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Assessment of novel nature-inspired fuzzy models for predicting long contraction scouring and related

《结构与土木工程前沿（英文）》 2021年第15卷第3期页码 665-681 doi: 10.1007/s11709-021-0713-0

摘要： The scouring phenomenon is one of the major problems experienced in hydraulic engineering. In this study, an adaptive neuro-fuzzy inference system is hybridized with several evolutionary approaches, including the ant colony optimization, genetic algorithm, teaching-learning-based optimization, biogeographical-based optimization, and invasive weed optimization for estimating the long contraction scour depth. The proposed hybrid models are built using non-dimensional information collected from previous studies. The proposed hybrid intelligent models are evaluated using several statistical performance metrics and graphical presentations. Besides, the uncertainty of models, variables, and data are inspected. Based on the achieved modeling results, adaptive neuro-fuzzy inference system–biogeographic based optimization (ANFIS-BBO) provides superior prediction accuracy compared to others, with a maximum correlation coefficient (R_test = 0.923) and minimum root mean square error value (RMSE_test = 0.0193). Thus, the proposed ANFIS-BBO is a capable cost-effective method for predicting long contraction scouring, thus, contributing to the base knowledge of hydraulic structure sustainability.

关键词： long contraction scour prediction uncertainty ANFIS model meta-heuristic algorithm

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Local resistance of fluid flow across sudden contraction in small channels

Hang GUO, Ling WANG, Jian YU, Fang YE, Chongfang MA, Zhuo LI,

《能源前沿（英文）》 2010年第4卷第2期页码 149-154 doi: 10.1007/s11708-009-0060-7

摘要： The pressure drop caused by flow area contraction in microchannels has been experimentally studied in this paper using the tiny gap pressure measurement method. The working fluid was deionized water at room temperature at near-atmospheric pressure. Three test sections with area ratios of 0.284 and 0.274 and at different tube diameter sizes were used. The experimental results show that the abrupt contraction coefficient decreases with the Reynolds number increasing, and it is much higher than that of conventional tubes in laminar flow. The widely-applied correlation =0.5(1−) could not predict the contraction coefficient of turbulent flow in the micro tubes. The decreases as the tube diameter increases. The transition from laminar to turbulent flow is not obvious when the diameter of the small tube is 0.32mm.

关键词： microchannels pressure drop abrupt contraction loss coefficients

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Particle swarm optimization model to predict scour depth around a bridge pier

Shahaboddin SHAMSHIRBAND, Amir MOSAVI, Timon RABCZUK

《结构与土木工程前沿（英文）》 2020年第14卷第4期页码 855-866 doi: 10.1007/s11709-020-0619-2

摘要： Scour depth around bridge piers plays a vital role in the safety and stability of the bridges. The former approaches used in the prediction of scour depth are based on regression models or black box models in which the first one lacks enough accuracy while the later one does not provide a clear mathematical expression to easily employ it for other situations or cases. Therefore, this paper aims to develop new equations using particle swarm optimization as a metaheuristic approach to predict scour depth around bridge piers. To improve the efficiency of the proposed model, individual equations are derived for laboratory and field data. Moreover, sensitivity analysis is conducted to achieve the most effective parameters in the estimation of scour depth for both experimental and filed data sets. Comparing the results of the proposed model with those of existing regression-based equations reveal the superiority of the proposed method in terms of accuracy and uncertainty. Moreover, the ratio of pier width to flow depth and ratio of 50 (mean particle diameter) to flow depth for the laboratory and field data were recognized as the most effective parameters, respectively. The derived equations can be used as a suitable proxy to estimate scour depth in both experimental and prototype scales.

