hollowbar的部落格

 The concept of an anchored wall system is to create an internally stable mass of soil that will resist external failure modes at an adequate level of serviceability. The design of anchored walls concentrates on achieving a final constructed wall that is secure against a range of potential failure conditions. These conditions are illustrated in figure 11. The design should limit movements of the soil and the wall while providing a practical and economical basis for construction.

The design should consider the mobilization of resistance by both self-drilling anchors and wall elements in response to loads applied to the wall system. The magnitude of the total anchor force required to maintain the wall in equilibrium is based on the forces caused by soil, water, and external loads. Anchors can provide the required stabilizing forces which, in turn, are transmitted back into the soil at a suitable distance behind the active soil zone loading the wall, as illustrated in figure 12a.

This requirement that the anchor forces must be transmitted behind the active zone generally defines the minimum distance behind the wall at which the anchor bond length is formed. The anchor bond length must extend into the ground to intersect any potentially critical failure surfaces which might pass behind the anchors and below the base of the wall as illustrated in figure 12b. The required depth to which anchors must be installed in the soil should be determined based on the location of the deepest potential failure surfaces that have an insufficient factor of safety without any anchor force.

In summary, to provide a new slope geometry by means of an excavation supported by an anchored wall, the following is necessary: 

• The anchored wall should support the soil immediately adjacent to the excavation in equilibrium. This support typically governs the maximum required force in the anchors and the maximum required dimensions, strength, and bending moments in the wall section. 

• The self-drilling anchors should be extended sufficiently deep into the soil to beneficially affect a range of shallow and deep-seated potential failure surfaces with inadequate factors of safety. The anchor forces act on these potential slip surfaces to ensure they have an acceptable factor of safety.