Abstract
There are some practical problems in bridge engineering, such as high construction risk, special construction technology, complex construction equipment and so on, which lead to high ...difficulty in the construction activities of bridge engineering, especially large-scale bridge engineering. With its utilization in bridge design, BIM Tech can effectively guarantee the amelioration of bridge design quality and efficiency, which has important research value. Based on this, this paper first analyses the connotation and value of BIM Tech, and then studies the utilization points of BIM Tech in the bridge design stage. Finally, the utilization path of BIM Tech in bridge design is given.
Abstract
Architecture of bridge model between AXI Lite and AHB for this paper were simulated using Synopsys VCS and DC in Verilog HDL. Bridge structure mainly comprises of arbitration techniques, ...control signals, multiplexing techniques for writing data signals and Decoder for reading data section. In this work, bridge model between AHB and AXI lite was simulated and characterized. The proposed model of bridge design provides efficient communication between on chip bus protocols like AXI and AHB on chip in the era of deep sub-micron technology where channel side is reduced as much as 5 nm.
In this paper, the digital design and manufacturing of a post-tensioned concrete girder is presented. We bring together two emerging technologies that show great potential for realizing ...highly-efficient concrete structures: topology optimization for simulation-driven design and 3D concrete printing (3DCP) for manufacturing of optimized shapes. While this is not the first-ever 3D-printed concrete structure, it is the first demonstration of how topological design in combination with 3D concrete extrusion printing allows for creating efficient structures with reduced use of materials. As the implementation of a specific optimization procedure for post-tensioned concrete structures is so far available in 2D only, some design post-processing was necessary, and a 3D finite element analysis was performed. After realization of the 3DCP element (i.e. printing and assembly), the girder's structural performance was experimentally verified using digital image correlation. The deflection of the girder was compared with the numerical results. The manuscript includes thorough discussions on the manufacturing challenges – including printing setup, assembly and integration of reinforcement.
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•Digital design-to-manufacture process of a post-tensioned concrete girder•Unique and concurrent topology and shape optimization procedure•3D concrete printing, post-tensioning and grouting to realize the optimized design•Experimental verification of the girder's load-carrying capacity•Demonstration of 3D printing for optimized structures, enabling significant material reduction
The inverted pendulum pedestrian model (IPM) for walking on laterally-oscillating structures, originally proposed by Macdonald, has been recently calibrated based on data from pedestrians walking on ...a laterally-oscillating instrumented treadmill. It was then generalised to be suitable for the application in a predictive manner, i.e. in simulations of lateral structural response for any population of pedestrians. The generalised IPM captures the fundamental pedestrian-structure interaction mechanism and pedestrian-generated lateral forces onto a structure, including the self-excited forces which are critical from the point of view of structural stability. However, since the closed-form solutions of the generalised IPM are currently unavailable, its application requires numerical integration. To address this shortcoming, closed form solutions for the long-term average lateral self-excited forces are derived in this study based on the framework introduced by McRobie. A parametric study is conducted revealing complex interdependencies between pedestrian and bridge behaviour and their influence on the self-excited forces. The presented results are related to the measurements from full-scale bridges and laboratory investigations.
•Analytical solutions are derived for the calibrated and generalised IPM.•Phase drift and synchronisation are considered for pedestrian stepping behaviour.•Analytical solutions are verified against results obtained from numerical simulations.•A parametric study is conducted to understand the dependence of self-excited forces.•Results are compared with measurements from laboratories and full-scale bridges.
Organic solar cells (OSCs) exhibit complex charge dynamics, which are closely correlated with the dielectric constant (ɛr) of photovoltaic materials. In this work, a series of novel conjugated ...copolymers based on benzo1,2‐b:4,5‐b′difuran (BDF) and benzotriazole (BTz) is designed and synthesized, which differ by the nature of π‐bridge from one another. The PBDF‐TF‐BTz with asymmetric furan and thiophene π‐bridge demonstrates a larger ɛr of 4.22 than PBDF‐dT‐BTz with symmetric thiophene π‐bridge (3.15) and PBDF‐dF‐BTz with symmetric furan π‐bridge (3.90). The PBDF‐TF‐BTz also offers more favorable molecular packing and appropriate miscibility with non‐fullerene acceptor Y6 than its counterparts. The corresponding PBDF‐TF‐BTz:Y6 OSCs display efficient exciton dissociation, fast charge transport and collection, and reduced charge recombination, eventually leading to a power conversion efficiency of 17.01%. When introducing a fullerene derivative (PCBO‐12) as a third component, the PBDF‐TF‐BTz:Y6:PCBO‐12 OSCs yield a remarkable FF of 80.11% with a high efficiency of 18.10%, the highest value among all reported BDF‐polymer‐based OSCs. This work provides an effective approach to developing high‐permittivity photovoltaic materials, showcasing PBDF‐TF‐BTz as a promising polymer donor for constructing high‐performance OSCs.
•The evolution in design details for Californian box-girder bridges is captured.•The importance of design details on the fragility of box-girder bridges is quantified.•The framework for fragility ...analyses considers multiple component vulnerability.•Seismic vulnerability reduces with evolution of column design philosophy.•Pre 1971 era bridges with multi column bents and seat abutments are most vulnerable.
