The damages of building structures subjected to multifarious explosions cause huge losses of lives and property. It is the reason why the blast resistance and explosion protection of building structures become an impo...The damages of building structures subjected to multifarious explosions cause huge losses of lives and property. It is the reason why the blast resistance and explosion protection of building structures become an important research topic in the civil engineering field all over the world. This paper provides an overview of the research work in China on blast loads effect on building structures. It includes modeling blast shock wave propagation and their effects, the dynamic responses of various building structures under blast loads and the measures to strengthen the building structures against blast loads. The paper also discusses the achievements and further work that needs be done for a better understanding of the blast loads' effects on building structures, and for deriving effective and economic techniques to design new or to strengthen existing structures.展开更多
The seismic behavior of tall buildings can he greatly affected by non-linear soil-pile interaction during strong earthquakes.In this study a 20-storey building is examined as a typical structure supported on a pile fo...The seismic behavior of tall buildings can he greatly affected by non-linear soil-pile interaction during strong earthquakes.In this study a 20-storey building is examined as a typical structure supported on a pile foundation for different conditions:(1) rigid base,i.e.no deformation in the foundation:(2) linear soil-pile system;and (3) nonlinear soil-pile system. The effects of pile foundation displacements on the behavior of tall building are investigated,and compared with the behavior of buildings supported on shallow foundation.With a model of non-reflective boundary between the near field and far field, Novak's method of soil-pile interaction is improved.The computation method for vibration of pile foundations and DYNAN computer program are introduced comprehensively.A series of dynamic experiments have been done on full-scale piles, including single pile and group,linear vibration and nonlinear vibration,to verify the validity of boundary zone model.展开更多
To date, the high power arc plasma technology is widely used. A next generation high power arc plasma system based on building block structure is presented. The whole arc plasma inverter system is composed of 12 paral...To date, the high power arc plasma technology is widely used. A next generation high power arc plasma system based on building block structure is presented. The whole arc plasma inverter system is composed of 12 paralleled units to increase the system output capability. The hierarchical control system is adopted to improve the reliability and flexibility of the high power arc plasma inverter. To ensure the reliable turn on and off of the IGBT module in each building block unit, a special pulse drive circuit is designed by using pulse transformer. The experimental result indicates that the high power arc plasma inverter system can transfer 300 kW arc plasma energy reliably with high efficiency.展开更多
This study investigates the effectiveness of the non-smooth semi-active control algorithm on suppressing the vibration performance of a building structure subjected to seismic waves. According to the Lyapunov stabilit...This study investigates the effectiveness of the non-smooth semi-active control algorithm on suppressing the vibration performance of a building structure subjected to seismic waves. According to the Lyapunov stability theory, it has bene proven that the non-smooth semi-active control algorithm can achieve a finite-time stability of the vibration relative to the isolation layer of a building structure. Through numerical simulation of two buildings with different parameters subjected to the input of a seismic wave, the vibration conditions of passive control, LQR semi-active control and non-smooth semiactive control are compared and analyzed. The simulation results show that the non-smooth semi-active control algorithm has a better robustness and effectiveness in restraining the impact of earthquakes on the structure.展开更多
In this study,an innovative solution is developed for vibration suppression of the high-rise building.The infinite dimensional system model has been presented for describing high-rise building structures which have a ...In this study,an innovative solution is developed for vibration suppression of the high-rise building.The infinite dimensional system model has been presented for describing high-rise building structures which have a large inertial load with the help of the Hamilton’s principle.On the basis of this system model and with the use of the Lyapunov’s direct method,a boundary controller is proposed and the closed-loop system is uniformly bounded in the time domain.Finally,by using the Smart Structure laboratory platform which is produced by Quancer,we conduct a set of experiments and find that the designed method is resultful.展开更多
Progressive collapse of building structures under blast and impact loads has attracted great attention all over the world. Progressive collapse analysis is essential for an economic and safe design of building structu...Progressive collapse of building structures under blast and impact loads has attracted great attention all over the world. Progressive collapse analysis is essential for an economic and safe design of building structures against progressive collapse to blast and impact loads. Because of the catastrophic nature of progressive collapse and the potentially high cost of constructing or retrofitting buildings to resist it, it is imperative that the progressive collapse analysis methods be reliable. For engineers, their methodology to carry out progressive collapse evaluation need not only be accurate and concise, but also be easily used and works fast. Thus, many researchers have been spending lots of effort in developing reliable, efficient and straightforward progressive collapse analysis methods recently. In the present paper, current progressive collapse analysis methods available in the literature are reviewed. Their suitability, applicability and reliability are discussed. Our recent proposed new method for progressive collapse analysis of reinforced concrete frames under blast loads is also introduced.展开更多
