花山岩画岩体开裂机理统计分析

Statistical analysis on the mechanism of cracking of the Huashan rock paintings

岩体开裂是危害花山岩画最严重的病害,会对岩画造成毁灭性的破坏。为制定有效的灌浆加固措施,在对岩体开裂成因及影响因素分析和现场调查的基础上,做了统计分析。结果表明:1)岩画区共有418处开裂病害,开裂岩体以风化开裂体为主,占69%,且构造开裂体的厚度大于风化开裂体;2)构造开裂体的钙质、钙质与泥质共同充填比例为78%,高于风化开裂体的52%;3)构造裂隙和风化裂隙的张开度均以小于6mm为主,可知当张开度大于6mm时,开裂体将发生剥离掉块;4)风化开裂体的危险性I级、Ⅱ级所占的比例为57%和22%,小于构造开裂体的64%和27%,但风化开裂体多发育于岩画存在部位,易出现开裂和掉块,破坏更大;5)构造开裂体的厚度较大、裂隙连通性好、危险等级高,而风化开裂体厚度较薄、裂隙贯通性差、危险等级较高。本研究结果可为开裂岩画岩体灌浆加固及后期修复提供理论依据。

Rock cracking is the most serious disease faced by the Huashan rock paintings,causing devastating damage to the paintings. In order to develop effective grouting reinforcement measures based on analysis of the causes and factors influencing rock cracking and field surveys,astatistical analysis was done. The results show that 1）the rock painting area has 418 cracks. The rock cracks are mostly（ 69%） due to weathering; 2） the thickness of structural cracksis greater than weathering cracks; carbonate,calcium and mud common filling ratio of structural cracking rock is 78%,higher than the weathering cracking rock 52%; 3） the apertures of tectonic fissures and weathering fissures are smaller than 6mm; when the opening is greater than 6mm,the cracking body will be stripped off the block; 4） the I and II levels of the danger due to weathering cracks is 57% and 22%,respectively,less than the 64% and 27% due to structural cracking,but weathering is more developed in the rock art area;the paintings are prone to cracking and falling; 5） because the structural cracks are thick and have good connectivity; they present a very high level of danger. The weathering cracking rocks are thinner,and have low cracking connectivity,so they have lower level of danger.