The capacity and size of hydro-generator units are increasing with the rapid development of hydroelectric enterprises, and the vibration of the powerhouse structure has increasingly become a major problem. Field testi...The capacity and size of hydro-generator units are increasing with the rapid development of hydroelectric enterprises, and the vibration of the powerhouse structure has increasingly become a major problem. Field testing is an important method for research on dynamic identification and vibration mechanisms. Research on optimal sensor placement has become a very important topic due to the need to obtain effective testing information from limited test resources. To overcome inadequacies of the present methods, this paper puts forward the triaxial effective independence driving-point residue (EfI3-DPR3) method for optimal sensor placement. The Efl3-DPR3 method can incorporate both the maximum triaxial modal kinetic energy and linear independence of the triaxial target modes at the selected nodes. It was applied to the optimal placement oftriaxial sensors for vibration testing in a hydropower house, and satisfactory results were obtained. This method can provide some guidance for optimal placement of triaxial sensors of underground powerhouses.展开更多
In order to obtain a deeper understanding of the behavior of the structure under high wind load,this paper conducted an experimental study on a full-scale L-shaped single story light frame wood house under the uniform...In order to obtain a deeper understanding of the behavior of the structure under high wind load,this paper conducted an experimental study on a full-scale L-shaped single story light frame wood house under the uniform lateral load simulated using a gasbag.The investigation involved the performance of light frame wood structure after it experienced the repeated cyclic lateral wind load as well as the performance of the structure under the ultimate lateral load.Then,the study verified that light frame wood structure can resist repeated cyclic wind loads without observable degradation in stiffness during the anticipated serve life,and recommended shear wall percent drift restriction for lateral wind load design of wood structure in serviceability limit states is 1/400 drift,and in ultimate limit states is 1/80 drift.The conclusions of this paper can be benefit for the engineering practice of the light frame wood structures in high wind load regions.展开更多
Cities and municipalities are involved in the economic development of the whole country. One of the priorities of mayors is the usefulness of spatial disproportions of area as well as the structure and development of ...Cities and municipalities are involved in the economic development of the whole country. One of the priorities of mayors is the usefulness of spatial disproportions of area as well as the structure and development of housing construction. They are natural canters of public and commercial services. The aim of the article is to determine if the geographic location of the region influences the number of new apartments with planning permission and completed apartments with a completion approval by using the methods of mathematical statistics "Analysis of variance". Meaning of the geographical location of the region as a factor, which influences the construction of apartments as well as regional differences in selected Central European countries, is subject of the conclusions of the paper.展开更多
Urbanization is the physical growth of urban areas as a result of global change. As the land cost is increasing tremendously and decreasing availability of good construction site is building up pressure on the enginee...Urbanization is the physical growth of urban areas as a result of global change. As the land cost is increasing tremendously and decreasing availability of good construction site is building up pressure on the engineers to utilize even the poorest site either by providing special type of foundation or by improving ground in urban centres. In this context literature is reviewed for use of landfill site for housing. The site exploration for old dump site was carried out to assess subsoil characteristics. The objective was to evolve strategy for economical feasible ground improvement technique to obtain permissible bearing capacity of 150 kPa and total settlement not more than 50 mm. The tests carried out are load tests with geotextile mat and stone filled wire mess matress. The analysis was attempted to evaluate the soil response and bearing capacity. The site can be used for construction of low rise housing for rehabilitation of displaced persons under TP scheme within city area utilizing old landfill sites.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 50909072)the New Teachers' Fund for Doctor Station, the Ministry of Education of China (Grant No. 20090032120082)the Communication Research Item for the West Area, the Ministry of Communications of China (Grant No. 2009328000084)
文摘The capacity and size of hydro-generator units are increasing with the rapid development of hydroelectric enterprises, and the vibration of the powerhouse structure has increasingly become a major problem. Field testing is an important method for research on dynamic identification and vibration mechanisms. Research on optimal sensor placement has become a very important topic due to the need to obtain effective testing information from limited test resources. To overcome inadequacies of the present methods, this paper puts forward the triaxial effective independence driving-point residue (EfI3-DPR3) method for optimal sensor placement. The Efl3-DPR3 method can incorporate both the maximum triaxial modal kinetic energy and linear independence of the triaxial target modes at the selected nodes. It was applied to the optimal placement oftriaxial sensors for vibration testing in a hydropower house, and satisfactory results were obtained. This method can provide some guidance for optimal placement of triaxial sensors of underground powerhouses.
基金Sponsored by the National Natural Science Foundation of China(Grant No. 50508012)
文摘In order to obtain a deeper understanding of the behavior of the structure under high wind load,this paper conducted an experimental study on a full-scale L-shaped single story light frame wood house under the uniform lateral load simulated using a gasbag.The investigation involved the performance of light frame wood structure after it experienced the repeated cyclic lateral wind load as well as the performance of the structure under the ultimate lateral load.Then,the study verified that light frame wood structure can resist repeated cyclic wind loads without observable degradation in stiffness during the anticipated serve life,and recommended shear wall percent drift restriction for lateral wind load design of wood structure in serviceability limit states is 1/400 drift,and in ultimate limit states is 1/80 drift.The conclusions of this paper can be benefit for the engineering practice of the light frame wood structures in high wind load regions.
文摘Cities and municipalities are involved in the economic development of the whole country. One of the priorities of mayors is the usefulness of spatial disproportions of area as well as the structure and development of housing construction. They are natural canters of public and commercial services. The aim of the article is to determine if the geographic location of the region influences the number of new apartments with planning permission and completed apartments with a completion approval by using the methods of mathematical statistics "Analysis of variance". Meaning of the geographical location of the region as a factor, which influences the construction of apartments as well as regional differences in selected Central European countries, is subject of the conclusions of the paper.
文摘Urbanization is the physical growth of urban areas as a result of global change. As the land cost is increasing tremendously and decreasing availability of good construction site is building up pressure on the engineers to utilize even the poorest site either by providing special type of foundation or by improving ground in urban centres. In this context literature is reviewed for use of landfill site for housing. The site exploration for old dump site was carried out to assess subsoil characteristics. The objective was to evolve strategy for economical feasible ground improvement technique to obtain permissible bearing capacity of 150 kPa and total settlement not more than 50 mm. The tests carried out are load tests with geotextile mat and stone filled wire mess matress. The analysis was attempted to evaluate the soil response and bearing capacity. The site can be used for construction of low rise housing for rehabilitation of displaced persons under TP scheme within city area utilizing old landfill sites.