophorolipids, at different concentrations and pH levels and at two different temperatures (15°C and 23°C), to remove arsenic and heavy metals from mine tailings. Furthermore, the effect of sophorolipids on the speciation of arsenic and the effectiveness

Class F fly ash cannot be used alone as a construction material due to its low self-cementing properties. This paper reports the compaction characteristics, strength properties and microstructure of lime-amended fly ash with varying lime content from 0 to 12%. The effects of the curing temperature on the strength and microstructure of the lime-amended fly ash are studied at different curing periods

Cob is a vernacular earth-building technique which has encountered renewed interest for its low environmental impact compared to conventional construction materials. Relevant mechanical characterisation is essential for cob building structure design and calculation. This paper presents an improved laboratory procedure to better the characterisation of representative cob samples. Samples prepared by

The paper describes the thermo-mechanical behaviour of an experimental pre-cast driven pile, properly instrumented and prepared to operate as a heat exchanger foundation element under the simultaneous action of mechanical and thermal loads. Firstly, in situ static vertical load tests were carried out to analyse the pile mechanical behaviour. Afterwards, two thermal tests were performed under constant

This paper describes the instrumentation of a full-scale test, known as the Multi-Purpose Test, of the KBS-3H spent nuclear fuel design alternative carried out in the Äspö Hard Rock Laboratory (Sweden). This test is part of the Large Underground Concept Experiments EU project, where Posiva and Svensk Kärnbränslehantering are partners. The test consists of two aspects. The first is that of a ‘demo’

Isostatic compression is a technically highly specialised technology for manufacturing solid components from powder. There are only few reported experiences for isostatic compression of bentonite clay, which forms the basis of the engineered barrier system in the geological disposal concept KBS-3V, currently under investigation in Sweden and Finland. An isostatically compressed middle-scale MX-80 bentonite

The interactions between copper, the canister material in the nuclear waste disposal concept in Finland and Sweden, and micro-organisms in groundwater in their expected near-field environment are the core interest of this paper. Copper specimens were incubated with ammonia-oxidising bacteria for different time periods and then subjected to electrochemical measurements and surface characterisation to

High-level radioactive waste (HLW) management in Japan stalled prior to selecting any candidate sites for a literature survey, the first step of a staged programme for selecting a disposal site. The situation deteriorated after the Fukushima Daiichi accident. The Nuclear Waste Management Organization of Japan has suffered a loss of national/international credibility in the geological disposal project

The in situ Full-scale Engineered Barriers Experiment or Febex was a full-scale test reproducing the near field of a nuclear waste repository. It was performed in a gallery excavated in granite at the Grimsel Test Site in Switzerland, with a heater whose surface temperature was set to 100°C, simulating the waste canister and a bentonite barrier composed of highly compacted blocks. The test was completely