Seismic response of earth dams considering dynamic properties of unsaturated zone

abstract The seismic response of multistory building and other structural systems is affected by the existence of self strains which may be induced by temperature gradients, mechanical actions, or prestraining. The fundamental dynamic properties such as natural frequencies and mode shapes are influenced by the presence of these strains. As a consequence, the response of the structure changes to the extent that the self strains change its dynamic characteristics and to the extent that these characteristics are relevant in the interaction of a particular structure with a given ground motion. This paper presents a detailed study of some simple structures such as beams and frames whose members are subjected to initial strains. The homogeneous differential equations of motion are expressed in terms of the stiffness, mass, and geometry matrices and a parameter accounting for the self-strain effect. The solution of the resulting eigenvalue problem is used to write the modal equations into which the desired ground motion is applied. The final response is obtained from the appropriate shock spectrum and the application of root-mean-square superposition technique. The disturbing action produced by the ground motion of the well known El Centro earthquake of 1940 is applied to several structures in which the amount of self-strain is varied as a parameter.

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Seismic response of earth dams: some recent developments

Soil Dynamics and Earthquake Engineering ◽

10.1016/0267-7261(87)90008-x ◽

1987 ◽

Vol 6 (1) ◽

pp. 2-47 ◽

Cited By ~ 148

Author(s):

George Gazetas

Keyword(s):

Seismic Response ◽

Earth Dams ◽

Recent Developments

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Optimization Design of Core Thickness of Exterior Frame and Core Hybrid Structures in High-Rise Buildings

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.166-169.14 ◽

2012 ◽

Vol 166-169 ◽

pp. 14-18

Author(s):

Shu Yun Zhang ◽

Wen Wei Zhao ◽

Hai Hua Wang

Keyword(s):

Seismic Response ◽

Optimization Design ◽

Dynamic Properties ◽

Response Spectrum ◽

Optimization Method ◽

Hybrid Structure ◽

Hybrid Structures ◽

Response Analysis ◽

High Rise ◽

Core Thickness

Considering core thickness is important issue to performance of exterior frame and core hybrid structure in high-rise buildings, seismic response analysis is conducted by response spectrum method for finite element models with different core thickness. The optimization design of core thickness of hybrid Structures on the basis of the seismic response is studied, the core thicknesses are chosen as design variables, the objective function about core volume is adopted, some specification requirements such as deformation, the ratio of lateral stiffness to gravity, storey shear to gravity, storey shear of exterior frame, axial compression ratio of column and wall limb, bearing capacity of structural member and core construction are regarded as restricting conditions, the optimal mathematical model is established for reflecting integrity dynamic properties of hybrid structure. The ANSYS software is used for optimizing tool, the hybrid structures optimization design are made through different initial values for verifying convergence of optimization method, the optimal result show that the performances of hybrid structure are improved, the internal forces are reduced and the ratios of inner force born by exterior frames are increased in the optimal scheme.

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Elasto-plastic seismic response of 3-D earth dams: Application

International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts ◽

10.1016/0148-9062(88)92637-x ◽

1988 ◽

Vol 25 (3) ◽

pp. 145

Keyword(s):

Seismic Response ◽

Earth Dams

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Elasto‐Plastic Seismic Response of 3‐D Earth Dams: Application

Journal of Geotechnical Engineering ◽

10.1061/(asce)0733-9410(1987)113:11(1309) ◽

1987 ◽

Vol 113 (11) ◽

pp. 1309-1325 ◽

Cited By ~ 10

Author(s):

Ahmed‐Waeil M. Elgamal ◽

Ahmed M. Abdel‐Ghaffar

Keyword(s):

Seismic Response ◽

Earth Dams

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The Role of Shear Wave Velocity and Non-Linearity of Soil in the Seismic Response of a Coupled Tunnel-Soil-Above Ground Building System

Geosciences ◽

10.3390/geosciences9110473 ◽

2019 ◽

Vol 9 (11) ◽

pp. 473 ◽

Cited By ~ 2

Author(s):

Glenda Abate ◽

Salvatore Grasso ◽

Maria Rossella Massimino

Keyword(s):

Seismic Response ◽

Shear Wave ◽

Wave Velocity ◽

Shear Wave Velocity ◽

Dynamic Properties ◽

Kinematic Hardening ◽

System Response ◽

Flow Rule ◽

Elastic Model

The presence of tunnels close to aboveground structures may modify the response of these structures, while the contrary is also true, the presence of aboveground structures may modify the dynamic response of tunnels. In this context, the dynamic properties of the soil through which the aboveground and underground structures are “connected” could play an important role. The paper reports dynamic FEM (Finite Element Method) analyses of a coupled tunnel-soil-above ground structure system (TSS system), which differ in regards to the soil shear wave velocity and in turns for the damping ratio, in order to investigate the role of these parameters in the full-coupled TSS system response. The analyses were performed using three different seismic inputs. Moreover, the soil non-linearity was taken into account adopting two different constitutive models: i) an equivalent linear visco-elastic model, characterized by degraded soil shear moduli and damping ratios, according to suggestions given by EC8 in 2003; and ii) a visco-elasto-plastic constitutive model, characterized by isotropic and kinematic hardening and a non-associated flow rule. The seismic response of the system was investigated in the time and frequency domains, in terms of: acceleration ratios; amplification ratios and response spectra; and bending moments in the tunnel.

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