This paper presents the restraining moments of outriggers acting on the core wall and the equation of the horizontal top deflection based on a simplified outrigger model. The deformation compatibility conditions betwe...This paper presents the restraining moments of outriggers acting on the core wall and the equation of the horizontal top deflection based on a simplified outrigger model. The deformation compatibility conditions between outriggers and core wall as well as the finite rigidities of outriggers are also considered. One case study was carried out to analyze the horizontal top deflection and the mutation of the restraining moments caused by the variation of outrigger location. The results showed that the method adopted in the paper is simple and reasonable. Some conclusions are valuable to the safety design of high-rise building structures.展开更多
Coal mining under buildings certainly causes surface movement and deformation, therefore, it brings about deformation even fracture for buildings. It is an important task to evaluate correcly the buildings’ damage gr...Coal mining under buildings certainly causes surface movement and deformation, therefore, it brings about deformation even fracture for buildings. It is an important task to evaluate correcly the buildings’ damage grabe caused by coal mining. Fuzzy comprehensive evaluation,considering some factors of buildings’ fracture, has been applied to analyze the masonry structure buildings’ damage grade affer coal mining in this paper. It provides a scientific basis for buildings’reidercement before mining and maintenance or compensation after mining.展开更多
This paper presents the results from unidirectional shaking table tests of two reduced scale steel models of a building frame, with one and two floors, respectively. These frames incorporate friction dissipators at ev...This paper presents the results from unidirectional shaking table tests of two reduced scale steel models of a building frame, with one and two floors, respectively. These frames incorporate friction dissipators at every floor. The inputs are sine-dwells and artificial and registered earthquakes. This study is part of a larger research project aiming to assess the seismic efficiency of friction dissipators by means of an integrated numerical and experimental approach. Inside this framework, the main objectives of these experiments are to： （i） collect a wide range of results to calibrate a numerical model derived within the project, （ii） clarify some of the most controversial issues about friction dissipators （including behavior for inputs containing pulses, capacity to reduce resonance peaks, introduction of high frequencies in the response, and self- generated eccentricities）, （iii） better understand their dynamic behavior, （iv） provide insight on the feasibility and reliability of using simple friction dissipators for seismic protection of building structures and （v） characterize the hysteretic behavior of these devices. Most of these objectives are satisfactorily reached and relevant conclusions are stated.展开更多
Light-framed timber structure(LTS)buildings have been highly valued in recent years due to their low-carbon characteristics.However,the applicability of the building envelope is closely related to indoor and outdoor c...Light-framed timber structure(LTS)buildings have been highly valued in recent years due to their low-carbon characteristics.However,the applicability of the building envelope is closely related to indoor and outdoor conditions.The hot summer and cold winter(HSCW)climate zone in China has high humidity and great temperature variation throughout the year,resulting in distinct outdoor environments in different seasons.The indoor environment is greatly affected by energy-consumption patterns and window-opening habits,which largely depend upon the regulation operations of occupants.All these interrelated factors lead to extremely complex boundary conditions on each side of the building envelope.Whether the structures of LTS buildings are applicable in this climate zone,therefore,needs to be carefully considered.In this study,two LTS buildings with different envelopes were established in Haining,China,situated in the HSCW climate zone,and selected as the study objects.Different operation modes were adopted to create a variety of indoor environments.Under each condition,the processes of heat and moisture transfer within the building envelopes and the indoor environment were monitored and compared.The comparison indicated that the building envelope with high moisture storage and insulation ability maintained a relatively stable indoor environment,especially when the environment changed abruptly.Conversely,if the outdoor environment was equable(e.g.,relative humidity within the range of 30%–60%)or intermittent energy consumption modes were adopted,the building envelope with a low thermal inertia index and weak moisture-buffering ability performed better because it enabled a faster response of the indoor environment to air conditioning.Moreover,a high risk of moisture accumulation between the thermal insulation layer and other materials with a large water vapour transfer resistance factor was also identified,suggesting a higher requirement for the vapour insulation of the envelopes of LTS buildings.展开更多