关键词： scour depth bridge design and construction particle swarm optimization computational mechanics artificial intelligence bridge pier

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基于空间收缩的并行演化算法

王涛,李歧强

《中国工程科学》 2003年第5卷第3期页码 57-61

摘要：

提出了一种基于空间收缩的求解MINLP问题的新算法。算法应用了快速有效的不完全演化搜索较优解的分布信息，通过分布信息定位最优解的可能分布，再由精英个体信息决定下次搜索空间。仿真结果表明该算法在搜索效率、应用范围、解的精确性和鲁棒性上都优于其他现存演化算法。

关键词：空间收缩演化算法 MINLP

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Numerical modeling of current-induced scour around multi-wall foundation using large-eddy simulation

《结构与土木工程前沿（英文）》 2023年第17卷第4期页码 546-565 doi: 10.1007/s11709-023-0943-4

摘要： Scouring is one of the primary triggers of failure for bridges across rivers or seas. However, research concerning the scour mechanism of multi-wall foundations (MWFs) remains scarce, hindering the further application of MWFs. In this study, for the first time, the scouring effect caused by unidirectional flow around MWFs was examined numerically using FLOW-3D involving a large-eddy simulation. Initially, the applicability of the scouring model and input parameters was validated using a case study based on published measured data. Subsequently, the scouring effects of four MWFs with different wall arrangements and inflow angles, including the flow field analysis and scour pit and depth, were investigated thoroughly. It was found that the maximum scour depth of MWFs with an inflow angle of 0° was smaller than that of those with an inflow angle of 45°, regardless of the wall arrangement. Meanwhile, changing the inflow angle significantly affects the scour characteristics of MWFs arranged in parallel. In practical engineering, MWFs arranged in parallel are preferred considering the need for scouring resistance. However, a comparative analysis should be performed to consider comprehensively whether to adopt the form of a round wall arrangement when the inflow angle is not 0° or the inflow direction is changeable.

关键词： multi-wall foundation current-induced scour bridge foundation large-eddy simulation numerical analysis

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考虑射流掺气的改进冲刷模型

Rafael Duarte,António Pinheiro,Anton J. Schleiss

《工程（英文）》 2016年第2卷第3期页码 294-301 doi: 10.1016/J.ENG.2016.03.003

摘要：

基于受高速射流冲击的水垫塘中掺气对岩块稳定性影响的系统试验研究，本文给出了一种基于物理特性冲刷模型的适应性研究成果。在综合冲刷模型中实现了对射流掺气模型的改进，使其得以再现有关冲刷形成的物理– 机械过程，其中涉及三相，即水、岩体和空气。改进方法考虑了因挟带气泡引起的掺气射流动量减少以及射流扩散剪切层的能量消耗。岩块从岩体脱离取决于掺气的时均压强系数及修正的最大动力冲击系数的组合，对于深水垫塘中的高速射流，该系数为定值0.2。上述改进模型的模拟结果与卡里巴大坝冲坑原型观测结果吻合良好。

关键词：掺气上举力岩体冲刷大坝安全高速射流岩块稳定性冲刷评估

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Crk-associated substrate, vascular smooth muscle and hypertension

TANG Dale

《医学前沿（英文）》 2008年第2卷第4期页码 323-331 doi: 10.1007/s11684-008-0062-6

摘要： Hypertension is characterized by vascular smooth muscle constriction and vascular remodeling involving cell migration, hypertrophy and growth. Crk-associated substrate (CAS), the first discovered member of the adapter protein CAS family, has been shown to be a critical cellular component that regulates various smooth muscle functions. In this review, the molecular structure and protein interactions of the CAS family members are summarized. Evidence for the role of CAS in the regulation of vascular smooth muscle contractility is presented. Contraction stimulation induces CAS phosphorylation on Tyr-410 in arterial smooth muscle, creating the binding site for the Src homology (SH) 2/SH3 protein CrkII, which activates neuronal Wiskott-Aldrich syndrome protein (N-WASP)-mediated actin assembly and force development. The functions of CAS in cell migration, hypertrophy and growth are also summarized. Abelson tyrosine kinase (Abl), c-Src, focal adhesion kinase (FAK), proline-rich tyrosine kinase 2 (PYK2), protein tyrosine phosphatase-proline, glutamate, serine and threonine sequence protein (PTP-PEST) and SHP-2 have been documented to coordinate the phosphorylation and dephosphorylation of CAS. The downstream signaling partners of CAS in the context of cell motility, hypertrophy, survival and growth are also discussed. These new findings establish the important role of CAS in the modulation of vascular smooth muscle functions. Furthermore, the upstream regulators of CAS may be new biologic targets for the development of more effective and specific treatment of cardiovascular diseases such as hypertension.

