鉴于当前长大跨海桥梁在不同服役时间及不同跨段结构类型上受撞倒塌风险差异显著，且现有代表船型确定方法仅基于静态航道船舶数据，亟需开发科学合理的动态设防船型确定方法。采用理论分析、数值模拟与案例分析的研究手段，开展了考虑桥梁结构特性与桥墩刚度退化的受撞倒塌设防船型确定方法研究。主要内容包括：推导了受撞桥墩能耗比和船舶航速阈值计算公式，确定了设防船型参数与桥墩极限侧向抗力之间的量化关系；以沿海某长大桥梁非通航孔段为研究对象，发现所建立的数值模型与理论计算结果偏差低于10%，验证了理论方法的可靠性；计算了案例桥梁在不同桥墩刚度退化程度下各吨位船舶的航速阈值和桥墩极限侧向抗力。本研究提出的理论方法可高效快速地确定桥梁倒塌设防船型，研究内容可为桥梁倒塌风险评估与防船撞设计工作提供参考价值。

Barge-bridge collision represents a complex nonlinear dynamic problem characterized by multiple interacting physical fields. Its failure mechanisms are influenced by several forms of nonlinearity, including material, geometric, contact, and motion nonlinearities. A theoretical model is proposed for calculating longitudinal displacements of bridge piers subjected to oblique barge collisions. The effects of impact angle and velocity are examined through scaled physical model tests. In the theoretical formulation, the piers are idealized as Timoshenko beams, and high-order differential equations are solved using Laplace transforms followed by numerical inversion. Results demonstrate that the theoretical predictions agree well with experimental data within the elastic range, showing a maximum discrepancy of 9.3%. Conventional static methods, which neglect dynamic effects, may lead to considerable inaccuracies, whereas the proposed model offers a balanced combination of computational efficiency and accuracy. Additionally, the analysis reveals the key role of bridge directional stiffness differences in governing impact energy distribution. This research provides a validated theoretical foundation and test benchmarks for evaluating the impact resistance of bridge structures and for supporting design optimization. It also offers practical references for structural safety assessments under multi-angle collision conditions.

This study introduces a novel carbon nanotube (CNT) cementitious composite sensor developed using pore conductivity theory to address durability and structural compatibility requirements for monitoring ship-bridge collisions in marine environments. The sensor employs a dual-channel sensing mechanism by integrating CNT networks with conductive pathways formed by electrolyte solutions within cement pores. Experimental results demonstrate high sensing accuracy across sensors with varying slenderness ratios, achieving axial and lateral errors under 8%. Notably, sensors with a 1:4 slenderness ratio exhibit significantly enhanced resistance change rates under axial loading, up to 281% within a 10 kN lateral load range. Impact tests further confirm strong correlation between electrical signals and strain gauge measurements when collision speeds range between 1-2 m/s, validating real-time collision damage monitoring capabilities. This research establishes design principles for pore conductivity-based CNT cement sensors while providing theoretical foundations for smart concrete applications in ship-bridge collision monitoring. Copyright © 2025 Techno-Press, Ltd.

中国东部沿海地区常受台风侵扰，各台风不同的气旋结构和登陆位置使其对跨海桥梁结构的影响有较大差异。台风期间桥位处的风速概率模型是分析桥位风场特征、评估桥梁抗风能力重要依据。安装于跨海桥梁上的结构健康监测系统实时获取的风场监测数据为了解台风期间桥位风场特征和开展风速概率模型分析提供了数据基础。以影响西堠门大桥的三个典型台风为研究对象，结合桥位风场实时监测数据，采用贝叶斯方法对风速概率模型参数进行动态识别与持续更新，建立的风速概率分布时变模型能够呈现不同时刻的风速概率分布及其在台风全过程中的演变规律，并对三个台风的风速分布及其演变进行了对比分析。对于近侧的登陆风，桥址风场的风速分布具有较大波动性；而对于远端风场，台风影响半径范围内风速分布相对稳定，影响半径范围外则风速分布波动强烈。

The height-resolving model is thought to be an optimal scheme for modeling the tropical cyclone (TC) wind fields in the boundary layer because it explicitly depicts the wind structures in that layer as TC evolves over time. However, the vertical advection process which exists in TCs has not been well considered in previously proposed parametric TC models. Neglecting this process may cause deviations of the simulated wind field structure in the boundary layer. Herein, a height-resolving boundary layer wind field model incorporating both the vertical advection and vertical diffusion processes is proposed and a semi-analytical solution to the governing equations is developed. The adequacy of this model is evaluated by comparing with the Weather Research and Forecasting model simulations, the Hurricane Research Division's H*Wind snapshots, GPS dropsonde datasets and ground measurements of several TC events. Results show that the proposed model with vertical advection can reasonably produce the wind fields of TCs, and its advantage lies in the production of a more realistic three-dimensional wind structure in the boundary layer.