This paper introduces the structural design optimization of a tall building with reinforced concrete frame-core shear walls in Guangzhou downtown.To decrease the construction cost,wide flat beam with 400 mm ×650 ...This paper introduces the structural design optimization of a tall building with reinforced concrete frame-core shear walls in Guangzhou downtown.To decrease the construction cost,wide flat beam with 400 mm ×650 mm rectangular cross-section are adopted for main beam.Special measures are used to decrease noncoincident centers of mass and stiffness.Because subway tunnels cross the building underground,inclined columns,the second and third floor underground together function as the underpinning structures.Different from traditional transform beam,the proposed underpinning structures show good performance without using large dimensional bending members.Special attentions should be paid to the beams connecting with the inclined column in the underpinning structures,and these beams show large tensile or compressive forces.Settlement observations after completion construction indicate that the building as well as the proposed design measures work well.展开更多
A novel 2D Cu coordination polymer [Cu4(pca)4(H2O)2(DMSO)2·2DMSO·2H2O]n(2, H2 pca = pyrazole-3-carboxylic acid) has been prepared by dissolving a dinuclear Cu complex Cu2(py)3(pca)2(H2O)·(H2O)(1) in DMS...A novel 2D Cu coordination polymer [Cu4(pca)4(H2O)2(DMSO)2·2DMSO·2H2O]n(2, H2 pca = pyrazole-3-carboxylic acid) has been prepared by dissolving a dinuclear Cu complex Cu2(py)3(pca)2(H2O)·(H2O)(1) in DMSO solution and structurally characterized by X-ray diffraction. The polymer crystallizes in space group P1 with a = 9.538(3), b = 9.714(3), c = 10.765(3) A, α = 86.492(6), β = 84.007(7), γ = 82.592(6)o, Mr = 1079.04, V = 982.4(5) A3, Z = 1, Dc = 1.824 g/cm3, μ = 2.425 mm-1 and F(000) = 548. The final refinement gave R = 0.0785 and w R = 0.1940 for 2787 reflections with I 】 2σ(I). The structure of 2 consists of Cu4(pca)4(H2O)2(DMSO)2·2DMSO·2H2O units, which can be viewed as two dinuclear subunits of Cu2(pca)2(H2O)2 and Cu2(pca)2(DMSO)2 connected to each other alternately, with solvent DMSO and H2 O molecules around. The framework features a grid-like topology, with the walls of the grids composed of Cu4(pca)4 units, and the coordinated solvent molecules trapped in the grids.展开更多
Background Three-dimensional(3D)building models with unambiguous roof plane geometry parameters,roof structure units,and linked topology provide essential data for many applications related to human activities in urba...Background Three-dimensional(3D)building models with unambiguous roof plane geometry parameters,roof structure units,and linked topology provide essential data for many applications related to human activities in urban environments.The task of 3D reconstruction from point clouds is still in the development phase,especially the recognition and interpretation of roof topological structures.Methods This study proposes a novel visual perception-based approach to automatically decompose and reconstruct building point clouds into meaningful and simple parametric structures,while the associated mutual relationships between the roof plane geometry and roof structure units are expressed by a hierarchical topology tree.First,a roof plane extraction is performed by a multi-label graph cut energy optimization framework and a roof structure graph(RSG)model is then constructed to describe the roof topological geometry with common adjacency,symmetry,and convexity rules.Moreover,a progressive roof decomposition and refinement are performed,generating a hierarchical representation of the 3D roof structure models.Finally,a visual plane fitted residual or area constraint process is adopted to generate the RSG model with different levels of details.Results Two airborne laser scanning datasets with different point densities and roof styles were tested,and the performance evaluation metrics were obtained by International Society for Photogrammetry and Remote Sensing,achieving a correctness and accuracy of 97.7%and 0.29m,respectively.Conclusions The standardized assessment results demonstrate the effectiveness and robustness of the proposed approach,showing its ability to generate a variety of structural models,even with missing data.展开更多
Many closely located adjacent buildings have suffered from pounding during past earthquakes because they vibrated out of phase. Furthermore, buildings are usually constructed on soil; hence, there are interactions bet...Many closely located adjacent buildings have suffered from pounding during past earthquakes because they vibrated out of phase. Furthermore, buildings are usually constructed on soil; hence, there are interactions between the buildings and the underlying soil that should also be considered. This paper examines both the interaction between adjacent buildings due to pounding and the interaction between the buildings through the soil as they affect the buildings＇ seismic responses. The developed model consists of adjacent shear buildings resting on a discrete soil model and a linear visco- elastic contact force model that connects the buildings during pounding. The seismic responses of＇ adjacent buildings due to ground accelerations are obtained for two conditions： fixed-based （FB） and structure-soil-structure interaction （SSSI）. The results indicate that pounding worsens the buildings＇ condition because their seismic responses are amplified after pounding. Moreover, the underlying soil negatively impacts the buildings＇ seismic responses during pounding because the ratio of their seismic response under SSSI conditions with pounding to those without pounding is greater than that of the FB condition.展开更多