Fragility analyses is a powerful tool for the seismic risk assessment of highway bridges. Multispan continuous concrete box-girder bridges account for the bulk of the California bridge inventory. Although several studies have looked at the seismic response and fragility of individual box-girder bridges, very little research has explored the fragility of the box-girder bridge class holistically. Exacerbating this situation is the lack of considerations of design details unique to the era in which the bridges were designed and constructed, in their fragility development. This paper addresses this gap by investigating the influence of evolution of seismic design principles and details on the seismic performance of multispan continuous concrete box-girder bridge class, as well as the failure probability through the development of fragility curves across three design eras demarcated by the 1971 San Fernando and 1989 Loma Prieta earthquakes. Detailed nonlinear analytical models capturing the bridge characteristics within a design era are developed and nonlinear time history analysis is employed to develop analytical fragility curves. Significant improvement in performance is seen in modern bridges designed according to capacity design principles.
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•Automated truck platoon load on highway bridges may cause two types of resonance.•Both types of resonance can lead to an increase in DAFs of highway bridges.•Bridge DAFs can be ...effectively described by the generalized extreme value distribution.•Proper DAFs are proposed for highway bridges to accommodate truck platoon loads.
Automated truck platooning (ATP) has a good potential in energy conservation and carbon emissions reduction, yet it has raised a wide concern to the safety and performance of highway bridges. Accurately estimating ATP-induced load effects on highway bridges is necessary since it plays a crucial role in both bridge safety evaluation and traffic/ATP decision-making. Conventionally, the dynamic load effects induced by ATP on highway bridges are simplified by multiplying the static load effects with the code-specified dynamic amplification factor (DAF) which has not taken the ATP into consideration. This approach may need improvements as the actual DAFs of a bridge can be significantly affected by ATP loads. In this study, the DAFs of highway bridges under ATP loads are investigated via both theoretical analyses and numerical simulations. Several standard highway bridges with different cross-sections and span lengths and probable ATP loading scenarios are considered, and the influences of multiple factors are investigated, including the truck mass, the number of platooned trucks, and the road surface condition. Both theoretical and simulation results show that highway bridges are at risk of two types of resonance due to ATP loads. The resonance types can be roughly identified by the span length of the bridge. Specifically, bridges with span lengths shorter than 15 m are mainly affected by steady resonance while bridges with longer span lengths are at high risk of transient resonance. Both types of resonance can lead to increased DAFs of highway bridges, which may exceed the DAFs specified in bridge design codes. To accommodate ATP loads, proper DAFs are proposed as a supplement to the current bridge design codes.
Vehicle collisions with bridge piers result in a complex set of actions and reactions between the structural system and the vehicle. The design of these piers is very important as it can have an ...adverse effect on both the economy and the health and safety of users. Current design provisions, although simple to apply, do not account for the many variables that influence demand and capacity. The goal of this study was to analyze the behavior of bridge piers under vehicle collisions with respect to vehicle mass, velocity, pier diameter, and transverse reinforcement. The commercial finite element software LS-DYNA was used to simulate and analyze the vehicle collisions. The finite element models were first validated with available experimental data, then verified with the available finite element models to ensure accuracy and reliability of the results. Conservation of energy was continuously checked throughout the analyses to assure stability within each impact simulation. The results of the study show that the pier diameter governed the overall failure mode of the pier while the transverse reinforcement governed the degree of local failure. The results could be useful to bridge design engineers in ensuring that performance measures are acceptable.
•A new type of self-centering rocking (SCR) bridge pier is proposed.•Superelastic SMA washer springs are the kernel elements for the pier.•Five proof-of-concept tests are carried out on a small-scale ...SCR pier specimen.•A numerical study examining an extended range of design parameters is conducted.•Preliminary design recommendations are given.
The emergence of rocking bridge piers provides the community of civil engineers with a broader vision of next-generation seismic-resilient bridge design. This study introduces a new type of shape memory alloy (SMA) washer spring-based self-centering rocking (SCR) systems which could be an important addition to the existing rocking pier family. The proposed system combines the advantage of the existing rocking pier solution with extra benefits such as simplified construction, excellent fatigue and corrosion resistance, and extra “locking mechanism” which safely prevents the pier from excessive rocking. The working principle of the SCR piers is discussed first, and five tests are subsequently carried out on proof-of-concept SCR pier specimens. This is followed by a further numerical study examining an extended range of design parameters. The SCR pier shows excellent self-centering capability with minimal damage to the pier, which is attributed to the intended gap-opening deformation mode. Moderate energy dissipation is offered by the SMA washer springs, and once they are fully flattened, further drift is provided by the flexural deformation of the pier itself. The SMA washers can be used repeatedly with no need for repair/replacement, and the highly flexible stack pattern caters to different design objectives and requirements. An effective supplementary source of energy dissipation is enabled by installing steel angles at the gap opening interface. The experimental and numerical investigations provide a strong proof of feasibility of this innovative structural system.
STUDY ON THE ARCH DESIGN OF THE KINTAIKYO MATSUTSUKA, Nobukado; WADA, Akira
Journal of Structural and Construction Engineering (Transactions of AIJ),
2023/12/01, Letnik:
88, Številka:
814
Journal Article
Recenzirano
Odprti dostop
The Kintaikyo in Iwakuni-City, which spans the Nishiki-River in Yamaguchi Prefecture, was built in 1673. The design of the arch of this bridge was studied. It was assumed that the arch of this bridge ...were designed in arch coordinates with multiple catenary. As a result, the design theory of this bridge was derived for the first time. The multiple catenary was identified from the Kintaikyo in Heisei, and The new Kintaikyo drawing for KAKEKAE was created that is harmony and orderly. Based on this drawing, it was proved that a harmony and orderly bridge can be realized by 3D-CG.
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