What are the common types of subgrade slope protection?

There are many common types of subgrade slope protection, such as planting grass or turf, planting shrubs, plastering, shotcreting or shotcreting. Can be used alone, can also be used in combination, according to local conditions and reasonable choice.

Grass or turf

Soil slope suitable for grass growth can be adopted, which is a simple, economical and practical protective measure. It can cover the topsoil, prevent the rain from washing the slope, unite the soil, adjust the soil moisture, prevent cracks and strengthen the stability of the slope.

Planting shrubs

Suitable for soil and strongly weathered rock slopes, shrubs with developed roots and lush foliage are suitable, and Amorpha fruticosa, oleander, Vitex negundo, mountain ballast, etc. are generally selected. Seabuckthorn, yellow willow, Caragana korshinskii, Andy, etc. It should be used in windy and dry areas. It is better to plant shrubs and grass together. Shrubs should be planted in late autumn or early spring.

Paint the wall with plaster.

It is suitable for slopes that are easy to weather but not easy to peel off, and the rock surface is relatively complete. The commonly used material is concrete, which consists of cement, lime and slag. Cement, sand, slag; Sand, lime, etc. The plastering protective layer can't bear the lateral pressure, and the plastering slope should be relatively dry and stable. If groundwater is exposed locally, drainage measures must be taken to cooperate.

Shotcrete or shotcrete anchor

Shotcrete is suitable for rock slopes which are easy to be weathered but not seriously weathered, and it is an effective measure to prevent slope weathering. Shotcrete is divided into gravity manual shotcrete and mechanical shotcrete. Gravity shotcrete is to put the slurry bucket at the top of the slope, connect the rubber pipe at the bottom of the bucket, and spray the slurry evenly to the slope by gravity. Mechanical shotcrete is a kind of shotcrete machinery, which sprays slurry onto the slope through the nozzle. Due to a certain pressure, the slurry has good adhesion to the slope, and its quality is obviously better than that of gravity sprayed concrete. Before spraying concrete, the slope should be cleaned, and the spraying thickness is 1 ~ 2 cm. Commonly used pastes are cement mortar and cement lime mortar. If the rock joints on the slope are developed and the weathering is serious, shotcrete with anchor net or steel fiber concrete should be adopted.

Joints and grouting

Jointing is suitable for hard rock slopes with less weathering and more details and cracks, so as to prevent rainwater from invading the cracks and destroying the slope stability. Grouting is suitable for hard rock slopes with large and deep cracks. Use mortar to bond cracked rocks into a whole, to prevent falling off or collapse, to prevent rainwater from invading and to promote rock weathering. Jointing mortar is generally (1: 2) ~ (1: 3) cement mortar or 1: 0.5: 3 and 1: 2: 9 cement lime mortar (volume ratio). Cement mortar of 1: 4 or 1: 5 can be used for grouting, grouting machine can be used if necessary, and concrete can also be poured when cracks are wide.

Mortar rubble retaining wall

It is suitable for steep soil slopes [(1:0.3) ~ (1:1)] and rocky slopes that are easy to be weathered, peeled off or jointed. The retaining wall does not bear earth pressure, and the slope it protects should be stable. The thickness of retaining wall is determined by its own stability and the bearing capacity of the base. There are many types of retaining walls, which should be selected reasonably according to the specific conditions of slopes. The slope is soil or broken rock, and solid retaining wall is adopted; When the slope is not steeper than 1: 0.75, in order to save masonry, the hole and window retaining wall can be used; For relatively complete steep slopes, ribbed retaining walls can be used; Just protect the top half of the skirt and arch the wall.

Dry-laid rubble retaining wall

It is a widely used slope protection. In addition to severe freezing damage, generally slow soil and earth-rock slopes can be used. Used to protect slopes from rainfall and surface runoff. Dry paving flaky slope protection can be in the form of single-layer paving and double-layer paving, which can be selected as appropriate.

Mortar rubble slope protection

It is suitable for soil storage of rocky slopes with gradient of [(1:0.75) ~ (1:1.5)] and easy weathering and crushing. In order to prevent the infiltration and erosion of surface water, it is a relatively strong slope protection, sometimes combined with retaining walls or retaining walls to protect different rock strata and slopes in different positions. Mortar rubble slope protection generally adopts equal cross-section form; When the slope protection area is large and the slope is steep, rib slope protection can be used to enhance the stability of slope protection itself.