Aiming at the problem that it is difficult to obtain the explicit expression of the structural matrix in the traditional train-bridge coupling vibration analysis,a combined simulation system of train-bridge coupling s...Aiming at the problem that it is difficult to obtain the explicit expression of the structural matrix in the traditional train-bridge coupling vibration analysis,a combined simulation system of train-bridge coupling system(TBCS)under earthquake(MAETB)is developed based on the cooperative work of MATLAB and ANSYS.The simulation system is used to analyze the dynamic parameters of the TBCS of a prestressed concrete continuous rigid frame bridge benchmark model of a heavy-haul railway.The influence of different driving speeds,seismic wave intensities,and traveling wave effects on the dynamic response of the TBCS under the actions of the earthquakes is discussed.The results show that the bridge displacement increase in magnitude in the lateral direction is more significant than in the vertical direction under the action of an earthquake.The traveling wave effect can significantly reduce the lateral response of the bridge,but it will significantly increase the train derailment coefficient.When the earthquake intensity exceeds 0.2 g,the partial derailment coefficient of the train has exceeded the limit value of the specification.展开更多
Extensive high-speed railway(HSR)network resembled the intricate vascular system of the human body,crisscrossing mainlands.Seismic events,known for their unpredictability,pose a significant threat to both trains and b...Extensive high-speed railway(HSR)network resembled the intricate vascular system of the human body,crisscrossing mainlands.Seismic events,known for their unpredictability,pose a significant threat to both trains and bridges,given the HSR’s extended operational duration.Therefore,ensuring the running safety of train-bridge coupled(TBC)system,primarily composed of simply supported beam bridges,is paramount.Traditional methods like the Monte Carlo method fall short in analyzing this intricate system efficiently.Instead,efficient algorithm like the new point estimate method combined with moment expansion approximation(NPEM-MEA)is applied to study random responses of numerical simulation TBC systems.Validation of the NPEM-MEA’s feasibility is conducted using the Monte Carlo method.Comparative analysis confirms the accuracy and efficiency of the method,with a recommended truncation order of four to six for the NPEM-MEA.Additionally,the influences of seismic magnitude and epicentral distance are discussed based on the random dynamic responses in the TBC system.This methodology not only facilitates seismic safety assessments for TBC systems but also contributes to standard-setting for these systems under earthquake conditions.展开更多
In recent years,high-speed railways in China have developed very rapidly,and the number and span of the railway bridges are keeping increasing.Meanwhile,frequent extreme disasters,such as strong winds,earthquakes and ...In recent years,high-speed railways in China have developed very rapidly,and the number and span of the railway bridges are keeping increasing.Meanwhile,frequent extreme disasters,such as strong winds,earthquakes and floods,pose a significant threat to the safety of the train–bridge systems.Therefore,it is of paramount importance to evaluate the safety and comfort of trains when crossing a bridge under external excitations.In these aspects,there is abundant research but lacks a literature review.Therefore,this paper provides a comprehensive state-of-the-art review of research works on train–bridge systems under external excitations,which includes crosswinds,waves,collision loads and seismic loads.The characteristics of external excitations,the models of the train–bridge systems under external excitations,and the representative research results are summarized and analyzed.Finally,some suggestions for further research of the coupling vibration of train–bridge system under external excitations are presented.展开更多
To choose the optimum construction method of metro tunneling, we conducted research with numerical simulation on strata consolidation subsidence by dewatering, dynamic dewatering, and non-dewatering construction metho...To choose the optimum construction method of metro tunneling, we conducted research with numerical simulation on strata consolidation subsidence by dewatering, dynamic dewatering, and non-dewatering construction method, taking the integrated effects of fluid-solid coupling and tunneling mechanics into account. We obtained the curved surfaces of ground surface subsidence and strata consolidation subsidence. The results show that the quantity of ground surface subsidence is 31 mm for the non-dewatering method, 39 mm for the dynamic dewatering method, and 105 mm for the dewatering method. Their ratio is 1：1.3：3.4; and the percentages of strata consolidation subsidence to whole ground surface subsidence of each construction method is 27% （no-dewatering）, 50% （dynamic dewatering）, and 79% （dewatering）. It is obvious that the non-dewatering construction method is the most effective method to control the strata consolidation subsidence induced by metro tunneling in saturated soft clay strata, and it has been successfully applied to the construction of the Shenzben metro line 1.展开更多
基金funded by the Open Projects Foundation of Engineering Research Center of Disaster Prevention and Mitigation of Southeast Coastal Engineering Structures of Fujian Province University(Grant No.2022009)the National Natural Science Foundation of China(Grant No.51708429)the Construction Science and Technology Plan Projects of Hubei Province(Grant No.2023011).
