Natural Disaster Phenomena: Storms, Floods, and Landslides
Tornadoes: Formation and Impact
Tornadoes are violent storms that strike as a powerful, rotating mixture of wind and thunderstorm clouds, extending from the clouds to the ground in a funnel shape. They are known to be the most powerful and destructive atmospheric wind systems. They are very common in the USA, particularly across the middle belt extending to the East Coast.
When and How Tornadoes Form
Tornadoes usually occur during the daytime, typically from mid-afternoon until early evening. Their
Read MoreMine Site Restoration and Fossil Fuel Energy Insights
Mine Site Restoration and Revegetation
Primary Goals of Revegetation
The primary goals of revegetation are restoration, erosion reduction, water resource protection, and landscape integration. Establishing a mulch cover in areas affected by mining aims to stabilize the ground immediately and prepare it for the planned conditioning systems.
Limiting Factors in Restoration
Key limiting factors are largely dependent on the revegetation system, the mine’s operating and rebuilding plan, the final resulting
Read MoreConstruction Materials: Stone Properties, Cement Standards, and Concrete Testing
Properties of Natural Stones
Granite: Primitive Plutonic Rock
- Origin: Primitive rock, plutonic origin.
- Composition: Quartz (30–35%), Feldspar (50%), and Mica (15–20%).
- Structure: Multi-phase, polycrystalline structure; homogeneous, small grains.
- Mechanical Properties: High mechanical compressive strength, high density, high degree of compactness.
- Behavior: Almost isotropic behavior; hard to sculpt, easy to polish.
- Vulnerabilities: Problems due to freeze-thaw cycles and changes in the feldspars.
Sandstone:
Read MoreEarth’s Geodynamic Cycle: Rock Formation and Volcanoes
The Geodynamic Cycle: Earth Material Transformation
Also called the Geodynamic Cycle or Rock Cycle, this set of processes explains how Earth materials change and transform geological substances. This cycle relates to erosion and plate tectonics operating over vast temporal scales.
Stages of Rock Formation
The cycle involves various stages, resulting in different rock formations:
Stage 1: Formation of Igneous Rocks
Igneous rocks form when magma cools and solidifies into interlocking crystals. These rocks
Read MoreEssential Building Construction Techniques and Material Properties
Methods of Underpinning
Underpinning involves strengthening or increasing the depth of an existing foundation. The primary methods include:
- Pit Method
- Pile Method
- Miscellaneous Methods
1. Pit Method of Underpinning
In this method, the existing wall is divided into suitable sections, typically measuring about 1.20 m to 1.50 m in width.
Holes are made in the existing wall. Needles with bearing plates are then inserted through these holes and supported on jacks (as shown in diagrams). The pit is excavated,
Read MoreGeological Processes, Mineral Deposits, and Geohazards
Mineral Deposits and Formation Processes
Mineral deposits are concentrations of materials linked to geological processes, requiring sufficient concentration factors to be economically viable.
Geological Processes
These are categorized into two main types:
- Exogenous Processes: External processes (e.g., weathering, sedimentation).
- Endogenous Processes: Internal processes (e.g., volcanism, tectonics).
Endogenous Mineralization
Associated with volcanic construction at plate boundaries (active margins, destructive
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