Approach to LMFBR floor response reduction - partially embedded building

(1) Effectiveness of embedding was recognized with both of structures of flat base mat type and stepped base mat type, in the reduction of mechanical equipment response (main vessel in particular). (2) With the structure of stepped base mat type used as the object, response analysis were made using SR model, advanced SR model, lattice model and BEM, and comparative evaluation was made. Each response of the BEM and the advanced SR model, were almost equivalent and the lowest among the four models. The response of the lattice model was the next, and of the SR model was the highest. (3) The response with lattice model is relatively high by the extent neglecting filter effect. But the response of vibration of the embedded portion are well expressed. Simulation analyses to the result of earthquake observation of actually embedded structures are currently in progress in order to evaluate the adequacy of these analytical methods. (4) Structural integrity of the stepped base mat type during earthquake is confirmed as a result of stress analysis. (orig.)