Bedding rock slopes are common geological features in nature that are prone to failure under strong earthquakes. Their failures induce catastrophic landslides and form barrier lakes, posing severe threats to people’s...Bedding rock slopes are common geological features in nature that are prone to failure under strong earthquakes. Their failures induce catastrophic landslides and form barrier lakes, posing severe threats to people’s lives and property. Based on the similarity criteria, a bedding rock slope model with a length of3 m, a width of 0.8 m, and a height of 1.6 m was constructed to facilitate large-scale shaking table tests.The results showed that with the increase of vibration time, the natural frequency of the model slope decreased, but the damping ratio increased. Damage to the rock mass structure altered the dynamic characteristics of the slope;therefore, amplification of the acceleration was found to be nonlinear and uneven. Furthermore, the acceleration was amplified nonlinearly with the increase of slope elevation along the slope surface and the vertical section, and the maximum acceleration amplification factor(AAF) occurred at the slope crest. Before visible deformation, the AAF increased with increasing shaking intensity;however, it decreased with increasing shaking intensity after obvious deformation. The slope was likely to slide along the bedding planes at a shallow depth below the slope surface. The upper part of the slope mainly experienced a tensile-shear effect, whereas the lower part suffered a compressive-shear force. The progressive failure process of the model slope can be divided into four stages, and the dislocated rock mass can be summarized into three zones. The testing data provide a good explanation of the dynamic behavior of the rock slope when subjected to an earthquake and may serve as a helpful reference in implementing antiseismic measures for earthquake-induced landslides.展开更多
This paper presents results of experimental and numerical investigations of a seesaw energy dissipation system （SEDS） using fluid viscous dampers （FVDs）. To confirm the characteristics of the FVDs used in the test...This paper presents results of experimental and numerical investigations of a seesaw energy dissipation system （SEDS） using fluid viscous dampers （FVDs）. To confirm the characteristics of the FVDs used in the tests, harmonic dynamic loading tests were conducted in advance of the flee vibration tests and the shaking table tests. Shaking table tests were conducted to demonstrate the damping capacity of the SEDS under random excitations such as seismic waves, and the results showed SEDSs have sufficient damping capacity for reducing the seismic response of flames. Free vibration tests were conducted to confirm the reliability of simplified analysis. Time history response analyses were also conducted and the results are in close agreement with shaking table test results.展开更多
Over the past decade the use of large size glazing has increased with timber structures. Most of the research works done so far have focused on the building physics aspects of the glazing. This paper, however, deals w...Over the past decade the use of large size glazing has increased with timber structures. Most of the research works done so far have focused on the building physics aspects of the glazing. This paper, however, deals with the seismic behaviour of timber-glass systems. A series of experiments were performed on the shaking table of the IZIIS institute inSkopje,Macedonia. Oneand two-story full scale structures were subjected to a series of ground motions, namely sinus sweep testing, natural and modified ground motion accelerograms. All together 8 different setups were tested in elastic and inelastic behaviour range. Displacements and accelerations were measured in each floor as well as the slipping of walls, uplifting of their corners and the shear deformation of the adhesive between the glass panels and the timber frames. The tested combination of timber-glass walls exhibited a rocking type of behaviour, resulting in a desirable ductile failure of steel hold-downs and not brittle failure of the glazing nor failure of the adhesive. Hence such a combination of glass and timber in wall systems could potentially be used in seismically active areas.展开更多
基金funded by the National Natural Science Foundation of China (Grant No. 41825018)the National Key Research and Development Plan of China (Grant No. 2019YFC1509704)the Second Tibetan Plateau Scientific Expedition and Research Program (STEP, Grant No. 2019QZKK0904)。
文摘Bedding rock slopes are common geological features in nature that are prone to failure under strong earthquakes. Their failures induce catastrophic landslides and form barrier lakes, posing severe threats to people’s lives and property. Based on the similarity criteria, a bedding rock slope model with a length of3 m, a width of 0.8 m, and a height of 1.6 m was constructed to facilitate large-scale shaking table tests.The results showed that with the increase of vibration time, the natural frequency of the model slope decreased, but the damping ratio increased. Damage to the rock mass structure altered the dynamic characteristics of the slope;therefore, amplification of the acceleration was found to be nonlinear and uneven. Furthermore, the acceleration was amplified nonlinearly with the increase of slope elevation along the slope surface and the vertical section, and the maximum acceleration amplification factor(AAF) occurred at the slope crest. Before visible deformation, the AAF increased with increasing shaking intensity;however, it decreased with increasing shaking intensity after obvious deformation. The slope was likely to slide along the bedding planes at a shallow depth below the slope surface. The upper part of the slope mainly experienced a tensile-shear effect, whereas the lower part suffered a compressive-shear force. The progressive failure process of the model slope can be divided into four stages, and the dislocated rock mass can be summarized into three zones. The testing data provide a good explanation of the dynamic behavior of the rock slope when subjected to an earthquake and may serve as a helpful reference in implementing antiseismic measures for earthquake-induced landslides.
文摘This paper presents results of experimental and numerical investigations of a seesaw energy dissipation system （SEDS） using fluid viscous dampers （FVDs）. To confirm the characteristics of the FVDs used in the tests, harmonic dynamic loading tests were conducted in advance of the flee vibration tests and the shaking table tests. Shaking table tests were conducted to demonstrate the damping capacity of the SEDS under random excitations such as seismic waves, and the results showed SEDSs have sufficient damping capacity for reducing the seismic response of flames. Free vibration tests were conducted to confirm the reliability of simplified analysis. Time history response analyses were also conducted and the results are in close agreement with shaking table test results.
文摘Over the past decade the use of large size glazing has increased with timber structures. Most of the research works done so far have focused on the building physics aspects of the glazing. This paper, however, deals with the seismic behaviour of timber-glass systems. A series of experiments were performed on the shaking table of the IZIIS institute inSkopje,Macedonia. Oneand two-story full scale structures were subjected to a series of ground motions, namely sinus sweep testing, natural and modified ground motion accelerograms. All together 8 different setups were tested in elastic and inelastic behaviour range. Displacements and accelerations were measured in each floor as well as the slipping of walls, uplifting of their corners and the shear deformation of the adhesive between the glass panels and the timber frames. The tested combination of timber-glass walls exhibited a rocking type of behaviour, resulting in a desirable ductile failure of steel hold-downs and not brittle failure of the glazing nor failure of the adhesive. Hence such a combination of glass and timber in wall systems could potentially be used in seismically active areas.
