CTS / TITAN IBO Soil NailsCTS/TITAN Soil Nailing is a method of earth reinforcement. It is a very economical process which allows a controlled improvement of the natural stability of the soil. CTS/TITAN Soilnails provide friction, shear and tension strength in loose materials, combining all into a new monolithic structure. CTS/TITAN Soil Nails use threaded hollow Titan bars, which act as drill rods and as load carrying members. Simultaneous injection tremi grouting through the bar during the drilling process stabilizes the annulus and eliminates the need of casings. The drill bit is sacrificial. Consequently, CTS/TITAN Soil Nails are installed using a standard rotary percussive drill rig in a one visit drilling operation. The installation of CTS/TITAN Soil Nails is practically free of vibrations. Since no casing is needed, only small drill rigs are required resulting in greatly reduced drill spoil and lower mobilization costs. Soil Nailing consists of three basic elements:
The concept of soilnails can be compared to timber technology, whereby two planks are joined by nails to resist shear movements, or steel reinforcement (stirrup) used in concrete beams to resist diagonal tension. CTS/TITAN soil nails guarantee the maximum shear value at the grout/ground interface. The tremi grouting through the TITAN hollow bar fills all cracks and fissures on the way to the surface, producing a grout body of approximately twice the diameter in comparison to conventionally grouted solid bar soil nails in non-cohesive soils. The dynamic rotary drilling and injection grouting process penetrates into loose material around the annulus increasing the surface friction dramatically compared to traditionally installed nails. The patented threads on the TITAN bars secure an equal crack distribution in the grout body under tension with a maximum crack width of 0.1 mm up to 1.25 of the design load. This has been shown by the geotechnical department of the University of Munich on excavated pile grout bodies reinforced with TITAN 30/11 bars. Consequently, it can be assumed that under normal circumstances, additional corrosion protection is not required. Soilnails differ from grouted piles, which act independently, and ground anchors, which transfer loads via walls or walings. Soil nails are installed, in a grid pattern, in the active zone intersecting the perceived slip plane and penetrating the passive zone (see the picture). Soil nails are unstressed until ground movement takes place. When movement occurs the shear and tension values in the grouted soil nails are activated. |
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