With the rapid development of high-rise buildings and long-span structures in the recent years, high performance com- putation (HPC) is becoming more and more important, sometimes even crucial, for the design and cons...With the rapid development of high-rise buildings and long-span structures in the recent years, high performance com- putation (HPC) is becoming more and more important, sometimes even crucial, for the design and construction of com- plex building structures. To satisfy the engineering requirements of HPC, a parallel FEA computing kernel, which is designed typically for the analysis of complex building structures, will be presented and illustrated in this paper. This kernel program is based on the Intel Math Kernel Library (MKL) and coded by FORTRAN 2008 syntax, which is a parallel computer language. To improve the capability and efficiency of the computing kernel program, the parallel concepts of modern FORTRAN, such as elemental procedure, do concurrent, etc., have been applied extensively in coding and the famous PARDISO solver in MKL has been called to solve the Large-sparse system of linear equations. The ultimate objective of developing the computing kernel is to make the personal computer have the ability to analysis large building structures up to ten million degree of freedoms (DOFs). Up to now, the linear static analysis and dynamic analysis have been achieved while the nonlinear analysis, including geometric and material nonlinearity, has not been finished yet. Therefore, the numerical examples in this paper will be concentrated on demonstrating the validity and efficiency of the linear analysis and modal analysis for large FE models, while ignoring the verification of the nonlinear analysis capabilities.展开更多
First, the high-rise building structure design process is divided into three relevant steps, that is, scheme generation and creation, performance evaluation, and scheme optimization. Then with the application of relat...First, the high-rise building structure design process is divided into three relevant steps, that is, scheme generation and creation, performance evaluation, and scheme optimization. Then with the application of relational database, the case database of high-rise structures is constructed, the structure form-selection designing methods such as the smart algorithm based on CBR, DM, FINS, NN and GA is presented, and the original forms system of this method and its general structure are given. CBR and DM are used to generate scheme candidates; FINS and NN to evaluate and optimize the scheme performance; GA to create new structure forms. Finally, the application cases are presented, whose results fit in with the real project. It proves by combining and using the expert intelligence, algorithm intelligence and machine intelligence that this method makes good use of not only the engineering project knowledge and expertise but also much deeper knowledge contained in various engineering cases. In other words, it is because the form selection has a strong background support of vast real cases that its results prove more reliable and more acceptable. So the introduction of this method provides an effective approach to improving the quality, efficiency, automatic and smart level of high-rise structures form selection design.展开更多
Numerous field tests indicate that the soilestructure interaction （SSI） has a significant impact on thedynamic characteristics of super-tall buildings, which may lead to unexpected structural seismic responsesand/or...Numerous field tests indicate that the soilestructure interaction （SSI） has a significant impact on thedynamic characteristics of super-tall buildings, which may lead to unexpected structural seismic responsesand/or failure. Taking the Shanghai Tower with a total height of 632 m as the research object, thesubstructure approach is used to simulate the SSI effect on the seismic responses of Shanghai Tower. Therefined finite element （FE） model of the superstructure of Shanghai Tower and the simplified analyticalmodel of the foundation and adjacent soil are established. Subsequently, the collapse process of ShanghaiTower taking into account the SSI is predicted, as well as its final collapse mechanism. The influences ofthe SSI on the collapse resistance capacity and failure sequences are discussed. The results indicate that,when considering the SSI, the fundamental period of Shanghai Tower has been extended significantly,and the collapse margin ratio has been improved, with a corresponding decrease of the seismic demand.In addition, the SSI has some impact on the failure sequences of Shanghai Tower subjected to extremeearthquakes, but a negligible impact on the final failure modes. 2014 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting byElsevier B.V. All rights reserved.展开更多
China is a country with many earthquakes. Seismic safety monitoring and building earthquake-proofing technique are important means to protect the safety of people’s property in China. However, up to now, China’s sei...China is a country with many earthquakes. Seismic safety monitoring and building earthquake-proofing technique are important means to protect the safety of people’s property in China. However, up to now, China’s seismic reinforcement and identification technology is still not mature enough. In particular, the 2008 Wenchuan earthquake caused great loss of life and safety to the Chinese people. This paper, takes seismic identification and reinforcement technology of building structures as the research object and summarizes the main methods of building structure seismic resistance in China. This paper is based on an in-depth analysis of the main seismic reinforcement and identification techniques in China, deeply analyzes the crux of anti-seismic and reinforcement of building structure combining with the current building seismic reinforcement typical cases, and puts forward some reasonable suggestions and improvement methods for the future development of building seismic identification and reinforcement design.展开更多
