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This paper presents an analysis on a geogrid-reinforced embankment with clay-cover by model tests under static and cyclic loading. The deformation and failure surface inside the embankment were obtained by particle image velocimetry (PIV). The test results showed that geogrids effectively improved the ultimate bearing capacity and reduced the vertical settlement and lateral displacement of reinforced embankment. The reinforcement effect increased with the increase in geogrid length, and the ultimate bearing capacity of the embankment reinforced with the longest geogrid was 51.9 kPa, which was 79% higher than that of unreinforced embankment. The wrapped clay formed an effective lateral constraint on the outward movement of the slope soil under pressure. When the reinforced embankment was damaged, the internal displacement significantly reduced, and the sliding surface in the middle of the embankment pointing to the foot of slope began to move into the embankment in an arc shape. In the cyclic loading test, the stress concentration effect inside embankment reduced by geogrid reinforcement. During each cycle, the earth pressure varied with a stable half-sine wave. The conclusions drawn from this study can provide an important fundamental data for the construction in geotechnical and road engineering.

In recent years, there has been growing interest in developing methods for mitigating greenhouse effect, as greenhouse gas emissions continue to contribute to global temperature rise. On the other hand, investigating geopolymers as environmentally friendly binders to mitigate the greenhouse effect using soil stabilization has been widely conducted. However, the effect of CO2exposure on the mechanical properties of geopolymer-stabilized soils is rarely reported. In this context, the effect of CO2exposure on the mechanical and microstructural features of sandy soil stabilized with volcanic ash-based geopolymer was investigated. Several factors were concerned, for example the binder content, relative density, CO2pressure, curing condition, curing time, and carbonate content. The results showed that the compressive strength of the stabilized sandy soil specimens with 20% volcanic ash increased from 3 MPa to 11 MPa. It was also observed that 100 kPa CO2pressure was the optimal pressure for strength development among the other pressures. The mechanical strength showed a direct relationship with binder content and carbonate content. Additionally, in the ambient curing (AC) condition, the mechanical strength and carbonate content increased with the curing time. However, the required water for carbonation evaporated after 7 d of oven curing (OC) condition and as a result, the 14-d cured samples showed lower mechanical strength and carbonate content in comparison with 7-d cured samples. Moreover, the rate of strength development was higher in OC cured samples than AC cured samples until 7 d due to higher geopolymerization and carbonation rate.

In central areas of large cities, it is necessary to ensure the safety of the existing tunnel during the construction of a super-large diameter shield tunnel. Given the rapid development of the over-lapping tunnel excavation in recent years, detailed study of the stress and deformation responses under trains’ dynamic and vibration loads when a super-large diameter shield tunnel passes through the existing tunnels is essential to improve the stability of metro lines in operation. This study presents the influence of a super-large diameter shield tunnel excavation on the existing tunnel in the Shanghai North Cross Channel project. In this study, the construction disturbance of a super-large diameter shield tunnel and the influence of trains’ dynamic and vibration loads on the existing tunnel are considered. The results of numerical simulations show that there are differences in the dynamic response amplitudes of segments at different positions under the combined action of new tunnel excavation loadings and trains’ dynamic and vibration loads. The strong dynamic response area of the displacement and acceleration of the lining structure is mainly located at the bottom of the segment ring. The maximum compressive stress of segments appears at the arch waist of the tunnel, and the maximum tensile stress appears in arch crown.

Hybrid optimisation of multiple energy resources has been performed on a micro grid model of a hospital to investigate the capability of a standalone energy system and simultaneous mitigation of hospital waste. The main objectives of this study were to collect renewable energy resource data of a hybrid hospital, use the average amount of hospital waste from the literature and NASA surface meteorology in addition to the solar energy database from HOMER Pro software to construct a hybrid model for a conceptual hospital in the new green city in Saudi Arabia, NEOM. The hybrid model consisted of biogas cofire and diesel generators, PV solar array and batteries. Simulations were performed to analyse the load requirements of a standalone hospital. The mechanism of energy storage was designed based on Tesla batteries. Then, the hybrid hospital model was tested with NEOM’s natural resources, load demand of 250 kWh/day and the average amount of daily hospital waste of 0.6 tons based on the literature data. This condition allows the smart hospital to be tested with real features. The outcome of the COE, NPC and the amount of reduction of carbon dioxide in the hybrid hospital were analysed. Many of the hybrid properties and constraints that define the hospital were adopted from previous literature concentrating on similar domains. The optimal solution of a hybrid micro grid consisted of biogas cofire, PV array, and batteries. Of the total load demand, 32.3% and 67.6% were produced by PV array and biogas cofire generators, respectively, together with eight Tesla PowerWall2.0 batteries. The cost of energy was 0.21 USD/kWh and the net present cost was 243,699.17 USD. In this study, we compared renewable energy with conventional energy and found that the optimal solution would be able to reduce carbon emission and diesel consumption by almost 84% and 81%, respectively. The results were verified through a sensitivity study and compared with other studies.

