干旱区土遗址掏蚀区土盐渍劣化与风蚀损耗效应

Effects of salinized deterioration and aeolian ullage on soils in undercutting area of earthern ruins in arid region

掏蚀区的形成和发展是中国干旱地区受气候因素控制最为典型和危害最为普遍的土遗址病害之一,研究基于吐鲁番高昌故城、瓜洲锁阳城、西宁明长城和银川西夏王陵4处典型遗址掏蚀区特征描述和盐分监测结果,证实了土遗址底部掏蚀区有盐渍土带的客观存在。结合经充分脱盐后人为掺入不同类型和含量盐分并经历3次干湿循环的遗址土重塑土样的弹性波速测试实验和风洞实验结果分析,揭示了土遗址掏蚀病害形成和发展过程中盐渍劣化和风蚀损耗两种重要效应;进而对其机理进行深入分析和阐释,并揭示了盐分类型、盐分含量和挟沙风风速对其产生的显著的影响;进一步结合工程地质学和力学理论进行分析,归纳出三类由其导致的土遗址变形破坏演化机制,为防治和监测此类病害的发生和发展及其对土遗址稳定造成的影响提供有益的参考。

The formation and development of undercutting area is one of the typical diseases controlled by climatic factors and will commonly and directly do harm to earthern ruins in arid region.Based on the results of feature description and salinity monitoring of undercutting area in some typical relics in Turpan Gaochang ancient ruins,Guazhou Suoyang ruins,Yinchuan Xixia King tomb and Xining Ming Great Wall,it is found that aeolian bond exists in the bottom undercutting area of earthern ruins.Based on the results of wind tunnel and elastic wave velocity experiments in laboratory on remodeling samples mixed with different salt contents and undergoing three dry-moisture cycles after desalination,it is revealed that salinized deterioration and aeolian ullage are two important effects in the process of the diseases.In-depth analysis and interpretation of mechanism of disease are performed so as to discover influences of salt type,salt content and wind velocity on the two effects.Through engineering geology and mechanical theory analysis,three categories of deformation and failure mechanism of evolution due to ruin＇s undercutting are summarized.It may be useful for controlling and monitoring the disease and its impact on stability of ruins.