How global warming will affect the typhoon activities and therefore impact future wind hazard is of importance to human being's preparedness for climate change. Herein a statistical dynamics synthetic tropical cyclone (TC) model, combining with the environmental parameters produced by five global climate models, is proposed for exploring quantitatively the typhoon wind hazard in the period 2071-2100 under the scenario of the least constrained emission. Compared with the current climate of the period 1981-2010, the future annual TC occurrence number will decrease for most climate models, but the amplitude varies from different models. The shift of TC tracks to the northeast may mitigate typhoon risk in the southeast coast of China while increase typhoon hazards in northern East Asia. Additionally, the proportion of super typhoon increases, which turns to enhance the extreme wind speeds in most coastal areas of East Asia. In general, the future environmental conditions of warming climate will contribute to forming more extreme typhoons in the western North Pacific basin and the typhoon wind hazard tends to increase in East Asia.

近十多年发展起来的压缩感知技术将信号采集与压缩融为一体、对信号以压缩方式进行采样,是有别于传统奈奎斯特信号采集框架的一种全新采样策略。这种策略简化了数据获取过程,减少了数据采集和传输量,降低了数据采集硬件要求,在无线传感网络中具有潜在的应用前景。然而在结构健康监测领域,目前多数研究关注于采用常规变换基（如传统傅里叶基、小波基）对压缩振动信号进行重构,未深入挖掘压缩感知理论与结构振动模态分析理论之间内在联系,这种状况妨碍了压缩感知理论对结构振动信号压缩潜力的充分发挥。本文从两个方面探讨了压缩感知技术在结构健康监测领域中应用:一方面,探索并发展新的途径通过压缩观测值对结构进行模态参数识别,减少压缩采样重构误差对结构模态参数识别的影响;另一方面,根据结构振动响应特征设计压缩感知硬件采集电路,以简洁高效的策略实现结构振动响应的压缩采样。具体研究内容如下:针对结构振动信号压缩采样恢复过程中,传统傅里叶基包含的频率信息与信号频率成分不匹配问题,提出了基于Polar插值改进的正交匹配追踪IOMP算法。该算法以正交匹配追踪算法（OMP）挑选的傅里叶原子为基础,利用Polar插值构建局部频域连续原子库,采用凸优化算法修正原子频率参数,使之与信号频率更接近,从而减少信号重构误差。改进算法仅需在频域局部范围内构建Polar插值连续原子库,以较小的计算量为代价实现原子频率参数校正。算法性能通过数值算例与模型试验进行了验证,并考察了不同算法重构信号的误差对模态参数提取的影响。结果表明,压缩采样信号的重构误差对模态参数识别结果有不可忽略的影响,本文提出的IOMP算法大幅提升了信号重构精度,因而提取的模态参数精度更高。鉴于频域弱稀疏振动信号以傅里叶基重构存在明显误差,而且误差会向模态分析传播,本文发展了两种直接基于压缩采样的模态参数识别方法。首先发展了基于结构自由振动信号压缩观测值直接提取模态参数的稀疏分解SD算法。根据结构自由振动响应微分方程通解形式,采用指数衰减三角函数构建冗余原子库,然后利用分步选择原子的OMP算法对压缩观测值进行稀疏分解,最后根据分解产生的稀疏系数矩阵与挑选的原子分别得到模态振型和频率、阻尼。该算法性能通过数值算例与模型试验进行了验证,并进行了参数影响分析,对比了SD算法与基于压缩采样重构的ERA算法提取模态参数的表现。针对结构受迫振动响应,本文进一步发展了基于压缩采样的多变量自回归模型（MAR）直接提取模态参数的CMAR算法。对比多变量MAR模型和联合稀疏模型,发现了它们之间数学表达形式的相似性,提出将多变量MAR模型当做联合稀疏模型来应用压缩感知理论。通过设计特殊压缩观测矩阵,实现以压缩观测值直接构建MAR模型,然后利用该模型自回归系数求解结构模态参数。该算法的有效性通过数值算例与框架模型试验进行了验证,并进行了参数影响分析,对比了CMAR算法与基于压缩采样重构的MAR模型算法提取模态参数的表现。针对MAR模型模态识别法及本文发展的CMAR算法,提出了加强稳定图法剔除虚假模态。基于模态叠加方程讨论了结构响应MAR模型与模态响应MAR模型之间的联系,将结构响应MAR模型自回归系数作用于识别的模态响应,构建了模态响应MAR模型。采用模型残差二范数与模态响应二范数比值作为评判指标,将比值较大的模态判定为虚假模态,然后绘制稳定图以确定真实模态。该方法的有效性通过数值算例与模型试验进行了验证,并与常规稳定图进行了对比。压缩采集硬件是验证与应用压缩感知方法的重要条件,针对目前缺少适用结构振动信号压缩采样硬件的状况,本文研制开发了基于数字信号的压缩感知采集硬件。该硬件首先利用ADC模块将结构响应转换为数字信号,然后采用FPGA（现场可编程逻辑门阵列）芯片计算数字信号与观测矩阵的线性内积值作为压缩感测值。通过模型试验对采集硬件电路进行了测试,并利用本文发展的CMAR算法从压缩观测值中提取试验模型的模态参数。

