Non-linear seismic response of arch dams with contraction joint opening and joint reinforcements

Abstract

A comprehensive study of non-linear seismic response of arch dams with contraction joint opening and joint reinforcements has been conducted. A numerical model of contraction joint reinforcements is presented for optimization control of the joint opening. The objective of this control is to reduce the joint opening and expectantly to balance the sustained loads between the horizontal and the vertical components of the dam, thus avoiding an overstress in the cantilever while retaining the release of arch tensile stresses to some extent. Several parameter studies such as critical element size and required number of joints to be simulated for convergence are also performed. As an engineering application, a 292-m high arch dam (the Xiaowan arch dam) and the Big Tujunga dam are analysed in detail. The results demonstrate that the joint opening and the corresponding load transfer from the arch to cantilever components of the dam during strong earthquakes are substantial. It is also evident that by providing su$cient strength and reinforcement #exibility, the joint opening can be controlled to some extent. However, the stress redistribution due to reinforcement control is not su$cient to avoid the overstress in the cantilever for the Xiaowan arch dam. Thus, alternative measures are discussed.

Seismic safety of arch dams with aging effects

“…For each joint, the initial contact distance c = 0.005 mm and the pressure value p 0 = 50 MPa at zero opening are selected. The initial strength of the grouting material is ignored because it does not contribute to the joint resistance of the dam [11]. To analyze the effect of joints on the dynamic response of arch dams, a linear dam model is also built by removing the contraction joints from the nonlinear model.…”

“…In recent years, considerable research efforts have been devoted to seismic safety study of arch dams. Some major influential factors, including dynamic dam-water-foundation interaction [1][2][3], non-uniform seismic input [4][5][6], contraction joint opening and closing [7,8], damage evolution [9,10], contraction joint reinforcement [11], reservoir sediment [12], etc., have been considered in the safety assessment of arch dams against earthquakes. One unknown factor that may have effects on the seismic safety of dams is the aging of concrete dams.…”

Seismic performance assessment of arch dams using incremental nonlinear dynamic analysis

“…Many procedures have been developed to analyse the nonlinear seismic response of arch dams considering the contraction joints opening, but with the assumption of linear elastic concrete material (Du & Tu, 2006;Fenves, Mojtahedi, & Reimer, 1992;Lau, Noruziaan, & Razaqpur, 1998;Zhang, Xu, Wang, & Jin, 2000). The results of the studies show important effects of contraction joint opening on earthquake response of arch dams.…”

Effects of shear keys on nonlinear seismic responses of an arch-gravity dam

“…Based on the pioneering research, Zhang et al [7] improved a 3-D non-linear joint element which was originally developed by Ghaboussi and Wilson [8] to study the nonlinear seismic responses of arch dams with contraction joint opening and joint reinforcement. A nonlinear joint element was developed by Azmi and Paultre [9] and incorporated into ADAP-88 program to represent the dynamic behavior of contraction joints in concrete dams.…”