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Topic Review
Improvement of Vacuum Preloading System
The vacuum preloading system consists of vertical drains, horizontal vacuum pipes embedded in a layer of the sand blanket, membranes, and vacuum pumps. Studies have confirmed that vacuum preloading can effectively accelerate the consolidation process of soft soil. Further improvement in the efficiency of this method is still the continuing goal of scholars.
  • 475
  • 16 Dec 2022
Topic Review
Impact of Stress Path on Rock Strength
The strength of rock is a non-intrinsic property, and this means that numerous parameters influence the strength values. In most laboratory experiments, specimens are free of stress at the start of the tests, and the load is increased systematically until failure occurs. Around excavations, the opposite path occurs, i.e., the rock is in equilibrium under a triaxial stress state and at least one stress component decreases while another component may increase. Hence, the stress paths in classic laboratory experiments are different from the in situ stress paths. In the research presented, the effect of these different stress paths on the failure processes and failure envelopes was studied. The micro-fracturing when loading rock (from zero or low stress state) until failure was different from the micro-fracturing when unloading rock (from the in situ stress state) until failure. And, hence, by this difference in weakening processes, the failure envelopes were significantly different. The conventional loading resulted in the largest strength and, thus, overestimated the rock strength in comparison to the real in situ behavior. This finding, after being confirmed by additional experiments, will have a direct effect on how one characterizes rock material and on the design of rock excavations.
  • 137
  • 03 Nov 2023
Topic Review
Ground Movement Due to Swelling/Shrinkage of Nicosia Marl
The social and economic impact of expansive soils has been historically significant and is becoming more important in recent years as urban centers expand into areas covering such soils. The research mentioned here are meant to help in understanding the relationship between the spatial distribution of the causal factors and the magnitude of this phenomenon. Its findings can be of benefit to state authorities and other policy makers, as well as the construction industry, in planning future urban development and the maintenance of existing infrastructure.
  • 438
  • 29 Mar 2022
Topic Review
GPS in the Earthmoving Industry
GPS when applied in the earthmoving industry can be a viable asset to contractors and increase the overall efficiency of the job.
  • 279
  • 04 Nov 2022
Topic Review
Geothermal Heat Pump
A geothermal heat pump (GHP) or ground source heat pump (GSHP) is a type of heat pump used to heat and/or cool a building by exchanging heat with ground, often through a vapor-compression refrigeration cycle. It uses the earth all the time, without any intermittency, as a heat source (in the winter) or a heat sink (in the summer). This design takes advantage of the moderate temperatures in the ground to boost efficiency and reduce the operational costs of heating and cooling systems, and may be combined with solar heating to form a geosolar system with even greater efficiency. They are also known by other names, including geoexchange, earth-coupled, earth energy systems. The engineering and scientific communities prefer the terms "geoexchange" or "ground source heat pumps" to avoid confusion with traditional geothermal power, which uses a high-temperature heat source to generate electricity. Ground source heat pumps harvest heat absorbed at the Earth's surface from solar energy. The temperature in the ground below 6 metres (20 ft) is roughly equal to the local mean annual air temperature (MAAT). Depending on latitude, the temperature beneath the upper 6 metres (20 ft) of Earth's surface maintains a nearly constant temperature reflecting the mean average annual air temperature (in many areas, between 10 and 16 °C/50 and 60 °F), if the temperature is undisturbed by the presence of a heat pump. Like a refrigerator or air conditioner, these systems use a heat pump to force the transfer of heat from the ground. Heat pumps can transfer heat from a cool space to a warm space, against the natural direction of flow, or they can enhance the natural flow of heat from a warm area to a cool one. The core of the heat pump is a loop of refrigerant pumped through a vapor-compression refrigeration cycle that moves heat. Air source heat pumps are typically more efficient at heating than pure electric heaters, even when extracting heat from cold winter air, although efficiencies begin dropping significantly as outside air temperatures drop below 5 °C (41 °F). A ground source heat pump exchanges heat with the ground. This is much more energy-efficient because underground temperatures are more stable than air temperatures throughout the year. Seasonal variations drop off with depth and disappear below 7 metres (23 ft) to 12 metres (39 ft) due to thermal inertia. Like a cave, the shallow ground temperature is warmer than the air above during the winter and cooler than the air in the summer. A ground source heat pump extracts ground heat in the winter (for heating) and transfers heat back into the ground in the summer (for cooling). Some systems are designed to operate in one mode only, heating or cooling, depending on climate. Geothermal pump systems reach fairly high coefficient of performance (CoP), 3 to 6, on the coldest of winter nights, compared to 1.75–2.5 for air-source heat pumps on cool days. Ground source heat pumps (GSHPs) are among the most energy-efficient technologies for providing HVAC and water heating. Setup costs are higher than for conventional systems, but the difference is usually returned in energy savings in 3 to 10 years. Geothermal heat pump systems are reasonably warranted by manufacturers, and their working life is estimated at 25 years for inside components and 50+ years for the ground loop. As of 2004, there are over one million units installed worldwide providing 12 GW of thermal capacity, with an annual growth rate of 10%.
