SDA bolt has advantages in soil nailing wall

SDA bolt is the most basic constituent part of tunnel support. It reinforces tunnel with surrounding rocks, realizing self-support. Now, SDA bolt can not only applied in tunnel, but also in engineering technology, having reinforcement for slope, mine, dam and infrastructure construction. Especially in fractured rock mass, the function of rock bolt is obvious.
In the short term, from perspective of dominant benefit and taking tunnel for example, anchor bolt’s unit price is high. Compared with common supporting method, tunnel’s composite cost and total cost has got increased.
In the long term, from perspective of recessive benefit, anchor bolt can be anchored overall length sufficiently, it can also provide certain supporting resistance immediately after excavation to control surrounding rock’s looseness and deformation, ignore deceleration of engineering construction and occurrence of collapse or other accidents. Through grouting, SDA bolt can provide enough and even protective layer, enhance anchor bolt’s durability largely. These recessive economic benefits of anchor bolt cannot be matched by common supporting method.
SDA bolts applied in composite soil nailing wall in soft soil area can effectively solve the
problems of shrinkage, liquefaction, piping, quicksand, drilling, etc. Compared with steel pipe and rebar, SDA bolt has the following advantages in soft soil area of soil nailing wall engineering:
(1) It’s suitable for all kinds of soil layers, especially in silty soil and sandy soil which are
hard to construct in the conventional soil nailing wall.
(2) The length of the soil nail is not limited. Despite the restrictions of the existing soil nailing materials and construction equipment, the drilling length of anchor bolt is much longer than the conventional soil nailing wall due to small drilling resistance.
(3) It can be easily applied prestress and conducive to displacement control.
(4) It will save workload. Anchor bolts combine drilling, grouting, installing and anchoring in a process, simplifying the construction process.
(5) It’s suitable for construction in the narrow place. Anchor bolt has the characteristics of
cutting and lengthening, which can be used for the small drilling machine and narrow space.
(6) Using cement slurry to stabilize the hole wall. While supplying water slurry, the slurry can be quickly absorbed in the non - sticky soil layer and ensure the stability of the hole wall.