关键词： Contraction stimulation phosphatase-proline molecular structure discovered hypertension

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苏通大桥索塔深水群桩基础冲刷防护工程的设计与施工

何平,管义军,张雄文,张群,周建华

《中国工程科学》 2009年第11卷第3期页码 44-50

摘要：

从苏通大桥深水群桩基础结构方案出发，分析了冲刷及防护对大桥安全性的影响，进而从防护工程理念、结构设计与施工、防护效果监测等方面阐述了苏通大桥基础冲刷难题的解决方法。

关键词：苏通大桥深水群桩冲刷防护设计与施工

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海洋桥梁波流力作用与基础冲刷问题及对策研究

李永乐,房忱,裘放,唐浩俊,胡勇,夏云峰,魏凯,吴联活,杨绍林,向琪芪

《中国工程科学》 2019年第21卷第3期页码 18-24 doi: 10.15302/J-SSCAE-2019.03.011

摘要：

随着海洋桥梁不断向深海延伸，桥梁基础波流力作用与基础冲刷问题已成为威胁桥梁安全的主要因素。为了确保海洋桥梁设计的合理性以及建设运营的安全性，本文系统地梳理了海洋桥梁在波流力作用与基础冲刷方面所面临的主要问题，进而有针对性地提出了海洋桥梁需要在高精度预测方法、环境预报和预警系统、环境多因素耦合作用、冲刷数值模拟技术、波浪力计算方法等方向发展。研究表明，波流力作用与基础冲刷研究是海洋桥梁安全的重要保障，研究从宏观管理、行业应用、学术技术三个层面对当前问题提出了对策。

关键词：海洋桥梁波流力基础冲刷

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Alluvial channel hydrodynamics around tandem piers with downward seepage

Rutuja CHAVAN, Wenxin HUAI, Bimlesh KUMAR

《结构与土木工程前沿（英文）》 2020年第14卷第6期页码 1445-1461 doi: 10.1007/s11709-020-0648-x

摘要： In this paper, we report the turbulent flow structures and the scour geometry around two piers with different diameters. An experiment was conducted on a non-uniform sand bed with two types of tandem arrangements, namely, pier (T1) with a 75 mm front and 90 mm rear, and pier (T2) with a 90 mm front and 75 mm rear, with and without-seepage flows, respectively. A strong wake region was observed behind the piers, but the vortex strength diminished with downward seepage. Streamwise velocity was found to be maximum near the bed downstream of the piers and at the edge of the scour hole upstream of the piers. Quadrant analysis was used to recognize the susceptible region for sediment entrainment and deposition. Upstream of the piers near the bed, the moments, turbulent kinetic energy (TKE), and TKE fluxes were found to decrease with downward seepage, in contrast to those in a plane mobile bed without piers. The reduction percentages of scour depth at the rear pier compared with the front one were approximately 40% for T1 and 60% for T2. Downward seepage also resulted in restrained growth of scouring with time.

关键词： scour seepage Strouhal number tandem arrangement turbulent characteristics

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Control mode selection for modal control of long-span arch bridge

Zhengying LI, Zhengliang LI,

《结构与土木工程前沿（英文）》 2009年第3卷第4期页码 401-406 doi: 10.1007/s11709-009-0052-z

摘要： For seismic control of arch bridge, a model reduction of long-span arch bridge was implemented based on modal analysis. As for the critical mode selection, an approach based on the maximum modal displacement was presented. This approach takes into consideration the effect of external seismic excitation and is more reasonable than only considering dynamic bridge characteristics based on a modal contribution ratio. The time domain and frequency domain analysis method were used to verify the simplified model of the Nimu arch bridge in Tibet as an example. The numerical results show that the method of maximal modal displacement better analyze long-span arch bridge when multisupport seismic excitation must be considered. The reduced-order system also is more in line with the performance of the original model.

