| Petroleum reserves play an extremely important strategic role in national economy.As infrastructure in the field of transportation,petroleum storage tanks and storage depot systems play a key role in transportation engineering,which is as important as bridges,tunnels,and roads.Domestic and foreign earthquake disaster surveys have shown that strong earthquake can cause serious destructive consequences to petroleum storage depots,leading to secondary disasters,environmental pollution,casualties,and other negative effects such as social public opinion and environmental protection protests,and then affect the sustainable development of petroleum industry.In order to improve the safety and seismic resilience of petroleum storage depots,this thesis focuses on surface petroleum storage depot and conducts research on the seismic fragility of petroleum storage tanks and seismic resilience of storage depot system,and the main research contents are as follows:(1)To address the seismic damage problem of floating roof tank,the shaking table test of floating roof tank with the scale of 1:8 was carried out to study the suppression characteristics of floating roof on convective sloshing of liquid from a experimental perspective.Based on the velocity potential theory,simplified mechanical model and finite element numerical simulation model were established and compared with the shaking table test results.It was proved that the simplified mechanical model and finite element model can reproduce the dynamic response of floating roof storage tank reasonably,which provides a reliable numerical analysis model for fragility research based on a large number of ground motion records.(2)The sloshing wave height,base shear force and base bending moment of floating roof tank were selected as seismic response indicators,and a sensitivity analysis of modelling parameters was carried out using an orthogonal experimental design method.The inherent relationships between seismic responses such as liquid convective sloshing and fluid-solid coupling,and physical parameters such as liquid height ratio,liquid density and tank thickness were clarified.The results showed that the change of liquid height ratio had a highly significant influence on the seismic responses considered,and the changes of liquid density,tank wall thickness and steel elastic modulus had significant influence on the specific seismic response,and the changes of tank bottom plate thickness and steel yield strength had no significant influence on the seismic responses considered.(3)In order to solve the problem of selecting seismic intensity measure in probabilistic seismic demand analysis of floating roof tanks,nine seismic intensity measures were selected as the research object.The rationality of the logarithmic linear relationship between seismic demand and seismic intensity measures was verified,and a comprehensive probability evaluation was carried out from four aspects of efficiency,practicality,proficiency,and sufficiency.The results showed that the fundamental periodic spectral acceleration Sa(T1)was the most effective seismic intensity measure,which could meet the demand of hoop stress and meridional stress when adopting liquid-solid coupling period and could meet the demand of maximum sloshing wave height when adopting convective period.(4)Based on Latin hypercube sampling and cloud method,a seismic fragility analysis method for floating roof tank considering different sources of uncertainty was proposed.The results of the fragility analysis method were very close to those obtained by direct Monte Carlo simulation method,but the time and computational load were reduced by orders of magnitude.Considering the correlation among various failure modes of storage tank,a seismic fragility analysis method of storage tank system was put forward.By studying the influence of the uncertainty of ground motion records,geometric parameters,and material parameters on seismic fragility of floating roof tank,the results showed that the uncertain of ground motion records and geometry had the most significant influence,and in the seismic fragility assessment of storage tanks,the random variables related to ground motion records and geometric parameters should be included.(5)An analytical model with three levels of components,subsystems,and systems was established for the petroleum storage depot system,which was divided into four functional units,seven subsystems,and 26 types of components.The Delphi method and fuzzy analytic hierarchy process were used to calculate the importance coefficients of each functional unit,subsystem,and component,and the results were very close,ensuring the reliability of the importance coefficients.(6)A quantitative evaluation framework and evaluation methodology for seismic resilience of petroleum storage depot systems were established based on the total probability theorem.The classification criteria and evaluation indicators for seismic resilience of petroleum storage depot system were proposed.The damage index and average damage factor were introduced to quantify the loss of system function,and the calculation methods for functional loss and recovery time were clarified.Taking a petroleum storage depot with railway tanker loading and unloading trestle as an example,the seismic resilience was carried out,and the rationality and effectiveness of the proposed evaluation method were verified.The research results of this thesis have scientific significance and application value for deepening the understanding of earthquake disasters in petroleum storage depots,further guiding the seismic planning,resilience improvement,and disaster prevention and mitigation policies for petroleum storage depots. |
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