社区是城市防灾减灾的最基本单元,建立社区复原力,提升社区韧性是城市应对自然灾害的关键举措。文中以武汉市江岸区为例,对社区韧性展开评估。首先,将社区韧性与防灾减灾能力相结合,从经济、社会、基础设施和组织4个维度出发,选取能够反映社区财政投入、物资储备、公众避险、自救互救、医疗保障、转移安置、隐患排查和风险管理8项减灾能力的25个指标构建评估体系。其次,考虑到指标权重对评估结果的影响,分别采用AHP-TOPSIS、熵权-TOPSIS以及组合赋权-TOPSIS这3种评估模型对辖区内147个社区的韧性进行评估,并从评估趋势、等级划分和排名情况等方面对比分析不同模型的差异。然后,选取区分度更大、可解释性更强的组合赋权-TOPSIS模型对不同韧性维度进行细粒度的分析。研究结果表明,该区整体韧性较强,基础设施和组织韧性相对较弱; 在空间分布上,社区密集区域韧性等级高于社区分散区域,城市中心区域韧性等级高于边缘区域。最后,基于不同维度的评估结果,提出针对性的社区韧性治理建议,包括推动社区多元共治、优化布局、整合资源、共融共享以及构建数字化、智慧化社区等,为基层应急管理提供新的思路和参考。

Community is the most basic unit of urban disaster prevention and mitigation. Establishing and enhancing community resilience are pivotal strategies for cities to effectively tackle natural disasters. This article takes Jiang'an District in Wuhan City as an example and conducts an assessment of community resilience. Firstly, combining community resilience with disaster prevention and mitigation capabilities, we construct an evaluation system from four dimensions, including economy, society, infrastructure and organization. We select 25 indicators that reflect eight disaster reduction capabilities, including financial investment, material reserves, public evacuation, self-help and mutual assistance, medical support, relocation, hazard investigation and risk management. Secondly, considering the impact of indicator weights on evaluation results, three evaluation models, namely AHP-TOPSIS, EWM-TOPSIS and CWM-TOPSIS, were used to assess the resilience of 147 communities within the jurisdiction. The differences between different models were compared and analyzed from the aspects of evaluation trends, level division and ranking. Then, the CWM-TOPSIS model with stronger interpretability was selected to perform fine-grained evaluation of different resilience dimensions. The results show that the overall resilience of the area is strong, while economic resilience and social resilience are relatively weak. In terms of spatial distribution, resilience levels of densely populated areas are better than those of dispersed areas, and levels of urban central areas are better than those of peripheral areas. Finally, based on the evaluation results, suggestions for improving community resilience and governance were proposed, including promoting diverse community governance, optimizing layout, integrating resources, fostering inclusivity and sharing, as well as constructing digital and intelligent communities, which could provide new insights and references for grassroots social governance.

为有效应对自然灾害导致的舆情危机,以河北暴雨洪涝舆情事件为例,基于以往文献,提出了改进的舆情利益相关者划分规则以及一种针对不同利益相关者的网络舆情多维特征分析方法,旨在为政府政策制定和舆情治理提供有针对性的指导。借助以微博为代表的社交网络,以划分后的舆情生命周期和舆情利益相关者为基础,融合了狄利克雷分配(Latent Dirichlet allocation,LDA)主题模型、ERNIE 3.0情感分析与词共现网络分析方法,从内容特征、时空特征和网络特征多维度,对有关突发自然灾害的网络评论展开深入分析,揭示了河北暴雨洪涝舆情事件中的各类利益相关者舆论的演化特征。研究结果表明:普通网民关注点集中且多元,而网络媒体关注的主题集中而单一; 意见领袖则有利用流量的行为; 官方媒体注重灾害预警与安抚民心。值得注意的是,除了灾区外,主要媒体所在地的舆情危机高风险地区也应重点关注,相关部门亟需加强对后者舆情的引导与监督。文中所提方法提高了主题挖掘的准确率,同时也实现了各个舆情周期不同利益相关者的多维特征的精准刻画。研究可为暴雨洪涝等突发自然灾害引发的网络舆情危机提供有针对性的引导和应急方案。

