Differences among Anchor Rod, Anchor Cable, Soil Nail and Anchor Pipe

Differences among Anchor Rod, Anchor Cable, Soil Nail, and Anchor Pipe

In the construction site, it is generally believed that the drilling hole in the 150mm for the bolt, generally their hole depth, steel bar thick, and prestressed. Soil nails are generally short, aperture of 100mm, and only one bar. But what is the difference between anchor bolt, anchor cable, soil nail, and anchor pipe?

Anchor: Component that transmits tension to a stable rock soil layer. When using steel strands or high-strength steel wire bundles as rod material, it can also be called anchor cable.

Anchor cable: When the anchor rod body is made of a high-strength steel strand, it can be called anchor cable.

Soil anchor: An anchor bolt anchored in the soil.

A tension rod body is composed of steel bars or steel strands arranged in the borehole and extending into the stable soil layer at the end and a grouting body in the hole.

Rock bolt: Anchor bolt anchored in rock strata.

System anchor: In order to ensure the overall stability of the slope, the anchor group is set according to a certain format on the slope.

In order to make the overall stability of the surrounding rock, anchor groups are arranged in a certain format around the tunnel.

Anchorage: An engineering measure for reinforcing rock masses by using bolts anchored in cavern surrounding rock or rock slope.

Anchor retaining wall: Anchoring steel rods or multiple strands of steel wire cables in rock and soil with cement mortar as tensile members to maintain the stability of the wall and support the retaining wall of the soil.

Soil nailing wall: a supporting structure composed of soil and the protective surface of the foundation pit side wall reinforced by soil nailing.

Soil nailing: It is an in-situ reinforcement technology based on the principle of the new Austrian tunnel method, which is to set the reinforced bar horizontally in the natural slope or the slope formed by excavation, and to set the concrete surface layer along the slope surface, so as to improve the mechanical properties of the whole geotechnical system and improve the stability of the slope and foundation pit.

Soil nails can be regarded as small-sized passive anchors ( some similar to full-length bonded anchors ), which are divided into drilling grouting nails and striking nails. The soil nail materials are angle steel, round steel, steel bar, or steel pipe.

Anchor pipe: when the soil nailing rod body with steel flower tube ( is the steel pipe above a few grouting holes ) can be called anchor pipe.

Differences between soil nails and anchors:
1. Force mechanism
1) Soil nailing is a passive force, that is, after a certain deformation of the soil, the soil nailing is forced, thereby preventing the continued deformation of the soil;
2 ) Anchor is an active force, that is, through the anchor time pre-stress, before the excavation of the foundation pit, the soil is limited to excessive deformation;

2. Force range
1) Soil nail is full-length force, but the force direction is divided into two parts, the potential slip surface of the soil nail is divided into two parts, the first half of the force direction points to the potential slip surface direction, and the latter half of the force direction back to the potential slip surface direction ;
2) The first half of the bolt is the free end, and the second half is the stress section, so sometimes the first half of the bolt is not filled with mortar.
The above statement is the difference between a non-prestressed anchor and a prestressed anchor (cable).

3. The essential difference between the two is the different working mechanism

Soil nailing is a kind of soil reinforcement technology, which uses densely arranged reinforcement as a means of soil reinforcement to improve the strength and self-stability of the reinforced soil.

Anchor is a kind of anchoring technology, which transfers a load of the surface unstable rock mass to the deep stable position of rock mass through a tension bar, so as to realize the stability of reinforced rock mass.

When the soil has a certain deformation, the soil nail provides resistance to this deformation, and the force characteristics are the same as the anchor. Only it is full-length force. The two force directions divided by the sliding surface are the same, both pointing to the slope. Under the action of prestressing force, the anchor rod is actively stressed and always provides resistance to the slope in the slope. With the loss of prestressing force and the stop of slope deformation, it degenerates into soil nails.