Abstract
Soil slopes along highways, railways, canals, embankments and building sites are exposed to rainfall, surface runoff, seepage, weathering and, in some regions, earthquakes. If left unprotected, they suffer surface erosion, gully formation and shallow sliding, and may later fail in deep-seated movements that endanger life, disrupt transport and raise maintenance costs. This abstract reviews the two main families of slope-protection practice: frame methods and non-frame methods. Frame methods place a structural grid of reinforced concrete (cast-in-situ or precast) or masonry beams on the slope face. The grid is usually tied to stable ground with soil nails, rock bolts or prestressed anchors, and its cells are filled with vegetation, shotcrete or stone. Because it restrains the slope and spreads loads, it suits steeper, higher and weaker slopes. Non-frame methods protect or strengthen the slope surface directly, without a structural grid. They include vegetation and bioengineering, geosynthetics, shotcrete with wire mesh, stone pitching, riprap and gabions, always supported by surface and sub-surface drainage. They are faster, cheaper and more environment-friendly, but are generally limited to moderate slopes and shallow instability. The two families are compared on mechanism, suitable conditions, construction, cost, durability and environmental impact. The main conclusion is that selection should be governed by slope geometry, soil and groundwater conditions, climate, risk and maintenance capacity, and that a hybrid system, such as frame beams with vegetated infill and good drainage, often gives the most reliable and sustainable result.