In order to effectively handle public opinion crises caused by natural disasters, this paper takes the case of the public opinion events of heavy rain and flood in Hebei, and proposes improved rules for dividing public opinion stakeholders and a multi-dimensional characteristics analysis method for online public opinion targeting different stakeholders based on previous literature. The aim is to provide targeted guidance for government policy-making and public opinion governance. Specifically, this paper utilizes social networks represented by Weibo, based on the divided public opinion lifecycle and stakeholders, and integrates Latent Dirichlet allocation(LDA)topic modeling, ERNIE 3.0 sentiment analysis, and word co-occurrence network analysis methods to conduct an in-depth analysis of online comments related to unexpected natural disasters from multiple dimensions of content features, spatiotemporal characteristics, and network characteristics. This reveals the evolution characteristics of public opinion among various stakeholders in the public opinion events of heavy rain and flood in Hebei. The research results show that ordinary netizens have focused and diverse concerns, while online media focuses on centralized and singular themes. Opinion leaders tend to capitalize on traffic, and official media focuses on disaster warnings and reassuring the public. It is worth noting that in addition to the disaster-stricken areas, the locations of major media outlets, which are high-risk areas for public opinion crises, should also be given priority attention, and relevant departments urgently need to strengthen the guidance and supervision of public opinion in the latter. The method proposed in this paper not only improves the accuracy of topic mining, but also achieves accurate characterization of the multi-dimensional characteristics of different stakeholders in each public opinion cycle. This research can provide targeted guidance and emergency plans for online public opinion crises triggered by unexpected natural disasters such as heavy rain and floods.

为了准确快速评估地震人员死亡数量,提出一种基于统计经验模型与机器学习模型相结合的组合评估方法。首先利用我国部分省(区、市)发生的破坏性地震次数进行统计,划分出不同风险等级区域。然后分别使用刘金龙模型和粒子群优化支持向量回归模型进行评估。最后采用并联方式将2个模型组合,使用网格搜索法寻找最优并联权重,构建人员死亡评估组合模型。研究结果表明,组合模型评估结果优于单一模型评估结果,经过分区划分的模型评估效果更优。该方法可以为地震应急响应提供可靠的数据支撑。

Abstract:To accurately and quickly assess the number of deaths caused by earthquakes, this paper proposes a combined assessment method based on a statistical empirical model and a machine learning model. Firstly, the number of destructive earthquakes in most provinces(autonomous regions and municipalities)of China was counted to divide the areas with different risk levels. Secondly, the LIU Jinlong model and the particle swarm optimization support vector regression model were used for evaluation. Finally, the two models were combined in parallel, and the grid search method was used to find the optimal parallel weights to construct a combined model for assessing deaths. The results show that the evaluation results of the combined model are better than those of the single model, and the evaluation effect of the model after partitioning is better. This method can provide more reliable data support for earthquake emergency response.

在冰雹灾害中建筑外窗往往受损严重,导致建筑外围护结构功能失效。传统的损伤评估方法通常依赖于人工现场调查,客观性和效率不足,难以及时快速地量化评估冰雹导致的建筑外围护结构损伤。本研究提出了一种基于图像语义分割的建筑外窗受损情况的智能量化评估方法。基于网络数据训练建筑外窗损伤识别语义分割模型Swin Transformer,通过灾害现场的原位拍摄数据进行迁移学习,实现了建筑外窗损伤的智能量化识别,并据此提出了建筑外窗损伤指数。研究结果表明,本研究提出的方法能够准确识别建筑外窗的破损区域,精度超过85%,提出的建筑外窗损伤指数,能够较好地评估建筑外窗的损伤情况,并为灾损评估和灾后修复提供可靠的量化指标。

In hail disasters, building exterior windows often suffer severe damage, leading to the failure of the building envelope. Traditional damage assessment methods typically rely on manual on-site inspections, which is lack of objectivity and efficiency, making it difficult to promptly and accurately quantify the damage to the building envelope caused by hail. This study proposes an intelligent quantitative assessment method for damaged building exterior windows based on image semantic segmentation. The Swin Transformer model for identifying window damage is trained using online data, and the transfer learning is applied using on-site photography data from disaster scenes to achieve intelligent quantitative identification of damaged building exterior windows. An exterior window damage index(EWDI)is introduced based on this identification. Case studies demonstrate that the proposed method can accurately identify damaged areas of building exterior windows with an accuracy exceeding 85%. The proposed EWDI effectively evaluates the extent of damage to building exterior windows, providing reliable quantitative metrics for disaster assessment and post-disaster recovery efforts.