The objective of this paper is to investigate the dynamic characteristics of two adjacent building structures interconnected by viscoelastic dampers under seismic excitations. The computational procedure for an analyt...The objective of this paper is to investigate the dynamic characteristics of two adjacent building structures interconnected by viscoelastic dampers under seismic excitations. The computational procedure for an analytical model including the system model formulation, complex modal analysis and seismic time history analysis is presented for this purpose. A numerical example is also provided to illustrate the analytical model. The complex modal analysis is conducted to determine the optimal damping ratio, the optimal damper stiffness and the optimal damper damping of the viscoelastic dampers for each mode of the system. For the damper stiffness and damping with optimal values, the responses can be categorized into underdamped and critically damped vibrations. Furthermore, compared to the viscous dampers with only the energy dissipation mechanism, the viscoelastic dampers with both the energy dissipation and redistribution mechanisms are more effective for increasing the damping ratio of the system. The seismic time history analysis is conducted to assess the effectiveness of the viscoelastic dampers for vibration control. Based on the optimal damping ratio, the optimal damper stiffness, the optimal damper damping of the viscoelastic dampers for a certain mode of the system, and the viscoelastic dampers can be used to effectively suppress the root-mean-square responses as well as the peak responses of the two adjacent buildings.展开更多
基金Supported by National Science Fund for Distinguished Young Scholars of China (No. 50425824)
文摘The damages of building structures subjected to multifarious explosions cause huge losses of lives and property. It is the reason why the blast resistance and explosion protection of building structures become an important research topic in the civil engineering field all over the world. This paper provides an overview of the research work in China on blast loads effect on building structures. It includes modeling blast shock wave propagation and their effects, the dynamic responses of various building structures under blast loads and the measures to strengthen the building structures against blast loads. The paper also discusses the achievements and further work that needs be done for a better understanding of the blast loads' effects on building structures, and for deriving effective and economic techniques to design new or to strengthen existing structures.
文摘The seismic behavior of tall buildings can he greatly affected by non-linear soil-pile interaction during strong earthquakes.In this study a 20-storey building is examined as a typical structure supported on a pile foundation for different conditions:(1) rigid base,i.e.no deformation in the foundation:(2) linear soil-pile system;and (3) nonlinear soil-pile system. The effects of pile foundation displacements on the behavior of tall building are investigated,and compared with the behavior of buildings supported on shallow foundation.With a model of non-reflective boundary between the near field and far field, Novak's method of soil-pile interaction is improved.The computation method for vibration of pile foundations and DYNAN computer program are introduced comprehensively.A series of dynamic experiments have been done on full-scale piles, including single pile and group,linear vibration and nonlinear vibration,to verify the validity of boundary zone model.
基金supported by National Natural Science Foundation of China (50805051)Guangdong Provincial Science and Technology Project (2008B010400041)
文摘To date, the high power arc plasma technology is widely used. A next generation high power arc plasma system based on building block structure is presented. The whole arc plasma inverter system is composed of 12 paralleled units to increase the system output capability. The hierarchical control system is adopted to improve the reliability and flexibility of the high power arc plasma inverter. To ensure the reliable turn on and off of the IGBT module in each building block unit, a special pulse drive circuit is designed by using pulse transformer. The experimental result indicates that the high power arc plasma inverter system can transfer 300 kW arc plasma energy reliably with high efficiency.
基金National Natural Science Foundation(NNSF)of China under Grant No.51478132Guangzhou City College Scientific Research Project under Grant No.120163017
文摘This study investigates the effectiveness of the non-smooth semi-active control algorithm on suppressing the vibration performance of a building structure subjected to seismic waves. According to the Lyapunov stability theory, it has bene proven that the non-smooth semi-active control algorithm can achieve a finite-time stability of the vibration relative to the isolation layer of a building structure. Through numerical simulation of two buildings with different parameters subjected to the input of a seismic wave, the vibration conditions of passive control, LQR semi-active control and non-smooth semiactive control are compared and analyzed. The simulation results show that the non-smooth semi-active control algorithm has a better robustness and effectiveness in restraining the impact of earthquakes on the structure.
基金supported in part by the National Natural Science Foundation of China(61933001,62061160371,62003029)Beijing Natural Science Foundation(JQ20026)Beijing Top Discipline for Artificial Intelligent Science and Engineering,University of Science and Technology Beijing。
文摘In this study,an innovative solution is developed for vibration suppression of the high-rise building.The infinite dimensional system model has been presented for describing high-rise building structures which have a large inertial load with the help of the Hamilton’s principle.On the basis of this system model and with the use of the Lyapunov’s direct method,a boundary controller is proposed and the closed-loop system is uniformly bounded in the time domain.Finally,by using the Smart Structure laboratory platform which is produced by Quancer,we conduct a set of experiments and find that the designed method is resultful.
