【目的】 上下方向の振動力を受ける土間コンクリート を有する基礎として、土間コンクリートの上下振動の周 囲への伝播を少なくすることができる基礎を提供する。
【構成】 基礎杭６の頭部に土間コンクリート８を支持 させ、前記土間コンクリート８の下面と地盤７の上面と の間に空隙９を形成する。
PURPOSE: To restrain vertical vibration acting on a slab-on-earth from propagating to surroundings by a method wherein the slab-on-earth is supported with the heads of foundation piles, and a vacant space is formed between the undersurface of the slab-on-earth and the surface of the ground.
CONSTITUTION: Foundation piles 6 are driven into the ground 7 to which soil improvement is applied, and flat jacks 16 are mounted on heads of the piles 6 and damping units 10 are connected to the upper parts of the jacks 16. A sheet 17 is spread over laid gravels 11 and concrete 8 for slab-on-earth is placed over the sheet 17. After the concrete 8 is cured, the concrete 8 is lifted with the jacks 16 inflated, so that the concrete becomes afloat in a specified height H over the ground 7, and thereby a vacant space 9 is formed. In the case where downward impact acts on the concrete 8 because of pedestrian and vehicular traffic, the middle part of the concrete 8 makes vertical vibration because of existence of the vacant space, and vibration energy E1 and propagation energy E2 are partially consumed respectively by vibration of the concrete 8 and operation of the damping units 10. Thereby, vertical vibration occurring to the ground 7 can be restrained.