为定量描述大型冰崩运动过程中摩擦系数的演变过程与特性,结合冰崩高速运移中的热力学和动力学特性,考虑颗粒破碎效应以及融水与碎屑物质间相互掺混下的热融减阻效应,以冰崩厚度、剪切带厚度和剪切带内的初始含冰量为参数,运用COMSOL数值分析软件开展冰崩运动过程中的摩擦弱化与运动特性研究,分析不同条件下冰崩关键运动参数的演化规律。结果表明:冰崩运动过程中,由滑面热效应带来的摩擦弱化能够使摩擦系数从初始时刻的0.6左右降至0.05以下。并且,冰崩厚度越大,运动距离越远; 剪切带厚度与摩擦系数之间并非简单的线性关系,随着剪切带厚度的增大,冰崩的滑移距离会呈现出递增、平稳、递减、再趋于平稳的趋势; 一定条件下,剪切带内的初始含冰量越大,越有利于冰崩的远距离运动。通过数值模拟试验,揭示了不同影响因素下冰崩运动过程中的摩擦系数演化特性,该摩擦弱化模型可为冰崩灾害的动力学分析与科学减灾提供参考。

To quantitatively describe the evolution and characteristics of the friction coefficient during the large-scale ice avalanche movement, this paper integrates the thermodynamic and dynamic characteristics of high-speed ice avalanche movement to study the movement process of the ice avalanche. This paper takes the ice avalanche thickness, shear zone thickness, and initial ice content in the shear zone as parameters. It considers the particle fragmentation effect and the thermal melting resistance reduction effect under the mutual mixing of melt water and debris. By using the COMSOL numerical analysis software, it simulates the movement process of the ice avalanche and analyzes the evolution law of the key movement parameters of the ice avalanche under different conditions. The research results show that during the process of ice avalanche movement, the friction weakening caused by the thermal effect of the sliding surface can reduce the friction coefficient from approximately 0.6 at the initial moment to less than 0.05. Moreover, the thicker the ice avalanche, the farther the movement distance. The relationship between the thickness of the shear zone and the friction coefficient is not a simple linear one. As the thickness of the shear zone increases, the sliding distance of the avalanche will show a trend of increasing, stabilizing, decreasing, and then stabilizing again. Under certain conditions, the larger the initial ice content in the shear zone, the more conducive it is to the long-distance movement of the ice avalanche. Through numerical simulation experiments, the evolution characteristics of the friction coefficient during the ice avalanche movement under different influencing factors are revealed. This friction weakening model can provide a reference for the dynamic analysis and scientific disaster reduction of ice avalanche disasters.

山洪灾害极具破坏力,其承灾体的脆弱性是决定灾害破坏程度的重要因素之一。然而目前大多研究都只聚焦于县级以上大尺度评价,其精度不能满足山洪灾害精细化评价工作的需求。为更快、更精准地进行山洪灾害精细化风险控制与管理,以汶川县漩口镇古溪沟为例,利用该地区高精度遥感影像数据,结合实地调查获取的社会经济及人口数据,从暴露度、敏感性和应对力建立指标体系,基于博弈论(game theory,GT)思想,将主观赋权法与客观赋权法组合,构建符合该地区山洪灾害承灾体的脆弱性评价指标体。其中主观赋权法以基于三角模糊数的层次分析法为代表,客观赋权法以基于指标相关性的指标权重确定法为代表,再通过GIS技术,实现了精细像元尺度的山洪灾害脆弱性定量评价。结果表明:主观赋权、客观赋权和组合赋权3种方法在暴露度分析结果上存在较大差异,差异来源于土地利用类型指标的权重大小,而敏感性和应对力分析结果几乎相同,因此脆弱性分布特征在总体上具有较高的一致性; 客观赋权与组合赋权法的脆弱性评价结果高度一致,通过对土地利用类型的对比分析,验证了用组合赋权法进行脆弱性评价更为合理且精确; GT结果中,研究区内绝大部分区域为极低脆弱性,高达83%以上,主要是植被覆盖度较高的地区,极高脆弱性区域集中分布在学校、居民区等人口密集的地区,只占了0.4%。

