Many high earth-rockfill dams are constructed in the west of China. The seismic intensity at the dam site is usually very high, thus it is of great importance to ensure the safety of the dam in meizoseismal area. A 3D...Many high earth-rockfill dams are constructed in the west of China. The seismic intensity at the dam site is usually very high, thus it is of great importance to ensure the safety of the dam in meizoseismal area. A 3D FEM model is established to analyze the seismic responses of Shiziping earth-rockfill dam. The nonlinear elastic Duncan-Chang constitutive model and the equivalent viscoelastic constitutive model are used to simulate the static and dynamic stress strain relationships of the dam materials, respectively. Four groups of seismic waves are inputted from the top of the bedrock to analyze the dynamic responses of the dam. The numerical results show that the calculated dynamic magnification factors display a good consistency with the specification values. The site spectrum results in larger acceleration response than the specification spectrum. The analysis of relative dynamic displacement indicates that the displacement at the downstream side of the dam is larger than that at the upstream side. The displacement response reduces from the center of river valley to two banks. The displacement responses corresponding to the specification spectrum are a little smaller than those corresponding to the site spectrum. The analysis of shear stress indicates that a large shear stress area appears in the upstream overburden layer, where the shear stress caused by site waves is larger than that caused by specification waves. The analysis of dynamic principal stress indicates that the minimum dynamic stresses in corridor caused by specification and site waves have little difference. The maximum and minimum dynamic stresses are relatively large at two sides. The largest tensile stress occurs at two sides of the floor of grouting corridor, which may result in the crack near the corridor side. The numerical results present good consistency with the observation data of the grouting corridor in Wenchuan earthquake.展开更多
As a new type of structure which has never been built, submerged floating tunnel was studied mainly by numerical simulations. To further study the seismic response of a submerged floating tunnel, the first model exper...As a new type of structure which has never been built, submerged floating tunnel was studied mainly by numerical simulations. To further study the seismic response of a submerged floating tunnel, the first model experiment of submerged floating tunnel （SFT） under the earthquake was carried out on the unique underwater shaking table in China. The experimental results show that vertical excitation induces larger response than horizontal and different inclination degrees of the tether also cause different seismic responses. Subsequently, based on the fluid-structure interaction theory, the corresponding numerical model is established. And comparing the numerical results with the experimental results, those of shaking table test. Numerical model adopted is effective for it is shown that the numerical results are basically identical with dynamic response of SFT.展开更多
基金Foundation item： Project（IRTl125） supported by the Program for Changjiang Scholars and Innovative Research Team in Universities of China Project（B13024） supported by the ＂111＂ Project Project（BK2012811） supported by the Natural Science Foundation of Jiangsu Province, China
文摘Many high earth-rockfill dams are constructed in the west of China. The seismic intensity at the dam site is usually very high, thus it is of great importance to ensure the safety of the dam in meizoseismal area. A 3D FEM model is established to analyze the seismic responses of Shiziping earth-rockfill dam. The nonlinear elastic Duncan-Chang constitutive model and the equivalent viscoelastic constitutive model are used to simulate the static and dynamic stress strain relationships of the dam materials, respectively. Four groups of seismic waves are inputted from the top of the bedrock to analyze the dynamic responses of the dam. The numerical results show that the calculated dynamic magnification factors display a good consistency with the specification values. The site spectrum results in larger acceleration response than the specification spectrum. The analysis of relative dynamic displacement indicates that the displacement at the downstream side of the dam is larger than that at the upstream side. The displacement response reduces from the center of river valley to two banks. The displacement responses corresponding to the specification spectrum are a little smaller than those corresponding to the site spectrum. The analysis of shear stress indicates that a large shear stress area appears in the upstream overburden layer, where the shear stress caused by site waves is larger than that caused by specification waves. The analysis of dynamic principal stress indicates that the minimum dynamic stresses in corridor caused by specification and site waves have little difference. The maximum and minimum dynamic stresses are relatively large at two sides. The largest tensile stress occurs at two sides of the floor of grouting corridor, which may result in the crack near the corridor side. The numerical results present good consistency with the observation data of the grouting corridor in Wenchuan earthquake.
基金Projects(51108224,51179026) supported by the National Natural Science Foundation of China
文摘As a new type of structure which has never been built, submerged floating tunnel was studied mainly by numerical simulations. To further study the seismic response of a submerged floating tunnel, the first model experiment of submerged floating tunnel （SFT） under the earthquake was carried out on the unique underwater shaking table in China. The experimental results show that vertical excitation induces larger response than horizontal and different inclination degrees of the tether also cause different seismic responses. Subsequently, based on the fluid-structure interaction theory, the corresponding numerical model is established. And comparing the numerical results with the experimental results, those of shaking table test. Numerical model adopted is effective for it is shown that the numerical results are basically identical with dynamic response of SFT.