基金Supported by National Natural Science Foundation of China(No.50638030and No.50528808)National Key Technologies R&D Program of China(No.2006BAJ13B02)
文摘Progressive collapse of building structures under blast and impact loads has attracted great attention all over the world. Progressive collapse analysis is essential for an economic and safe design of building structures against progressive collapse to blast and impact loads. Because of the catastrophic nature of progressive collapse and the potentially high cost of constructing or retrofitting buildings to resist it, it is imperative that the progressive collapse analysis methods be reliable. For engineers, their methodology to carry out progressive collapse evaluation need not only be accurate and concise, but also be easily used and works fast. Thus, many researchers have been spending lots of effort in developing reliable, efficient and straightforward progressive collapse analysis methods recently. In the present paper, current progressive collapse analysis methods available in the literature are reviewed. Their suitability, applicability and reliability are discussed. Our recent proposed new method for progressive collapse analysis of reinforced concrete frames under blast loads is also introduced.
基金Project supported by the National Natural Science Foundation of China (No. 50378041) and the Specialized Research Fund for theDoctoral Program of Higher Education (No. 20030487016), China
文摘This paper presents the restraining moments of outriggers acting on the core wall and the equation of the horizontal top deflection based on a simplified outrigger model. The deformation compatibility conditions between outriggers and core wall as well as the finite rigidities of outriggers are also considered. One case study was carried out to analyze the horizontal top deflection and the mutation of the restraining moments caused by the variation of outrigger location. The results showed that the method adopted in the paper is simple and reasonable. Some conclusions are valuable to the safety design of high-rise building structures.
文摘Coal mining under buildings certainly causes surface movement and deformation, therefore, it brings about deformation even fracture for buildings. It is an important task to evaluate correcly the buildings’ damage grabe caused by coal mining. Fuzzy comprehensive evaluation,considering some factors of buildings’ fracture, has been applied to analyze the masonry structure buildings’ damage grade affer coal mining in this paper. It provides a scientific basis for buildings’reidercement before mining and maintenance or compensation after mining.
基金Supported by Spanish Government,Grant CGL2008-00869/BTE
文摘This paper presents the results from unidirectional shaking table tests of two reduced scale steel models of a building frame, with one and two floors, respectively. These frames incorporate friction dissipators at every floor. The inputs are sine-dwells and artificial and registered earthquakes. This study is part of a larger research project aiming to assess the seismic efficiency of friction dissipators by means of an integrated numerical and experimental approach. Inside this framework, the main objectives of these experiments are to： （i） collect a wide range of results to calibrate a numerical model derived within the project, （ii） clarify some of the most controversial issues about friction dissipators （including behavior for inputs containing pulses, capacity to reduce resonance peaks, introduction of high frequencies in the response, and self- generated eccentricities）, （iii） better understand their dynamic behavior, （iv） provide insight on the feasibility and reliability of using simple friction dissipators for seismic protection of building structures and （v） characterize the hysteretic behavior of these devices. Most of these objectives are satisfactorily reached and relevant conclusions are stated.
基金supported by the National Natural Science Foundation of China(No.51978623).
文摘Light-framed timber structure(LTS)buildings have been highly valued in recent years due to their low-carbon characteristics.However,the applicability of the building envelope is closely related to indoor and outdoor conditions.The hot summer and cold winter(HSCW)climate zone in China has high humidity and great temperature variation throughout the year,resulting in distinct outdoor environments in different seasons.The indoor environment is greatly affected by energy-consumption patterns and window-opening habits,which largely depend upon the regulation operations of occupants.All these interrelated factors lead to extremely complex boundary conditions on each side of the building envelope.Whether the structures of LTS buildings are applicable in this climate zone,therefore,needs to be carefully considered.In this study,two LTS buildings with different envelopes were established in Haining,China,situated in the HSCW climate zone,and selected as the study objects.Different operation modes were adopted to create a variety of indoor environments.Under each condition,the processes of heat and moisture transfer within the building envelopes and the indoor environment were monitored and compared.The comparison indicated that the building envelope with high moisture storage and insulation ability maintained a relatively stable indoor environment,especially when the environment changed abruptly.Conversely,if the outdoor environment was equable(e.g.,relative humidity within the range of 30%–60%)or intermittent energy consumption modes were adopted,the building envelope with a low thermal inertia index and weak moisture-buffering ability performed better because it enabled a faster response of the indoor environment to air conditioning.Moreover,a high risk of moisture accumulation between the thermal insulation layer and other materials with a large water vapour transfer resistance factor was also identified,suggesting a higher requirement for the vapour insulation of the envelopes of LTS buildings.
