The effect of material properties on the seismic performance of Arch Dams

B Sevim

doi:10.5194/nhess-11-2253-2011

Abstract

Abstract. The paper investigates the effect of material properties on the seismic performance of arch dam-reservoir-foundation interaction systems based on the Lagrangian approach using demand-capacity ratios. Type-5 arch dam is selected as a numerical application. The linear time history analyses of the arch dam-reservoir-foundation interaction system are carried out for different material properties. The foundation is taken into account as massless; behaviour of the reservoir is assumed to be linearly elastic, inviscid and irrotational. The north-south component of the Erzincan earthquake in 1992 is chosen as a ground motion. Dynamic equations of motions obtained from 3-D finite element modelling of the coupled system are solved by using the Newmark integration algorithm. The damage levels of the coupled system for the different material properties are demonstrated by using demand-capacity ratios and cumulative inelastic durations. The time histories and maximum values of the displacements and principal stresses, and performance curves, are obtained from linear analyses. It is clearly seen from the study that the different material properties affect the seismic behaviour of the dam.

Highlights

Built to obtain energy, is a solid concrete hydraulic structure curved in plan and possibly in elevation, which transmits a large portion of the water pressure and other loads by means of thrust to the abutment utilising the compressive strength of its material
The main purpose of this study is to assess the seismic performance of arch dams including dam-reservoir-foundation interaction using demand-capacity ratios and cumulative inelastic durations obtained for different material properties
The plotted by displa3y.0ing the demand-capacity ratios (DCR) in time histories of displacements for each case are similar to Fig. 19a–c

Summary

Introduction

Built to obtain energy, is a solid concrete hydraulic structure curved in plan and possibly in elevation, which transmits a large portion of the water pressure and other loads by means of thrust (arch action) to the abutment utilising the compressive strength of its material. Since the variables in the fluid and structure are different in this approach, special interface equations are required to solve the coupled system. The nonlinear procedures are required to assess the seismic damage level of concrete dams in earthquake-prone areas. It is possible to use linear procedures for qualitative estimating of the damage level of concrete arch dams subjected to earthquakes (Ghanaat, 2002; USACE, 2003). A linear earthquake analysis of a concrete dam subjected to strong ground motion gives peak tensile stresses greater than the dynamic tensile strength of concrete, so that nonlinear procedures are required to assess the seismic safety of concrete dams in earthquake-prone areas. The main purpose of this study is to assess the seismic performance of arch dams including dam-reservoir-foundation interaction using demand-capacity ratios and cumulative inelastic durations obtained for different material properties.

Damage criteria for Arch Dams

Numerical example

Findings

The effects of mass density on the seismic