Foundation criteria for Zimmermann FZ 32 gantry type portal milling ma

[jackb22]

I would appreciate any opinion or information regarding the foundation application for the support of a Zimmermann FZ 32 gantry type portal milling machine. The total machine weight is approximately 162 metric tons with a movable portal weight of 4 metric tons and a vertical slide weight of 2 metric tons. The equipment dynamic design criteria only lists limitations for the curvature (deflected shape)of the foundation due solely to the application of the movable loads. Plan dimensions of the foundation given on the equipment drawing are approximately 79' x 33' with cross-sections indicating recess requirements for the equipment table and chip conveyor. The cross-sections are drawn to a thickness of approximately 4 feet. Assuming an allowable net soil bearing pressure of 2 ksf and a subgrade modulus of 50 pci, it appears that the foundation dimensions as indicated would provide an acceptable factor of safety. Due to the high precision and sensitivity of the equipment, the foundation needs to be isolated. In addition, the foundation will be subjected to at times, heavy forklift traffic of around 50 kips. Excluding any design considerations and from a geometric standpoint only, the plan dimensions can be reduced somewhat as well as the average thickness. All opinions are greatly appreciated.

Thank You