The mountain flood disaster is extremely destructive, and the vulnerability of the disaster-bearing body is one of the major factors that determine the damage degree of the disaster. However, most of current studies only focus on large-scale evaluation above the county level, lacking accuracy for fine evaluation of mountain flood disasters. In order to control and manage the refined risk of mountain flood disasters more quickly and accurately, this article takes Guxi Gully in Xuankou Town, Wenchuan County as an example, using high-precision remote sensing image data from this region, combined with socioeconomic and demographic data from field surveys. Based on the idea of game theory(GT), the subjective and objective weighting methods are combined to establish an evaluation index system for the vulnerability of the disaster-bearing body in this region, which is in line with the exposure, sensitivity, and coping capacity. The subjective weighting method is represented by the triangular fuzzy number-based analytic hierarchy process, while the objective weighting method is represented by the criteria importance through intercriteria correlation. By using GIS technology, a quantitative evaluation of flash flood disaster vulnerability at fine pixel scale was achieved. The results found that there were significant differences in the exposure analysis results among the three methods of subjective, objective and combined weighting, and the differences came from the weight of land use type indicators, while the sensitivity and coping capacity analysis results were almost the same, so the vulnerability distribution characteristicswere generally high consistent. The results of vulnerability assessment by the objective weighting method and the combined weighting method were highly consistent. Through comparative analysis of land use types, it was verified that the combination weighting method is more reasonable and accurate for vulnerability assessment. In the result of GT, the majority of the areas in the study area were extremely low vulnerability, up to 83%, mainly in areas with high vegetation coverage, and the extremely high vulnerability areas were concentrated in densely populated areas such as schools and residential areas, accounting for only 0.4%.

因库水位下降而变形失稳的动水压力型滑坡,是库区多见的一种滑坡类型,且不同滑坡对水位下降的响应存在巨大差异。为探索动水压力型滑坡的失稳特征和诱发机制,基于不同影响因素的作用特点分析,开展了多组模型试验,揭示了滑面形态、滑体渗透系数和水位骤降速率对滑坡孔隙水压力、体积含水率及变形破坏全过程的影响规律。研究结果表明,多影响因素组合对动水压力型滑坡不利程度的排序,并总结了其变形失稳的主控因素、次生因素和诱发因素,发现了直线形滑面的滑坡失稳特征为浅层滑动诱发滑体逐层剥离的牵引式破坏、弧线形滑面的滑坡失稳特征为坡脚垮塌逐渐向后溯源的牵引式破坏,二者差异的内在机制是滑体厚度不同导致渗透压力的具体作用区域和持续时间显著不同。

A seepage-driven landslide is a common type of landslide in a reservoir area, it is deformed and unstable owing to the drawdown of reservoir water level. However, the response of different landslides to water level drawdown is significantly different. To understand the instability characteristics and inducing mechanism of seepage-driven landslide, multiple model tests were conducted based on the analysis of the action characteristics of different influencing factors. This study found that the effects of sliding surface morphology, the permeability coefficient of sliding mass and the rate of water level drawdown on the pore water pressure, volumetric water content and the whole process of deformation and failure are significant. The results can be summarized as follows: the order of the adverse degree of multi-factor combination to seepage-driven landslide was clarified, then the main control factors, derivative factors and inducement factors to landslide deformation and failure were summarized. It is discovered that the slide instability characteristic of a straight-line sliding surface is retrogressive failure induced by shallow sliding. Conversely, the landslide instability characteristic of an arc-line sliding surface is retrogressive failure of the slope toe collapse, which gradually traces back. The internal mechanism of the difference between these two landslides is that the different thickness of the sliding mass leads to the different position and duration of the seepage water pressure.

