利用洞穴调查和各类次生化学沉积物同位素测年技术等方法,对芙蓉洞内崩塌物进行研究.结果表明芙蓉洞内崩塌物规模巨大,为多期次崩塌作用的产物,分别形成于大于35万年、35～20万年间、10～2.6万年间、2.5万年后及旅游开放后的1995、2000、2003、2008年,既有洞顶围岩的规模性崩塌,也有洞顶石钟乳的崩落和洞底石笋、石柱的倒塌,分别起囡于地壳抬升背景下洞内水流下切使原先浮力消失引起洞顶围岩地应力失衡、洞顶石钟乳不断联合使重量超过联合体一洞顶围岩接触面的临界结合力和洞底石笋、石柱受崩落的钟乳石砸中或强地震引发.崩塌作用引起了洞腔的规模性扩大、钟乳石景观和旅游设施的破坏、被迫改变游览线路等环境效应.针对芙蓉洞崩塌特点,提出了洞穴旅游开发的一些建议.%Collapse of the Furong Cave in Chongqing City is studied by means of in-situ investigation and the U-series and 14C isotopic dating of speleothems.The results show that the enormous collapse piles were formed in different stages: 0.35Ma earlier, 0.2～0.35Ma, 0.026～0.1Ma, and 0.025Ma later BP as well as recent collapses following the exploitation of the cave for tourism (collapses occurred in 1995, 2000, 2003 and 2008).Three collapse phenomena are considered: roof stoping, falling stalactites, and tipping or falling of stalagmites and columns.Upward stoping results from the adjustment of stresses in the parent rock as buoyancy decreases when the groundwater table lowers due to tectonic uplift.This results in upward void migration and enlargement of the Cave passage.Stalactites fall as their weight increases beyond the critical force on the contact plane between the stalactites and parent rock.Stalagmites and/or columns tip and fall occur when the speleothems or parent rock are hit by falling stalactites or shook by earthquakes.The collapse functions are of the environmental effects as enlarge the space of the cave, damage of the stalagmites and tourism facilities, and make the tourism path has to be changed.Therefore, some proposals on cave tourism development are put forward according to the features of the collapses in the Furong Cave.
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