| 摘要 |
PURPOSE:To enable a control over a minute vibration to be performed without affecting a substantial influence against a utilized space by a method wherein upper floor slabs are constructed by a pair of flat plates arranged in parallel in space-apart relation in their vertical direction and a plurality of beams which are integrally formed with the flat plates. CONSTITUTION:Slabs 12 are made such that a pair of flat plates 12a, 12b arranged in parallel to each other in spaced-apart relation and a plurality of beams 12c crossing at a right angle with a longitudinal direction of a clean room which are integrally formed with the slabs. A plurality of air conditioning duct spaces 12d crossing at a right angle with their longitudinal direction are spaced apart in the upper slabs 12 and their longitudinal sections show a continuous sectional shape. With this arrangement, it is possible to improve substantially a rigidity more as compared with the flat plate like slabs constructed in the same weight and at the same time their total weight may also be increased. Therefore, it is possible to reduce substantially a transmittance of fine vibration generated on the slabs 12. Further, since the air conditioning ducts are stored in the upper floor slabs 12, even if a vertical layer flow system is employed, the utilization space in the clean room 10 may not be substantially reduced. |