为分析水电站不同蓄泄水期其流域滑坡灾害形变演化和滑坡灾害易发性规律,提出水电站流域蓄泄水期滑坡灾害识别的一般性时序InSAR监测方法流程,同时利用深度学习技术对光学遥感图像进行滑坡潜在区域识别。与InSAR结果对比验证,引入InSAR形变结果作为评价因子,同其它评价要素利用层次分析法进行滑坡灾害易发性评价。结果表明:三阶段蓄泄水期间水电站流域形变区域数量逐渐减少,形变量级先增大后减小,研究区地表形变速率值为-46.6～16.6 mm/a。基于U-net神经网络识别研究区滑坡潜在区域,与InSAR对比发现多数InSAR形变区域均在其识别范围内。滑坡灾害易发性评价结果显示三阶段蓄泄水期水电站流域滑坡灾害易发性逐渐下降。研究成果可为水电站的全生命周期监测运营管理提供技术支持。

In order to analyze the deformation evolution and the regularity of landslide hazard in the basin of hydropower station in different storage and discharge periods, the general time-series InSAR monitoring method process for landslide hazard identification in the drainage period of hydropower station basin is proposed. Meanwhile, the deep learning technology is used to identify the potential landslide areas in optical remote sensing images,which are compared and verified with InSAR results. InSAR deformation results are introduced as evaluation factors, andthe susceptibility to landslide hazards is evaluated using the hierarchical analysis method together with other evaluationfactors.The results show that the number of deformation areas in the basin of the hydropower station gradually decreases during the three-stage drainage period, the magnitude of deformation increases first and then decreases, and the surface deformation rate in the study area ranges from -46.6～16.6 mm/a. The U-net neural network was used to identify potential landslide areas in the study area, and compared with InSAR, it was found that most of the deformation regions of InSAR were within the recognition range. The results of landslide hazard susceptibility evaluation show that the landslide hazard susceptibility of hydropower station basin decreases gradually during the three-stage drainage period. The research results can provide technical support for the whole life cycle monitoring operation management of hydropower station.

滑坡易发性评价是目前防治滑坡的有效手段之一,然而,前人研究多集中于人口密集的地区,模型结果受到人为干扰,难以获取真实客观的评价模型差异。青藏高原西部地区人烟稀少,是进行模型对比的有利区域。同时,该地区道路交通网稀疏,道路的安全对于当地安全稳定有着至关重要的意义,因此,对该地区进行滑坡易发性评价极其重要。本研究以栅格为评价单元,在结合前人研究及工作区实际情况的基础上,选择7个因素作为易发性评价因子,采用信息量模型、逻辑回归模型和多层感知器作为评价模型,采用自然断点法将研究区域分为高、较高、中等、较低和低5个等级,并分别计算各等级滑坡占比,最后以受试者特征曲线(receiver operating characteristic curve, ROC)对结果适用性和可靠性进行对比分析。所有结果随着易发性等级的提升,滑坡占比呈增长趋势,且ROC值均大于85%。其中信息量-逻辑回归模型准确率最高,达到87.3%。揭示出在高海拔地区开展滑坡易发性评价是可行的。对比结果表明,传统模型较机器学习模型更加准确,混合模型优于单一模型。在此基础上,发现滑坡集中于距离道路900～1 800 m范围内,对于当地道路通行有着一定的威胁,应注意防范。

The evaluation of landslide susceptibility is one of the most effective methods for landslide prevention. However, previous studies have mainly focused on densely populated areas, the results of model are influenced by human activities, and difficult to obtain accurate and objective assessments. Due to the sparse population, western region of the Qinghai-Xizang Plateau provides a favorable area for model comparison. Additionally, the safety of sparse road network in this region has significant implications for local stability. Therefore, conducting landslide susceptibility assessment in this region is of great practical significance. In this study, using grid as evaluation units, seven factors were selected as susceptibility evaluation indicators based on previous research and the actual conditions of the study area. The information value model, logistic regression and multi-layer perceptron were employed as evaluation models. The natural break method was used to divide the study area into five levels:high, relatively high, medium, relatively low, and low, and the proportion of landslides in each level was calculated. Finally, the applicability and reliability of the results were analyzed using receiver operating characteristic curve(ROC). The results showed that the proportion of landslides increased with the increase in susceptibility level, and all the ROC values were above 85%. The logistic regression model demonstrated the highest accuracy, reaching 87.3%. This reveals that conducting landslide susceptibility assessment in high-altitude areas is feasible. Comparative results indicate that traditional models are more accurate than machine learning models, and hybrid models surpass individual models in performance. Based on these findings, it has been discovered that landslides are concentrated within 900～1 800 m from roads, which poses a certain threat to local road traffic and should be addressed with caution.