关键词： selection reduced-order excitation long-span simplified

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State-of-the-art of long-span bridge engineering in China

XIANG Haifan, GE Yaojun

《结构与土木工程前沿（英文）》 2007年第1卷第4期页码 379-388 doi: 10.1007/s11709-007-0051-x

摘要： This paper introduces the state-of-the-art of longspan bridge engineering in China with emphases on recent long-span bridge projects, bridge deck configuration and material, design codes of long-span bridges and improvement of aero

关键词： bridge engineering state-of-the-art long-span bridge configuration improvement

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引海水冲刷河口治理黄河下游

林秉南,周建军,张仁

《中国工程科学》 2000年第2卷第4期页码 25-33

摘要：

提出引海水5000～1 500m³/s在利津注入黄河冲刷河口。冲刷后，在利津将产生3.3～7.9m的水面跌差，可制止黄河河口延伸的溯源淤积作用上延，并诱发其上游产生溯源冲刷。估计可使艾山以下河道得到冲深。因挟沙海水的密度大于渤海环境水体的密度，咸浑水进入渤海时可形成异重流，将泥沙输去远方；而且断流期间河口还可能蚀退；因此引海水流量足够时，可使河口不外延或外延缓慢。从长远看，河口侵蚀基准面得到降低后，可以使黄河下游的淤积面均得到降低。这对缓解黄河下游河道持续淤高的局面和减少河口改道的风险都是有利的。

黄河下游额定冲沙水占黄河水资源总量很大比例，大量抽取淡水会增加下游的淤积。引海水冲刷河口，可以增加河口地区从黄河抽取淡水的数量。这样抽取的淡水是冲沙水的一部分，不受用水分配额度的限制，对河口地区的发展具有重要意义。引海水冲刷口门段，可向渤海注入大量咸浑水、有利于改进渤海的环境生态条件。当然，引海水冲刷时须解决河道和引海水渠道的咸水外渗问题。

关键词：引海水冲刷黄河下游悬河水资源利用

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Design and construction of super-long span bridges in China: Review and future perspectives

《结构与土木工程前沿（英文）》 2020年第14卷第4期页码 803-838 doi: 10.1007/s11709-020-0644-1

摘要： Super-long span bridges demand high design requirements and involve many difficulties when constructed, which is an important indicator to reflect the bridge technical level of a country. Over the past three decades, a large percentage of the new long-span bridges around the world were built in China, and thus, abundant technological innovations and experience have been accumulated during the design and construction. This paper aims to review and summarize the design and construction practices of the superstructure, the substructure, and the steel deck paving of the long-span bridges during the past decades as well as the current operation status of the existing long-span bridges in China. A future perspective was given on the developing trend of high-speed railway bridge, bridge over deep-sea, health monitoring and maintenance, intellectualization, standard system, and information technology, which is expected to guide the development direction for the construction of future super long-span bridges and promote China to become a strong bridge construction country.

关键词： long-span bridges steel box girder design technology construction technology review and future perspectives

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Stabilization-based soil remediation should consider long-term challenges

Zhengtao Shen, Zhen Li, Daniel S. Alessi

《环境科学与工程前沿（英文）》 2018年第12卷第2期 doi: 10.1007/s11783-018-1028-9

摘要： Soil remediation is of increasing importance globally, especially in developing countries. Among available remediation options, stabilization, which aims to immobilize contaminants within soil, has considerable advantages, including that it is cost-effective, versatile, sustainable, rapid, and often results in less secondary pollution. However, there are emerging challenges regarding the long-term performance of the technology, which may be affected by a range of environmental factors. These challenges stem from a research gap regarding the development of accurate, quantitative laboratory simulations of long-term conditions, whereby laboratory accelerated aging methods could be normalized to real field conditions. Therefore, field trials coupled with long-term monitoring are critical to further verify conditions under which stabilization is effective. Sustainability is also an important factor affecting the long-term stability of site remediation. It is hence important to consider these challenges to develop an optimized application of stabilization technology in soil remediation.

关键词： Stabilization Soil remediation Long-term Trace metals