Karst collapse, caused by natural or artificial abstraction of groundwater, has been a focus of environmental geological problems for its ever-increasing hazardousness. The potential erosion theory and vacuum suction ...Karst collapse, caused by natural or artificial abstraction of groundwater, has been a focus of environmental geological problems for its ever-increasing hazardousness. The potential erosion theory and vacuum suction erosion theory, which reveal the origin of karst collapse macroscopically, are popularly accepted. However, a mathematic prediction criterion for karst collapse cannot be established only by these two theories. From a new perspective, this paper attempts to explain the microcosmic mechanism of karst collapse on the basis of these two theories. When the shear stress surpasses the shear strength of soil, a certain point or a certain plane in the unconsolidated soil covering karst caves will fail under the mechanical effects of water and air as well as its load-pressure, and with the increase of damaged points, a breaking plane appears and the soil on karst caves is completely damaged; as a result, the karst ground collapses. On the basis of the Mohr-Coulomb failure theory and previous studies, the paper presents a prediction criterion of karst collapse. Finally, by taking, for example, nine typical cases of collapse caused by pumping tests in Guizhou, the paper gives the calculation process of the model and proves its reliability.展开更多
Profile:Natatorium of Southeast University is located on the Jiulong Lake Campus of Southeast University.The design of the natatorium makes full use of the compression and moisture-proof characteristics of concrete.Se...Profile:Natatorium of Southeast University is located on the Jiulong Lake Campus of Southeast University.The design of the natatorium makes full use of the compression and moisture-proof characteristics of concrete.Seven continuous concrete arches form the shape and internal space of the building.展开更多
This paper investigates the staying and moving characteristics of office workers in a non-territorial office using an ultra wide band(UWB)impulse radio sensor network.The differences between office workers’staying an...This paper investigates the staying and moving characteristics of office workers in a non-territorial office using an ultra wide band(UWB)impulse radio sensor network.The differences between office workers’staying and moving are clarified according to the individual workstation type that they select.The study determines the characteristics of each type of workstation.By clarifying office workers’preference for staying and moving with regard to individual workstation types and office worker post,the reasons why office workers in different posts tended to select different types of workstations were revealed.Specifically,leaders tended to select workstations at the“inner meeting corner side”most frequently,as they had a greater need to stay in other areas.In contrast,ordinary staff needed to visit office workers in other areas less often,and as such,they tended to select individual workstations at the“middle meeting corner side.”Barring this,they tended to select individual workstations at the“middle corridor side”or“outer-meeting corner side.”Temporary staff members had little need to visit or stay at other places so they tended to select individual workstations at the“window side,”which is seldom visited or stayed at by other office workers and they could be disturbed less often from their solo work.展开更多
文摘Karst collapse, caused by natural or artificial abstraction of groundwater, has been a focus of environmental geological problems for its ever-increasing hazardousness. The potential erosion theory and vacuum suction erosion theory, which reveal the origin of karst collapse macroscopically, are popularly accepted. However, a mathematic prediction criterion for karst collapse cannot be established only by these two theories. From a new perspective, this paper attempts to explain the microcosmic mechanism of karst collapse on the basis of these two theories. When the shear stress surpasses the shear strength of soil, a certain point or a certain plane in the unconsolidated soil covering karst caves will fail under the mechanical effects of water and air as well as its load-pressure, and with the increase of damaged points, a breaking plane appears and the soil on karst caves is completely damaged; as a result, the karst ground collapses. On the basis of the Mohr-Coulomb failure theory and previous studies, the paper presents a prediction criterion of karst collapse. Finally, by taking, for example, nine typical cases of collapse caused by pumping tests in Guizhou, the paper gives the calculation process of the model and proves its reliability.
文摘Profile:Natatorium of Southeast University is located on the Jiulong Lake Campus of Southeast University.The design of the natatorium makes full use of the compression and moisture-proof characteristics of concrete.Seven continuous concrete arches form the shape and internal space of the building.
基金supported by the officers of the Architecture&Engineering Division,TAISEI Corporation,in facilitating and cooperating with their investigations。
文摘This paper investigates the staying and moving characteristics of office workers in a non-territorial office using an ultra wide band(UWB)impulse radio sensor network.The differences between office workers’staying and moving are clarified according to the individual workstation type that they select.The study determines the characteristics of each type of workstation.By clarifying office workers’preference for staying and moving with regard to individual workstation types and office worker post,the reasons why office workers in different posts tended to select different types of workstations were revealed.Specifically,leaders tended to select workstations at the“inner meeting corner side”most frequently,as they had a greater need to stay in other areas.In contrast,ordinary staff needed to visit office workers in other areas less often,and as such,they tended to select individual workstations at the“middle meeting corner side.”Barring this,they tended to select individual workstations at the“middle corridor side”or“outer-meeting corner side.”Temporary staff members had little need to visit or stay at other places so they tended to select individual workstations at the“window side,”which is seldom visited or stayed at by other office workers and they could be disturbed less often from their solo work.