文摘Aiming at the problem that it is difficult to obtain the explicit expression of the structural matrix in the traditional train-bridge coupling vibration analysis,a combined simulation system of train-bridge coupling system(TBCS)under earthquake(MAETB)is developed based on the cooperative work of MATLAB and ANSYS.The simulation system is used to analyze the dynamic parameters of the TBCS of a prestressed concrete continuous rigid frame bridge benchmark model of a heavy-haul railway.The influence of different driving speeds,seismic wave intensities,and traveling wave effects on the dynamic response of the TBCS under the actions of the earthquakes is discussed.The results show that the bridge displacement increase in magnitude in the lateral direction is more significant than in the vertical direction under the action of an earthquake.The traveling wave effect can significantly reduce the lateral response of the bridge,but it will significantly increase the train derailment coefficient.When the earthquake intensity exceeds 0.2 g,the partial derailment coefficient of the train has exceeded the limit value of the specification.
基金National Natural Science Foundation of China under Grant Nos.11972379 and 42377184,Hunan 100-Talent PlanNatural Science Foundation of Hunan Province under Grant No.2022JJ10079+1 种基金Hunan High-Level Talent Plan under Grant No.420030004Central South University Research Project under Grant Nos.202045006(Innovation-Driven Project)and 502390001。
文摘Extensive high-speed railway(HSR)network resembled the intricate vascular system of the human body,crisscrossing mainlands.Seismic events,known for their unpredictability,pose a significant threat to both trains and bridges,given the HSR’s extended operational duration.Therefore,ensuring the running safety of train-bridge coupled(TBC)system,primarily composed of simply supported beam bridges,is paramount.Traditional methods like the Monte Carlo method fall short in analyzing this intricate system efficiently.Instead,efficient algorithm like the new point estimate method combined with moment expansion approximation(NPEM-MEA)is applied to study random responses of numerical simulation TBC systems.Validation of the NPEM-MEA’s feasibility is conducted using the Monte Carlo method.Comparative analysis confirms the accuracy and efficiency of the method,with a recommended truncation order of four to six for the NPEM-MEA.Additionally,the influences of seismic magnitude and epicentral distance are discussed based on the random dynamic responses in the TBC system.This methodology not only facilitates seismic safety assessments for TBC systems but also contributes to standard-setting for these systems under earthquake conditions.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.51978589 and 51778544).
文摘In recent years,high-speed railways in China have developed very rapidly,and the number and span of the railway bridges are keeping increasing.Meanwhile,frequent extreme disasters,such as strong winds,earthquakes and floods,pose a significant threat to the safety of the train–bridge systems.Therefore,it is of paramount importance to evaluate the safety and comfort of trains when crossing a bridge under external excitations.In these aspects,there is abundant research but lacks a literature review.Therefore,this paper provides a comprehensive state-of-the-art review of research works on train–bridge systems under external excitations,which includes crosswinds,waves,collision loads and seismic loads.The characteristics of external excitations,the models of the train–bridge systems under external excitations,and the representative research results are summarized and analyzed.Finally,some suggestions for further research of the coupling vibration of train–bridge system under external excitations are presented.
文摘To choose the optimum construction method of metro tunneling, we conducted research with numerical simulation on strata consolidation subsidence by dewatering, dynamic dewatering, and non-dewatering construction method, taking the integrated effects of fluid-solid coupling and tunneling mechanics into account. We obtained the curved surfaces of ground surface subsidence and strata consolidation subsidence. The results show that the quantity of ground surface subsidence is 31 mm for the non-dewatering method, 39 mm for the dynamic dewatering method, and 105 mm for the dewatering method. Their ratio is 1：1.3：3.4; and the percentages of strata consolidation subsidence to whole ground surface subsidence of each construction method is 27% （no-dewatering）, 50% （dynamic dewatering）, and 79% （dewatering）. It is obvious that the non-dewatering construction method is the most effective method to control the strata consolidation subsidence induced by metro tunneling in saturated soft clay strata, and it has been successfully applied to the construction of the Shenzben metro line 1.
