Self drilling soil nail has good supporting effect in good geological conditions
With the propulsion of reconstruction of old city, main high buildings are clustering in narrow and busy spaces, the construction conditions almost terrible. There are many permanent and public facilities, so it is very strict for stability and displacement control.If deep foundation excavated in complex geological conditions, such as soft soil and high groundwater table areas, it is easy to happen slippage of soil body, instability of deep foundation, deflection of pile body, severe leakage and damage, which will cause great threat for security.Soil nailing is widely used recent years. It can combine drilling, grouting and anchoring together, time-saving and high-efficient. In addition, during the construction, there is no shake, no noise and no deformation phenomenon, it has little influence on surrounding environment. After its installation, the intensity of wall is strong, stiffness is big and supporting stability is good.Soil nailing is a good mean for deep foundation.At present, self drilling soil nail has good supporting effect in good geological conditions, while in soft and complex conditions, such as crushing, high ground stress in tunnels with large deformation, the challenge of self drilling anchor support is quite difficult. Nowadays, self drilling soil nail at home and abroad is moving to the effect of improving anchoring force, efficiency of support and expanding application range. It is believed that developing self drilling soil nail with plenty properties is an effect way to control high stress and big deformation, which is also the direction of self drilling soil nail’s development.During the construction of diversion tunnel in water conservancy projects, collapse is impossible to be avoided, so adopting self drilling soil nail to handle with is an efficient technical method.It has the function of drilling holes and it combines drilling, grouting and anchoring together. Self drilling soil nail has been mainly used for excavation support or slope stabilization in IV or V cave surrounding rock and concretion in positions where is easy to collapse, such as gravel stratum.