When a ship-bridge collision occurs, prompt assessment of substructure damage is crucial. This study presents a novel approach for ship-bridge collision damage identification, addressing challenges inherent in traditional monitoring systems. The method overcomes issues such as complex installation, low efficiency, and high costs through a unique combination of the unscented Kalman filter (UKF) and computer vision technique. The approach exerts the structural equation of motion to derive a multirate UKF in the impact process, thereby identifying the stiffness of structures. Displacement and acceleration are fused to enhance the sampling rate of vision-measured displacement. Firstly, it monitors low sampling rate displacements on piers using computer vision, complemented by high-rate accelerometer data at the collision point. Secondly, displacement and acceleration data are integrated using a multirate UKF, addressing the challenge of image storage pressure associated with vision-based measurements. Finally, validation using finite-element and experimental models confirms the effectiveness of the approach in identifying substructure stiffness and recovering lost vibration characteristics. In experiment validation, the influence of computer vision algorithms and camera shooting distance on displacement monitoring and stiffness identification is also discussed separately. This approach provides a cost-effective and efficient solution for ship-bridge collision damage identification, contributing to advancements in the field of ship-bridge collision monitoring. © 2024 American Society of Civil Engineers.

Fatigue and corrosion are the main reasons for the failure of stay cables. Traffic load also plays a significant role in cable fatigue. To study the fatigue life of stay cables under the combined action of traffic load and corrosion, this study originally deduced the fatigue probability model for steel wires, considering the stress range and average stress based on the nonlinear fatigue damage model. Then, the weight loss rate was introduced into the fatigue probability model for steel wires in order to obtain the fatigue life probability model for corroded steel wires. Subsequently, a Monte Carlo simulation (MCS) was conducted to predict the fatigue life of stay cables under different guaranteed probabilities. Finally, using a cable-stayed bridge on the Yangtze River in China as an example, the fatigue life of the stay cables in the bridge under the combined effects of different corrosive environments and measured traffic loads was evaluated. Results indicate that both the stress range and mean stress affect the fatigue life of the steel wire. The fatigue life of stay cables is determined by a few steel wires with shorter lives, and the stress redistribution accelerates the failure of the inner wire of the stay cables. The fatigue life of the stay cables on background engineering is much less than the design life of the bridge under the combined actions of a middle-level or high-level corrosive environment and traffic load.

钢管桩因其加工制作简单、适用性高、施工方便、强度高等优点,在基础工程、支架工程、大型跨海桥梁等领域受到广泛的应用,也使得桥梁桩基在面临江河海域环境要承担更多的风险。桥梁水毁是跨海桥梁面临的首要灾害之一,其主要成因是由局部冲刷引起的。桩周最大冲刷深度的准确预测是跨海桥梁安全运行的基础。由于桥梁桩基周围水流运动的复杂性,使得准确预测桩基的冲刷深度变得十分困难。近年来,随着信息技术的发展,计算流体动力学软件已俨然成为桥梁冲刷研究的主要手段。本文通过试验模型结合仿真模拟的方法,以圆柱形桥桩为基础对钢管桩的局部冲刷进行深入研究。主要研究内容和结论如下:（1）基于流体力学的理论分析,考虑水流-桥桩-床沙相互作用,对钢管桩的冲刷进行了理论分析,揭示了水流-桥桩-泥沙三者相互作用机理;阐述了多种典型桥桩局部冲刷计算公式及其适用范围;通过与工程设计规范的对比分析,指出了各个桥桩局部冲刷预测公式的局限性。（2）基于Melville的经典水槽试验,通过FLOW-3D数值模拟软件建立了相同比尺的三维仿真模型,并对实验模型的局部冲刷进行仿真模拟和结果分析。获得了与Melville试验结果相似的流场分布、冲刷坑范围及冲刷深度,验证了该仿真模型对模拟桩周流场和冲刷的准确性。（3）研究了双圆柱钢管桩与单圆柱钢管桩冲刷深度影响的对比。研究表明,双圆柱钢管桩中,下游桥桩的冲刷深度随着桩心夹角的减小而减小,且最大冲刷深度发生在未阻挡一侧。此外,对牺牲桩的防护进行了研究,采用牺牲桩防护条件下的下游桥桩冲刷深度随着牺牲桩桩径增大而明显减小;随着牺牲桩桩心距的增大,先减小后逐渐增大直到形成相互独立的冲刷。