Risk Evaluation On Geological Hazards Under Construction Of Huangdao Underground Water-sealed Oil Storage Caverns

As an important national oil reserve system,the underground water-sealed oil storage caverns have special requirements on geological environment conditions of construction site.It is this particular geological environment conditions that determine the types of geological disasters which may exist in engineering construction.While geological disasters in underground construction are the major geological disasters.These disasters will cause a great impact on construction process and post-operation.Therefore,this paper takes Huangdao underground water-sealed oil storage caverns as study object and does further researches on evaluation of rockburst and collapse.Referencing to relational rockburst criterions and combined with the geological environment characteristic of underground water-sealed oil storage caverns,stress coefficient ??/?c,rock fragility coefficient ?c/?t,elastic energy index Wet and rock mass integrity indexes KV were selected to evaluate rockburst level.At the same time,the rockburst grading standard was established.Then the combination weighting method of information entropy and analytical hierarchy process was used to determine index weights.This method overcomes the shortcomings and deficiencies of subjective and objective weighting methods.Uncertainty measurement and information entropy-analytical hierarchy process were combined,while the incredible recognition rule was introduced to determine rockburst grade.Based on this,the rockburst unascertained measuring model was established.Finally,the tested model was applied to Huangdao underground water-sealed oil storage caverns.The results show that rockbursts are less likely to occur during excavation process.Only the surrounding rocks of grade I exist slight possibility of rockburst;the others will not generate rockburst.Collapse hazard evaluation index system was established on the basis of analyzing collapse impact factors.Then,fuzzy analytic hierarchy process was adopted to evaluate the possibility of collapse in the main caverns of Huangdao underground water-sealed oil storage caverns.The results show that most of cavern sections could not collapse during the construction process of Huangdao underground water-sealed oil storage caverns.Only a small part of cavern sections may collapse frequently because of the impact of faults or dykes.