  • 1.2K
  • 11 Oct 2022
Topic Review Peer Reviewed
Geographic Information System and Atomized Transportation Modes
Transportation is a spatial activity. The geographic Information System (GIS) is the process of capturing, managing, analyzing, and presenting spatial data. GIS techniques are essential to the study of various aspects of transportation. In this entry, the state of knowledge regarding atomized transportation modes is presented. Atomized transportation modes are defined as transportation modes which deal with low passenger numbers.
  • 473
  • 27 May 2022
Topic Review
Fractals in Engineered Particulate Materials
The fractal framework could help to better understand the inherent variability of granular materials’ behaviour, how these relate to structures at micro-scale, and how understanding, rationalizing, and reducing the randomness at micro-scale can facilitate the design at macro-scale.
  • 391
  • 29 Jun 2022
Topic Review
Forest Fires on Air Quality in Wolgan Valley
Forests are an important natural resource and are instrumental in sustaining environmental sustainability. Burning biomass in forests results in greenhouse gas emissions, many of which are long-lived. Precise and consistent broad-scale monitoring of fire intensity is a valuable tool for analyzing climate and ecological changes related to fire. Remote sensing and geographic information systems provide an opportunity to improve current practice’s accuracy and performance. 
  • 501
  • 28 Dec 2021
Topic Review
Drone-Based Package Delivery Logistics Systems
Autonomous Drone Delivery (ADD) modes are expected to become an important pillar of the future logistics industry for small parcel delivery at the last mile, as well as meal delivery service for fast food (e.g., pizza, etc.) and restaurants.
  • 706
  • 19 Apr 2022
Topic Review
Disintegration Characteristics of Red Soil
Red soil, widely distributed in South America, Africa and Southeast Asia (approximately between the 30° S and 30° N latitudes), is formed by the weathering of carbonate or other rocks rich in iron and aluminium oxides in hot and humid climates. The concept of problem soils was first proposed by Wiseman et al. (1988), and it received a rapid response from the international soil community. Problem soils have a wide horizontal distribution range and large longitudinal depth. Such soils represent a relatively difficult research object in the soil mechanics domain, and the related research is thus a key field of geotechnical engineering. At the 2004 International Conference on Progress in Geotechnical Engineering, Evans et al. indicated that red soil, as a type of problem soil, is prone to geological disasters. Red soil is a highly sensitive problem soil in the Earth’s crust, owing to its hydrologic characteristics and chemical behaviour, and is known as problematic red soil. In rain or a full water system, under the influence of physical and chemical solutions, the original water-soil composition and structure and micro-cracks in the problem soil are destroyed, and the variation in the physical and chemical fields changes the mechanical properties of the soil, which may result in critical disintegration and other types of deformation and failure. These geological hazards are closely related to the intergranular suction, which, in turn, is related to the mechanical properties of unsaturated red soil, and may threaten building foundations and project construction.
  • 1.0K
  • 25 Nov 2022
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