Earth helical anchor for construction
PRODUCT DESCRIPTION
Earth helical anchor for construction is governed by simple geotechnical engineering principles. In excavations, Earth helical anchor for construction be included. Since the helix shaft is in tension the Earth helical anchor for construction does not have to be examined in buckling. In principle the ultimate capacity of a Earth helical anchor for construction is determined as the most critical of the two basic modes of failure:
a) Individual bearing method: This is the sum of the bearing capacity at each helical plate. In this mode the total ultimate pullout resistance of a helical anchor is determined as:
Qtotal = sum {Ahelix (9 c + gamma' x Depth x Nq)}
The geotechnical helical anchor capacity should be smaller than the individual structural capacity of each plate.
b) Cylinder strength method: In this mode the capacity is calculated as the shear resistance of a cylinder of soil contained by the helical plates, plus the bearing resistance of the helical plate closer to the excavation. The cylinder method can be applied only in cases where the helical anchor has atleast two plates.
Qcylinder = AhelixPlate1 (9 c + gamma' x D x Nq) + side resistance.In practice the individual bearing method and the cylinder strength method have generally produced smaller geotechnical capacities than actually experienced by pullout tests. For this reason, a number of researchers have proposed the torque installation method that relates the pullout resistance to the installation torque which can be measured during eachEarth helical anchor for construction installation.
This creates a more conservative compression capacity for Earth helical anchor for construction when compared to the Individual Bearing Method. Also unlike the Individual Bearing Method, the number of helical plates on a pile is completely independent of the piles capacity based on the Torque Correlation Method.
