Produzidos a partir de tubos sem costura, os Tirantes Autoinjetáveis Incotep possuem como principal característica a alta resistência mecânica atuando simultaneamente como elemento de perfuração e armadura estrutural. Apresentam uma seção vazada em toda a sua extensão que permite a injeção de uma calda de cimento sobre pressões que variam de 25 a 100 bars.
Em sua extremidade, é acoplada uma broca de perfuração, cujo modelo varia em função do tipo de solo. Essa broca apresenta orifícios laterais e frontais dependendo do tipo de solo, permitindo a passagem da calda de cimento, que sobre pressão contra as paredes do solo, podem formar bulbos com diâmetros variáveis de até duas vezes o diâmetro da mesma. Os Tirantes Autoinjetáveis Incotep são especificados pela nomenclatura, INCO, XX, TD.
INCO – Representa o nome do fabricante – Incotep.
XX – Indica o valor aproximado da carga de trabalho permanente suportada pelo tirante (em tf).
TD – Indica que o Tirante é confeccionado a partir de um tubo.
Produtos fornecidos por:
Technical Characteristics – Tubular System
Capacity calculation of Self-Injection Rods Load (rods load)
Incotep Self-injection Rods assembly is very simple and fast, because the bars, sleeves, drill bits and other accessories are supplied by the factory, simply by assembling the rod in the construction itself.
The assembly starts with the drill bit installation at the end of the first bar which will be introduced into the soil. The other bars are implanted as drilling evolves, with the joining of the bars through splicing sleeves.
In the section correspondent to the anchored one, loose spacers are used, so as to avoid its own breaking. It is advisable that the bars which will compose the free section receive treatment with graphite grease and the placement of a PEAD (high density polyethylene) tube.
The rod is introduced in the soil with the help of a rotary or rotopercussive perforator with minimum torque of 400kgm. It is advisable that the rotation to implant the rod into the soil be between 50 and 90 rpm and the advance be between 0.50 and 1.50m/min. In case a rotopercussive perforator is used, the recommended flow rate and pressure for the air should be around 750pcm and 10 bar.
Simultaneously to the rod introduction, it is performed the aqueous fluid (water and cement) injection, which penetrates into the rod internal hole and flows under high pressure until the drill bit where it comes out through the small holes there are there.
In the section correspondent to the free section, the fluid is composed of “thin” water and cement slurry with factor = 0.80. In the anchored section, the fluid must be necessarily composed of water and cement with factor = 0.50, injected with minimum pressure of 25 kgf/cm².
The pressure of the slurry injection is a very important item, because the anchoring bulb dimension depends on it. It is the function of the soil granulometry and consistency or compactness, as well as the injection pump power, items which are impossible to control. To do so, the tricone holes must be used, according to technical characteristics chart, as well as altering the water and cement cream aspect, aiming at adjusting its viscosity to the needs of each work.
After the rod implantation, it is necessary to wait for four days (in case initial high resistance cement is used) or seven days (in case common cement is used) for the prestressing execution.
The Self-injection Rod prestressing is performed with the help of a jack-hydraulic pump set (available for rental by Incotep), installation of anchoring plate, degree ring and drill bits for the rod anchoring.