期刊：
Journal of Advanced Transportation,2022年2022 ISSN：0197-6729
通讯作者：
Yuan, J.
作者机构：
School of Traffic and Transportation Engineering, Changsha University of Science and Technology, Changsha, China;College of Civil Engineering, Hunan City University, Yiyang, China;Engineering Research Center of Catastrophic Prophylaxis and Treatment of Road and Traffic Safety of Ministry of Education, Changsha University of Science and Technology, Changsha, China;Xiangtan Technology Research Center of Urban Planning Information, Xiangtan, China
通讯机构：
School of Traffic and Transportation Engineering, Changsha University of Science and Technology, Changsha, China
摘要：
The glass fiber-reinforced polymer (GFRP) rebar reinforced cemented soil is widely employed to solve the weak foundation problem led by sludge particularly. The robustness of this structure is highly dependent on the interface bond strength between the GFRP tendon and cemented soils. However, its application is obstructed owing to the deficient studies on the influence factors. Therefore, this study investigates the effects of water content (C-w: 50%-90%), cement proportion (C-c: 6%-30%), and curing period (T (c): 28-90 days) on peak and residual interface bond strengths (T-p and T-t), as well as the unconfined compression strength (UCS). Results indicated that mechanical properties were positively responded to T-c and C-c, while negatively correlated to C-w. Besides, Random Forest (RF), one of the machine learning (ML) models, was developed with its hyperparameters tuned by the firefly algorithm (FA) based on the experimental dataset. The pullout strength was predicted by the ML model for the first time. High correlation coefficients and low root-mean-square errors verified the accuracy of established RF-FA models in this study. Subsequently, a coFA-based multi-objective optimisation firefly algorithm (MOFA) was introduced to optimise tri-objectives between UCS, T-p (or T-t), and cost. The Pareto fronts were successfully acquired for optimal mixture designs, which contributes to the application of GFRP tendon reinforced cemented soil in practice. In addition, the sensitivity of input variables was evaluated and ranked. (C)& nbsp;2022 The Authors. Published by Elsevier B.V.& nbsp;
摘要：
The analysis of time-frequency variation and energy refinement characteristics of blasting vibration signals has contributed to understanding the propagation law of blasting vibration wave and reducing the possible losses. Combined with the measured data of tunnel blasting excavation and based on the newly constructed wavelet function, the spectrum distribution and energy refinement characteristics of tunnel blasting vibration signals are deeply explored and studied. The results demonstrated that compared to the Fourier spectrum, the innovative method of scale energy spectrum can not only acquire the dominant frequency of the blasting vibration signals, but also the obtained spectrum curve is smoother and can clearly reflect the change trend of the signal spectrum. The newly constructed biorthogonal wavelet has the characteristics of high vanishing moment, high regularity and matching with the waveform variation of the measured blasting vibration signals, and can describe the subtle variation characteristics of blasting vibration signal frequency. The continuous wavelet transform energy spectrum can reflect the three-dimensional energy distribution of blasting vibration signal in the time-scale domain, and the occurrence time of frequency, the frequency duration interval and time range of blasting vibration signal can also be acquired. Wavelet packet algorithm can precisely calculate the energy distribution of each frequency component in the signal, the tunnel blasting vibration signals (YBJ1, YBJ2) generated near the power tower presents low frequency, while the signals (YBF3,YBF4) far away from the power tower presents relatively high frequency. Measures should be taken to control the vibration and resonance of power tower caused by tunnel blasting. This research is of great significance for recognizing the propagation law of vibration waves, reducing the impact of blasting on surrounding buildings, and ensuring the safety of tunnel construction and surrounding buildings.
摘要：
Facing the contradiction between increasing maintenance demand and limited financial, as well as smaller social and environmental impacts, the optimisation of bridge maintenance strategies should be carried out. In this paper, the assessment model of four objectives, including the safety performance, economic, social and environmental impacts, in sustainability criteria are proposed. Moreover, a systematic optimisation framework of maintenance strategy of deteriorating bridges considering sustainability criteria and a novel decision-making method are developed, based on fuzzy analytic hierarchy process (FAHP) and a decision-making algorithm based on linear programming techniques for multidimensional analysis of preference (LINMAP). The case analysis results verify the effectiveness and superiority of the previous optimisation framework, and also show that the final optimal strategy obtained by the proposed decision-making algorithm can reflect the will of experts well. Compare with the essential maintenance, the implementation of preventive maintenance is more conducive to realise the sustainable development of the deteriorating bridges. The sensitivity analysis results show that the monetary discount rate has a greater impact on the life cycle maintenance cost, which is mainly controlled by the total social cost, while the direct maintenance cost only accounts for a small part.
关键词：
Performance design;reinforced concrete column;energy dissipation capacity;damage index;performance index limits
摘要：
The quantitative relationship between the energy dissipation capacity of RC members and displacement deformation, cumulative energy dissipation and structural design parameters were established by the research group in the early stage, and then the damage index based on energy dissipation capacity and performance index limits were proposed. Based on the existing research, the seismic design method of RC square/rectangular column members for SDOF systems based on damage performance is proposed, and the method is introduced by an example. It is found that the seismic design method establishes a quantitative relationship between the structural design parameters and seismic parameters, which is convenient to guide the structural design. The increase in the ratio of transverse reinforcement can reduce the damage to RC column members, but when the ratio of transverse reinforcement exceeds a certain threshold value, the damage reduction effect is not obvious. The increase of the earthquake duration can aggravate the development of the damage to the RC column members, and the increasing effect is first fast and then slow. This seismic design method can make up for the deficiency that the duration effect is not considered in the current seismic code.
期刊：
Advances in Transportation Studies,2022年2(Special Issue):133-144 ISSN：1824-5463
通讯作者：
Gong, B.B.(24148408@qq.com)
作者机构：
[Gong, B.B.] College of Civil Engineering, Hunan City University, YiYang;413000, China;Hunan Engineering Research Center of Structural Safety and Disaster Prevention for Urban Underground infrastructure, YiYang;[Gong, B.B.] 413000, China<&wdkj&>Hunan Engineering Research Center of Structural Safety and Disaster Prevention for Urban Underground infrastructure, YiYang;[Gong, B.B.] 413000, China
通讯机构：
[Gong, B.B.] C;College of Civil Engineering, China
关键词：
Grey gm(1,N) model;Improving random forest;Risk projection;Road traffic safety;Similarity measure
作者机构：
[Yang, Rihua; Wang, Xinzhong; Yang, Yiming] Hunan City Univ, Sch Civil Engn, Yiyang 413000, Peoples R China.;[Wang, Xinzhong] Hunan City Univ, Hunan Engn Res Ctr Struct Safety & Disaster Preve, Yiyang 413000, Peoples R China.;[Liu, Peng] Cent South Univ, Sch Civil Engn, Changsha 410013, Peoples R China.
通讯机构：
[Yiming Yang] S;[Peng Liu] A;Authors to whom correspondence should be addressed.<&wdkj&>School of Civil Engineering, Central South University, Changsha 410013, China<&wdkj&>School of Civil Engineering, Hunan City University, Yiyang 413000, China<&wdkj&>Authors to whom correspondence should be addressed.
关键词：
basalt-fiber-reinforced concrete;concrete compressive strength;construction performance;ultimate bearing capacity;finite element analysis
