Surface weathering characteristics and degree of Niche of Sakyamuni Entering Nirvana at Dazu Rock Carvings, China

摘要

Study on the weathering characteristics of Niche of Sakyamuni Entering Nirvana at Dazu Rock Carvings is the first step of scientific conservation. Based on the in-depth investigation on the weathering characteristics of Niche of Sakyamuni Entering Nirvana, the weathering degree was measured and evaluated by means of the in-situ non-destructive surface hardness test and ultrasonic test. The results reveal that the weathering types of Niche of Sakyamuni Entering Nirvana consist of granular disintegration, salt efflorescence, scaling, blistering, cracking, missing parts, biological colonization, and water seepage. The weathering degree of the head and foot of the statues are higher than that of the chest and abdomen in the horizontal direction, and the weathering degree of the upper parts of the statues and the ground area are higher than that between them in the vertical direction. The results of surface hardness and ultrasonic velocity are in close accordance with the weathering degree of the statues. Sedimentary and structural characteristics of sandstone lay a material foundation for various weathering characteristics and degree. The research results pave the way for condition assessment, intervention decision-making, and preventative conservation of the studied statues.