以北京周口店猿人洞遗址侧壁上的钙质胶结砾岩为研究对象,通过12个岩石测缝计连续7年监测数据和周边环境监测数据的统计分析,得出自然条件下石窟岩石裂缝的变化规律.研究表明:(1)自然条件下,岩石裂缝宽度呈现出季节性、周期性变化规律,采用适宜于非平稳季节的差分自回归滑动平均模型(autoregressive integrated moving average model,简称ARIMA模型)对裂缝宽度进行预测,其中ARIMA(2,1,1)模型的拟合精度最高.(2)岩石裂缝宽度与环境温度、湿度呈负相关性关系,与环境温度的相关性明显高于湿度;岩石裂缝宽度变化滞后于环境温度和湿度的变化,与温度的滞后相关性高于湿度,与温度的滞后时间远小于与湿度的滞后时间.(3)岩石裂缝宽度与环境温度的相关性及滞后相关性程度为常温＞高温＞低温＞极端低温;滞后时间为极端低温＞低温＞高温;周边环境相对湿度越稳定,它们的相关性越高.(4)相同温度下,岩石裂缝宽度随时间呈缓慢增长趋势,近似呈指数增长或指数渐近式分布.(5)环境温度相同条件下,湿度越稳定,岩石裂缝宽度随时间的增长越缓慢;天然状态下,环境温度越低,岩石裂缝宽度随时间的增长越快.该研究成果有助于深入了解石窟岩石裂缝在自然条件下的扩展规律,为温带季风气候地区岩石古遗址、石窟、石刻等的预防性保护提供了裂缝变化的参考依据.
Changes in width of cracks in grotto rock under natural conditions
This study focuses on the calcareous cemented conglomerate on the side wall of the Zhoukoudian Ape Man Cave site in Beijing.We analyzed the change patterns of cracks in grotto rock under natural conditions using statistical analysis of continuous monitoring data from 12 rock fracture measurement points for 7 years and environmental monitoring data.The results indicated that:(1)Under natural conditions,rock fracture width exhibited seasonal and periodic variations,which can be predicted using autoregressive integrated moving average(ARIMA)model.The ARIMA(2,1,1)model has the highest fitting accuracy.(2)The width of rock fractures showed a negative correlation with ambient temperature and relative humidity,with a stronger correlation with temperature.Changes in fracture width lagged behind changes in temperature and relative humidity,with a higher lag correlation and shorter lag time for temperature compared to relative humidity.(3)The degree of correlation and lag correlation between rock fracture width and ambient temperature followed the trend of room-temperature＞high-temperature＞low-temperature＞extremely-low-temperature.The lag time followed the trend of extremely-low-temperature＞low-temperature＞high-temperature.Additionally,more stable relative humidity of the surroundings indicated a higher correlation.(4)At a constant,the width of rock fractures increased gradually over time,following an approximate exponential growth or asymptotic distribution.(5)At the same temperature,more stable relative humidity corresponded to a slower increase in rock fracture width over time.Under natural conditions,lower ambient temperatures led to a rapid increase in rock fracture width over time.These findings enhance our understanding of the expansion patterns of cracks in grotto rock under natural conditions.Moreover,they provide a reference framework for predicting crack changes in the preventive conservation of ancient rock sites,caves,and stone carvings in temperate monsoon climate regions.
rock crackstemperaturerelative humiditycorrelationApe Man Cave
万方数据
维普
