The difference between collapse and landslide in slope gravity landform

1.Slope slope: 50° for collapse; Landslides are generally 50°

2.Slope location where it occurs: Collapse occurs only on the slope above the foot of the slope; Landslides occur on the slope surface, or at the foot of the slope, or even cut out in front of the slope.

3.Boundary surface features: the side and bottom surface of the collapse exist independently and cannot form a unified plane; The side and bottom surfaces of a landslide can sometimes be joined together to form a uniform surface (flat or curved).

4.Characteristics of friction resistance of the bottom surface: the friction resistance of the collapse bottom surface is large; The bottom surface of the landslide forms a weak surface with low friction resistance.

5.Geometric characteristics of the bottom surface of the group: the bottom surface of each collapsed block often exists independently; The bottom surface of each slide is sometimes a uniform sliding surface.

6.Movement condition: collapse and cracking, mostly rolling, jumping, extremely fast; Landslide shear, relative to the overall slippage, extremely fast to very slow.

7.Typical signs: reverse dislocation on the collapsed slope, surface cracks in the landslide, and landslide platform.

8.Typical internal structure: collapse and loosening cracking, local overhead, shingle-like structure; In general, the landslide maintains the original structure and tectonic characteristics of the rock strata. Shingle-like structures can also occur.

9.Name of the accumulation: collapse to form a pile of fallen rocks; Landslides form landslide bodies.

Collapse is mainly the sudden collapse of soil or rock mass or debris due to gravity, and the sharp downward inclination.

Landslide is a phenomenon in which soil or rock mass or debris slides down the landslide surface under the action of gravity and water.

Collapse: mainly affected by gravity, with suddenness, landslide: mainly by gravity and water, with inducing.

The difference between landslide and collapse is mainly manifested in the following aspects:

1) After the collapse occurs, the collapse is often piled up at the foot of the hillside, which is cone-shaped, and the structure is scattered and there is no sequence; However, the landslide sediment often has a certain external shape, and the integrity of the landslide body is good, reflecting the sequence and structural characteristics. That is to say, in the landslide deposits, the upper and lower layers of the rock mass (soil) and the relationship between the old and the new have not changed much, and they are still regularly distributed.

2) The collapse body is completely separated from the parent body (mountain), while the landslide body is rarely completely separated from the parent body, and most of the sliding bodies remain on the sliding bed.

3) After the collapse, the vertical displacement of the collapse is much greater than the horizontal displacement, and the position of the center of gravity is much lowered. This is not the case for landslides, where the horizontal displacement of the landslide body is usually greater than the vertical displacement. The center of gravity of most landslide bodies is not lowered much, but the sliding distance is large. At the same time, landslides generally slide more slowly than collapses.

4) There is basically no crack distribution on the surface of the collapsed deposit. The surface of the landslide, especially the new landslide, has many longitudinal and horizontal cracks with certain regularity. For example:

arc-shaped tensile cracks distributed in the upper part (i.e., the rear part) of the landslide body; shear cracks (feathered) distributed on both sides of the middle part of the landslide; The direction of the bulging cracks distributed in the front part of the landslide body is perpendicular to the direction of the landslide, that is, the direction of compression; The fan-shaped tension cracks distributed in the middle and front of the landslide body, especially the landslide tongue, or the radial cracks at the front edge of the landslide.

The formation of landslides is divided into rock and soil types, geological structural conditions, and topography.

There are four kinds of conditions, hydrogeological conditions.

Causes of landslides:

1) Geotechnical type. Rock and soil are the material basis for landslides.

2) Geological and tectonic conditions. The condition that the rock and soil that make up the slope can only slide downward when it is cut and separated into a discontinuous state by various structural planes. At the same time, the tectonic plane provides a channel for water currents such as rainfall to enter the slope. Kill the fierce.

3) Topographic and geomorphological conditions. Landslides can only occur if they are in a certain landform location and have a certain slope.

4) Hydrogeological conditions. Groundwater plays a major role in the formation of landslides.

1. Causes.

Landslide refers to the natural phenomenon of soil or rock mass on the slope, which is affected by factors such as river erosion, groundwater activity, rainwater soaking, and artificial slope cutting, and under the action of gravity, along a certain weak surface or weak zone, as a whole or scattered, sliding down the slope.

Collapse (caving, collapse or collapse) is a geological phenomenon in which the rock and soil mass on a steep slope suddenly detached from the parent body under the action of gravity, collapses, rolls, and accumulates at the foot of the slope (or valley).

2. Hazards. The main hazards of landslides to rural areas are the destruction of farmland, houses, harm to people and livestock, destruction of forests, roads, agricultural machinery and facilities, water conservancy and hydropower facilities, etc., and sometimes even cause devastating disasters to rural areas. Landslides located in towns often bury houses, people and animals, destroy fields, destroy factories, schools, government agencies, etc., and destroy various facilities, causing power outages, water outages, work stoppages, and sometimes even entire towns.

Collapse destroys buildings, and sometimes entire settlements, and buries roads and railways. The losses caused by the collapse are not only the direct losses of the destruction of the building, but also often cause the traffic to be interrupted, resulting in significant losses to transportation.

3. Features. Landslide: The landslide platform is wide and leveled, and there is subsidence; The slope of the front edge of the landslide is steep, the soil is compact, overgrown with trees, and there is no loose collapse. The part of the front edge of the river is washed by the river; The river water is far away from the tongue of the landslide, and even has floodplains and terraces outside the tongue. The natural scouring ditches on both sides of the landslide body are cut very deeply, even reaching the bedrock; There is a clear spring flowing out of the foot of the tongue of the landslide body, etc.;

Collapse: fast speed (generally 5-200m s); The scale varies greatly (less than 1m3-108m3); After the collapse falls, the relative positions of each part of the collapse body are completely disrupted, and the size is mixed, forming a pile of fallen stones that are rolled far away.