Research shows that:
First,using the SDA bolt for foundation supporting, the angle of SDA bolt should adopt of 20°, at the same time，the load on the SDA bolt reaches the minimum, and the supporting effect is best.
Second,the increase of SDA bolt length,which can play a positive role on the stability of foundation support, but the greater the SDA bolt length, the load on the unit of SDA bolt is reduced,so it's not conducive to make full use of the materials, therefore the design was performed on the length of SDA bolt should be considered in the premise of guarantee the safety and stability of foundation supporting SDA bolt material utilization.
Third,the pretensioned stress on the SDA bolt can reduce the foundation support deformation, however, as the prestressed increases gradually,the effect gradually reduce.
Fourth,the SDA bolt in soil deformation modulus of soil layer , the increasing of shear strength which has certain positive role in the foundation supporting of SDA bolt, and it can effectively reduce the deformation of foundation support, the role of soil shear strength is larger than the effect of deformation modulus.
Fifth, more row of SDA bolt are used in foundation supporting, the axial force on the upper anchor bolt is greater than the lower, therefore,the upper SDA bolt length should be greater than the lower SDA bolt length when design.
