EVALUATION PERFORMANCE OF DUCTILE AND DAMAGED PROTECTED BRIDGE PIERS SUBJECTED TO BI-DIRECTIONAL EARTHQUAKE ATTACK

Manas Hardaha , Shikha Shrivastava

Incremental dynamic loading, pseudo dynamics, seismic response, risk assessement, Serviceability, Bi-directional loading, Hazard-recurrence.

Incremental Dynamic Analysis (IDA) procedures are advanced and then applied to a quantitative risk assessment for bridge structures. This is achieved by combining IDA with site-dependent hazard-recurrence relations and damage outcomes. The IDA procedure is also developed as a way to select a critical earthquake motion record for a one-off destructive experiment. Three prototype bridge substructures are designed according to the loading and detailing requirements of New Zealand, Japan and Caltrans codes. From these designs 30 percent reduced scale specimens are constructed as part of an experimental investigation. The Pseudo dynamic test is then to control on three specimens using the identified critical earthquake records. The results are presented in a probabilistic risk based format. The differences in the seismic performance of the three different countries’ design codes are examined. Seismic response is expected to be resulting damage on structures, which may threaten post-earthquake serviceability. To overcome this major performance shortcoming, the seismic behaviour under bi-directional lateral loading is investigated for a bridge pier designed and constructed in accordance with Damage Avoidance principles. Due to the presence of steel armoured rocking interface at the base, it is demonstrated that damage can be avoided, but due to the lack of hysteresis it is necessary to add some supplemental damping. Experimental results of the armoured rocking pier under bi-directional loading are compared with a companion ductile design specimen. The Pseudo dynamic (PD) test method was developed about 30 years ago by Takanashi et al. (1975) and is thought to be the most efficient and powerful alternative to both STT method and dynamic analytical method, especially when the real response behaviors, such as the damage state during and after a certain earthquake are need to be investigated. On the other hand, considerable number of the dynamic analysis programs running on conventional personal computers has been developed recently and the accuracy and reliability of the results improved as the new theories are applied to them. Also, the cost of running the computer becomes cheaper. Considering these background, the dynamic analysis is strong and reasonable tool for the seismic research except that the dynamic analysis method is needed to assume the simplified model for the properties of structures such as the lateral load and displacement relationship and hysteresis damping factors. On the other hand, considerable number of the dynamic analysis programs running on conventional personal computers has been developed recently and the accuracy and reliability of the results improved as the new theories are applied to them. Also, the cost of running the computer becomes cheaper. Considering these Back ground, the dynamic analysis is strong and reasonable tool for the seismic research except that the dynamic analysis method is needed to assume the simplified model for the properties of structures such as the lateral load and displacement relationship and hysteresis damping factors. As mentioned previously, this research explores the use of a newly developed Seismic Risk Assessment (SRA) methodology. This proposed methodology can be applied Performance-Based Earthquake Engineering as a tool to estimate the damage outcome corresponding to a certain level of an earthquake. Furthermore, this methodology makes it possible to select a critical input earthquake motion for a one off Experiment.

Volume 4 Issue 4, April-2019

Pages : 114 - 116