An Investigation of Collapsing of an Under-Construction Large Buddha Statue at Mae Sruay Luang Temple, Chiang Rai Province

Abstract

This article presents the results of a soil survey conducted at the Luang Pho Chiang Saen Buddha statue, located at Wat Mae Suai Luang in Chiang Rai Province. The statue was affected by the 6.3 M_L earthquake, with its epicenter located in Mae Lao District, on May 5, 2014, which caused its base to tilt and develop cracks, eventually leading to its collapse in the following days. The study involved subsurface investigations using Kunzelstab Penetration tests and soil property analyses through hand auger sampling. Laboratory tests were performed to determine moisture content, grain size distribution, and Atterberg limits. Additionally, the potential for soil liquefaction was assessed using a stress-based approach. Field and laboratory test results indicated that the uppermost 1.5 meters of soil consists of soft clay, underlain by a saturated sandy clay layer susceptible to liquefaction during an earthquake with the factor of safety against liquefaction less than 1.0, which aligns with observed sand boils at the site. These findings highlight the importance of designing foundations suitable for earthquake-prone areas, such as pile foundations, to minimize structural damage. Furthermore, future studies should investigate the softening behavior of low-plasticity clay under seismic loading.