kui 杭

Also kigui 木杭. Pile. A wooden stake or post driven into the ground. Closely placed round wooden posts, often shaved to a point, pounded into the ground to form a base that can transfer the down bearing load from the superstructure through the footing, sills, or foundation to the ground. This system has been used from very ancient periods for foundation ground work. Pine logs were most common, but Japanese cedar, sugi 杉, and evergreen oak, kashi 樫, were also used. The stakes had to reach down below the water table, as they decayed if they dried up. In order to strengthen the tip of the kui when driving into hard ground, a protective metal band called a pile shoe, kutsukanamono 沓金物, was sometimes added.