锚杆挡土墙概述

锚杆挡土墙概述

An overview of anchor retaining walls

Core prompt:

Anchor retaining wall is a kind of retaining structure formed by bolt technique. Bolt is a new type of tension member, one end of which is connected with engineering structures, the other end is anchored in the stable formation, to inherit the earth pressure exerted on the structure of the thrust, thus the use of anchor bolt and formation to maintain structure

Anchor retaining wall is a kind of retaining structure formed by bolt technique. Bolt is a new type of tension member, one end of which is connected with engineering structures, the other end is anchored in the stable formation, to inherit the earth pressure exerted on the structure of the thrust, thus the use of anchor bolt and formation to maintain the stability of structures.

Before 50s, bolt technology was only a temporary measure of construction process. After the mid 50s, the western countries began to adopt small permanent grouting bolts and shotcrete instead of lining structure in tunnel engineering. The anchor retaining wall in China began in the Chengdu Kunming railway line in 1966, and then in many railway line construction, the use effect is good. Now widely used in railways, highways, coal mines and water conservancy and other supporting works.

The anchor retaining wall can be divided into column, plate retaining wall and wallboard retaining wall according to the

structure of the wall, as shown in figure 10-35. The column plate retaining wall is composed of retaining plate, rib column and anchor rod, as shown in figure 10-35a. The rib column is bearing retaining plate, bolt is a support rib column, the wall of the lateral earth pressure acting on the retaining plate, and the retaining plate is transferred to the ribs, the ribs to anchor, balance by anchoring force between the anchor and the surrounding strata that anchors. In order to maintain the body wall, and the stability of the soil behind the wall. The panel type anchor retaining wall consists of a wall panel and a bolt, as shown in figure 10-40b. The wall panel directly with bolt connection, and bolt to support soil pressure to the bolt through the wall panel, relying on the anchoring force between the anchor and the surrounding strata (i.e. pullout resistance) earth pressure, in order to maintain the balance and stability of retaining wall. At present, multipurpose column plate anchor retaining wall.

(a) column plate B) panel type

Figure 10-40 types of anchor retaining walls

The anchor retaining wall can be designed as single or multistage according to the topography, and the height of each wall shall be no more than 8 m. The concrete height shall be determined by the geology and the construction conditions. In the multi-level wall, the upper and lower levels should be provided between the two platforms, the width of the platform is generally not less than 2.0m. The platform shall be made of C15 concrete with a thickness of not less than 0.15 m, and shall be inclined to the slope outside the wall, with a slope of 2%.

The total height of multi story wall shall not be greater than 18m.

The characteristics of retaining bolt is: (1) the light structure, the structure of light retaining wall, compared with gravity retaining wall, can save a lot of masonry and save the project investment; (2) to the mechanization and construction of the retaining wall, can improve labor productivity; (3) without excavation a large number of foundation pit, can overcome the bad foundation excavation difficulties for construction safety. But the anchor retaining wall has some shortcomings, so that the design and construction are limited, such as higher construction process requirements,

There must be drilling, grouting and other supporting special machinery and equipment, and the use of certain steel.

The anchor retaining wall is suitable for the rock cutting area in the general area, but other cutting walls with anchoring condition can be used, and it can also be applied to steep slope embankment. In the use of bad geological areas, we must take corresponding measures.

Another type of retaining bolt for vertical prestressed anchor retaining wall, it is the use of anchor technology, namely vertical anchor rock foundation, and prestressed, the vertical prestressed anchor part of masonry section instead of gravity retaining wall, reduce the number of masonry retaining wall and increase its stability. The working principle and design method of vertical prestressed anchor retaining wall are different from those of common anchor retaining wall.