Скачать с ютуб Behavior of UHPFRC Strengthened Bridge Piers Under Lateral Impact Loads в хорошем качестве

Behavior of UHPFRC Strengthened Bridge Piers Under Lateral Impact Loads

Presented By: Gholamreza Gholipour, Lakehead University Description: UHPFRC is one of the advanced high-strength concrete materials which demonstrates superior durability, strength and energy dissipation capacity against seismic and extreme loads. The impact performance of a UHPFRC-strengthened bridge pier is numerically investigated. The performance of the strengthened columns is assessed with the variations of different parameters including the thickness of UHPFRC jacket (tU), impact velocity (Vimp ), and axial load ratio (ALR). Since the full use of UHPFRC material for the whole cross- section of piers, can unreasonably increase the construction costs without any significant strength enhancement, exploring optimal levels for the thickness of UHPFRC jacket is as of interest. From sensitivity analysis of the damage index to tU, a thickness of 60 mm was recognized as the optimal level based on the behavioral trend of the UHPFRC-strengthened columns. That is, although tU had a marginal positive influence on the column impact resistance when it was beyond 60 mm, the application of a 60-mm-thickness UHPFRC jacket significantly increased the resistance of the column by reducing the damage index by 55% compared to conventional column. The columns with tU higher than 60 mm, endured low-level damage with an index of less than 0.2 when subjected to impact loads with velocities less than 10 m/s and the damage index was not highly sensitive to tU. Under impact loads with velocities higher than 10 m/s, a thickness of 60 mm was recognized as the optimal thickness of UHPFRC jacket for the column resistance. Also, an marginal positive effect of ALR on the impact resistance of the UHPFRC-strengthened columns.