Dynamic behavior of two-dimensional homogeneous earth dam models subjected to incident SH waves and synchronized input motion

الملخص EN

In many parts of the world, both industrialized and newly developing nations, the need for dam construction continues.

Dams are important for water storage as well as power generation.

In recent history, there have been many reports of damage to dams in major earthquakes.

Several earthquakes were speculated to have been triggered by a newly placed dam and its reservoir in the area.

Severe damage to a dam can be catastrophic for the cities downstream and therefore, better seismic analysis and design procedures for dams are needed.

There are three common types of dams: Arch Dams, Concrete Gravity Dams, and Earth Dams.

The method used to analyze concrete dams is somewhat different from that for earth dams.

Because of the geometry, the steel reinforcement and the properties of concrete, the stress analysis must account for bending in addition to shear effects.

With an irregular geometry, the only feasible method for analyzing concrete dams is the finite element method with element types that include bending effects.

However, earth dams may not experience large bending deformations, so they can be treated as a continuous but heterogeneous medium of irregular shape.

For this reason, methods commonly used in wave propagation studies but not presently used for dam analyses should be considered for possible applications.

Among the many methods that can be used to solve elastodynamic problems, the most versatile are: (a) the finite elements method [1,2]; (b) the finite difference method [3-5]; (c) the continuum mechanics methods [6]; (d) the hybrid discrete-continuum method [7, 8].

There are many methods that can be identified as continuum methods, even though most of them require numerical discretization.

Their solutions are written as a linear combination of continuous wave functions of mathematical physics, and the unknown coefficients associated with the wave functions are determined from the boundary conditions.

The Boundary Integral Equation Method (BIEM) is classified as a continuum method.

Unlike discrete methods, the Boundary Integral Equation Method does not require discretization of the entire volume; only the interfaces between contrasting material properties are considered.

Therefore, the BIEM is simpler than discrete methods when there are few interfaces.

In this paper, the Boundary Integral Equation Method is used to analyze the dynamic behavior of two-dimensional antiplane models resembling earth dams and subjected to SH incident waves and synchronized input excitation.

This analysis investigates primarily the physical effects caused by wave passage through the base of the dam while the hydrodynamic effects will be ignored [9].

The BIEM solution accuracy for semi-circular antiplane cross-section have been tested favorably against exact solutions.

Also, the behavior of a trapezoidal cross-section will be included in this study.

Numerically, the BIEM will be evaluated as a possibly useful tool for vibration problems.