This study investigated the performances of a new type of precast beam-column joint subjected to earthquake and impact loads.For sustainability and durability considerations,new materials such as corrosion-resistant f...This study investigated the performances of a new type of precast beam-column joint subjected to earthquake and impact loads.For sustainability and durability considerations,new materials such as corrosion-resistant fibre reinforced polymer(FRP)bolts and reinforcements,fibre reinforced concrete(FRC),and geopolymer concrete(GPC)were used to construct the joint.To examine the resilience,durability,sustainability,and multi-hazard resistance capacities,both cyclic and pendulum impact tests were carried out.The experimental results demonstrated that the proposed precast joints had the comparable or even better performances as compared with the traditional monolithic joints under cyclic and impact loads.Numerical simulations using ABAQUS were also adopted to determine the optimal values of the concrete-end-plate(CEP)thickness for the proposed dry joints and to further quantify other response parameters which could not be obtained during the test,e.g.,stress distribution,energy absorption,and stress contours.Discussion on the influences of various parameters on joint performances under different loading conditions was also presented in this study.展开更多
Accidental boiling liquid expansion vapour explosions(BLEVEs)caused by the bursting of liquified petroleum gas(LPG)tank inside a tunnel can induce vibrations of its surrounding geological media and threaten the stabil...Accidental boiling liquid expansion vapour explosions(BLEVEs)caused by the bursting of liquified petroleum gas(LPG)tank inside a tunnel can induce vibrations of its surrounding geological media and threaten the stability of adjacent tunnels and structures.Therefore,it is essential to understand the characteristics of vibrations induced by LPG BLEVEs inside the tunnel for the safety design of its adjacent structures.Owing to the difficulty in effectively predicting the LPG BLEVE loads,the current practice usually employs equivalent methods,e.g.,the TNT-equivalency method,in LPG BLEVE load predictions for structural response analysis,which may lead to inaccurate response predictions.This study compares ground vibrations induced by a BLEVE inside an arched road tunnel with those induced by its equivalent TNT explosion via high-fidelity numerical simulations.The results demonstrate that the frequency of BLEVEinduced vibrations is lower than that induced by the TNT explosion at the same scaled distance.The intensity of LPG BLEVE-induced vibrations at relatively small-scaled distances is lower than that of TNT explosion-induced vibrations at the same scaled distance,but becomes higher after a certain scaled distance because of the relatively low attenuation rate.In addition,parametric analysis is conducted to evaluate the effects of various factors on the characteristics of LPG BLEVE-induced ground vibrations.It is found that the surrounding rock type,the rock porosity,and the cover depth of the tunnel have more significant influences than the concrete grade of the tunnel lining.The recommendation for the tunnel design is also given based on the intensity and frequency characteristics of BLEVE-induced vibrations.展开更多
基金Project(2022YFC2903901)supported by the National Key R&D Project of ChinaProjects(52274249,52334003)supported by the National Natural Science Foundation of China+1 种基金Project(2020-24)supported by the Key Science and Technology Project of Guangxi Transportation Industry,ChinaProject(2023ZZTS0516)supported by the Fundamental Research Funds for the Central Universities,China。
基金financial support from the Australian Research Council Laureate Fellowships FL180100196。
文摘This study investigated the performances of a new type of precast beam-column joint subjected to earthquake and impact loads.For sustainability and durability considerations,new materials such as corrosion-resistant fibre reinforced polymer(FRP)bolts and reinforcements,fibre reinforced concrete(FRC),and geopolymer concrete(GPC)were used to construct the joint.To examine the resilience,durability,sustainability,and multi-hazard resistance capacities,both cyclic and pendulum impact tests were carried out.The experimental results demonstrated that the proposed precast joints had the comparable or even better performances as compared with the traditional monolithic joints under cyclic and impact loads.Numerical simulations using ABAQUS were also adopted to determine the optimal values of the concrete-end-plate(CEP)thickness for the proposed dry joints and to further quantify other response parameters which could not be obtained during the test,e.g.,stress distribution,energy absorption,and stress contours.Discussion on the influences of various parameters on joint performances under different loading conditions was also presented in this study.
文摘Accidental boiling liquid expansion vapour explosions(BLEVEs)caused by the bursting of liquified petroleum gas(LPG)tank inside a tunnel can induce vibrations of its surrounding geological media and threaten the stability of adjacent tunnels and structures.Therefore,it is essential to understand the characteristics of vibrations induced by LPG BLEVEs inside the tunnel for the safety design of its adjacent structures.Owing to the difficulty in effectively predicting the LPG BLEVE loads,the current practice usually employs equivalent methods,e.g.,the TNT-equivalency method,in LPG BLEVE load predictions for structural response analysis,which may lead to inaccurate response predictions.This study compares ground vibrations induced by a BLEVE inside an arched road tunnel with those induced by its equivalent TNT explosion via high-fidelity numerical simulations.The results demonstrate that the frequency of BLEVEinduced vibrations is lower than that induced by the TNT explosion at the same scaled distance.The intensity of LPG BLEVE-induced vibrations at relatively small-scaled distances is lower than that of TNT explosion-induced vibrations at the same scaled distance,but becomes higher after a certain scaled distance because of the relatively low attenuation rate.In addition,parametric analysis is conducted to evaluate the effects of various factors on the characteristics of LPG BLEVE-induced ground vibrations.It is found that the surrounding rock type,the rock porosity,and the cover depth of the tunnel have more significant influences than the concrete grade of the tunnel lining.The recommendation for the tunnel design is also given based on the intensity and frequency characteristics of BLEVE-induced vibrations.