Answer:
Step-by-step explanation:
a) Weathering refers to the process of breaking down and altering rocks, minerals, and other geological materials at or near the Earth's surface. It is a combination of physical, chemical, and biological processes that result in the disintegration and decomposition of rocks into smaller particles over time. Weathering plays a significant role in shaping the Earth's landscapes and is a crucial step in the formation of soils.
b) The following factors influence the process of weathering:
i) Nature of rocks: The composition and characteristics of rocks have a direct impact on the rate and type of weathering. Some rocks, like limestone and marble, are more susceptible to chemical weathering due to their mineral composition. Rocks with cracks, joints, or fractures provide pathways for water and other weathering agents to penetrate and accelerate the breakdown process. Rocks with high porosity, such as sandstone, are more susceptible to physical weathering as water can infiltrate and cause expansion and contraction during freeze-thaw cycles.
ii) Length of time: Weathering is a gradual process that occurs over extended periods. The longer the exposure of rocks to weathering agents, the more pronounced the effects. Over time, repeated cycles of weathering can lead to significant erosion and the eventual breakdown of rocks into smaller particles.
iii) Climate: Climate plays a crucial role in the intensity and type of weathering that occurs in a particular region. Temperature, precipitation, and freeze-thaw cycles are significant factors. In humid and warm climates, chemical weathering is more prevalent as moisture and heat accelerate chemical reactions. In colder regions, freeze-thaw cycles can lead to physical weathering as water freezes and expands within cracks, causing the rocks to fracture.
c) The engineering importance of rock weathering lies in its impact on the stability and durability of structures built on or with rock materials. Understanding the extent of weathering in a specific area is essential for construction and engineering projects. Weathering affects the mechanical properties of rocks, such as strength, cohesion, and permeability, which are crucial considerations for foundations, tunnels, slopes, and other infrastructure. Engineers need to assess the degree of weathering to determine the appropriate design, construction methods, and materials for projects. Weathered rocks may require additional reinforcement or treatment to ensure stability and prevent potential failures or collapses.