Gantry crane base and its stability analysis of the relationship

gantry crane base is a star, and in a smaller crane (eg locomotive coal loading crane), the Department made ​​of cast iron, in a larger crane, then line with district-based or work-based iron. Initially designed to draw the line feel of it, and then checking its strength.
Insert bottom part of the pillar often tapered bottom center of the star even as strong, into the hole of the pillars of the role by the couple, because the couple's arm is very small, so the force is quite large, so in between the pillars and the center hole must have a sufficiently large contact surface.
Steel and cast iron surface pressure between the license: 600-800 kg / cm.
Steel and steel surface pressure between the license :800-1500 kg / cm.
Gantry crane chassis with 6 or 8 Tiebi, such as floor is made ​​of cast iron, this section is shaped or D-shaped work, Tiebi as anchor bolts and bending forces, according to the distribution of the bending moment, iron sectional area of ​​the arm from the center line gravitropism foot screws gradually shrinking.
If the bottom line Tiebi by the rolled steel section is symmetric shape.
Cast permission bending stress of 200-400 kg / cm, steel is 600-1200 kg / cm.
Gantry  eot crane  up and down the center floor must be a sufficient number of rivets and Tiebi connection. Tiebi as working shape when the foot screw holes line cut with oxy-acetylene flame from burning.
Recently, the floor is no longer with the Department of welded riveted knot, so much cheaper in production.
Anchor bolts permission tensile stress: about 600 kg / cm.
Determine the stability of the foundation gantry jib crane  size, stability, not only for the basis of the nature of the soil Qieyi, because the soil is always a low surface pressure permission sake.
The underside is often a square foundation, its size was initially estimated to come in order to manufacture cement or diamonds, its unit weight of 1.6-2.0 tonnes / cubic meter.