基金Sponsored by the Research Foundation of State Key Lab of Subtropical Building Science(Grant No.2014KB28)
文摘This paper introduces the structural design optimization of a tall building with reinforced concrete frame-core shear walls in Guangzhou downtown.To decrease the construction cost,wide flat beam with 400 mm ×650 mm rectangular cross-section are adopted for main beam.Special measures are used to decrease noncoincident centers of mass and stiffness.Because subway tunnels cross the building underground,inclined columns,the second and third floor underground together function as the underpinning structures.Different from traditional transform beam,the proposed underpinning structures show good performance without using large dimensional bending members.Special attentions should be paid to the beams connecting with the inclined column in the underpinning structures,and these beams show large tensile or compressive forces.Settlement observations after completion construction indicate that the building as well as the proposed design measures work well.
基金supported by the National Natural Science Foundation of China(Nos.21173219 and 21303201)
文摘A novel 2D Cu coordination polymer [Cu4(pca)4(H2O)2(DMSO)2·2DMSO·2H2O]n(2, H2 pca = pyrazole-3-carboxylic acid) has been prepared by dissolving a dinuclear Cu complex Cu2(py)3(pca)2(H2O)·(H2O)(1) in DMSO solution and structurally characterized by X-ray diffraction. The polymer crystallizes in space group P1 with a = 9.538(3), b = 9.714(3), c = 10.765(3) A, α = 86.492(6), β = 84.007(7), γ = 82.592(6)o, Mr = 1079.04, V = 982.4(5) A3, Z = 1, Dc = 1.824 g/cm3, μ = 2.425 mm-1 and F(000) = 548. The final refinement gave R = 0.0785 and w R = 0.1940 for 2787 reflections with I 】 2σ(I). The structure of 2 consists of Cu4(pca)4(H2O)2(DMSO)2·2DMSO·2H2O units, which can be viewed as two dinuclear subunits of Cu2(pca)2(H2O)2 and Cu2(pca)2(DMSO)2 connected to each other alternately, with solvent DMSO and H2 O molecules around. The framework features a grid-like topology, with the walls of the grids composed of Cu4(pca)4 units, and the coordinated solvent molecules trapped in the grids.
基金Supported by the National Natural Science Foundation of China(41901405,41725005,41531177)and the National Key Research and Development Program of China(2016YFF0103501).
文摘Background Three-dimensional(3D)building models with unambiguous roof plane geometry parameters,roof structure units,and linked topology provide essential data for many applications related to human activities in urban environments.The task of 3D reconstruction from point clouds is still in the development phase,especially the recognition and interpretation of roof topological structures.Methods This study proposes a novel visual perception-based approach to automatically decompose and reconstruct building point clouds into meaningful and simple parametric structures,while the associated mutual relationships between the roof plane geometry and roof structure units are expressed by a hierarchical topology tree.First,a roof plane extraction is performed by a multi-label graph cut energy optimization framework and a roof structure graph(RSG)model is then constructed to describe the roof topological geometry with common adjacency,symmetry,and convexity rules.Moreover,a progressive roof decomposition and refinement are performed,generating a hierarchical representation of the 3D roof structure models.Finally,a visual plane fitted residual or area constraint process is adopted to generate the RSG model with different levels of details.Results Two airborne laser scanning datasets with different point densities and roof styles were tested,and the performance evaluation metrics were obtained by International Society for Photogrammetry and Remote Sensing,achieving a correctness and accuracy of 97.7%and 0.29m,respectively.Conclusions The standardized assessment results demonstrate the effectiveness and robustness of the proposed approach,showing its ability to generate a variety of structural models,even with missing data.
文摘Many closely located adjacent buildings have suffered from pounding during past earthquakes because they vibrated out of phase. Furthermore, buildings are usually constructed on soil; hence, there are interactions between the buildings and the underlying soil that should also be considered. This paper examines both the interaction between adjacent buildings due to pounding and the interaction between the buildings through the soil as they affect the buildings＇ seismic responses. The developed model consists of adjacent shear buildings resting on a discrete soil model and a linear visco- elastic contact force model that connects the buildings during pounding. The seismic responses of＇ adjacent buildings due to ground accelerations are obtained for two conditions： fixed-based （FB） and structure-soil-structure interaction （SSSI）. The results indicate that pounding worsens the buildings＇ condition because their seismic responses are amplified after pounding. Moreover, the underlying soil negatively impacts the buildings＇ seismic responses during pounding because the ratio of their seismic response under SSSI conditions with pounding to those without pounding is greater than that of the FB condition.
