A FUNDAMENTAL STUDY ON FROST HEAVE AND THAW BEHAVIOR OF PILES AND FOUNDATIONS USED INPHOTOVOLTAIC POWER GENERATION FACILITIES

Abstract

In recent years, photovoltaic power generation facilities have been actively constructed in Hokkaido, Japan, a region characterized by a cold and snowy climate. However, considerable frost heave damage has been observed. In this study, a full-scale model experiment was conducted on piles and foundations used at photovoltaic power generation facilities to clarify their frost heave and thaw behavior. The experimental results show that the amount of frost heave decreases for both spiral piles and H-beam steel piles when the pile embedment depth is two to three times the maximum freezing depth. The results also indicate that, when the top surface of the footings is deeper than the freezing depth, the amount of frost heave of independent foundations becomes smaller. However, frost heave was observed in independent foundations with no footings or small footings. Based on these findings, effective frost heave countermeasures were examined and incorporated into the existing design guideline published in Japan.