Expansion Power Of Compressed Micro Fluid Inclusions As The Cause Of Rockburst

Abstract

The rockburst (rock burst) is a peculiar, abnormal, localized, isolated, delayed, sudden and damaging phenomenon associated with the underground rock excavation. Several hours after the completion of the excavation, some parts of the in-situ intact rock wall might be actively, suddenly and vigorously ejected, thrown and blown off from the original wall into the excavated open space, with high initial ejecting velocity and kinetic energy. It often causes fatality, injury and damage because its occurrence is usually unforeseeable and unpredictable. The rockburst is still a worldwide tough problem that puzzles the international communities of rock mechanics in spite of tremendous research efforts over the past 50 years. This paper puts forward a hypothesis of micro-fluid inclusions as the cause and mechanism of the rockburst. The fluid inclusions in the micro-voids of intact rocks may have a high initial pressure equaling to the average of the three in-situ principal stresses. The fluid inclusions with a high initial pressure can have a high expansion power. They can flow, migrate and turn from the liquid phase into the gas phase after the rock excavation. Their physical and chemical expansion power can cause the rockburst of the excavated intact rock wall. This hypothesis offers effective solutions for the rockburst problem to reduce and eliminate its damage.

巖爆是地下工程中的一種奇異力學破壞現象.開挖后的圍巖塊石突然、猛烈地向開挖空間彈射、拋擲和噴出.它具局部性、突發性、隱蔽性、滯后性、無前兆性、高初速度和高沖擊動能.巖爆常常導致深部巖石工程重大人員傷亡和經濟損失.雖然人們對巖爆做了大量研究,巖爆的成因機理依然是公認的'國際巖石力學領域的世界性難題'.本文指出、分析、論證了造成這個'世界性難題'的原因是,國際巖石力學領域忽略了連續完整巖石中微小流體包裹體的存在和異常作用.本文進一步提出、分析和論證了封閉在完整巖石中的微細流體包裹體可能處于被壓縮狀態,能夠擁有高壓強,能夠造成完整巖石內部的局部異常高地應力場.巖石開挖可導致封閉在巖石內部的眾多微細高壓縮流體包裹體重新隨時間而滲流、移動和相變,再造成局部完整脆性圍巖的巖爆.對巖石流體包裹體的力學研究能讓我們破解世界性巖爆難題.