Estimation of elemental distribution with low value of error is essential for block modelling based on subsurface data. This paper proposes an application of inverse distance weighted anisotropic method (IDWAM) based on combined variograms to generate block models in Kahang Cu-Mo porphyry deposit, Central Iran. To do this, cell declustering for dataset with respect to Cu concentrations as the main target in this deposit was conducted in order to validate the chosen voxel dimension. Moreover, 'Variogram Maps' have been created to find out if there are any anisotropic characteristics within the deposit. Finally, correlation between results for Cu estimated, achieved from the proposed estimator and raw data were carried out using optical verification and jackknife. The results obtained by the combination of IDWAM and experimental variograms showed that the enriched elemental concentrations for Cu and Mo are associated with the central, NE and NW parts of the area.

AbstractThe flow pattern changes at open channel bend as the result of the presence of centrifugal force. Parameters such as water surface level, the transverse and depth velocity distribution, secondary flow and separation zones deeply depend on bend angel and radius, while many researchers are interested in flow patterns at bends. This paper presents an experimental and numerical study of the flow patterns in a strongly-curved 90° open channel bend. The numerical modelling was carried out using the finite volume method. In this numerical study, the k– ε (RNG) model was used to predict the turbulence, and the volume of fluid (VOF) method was used to simulate the water free surface. The numerical results were verified against data from a program of experiments conducted in this study. A comparison between the experimental data and the results of the numerical model showed that the k– ε (RNG) and VOF methods are capable of simulating the flow pattern in the strongly-curved bends. The results showed that along a strongly-curved 90° bend, the maximum flow velocity always occurs near the inner wall and in such bends the effect of the secondary flows is not limited to the sections within the bend. Also the overall shape of streamlines along the bend and at different water levels is different. In addition, the results revealed that the transverse slope of the water surface is non-linear in these bends. This situation occurs in bends even though maintaining a steady uniform flow condition in straight sections.

Industrialised nations have a legacy of contaminated land, which is often abandoned and derelict, and pose unprecedented risks to human health, animals and protected resources like surface and groundwater, flora and fauna, and the ecosystem as a whole. The management and clean-up processes of these lands are complex and time intensive, with high cost overruns and depend on input from a range of disciplines. This paper gives an overview of contaminated land, its effects and current management techniques and practices, with references to the UK regulatory framework. It reviews some recent and important patents relevant to contaminated land management, highlighting the significance and limitations of reviewed patents. It concludes by highlighting current and future developments in the field.

•The performance of two liquid cooling designs for lithium-ion battery packs was investigated.•The effects of channel number, hole diameter, mass flow rate and inlet locations are investigated.•This study shows the maximum temperature difference of the CCHS is significantly less than the MCC.•Considering maximum temperature and temperature uniformity, the MCC design provides superior performance to the CCHS.

Nowadays, using biopolymer as a ground improvement method has become very popular. However, since biopolymers are organic and degradable, their long-term effect is not fully known. In this study, the effects of biopolymers on the mechanical behavior of kaolin clay were investigated through a comprehensive program of experiments. Two types of biopolymer, i.e. xanthan gum and guar gum were chosen to investigate the effect of biopolymer type. For this purpose, specimens were prepared using standard Proctor energy at four different water contents (25%, 30% 35% and 40%) with 0.5%, 1%, 1.5% and 2% biopolymer inclusions. The specimens were cured for 1 d, 7 d, 28 d and 90 d. Moreover, some of the specimens were kept in the curing room for 3 years to observe the long-term effect of the biopolymers. At the end of the curing periods, the specimens were subjected to unconfined compression test, and scanning electron microscopy (SEM) analysis was performed to observe the mechanism of strength improvement. The results revealed that the unconfined compressive strength (UCS) of the specimens treated with biopolymers increased in all biopolymer inclusion levels and water contents up to a 90-d curing period. For specimens containing xanthan gum, the maximum strength increase was observed at 25% water content and 2% xanthan gum with 90-d curing. The strength increased 5.23 times induced by xanthan gum addition when compared to the pure clay. Moreover, the increase in strength reached 8.53 times in specimens treated with guar gum. Besides, increasing water content caused more ductile behavior, thus increasing the axial deformation.

This paper presents an experimental study involving the design, manufacturing and testing of a prototype integrated collector storage (ICS) solar water heater (SWH) in combination with a compound parabolic concentrator (CPC). The thermal efficiency of the developed system is evaluated in Kerman (latitude 30.2907° N, longitude 57.0679° E), Iran. The developed system is intended to supply hot water for a family in remote rural areas. A 6-month experimental study was undertaken to investigate the performance of the ICS SWH system. The mean daily efficiency and overnight thermal loss coefficient of each experiment were analyzed to examine the appropriateness of these collectors for regions in Kerman. The results showed that mirror has the highest mean daily efficiency (66.7%), followed by steel sheet (47.6%) and aluminum foil (43.7%). The analysis of hourly and monthly operation diagrams for variations of water temperature for the developed ICS system showed that by increasing the amount of radiation entering the water heater, the thermal efficiency of the system decreases, such that the highest efficiency was in April and the lowest in July. With the distribution of radiation intensity in the months of August and September, the thermal efficiency of the system increased. This regional study illustrates how selecting a proper concentrator can increase the thermal efficiency of this solar-based system. It also shows how the temperature gradient between the ambient air and internal water in the storage tank can influence the performance of such systems, and how a controlled amount of hot water withdrawal can affect the system’s efficiency. Developing the ICSSWH system is an ideal sustainable solution in countries that benefit from a large amount of solar intensity.