The Effects of Long-Duration Subduction Earthquakes on Inelastic Behavior of Bridge Pile Foundations Subjected to Liquefaction-Induced Lateral Spreading

Effective-stress nonlinear dynamic analyses (NDA) were performed for a large-diameter reinforced concrete (RC) pile in multi-layered liquefiable sloped ground. The objective was to assess the effects of earthquake duration on the combination of inertia and liquefaction-induced lateral spreading. A parametric study was performed using input motions from subduction and crustal earthquakes covering a wide range of motion durations. The NDA results showed that the pile head displacements increased under liquefied conditions, compared to nonliquefied conditions, due to liquefaction-induced lateral spreading. The NDA results were used to develop a displacement-based equivalent static analysis (ESA) method that combines inertial and lateral spreading loads for estimating elastic and inelastic pile demands

Influence of highway 3D coordination on drivers' perception of horizontal curvature and available sight distance

"This paper is a preprint of a paper submitted to [journal] and is subject to Institution of Engineering and Technology Copyright. If accepted, the copy of record will be available at IET Digital Library"Drivers' road perception is an important human factor of comfort and safety on driving. Available sight distance of crest vertical curves superimposed on horizontal curves can be geometrically optimised by applying 3D coordination criteria. However, drivers might not perceive available sight distance improvements. Two approaches were used to investigate the effect of geometrical optimised design on perceived sharpness and visibility of isolated crest vertical curves overlapped with horizontal curves. A survey-based approach was used to evaluate subjective perception of 100 drivers. Three-dimensional renderings were displayed to subjects; who were asked to rank the curves by sharpness and sight distance. Moreover, 50 of those drivers previously participated on a driving simulation experiment involving the same curves, so objective driving data were collected too. Drivers' survey results indicate that driver's curve perception depends on the algebraic difference of grades while coordination of vertical and horizontal curves does not appear to affect this perception. On the other hand, the operating speeds on different curves were not statistically different from each other. Surprisingly, the operating speeds on a flat curve tended to be lower than on the vertical crest curves superimposed on the same horizontal curve. Likely causes are discussed in the paper.Moreno Chou, AT.; García García, A.; Camacho Torregrosa, FJ.; Llorca Garcia, C. (2013). Influence of highway 3D coordination on drivers' perception of horizontal curvature and available sight distance. IET Intelligent Transport Systems. 7(2):244-250. doi:10.1049/iet-its.2012.0146S24425072Hassan, Y., & Easa, S. M. (2000). Modeling of Required Preview Sight Distance. Journal of Transportation Engineering, 126(1), 13-20. doi:10.1061/(asce)0733-947x(2000)126:1(13)García, A. (2004). Discussion of «Optimal Vertical Alignment Analysis for Highway Design» by T. F. Fwa, W. T. Chan, and Y. P. Sim. Journal of Transportation Engineering, 130(1), 138-138. doi:10.1061/(asce)0733-947x(2004)130:1(138)Bidulka, S., Sayed, T., & Hassan, Y. (2002). Influence of Vertical Alignment on Horizontal Curve Perception: Phase I: Examining the Hypothesis. Transportation Research Record: Journal of the Transportation Research Board, 1796(1), 12-23. doi:10.3141/1796-02Hassan, Y., Sayed, T., & Bidulka, S. (2002). Influence of Vertical Alignment on Horizontal Curve Perception: Phase II: Modeling Perceived Radius. Transportation Research Record: Journal of the Transportation Research Board, 1796(1), 24-34. doi:10.3141/1796-03Hasan, M., Sayed, T., & Hassan, Y. (2005). Influence of vertical alignment on horizontal curve perception: effect of spirals and position of vertical curve. Canadian Journal of Civil Engineering, 32(1), 204-212. doi:10.1139/l04-090Wang, F., & Easa, S. M. (2009). Validation of Perspective-View Concept for Estimating Road Horizontal Curvature. Journal of Transportation Engineering, 135(2), 74-80. doi:10.1061/(asce)0733-947x(2009)135:2(74)Bella, F. (2007). Parameters for Evaluation of Speed Differential. Transportation Research Record: Journal of the Transportation Research Board, 2023(1), 37-43. doi:10.3141/2023-05Ben-Bassat, T., & Shinar, D. (2011). Effect of shoulder width, guardrail and roadway geometry on driver perception and behavior. Accident Analysis & Prevention, 43(6), 2142-2152. doi:10.1016/j.aap.2011.06.004Jia, L., Wang, J., & Lu, M. (2011). Using real-world data to calibrate a driving simulator measuring lateral driving behaviour. IET Intelligent Transport Systems, 5(1), 21-31. doi:10.1049/iet-its.2009.0094Antonson, H., Mårdh, S., Wiklund, M., & Blomqvist, G. (2009). Effect of surrounding landscape on driving behaviour: A driving simulator study. Journal of Environmental Psychology, 29(4), 493-502. doi:10.1016/j.jenvp.2009.03.005Land, M. F., & Lee, D. N. (1994). Where we look when we steer. Nature, 369(6483), 742-744. doi:10.1038/369742a0Zuriaga, A. M. P., García, A. G., Torregrosa, F. J. C., & D’Attoma, P. (2010). Modeling Operating Speed and Deceleration on Two-Lane Rural Roads with Global Positioning System Data. Transportation Research Record: Journal of the Transportation Research Board, 2171(1), 11-20. doi:10.3141/2171-02Kweon, B.-S., Ellis, C. D., Lee, S.-W., & Rogers, G. O. (2006). Large-Scale Environmental Knowledge. Environment and Behavior, 38(1), 72-91. doi:10.1177/001391650528009

Dynamic Effects of Turbulent Crosswind on the Serviceability State of Vibrations of a Slender Arch Bridge Including Wind-Vehicle-Bridge Interaction

The use of high-performance materials in bridges is leading to structures that are more susceptible to wind- and traffic-induced vibrations due to the reduction in the weight and the increment of the slenderness in the deck. Bridges can experience considerable vibration due to both moving vehicles and wind actions that affect the comfort of the bridge users and the driving safety. This work explored the driving safety and comfort in a very slender arch bridge under turbulent wind and vehicle actions, as well as the comfort of pedestrians. A fully coupled wind–vehicle–bridge interaction model based on the direct integration of the system of dynamics was developed. In this model, the turbulent crosswind is represented by means of aerodynamic forces acting on the vehicle and the bridge. The vehicle is modeled as a multibody system that interacts with the bridge by means of moving contacts that also simulate road-surface irregularities. A user element is presented with generality and implemented using a general-purpose finite-element software package to incorporate the aeroelastic components of the wind forces, which allows modeling and solving of the wind–vehicle–bridge interaction in the time domain without the need for using the modal superposition technique. An extensive computational analysis program is performed on the basis of a wide range of turbulent crosswind speeds. The results show that bridge vibration is significantly affected by the crosswind in terms of peak acceleration and frequency content when the crosswind intensity is significant. The crosswind has more effect on the ride comfort of the vehicle in the lateral direction and, consequently, on its safety in terms of overturning accidents