The length of self drilling anchor affects the grouting self drilling anchors

Since the total length of grouting self drilling anchors with safe and reliable, simple construction and low cost, they are widely used in slope engineering. When self drilling anchors reinforced slope, depending on the interaction between surrounding rock mass and self drilling anchor transmitting rod tension, making themselves get reinforced in geotechnical engineering, limiting the deformation, and improving stress state of the mechanical parameters of rock mass and to maintain stability. Due to the self drilling anchors load transfer mechanism is very complicated, so far still assumes that the lateral resistance distribution patterns in self drilling anchors  design is uniform distribution.

But a large number of measured results show that it is unreasonable according to uniform distribution pattern calculated. In recent years, with the development of computer technology, numerical simulation methods are widely used in geotechnical engineering, adopting double spring self drilling anchor element, the establishment of a model of Highway slope was simulated excavation process of the rock bolts reinforcement effect.
While the combination of the long self drilling anchor and the short self drilling anchor can foster strengths and circumvent weaknesses. The supporting effect is definitely better.


In the combining support of the long self drilling anchor and short self drilling anchor, the former on one hand controls the deformation of
surrounding rock except the reinforced composite arch. On the other hand, it can reinforce the combination arch structure to hang on the stable rock for coordinate deformation of surrounding rock.

Relating to the short self drilling anchor, it can reduce the hulking deformation of the rock and the further damage of the fracture by limiting the deformation of the near area and the development of the fracture surface. The short self drilling anchor can also form reinforced composite arch structure which has a certain bearing capacity near tunnel surrounding rock. All these can strengthen the integrity and stability of the surrounding rock effectively.
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