PURPOSE: To increase the working efficiency and reduce the construction period, by providing a notch at the end of a rising foundation attached to a main foundation and embedding female screws and after connection of these foundations with a both-screw end bolt, filling the notch with mortar.

CONSTITUTION: Notches 4, 5 for fixing bolts are provided at the end of a rising PC foundation 1 of an extended part for a bay window or the like, attached to a main foundation 2 made of precast concrete(PC). Female screws 71, 72 for fastening bolts are joined to anchor rods and embedded in the rising foundation 1 and the main foundation 2. A both-screw end bolt is fixed to the rising foundation 1 and the main foundation 2 and connected together through a nut 77. In this case, a positioning nut 77 is provided at the movable side bolt 74. After completion of connection, the notches are filled with mortar to unify them. In this way a PC rising foundation can be efficiently constructed.