文摘With the rapid development of high-rise buildings and long-span structures in the recent years, high performance com- putation (HPC) is becoming more and more important, sometimes even crucial, for the design and construction of com- plex building structures. To satisfy the engineering requirements of HPC, a parallel FEA computing kernel, which is designed typically for the analysis of complex building structures, will be presented and illustrated in this paper. This kernel program is based on the Intel Math Kernel Library (MKL) and coded by FORTRAN 2008 syntax, which is a parallel computer language. To improve the capability and efficiency of the computing kernel program, the parallel concepts of modern FORTRAN, such as elemental procedure, do concurrent, etc., have been applied extensively in coding and the famous PARDISO solver in MKL has been called to solve the Large-sparse system of linear equations. The ultimate objective of developing the computing kernel is to make the personal computer have the ability to analysis large building structures up to ten million degree of freedoms (DOFs). Up to now, the linear static analysis and dynamic analysis have been achieved while the nonlinear analysis, including geometric and material nonlinearity, has not been finished yet. Therefore, the numerical examples in this paper will be concentrated on demonstrating the validity and efficiency of the linear analysis and modal analysis for large FE models, while ignoring the verification of the nonlinear analysis capabilities.
文摘First, the high-rise building structure design process is divided into three relevant steps, that is, scheme generation and creation, performance evaluation, and scheme optimization. Then with the application of relational database, the case database of high-rise structures is constructed, the structure form-selection designing methods such as the smart algorithm based on CBR, DM, FINS, NN and GA is presented, and the original forms system of this method and its general structure are given. CBR and DM are used to generate scheme candidates; FINS and NN to evaluate and optimize the scheme performance; GA to create new structure forms. Finally, the application cases are presented, whose results fit in with the real project. It proves by combining and using the expert intelligence, algorithm intelligence and machine intelligence that this method makes good use of not only the engineering project knowledge and expertise but also much deeper knowledge contained in various engineering cases. In other words, it is because the form selection has a strong background support of vast real cases that its results prove more reliable and more acceptable. So the introduction of this method provides an effective approach to improving the quality, efficiency, automatic and smart level of high-rise structures form selection design.
基金the financial support received from the National Nature Science Foundation of China (Nos.51222804,91315301)the Beijing Natural Science Foundation (No.8142024)the Fok Ying Dong Education Foundation (No.131071)
文摘Numerous field tests indicate that the soilestructure interaction （SSI） has a significant impact on thedynamic characteristics of super-tall buildings, which may lead to unexpected structural seismic responsesand/or failure. Taking the Shanghai Tower with a total height of 632 m as the research object, thesubstructure approach is used to simulate the SSI effect on the seismic responses of Shanghai Tower. Therefined finite element （FE） model of the superstructure of Shanghai Tower and the simplified analyticalmodel of the foundation and adjacent soil are established. Subsequently, the collapse process of ShanghaiTower taking into account the SSI is predicted, as well as its final collapse mechanism. The influences ofthe SSI on the collapse resistance capacity and failure sequences are discussed. The results indicate that,when considering the SSI, the fundamental period of Shanghai Tower has been extended significantly,and the collapse margin ratio has been improved, with a corresponding decrease of the seismic demand.In addition, the SSI has some impact on the failure sequences of Shanghai Tower subjected to extremeearthquakes, but a negligible impact on the final failure modes. 2014 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting byElsevier B.V. All rights reserved.
文摘China is a country with many earthquakes. Seismic safety monitoring and building earthquake-proofing technique are important means to protect the safety of people’s property in China. However, up to now, China’s seismic reinforcement and identification technology is still not mature enough. In particular, the 2008 Wenchuan earthquake caused great loss of life and safety to the Chinese people. This paper, takes seismic identification and reinforcement technology of building structures as the research object and summarizes the main methods of building structure seismic resistance in China. This paper is based on an in-depth analysis of the main seismic reinforcement and identification techniques in China, deeply analyzes the crux of anti-seismic and reinforcement of building structure combining with the current building seismic reinforcement typical cases, and puts forward some reasonable suggestions and improvement methods for the future development of building seismic identification and reinforcement design.
文摘The objective of this paper is to investigate the dynamic characteristics of two adjacent building structures interconnected by viscoelastic dampers under seismic excitations. The computational procedure for an analytical model including the system model formulation, complex modal analysis and seismic time history analysis is presented for this purpose. A numerical example is also provided to illustrate the analytical model. The complex modal analysis is conducted to determine the optimal damping ratio, the optimal damper stiffness and the optimal damper damping of the viscoelastic dampers for each mode of the system. For the damper stiffness and damping with optimal values, the responses can be categorized into underdamped and critically damped vibrations. Furthermore, compared to the viscous dampers with only the energy dissipation mechanism, the viscoelastic dampers with both the energy dissipation and redistribution mechanisms are more effective for increasing the damping ratio of the system. The seismic time history analysis is conducted to assess the effectiveness of the viscoelastic dampers for vibration control. Based on the optimal damping ratio, the optimal damper stiffness, the optimal damper damping of the viscoelastic dampers for a certain mode of the system, and the viscoelastic dampers can be used to effectively suppress the root-mean-square responses as well as the peak responses of the two adjacent buildings.
