Rehabilitation of bridges after heavy vehicle impacts with the parapet

Author(s):  
F. Collazos-Arias ◽  
D. García-Sánchez
Keyword(s):  
2021 ◽  
Vol 16 (2-3) ◽  
pp. 61-74
Author(s):  
Sahar Ghasemi ◽  
Amir Mirmiran ◽  
Yulin Xiao ◽  
Kevin Mackie

A super lightweight deck can enhance load rating and functionality of a bridge, especially those identified as structurally deficient. This study was aimed to develop and experimentally validate a novel bridge deck as an ultra-lightweight low-profile waffle slab of ultra-high-performance concrete (UHPC) with either carbon fiber reinforced polymer (CFRP) or high strength steel (HSS) reinforcement. The proposed system lends itself to accelerated bridge construction, rapid deck replacement in bridges with load restrictions, and bridge widening applications without the need to replace girders. Performance and failure modes of the proposed deck were initially assessed through extensive lab experiments and finite element analysis, which together confirmed that the proposed deck panel meets the AASHTO LRFD requirements. The proposed deck system is not susceptible to punching shear of its thin slab and fails in a rather ductile manner. To evaluate its long-term performance, the system was further tested under the dynamic impact of wheel load at the Accelerated Pavement Testing (APT) facility of the Florida Department of Transportation using a Heavy Vehicle Simulator (HVS).


1999 ◽  
Author(s):  
Nigel Clark ◽  
James J. Daley ◽  
Ralph D. Nine ◽  
Christopher M. Atkinson
Keyword(s):  

1971 ◽  
Author(s):  
Norman J. Deleys ◽  
Melvin O. Ryder
Keyword(s):  

Author(s):  
N. I. Rajapakse ◽  
G. S. Happawana ◽  
Y Hurmuzlu

The current paper presents a robust control method that combines sliding-mode control (SMC) and quantitative feedback theory (QFT) for designing a driver seat of a heavy vehicle to reduce driver fatigue. A mathematical model is considered to analyse tracking control characteristics through computer simulation in order to demonstrate the effectiveness of the proposed control methodology. The SMC is used to track the trajectory of the desired motion behaviour of the seat. However, when the system enters into sliding regime, chattering occurs owing to switching delays as well as vehicle system vibrations. The chattering is eliminated with the introduction QFT inside the boundary layer to ensure smooth tracking. Furthermore, using SMC alone requires higher actuator forces for tracking than using both the control schemes together, and causes various problems in selecting hardware. Problems with noise amplification, resonances, presence of uncertainties, and unmodelled high-frequency dynamics can largely be avoided with the use of QFT over other optimization methods. The main contribution of the present paper is to provide guidance in designing the controller to reduce heavy vehicle seat vibration so that the driver's sensation of comfort maintains a certain level at all times.


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