The concept of sustainability is described in this paper using a single sustainable principle,two goals of sustainable development,three dimensions of sustainable engineering,four sustainable requirements and five pha...The concept of sustainability is described in this paper using a single sustainable principle,two goals of sustainable development,three dimensions of sustainable engineering,four sustainable requirements and five phases of sustainable construction.Four sustainable requirements and their practice in China are discussed in particular.The safe reliability of bridges is first compared with the events of bridge failure in China and in the rest of the world and followed by structural durability,including the cracking of concrete cable-stayed bridges,deflection of concrete girder bridges and fatigue cracks of orthotropic steel decks.With respect to functional adaptability,lateral wind action on vehicles and its improvement are introduced regarding a sea-crossing bridge located in a typhoon-prone area.The Chinese practice of using two double main span suspension bridges and a twin parallel deck cable-stayed bridge is presented in discussing the final sustainable requirement:capacity extensibility.展开更多
Tower cranes are commonly used facilities for the construction of high-rise structures.To ensure their workability,it is very important to analyze their response and evaluate their condition under extreme conditions.T...Tower cranes are commonly used facilities for the construction of high-rise structures.To ensure their workability,it is very important to analyze their response and evaluate their condition under extreme conditions.This paper proposes a general scheme for safety and serviceability assessment of high-rise tower crane to turbulent winds based on time domain buffeting response analysis.Spatially correlated wind velocity field at the location of the tower crane was first simulated using an algorithm for generating the time domain samples of a stationary,multivariate stochastic process according to some prescribed spectral density matrix.The buffeting forces applied to the structure were computed according to the above-simulated wind velocity fluctuations and the lift,drag,and moment coefficients obtained from a CFD computation.Those spatially correlated loads were then fed into a well calibrated finite element model and the nonlinear time history analysis was conducted to compute structural buffeting response.Compared with structural onsite response measurement,the computed response using the proposed method has good precision.The proposed method is then adopted for analyzing the buffeting response of an in-use tower crane under the design wind speed and the maximum operational wind speed for safety and serviceability assessment.展开更多
基金The work described in this paper is partially supported by the Natural Science Foundation of China(Grant Nos.90715039 and 51021140005)by the Ministry of Science and Technology of China(Grant Nos.2006AA11Z108 and 2008BAG07B02).
文摘The concept of sustainability is described in this paper using a single sustainable principle,two goals of sustainable development,three dimensions of sustainable engineering,four sustainable requirements and five phases of sustainable construction.Four sustainable requirements and their practice in China are discussed in particular.The safe reliability of bridges is first compared with the events of bridge failure in China and in the rest of the world and followed by structural durability,including the cracking of concrete cable-stayed bridges,deflection of concrete girder bridges and fatigue cracks of orthotropic steel decks.With respect to functional adaptability,lateral wind action on vehicles and its improvement are introduced regarding a sea-crossing bridge located in a typhoon-prone area.The Chinese practice of using two double main span suspension bridges and a twin parallel deck cable-stayed bridge is presented in discussing the final sustainable requirement:capacity extensibility.
基金supported by the National Natural Science Foundation of China(Grant No.50508027)the Key Program of NSFC(Grant No.50538020)the 863 Program of Ministry of Science and Technology of China(No.2006AA11Z109).
文摘Tower cranes are commonly used facilities for the construction of high-rise structures.To ensure their workability,it is very important to analyze their response and evaluate their condition under extreme conditions.This paper proposes a general scheme for safety and serviceability assessment of high-rise tower crane to turbulent winds based on time domain buffeting response analysis.Spatially correlated wind velocity field at the location of the tower crane was first simulated using an algorithm for generating the time domain samples of a stationary,multivariate stochastic process according to some prescribed spectral density matrix.The buffeting forces applied to the structure were computed according to the above-simulated wind velocity fluctuations and the lift,drag,and moment coefficients obtained from a CFD computation.Those spatially correlated loads were then fed into a well calibrated finite element model and the nonlinear time history analysis was conducted to compute structural buffeting response.Compared with structural onsite response measurement,the computed response using the proposed method has good precision.The proposed method is then adopted for analyzing the buffeting response of an in-use tower crane under the design wind speed and the maximum operational wind speed for safety and serviceability assessment.