构建准确的滑坡预测模型和确定环境因子的贡献程度,对滑坡易发性评价具有重要意义。在以往研究中,最大熵物种分布(maximum entropy model, MaxEnt)模型因其对样本量要求低、预测精度高和可避免模型过度拟合等优点,被广泛运用在生态学领域。以沅陵县为研究区,基于342处滑坡灾害点数据和9个环境变量,分别采用确定性系数(certainty factor, CF)模型、逻辑回归(Logistic)模型和MaxEnt模型对沅陵县进行滑坡易发性分区预测。同时采用刀切法(Jackknife)检验环境因子对预测结果的贡献程度,确定滑坡地质灾害的主要影响因素。结果表明:确定性系数模型、逻辑回归模型和MaxEnt模型的受试者特征曲线(receiver operating characteristic, ROC)下面积(area under the curve, AUC)值分别为0.827、0.803、0.911,3种模型的预测精度均较高,且MaxEnt模型精度最高,表现较好; 河流是影响研究区滑坡灾害发生贡献程度最高的环境因子; 滑坡灾害主要发育在以河流为中心向外延伸100 m范围内,集中分布在沅江、深溪和兰溪附近。研究能为沅陵县地质灾害易发性评价提供一种新的方法。

Constructing an accurate landslide prediction model and determining the contribution of environmental factors are of paramount importance for evaluating landslide susceptibility. In previous studies, MaxEnt model has been widely applied in ecology due to its advantages, such as low sample requirements, high prediction accuracy, and the ability to avoid overfitting. Focusing on Yuanling County, this study employs certainty factor model, logistic regression model and MaxEnt model for landslide susceptibility zoning predictions based on data from 342 landslide disaster points and nine environmental variables. The Jackknife method is utilized to assess the contribution of environmental factors to the prediction results, identifying the primary influencing factors of landslide geological disasters.The results indicate that the areas under the receiver operating characteristic(ROC)of the certainty factor model,logistic regression model and MaxEnt model are 0.827, 0.803 and 0.911, respectively.All three models exhibit high prediction accuracy, with the MaxEnt model demonstrating the highest precision. River is the environmental factor that contributes the most to landslide disasters in the study area. Landslide disasters predominantly occur within a 100 m radius extending outward from rivers, concentrated in the vicinity of Yuanjiang, Shenxi, and Lanxi. This research offers a novel approach for evaluating the susceptibility of geological disasters in Yuanling County.

文中选取长宁县为研究区,将长宁县境内179个历史滑坡灾害点作为评价样本,结合时序干涉合成孔径雷达(interferometric synthetic aperture radar, InSAR)技术获取地表形变数据,选取地层岩性、多年平均降雨量、坡向、土地利用、距水系距离、距道路距离、植被覆盖度、高程、坡度、土壤类型、地表曲率以及地表起伏度共计13个影响因子,采用信息量-逻辑回归耦合模型(information value-logistic regression coupling model, I-LR)、频率比-逻辑回归耦合模型(frequency ratio-logistic regression coupling model, FR-LR)对长宁县开展滑坡灾害易发性评价及分区。结果表明,I-LR模型的曲线下的面积(area under curve, AUC)值为0.801,FR-LR模型的AUC值为0.793,2种模型均能较好地预测滑坡发生的概率,前者的预测效果略优。根据滑坡易发性评价结果,将长宁县划分为5个易发性等级区域。I-LR模型评价结果中,高、极高易发性区域面积分别占研究区总面积18.2%和9.9%; FR-LR模型评价结果中,高和极高易发区域面积分别占21.4%和11.9%。高、极高易发性区域主要分布在乡镇周边、陡坡地区。

To effectively prevent landslide disasters, this study focuses on Changning County as the research area. A total of 179 historical landslide disaster points within Changning County are used as evaluation samples. Thirteen influencing factors, including surface deformation data obtained through time-series interferometric synthetic aperture radar(InSAR)technology, lithology, multi-year average rainfall, aspect, land use, distance to waterbodies, distance to roads, vegetation coverage, elevation, slope, soil type, surface curvature, and surface relief, are selected. The information value-logistic regression coupling model(I-LR)and frequency ratio-logistic regression coupling model(FR-LR)are employed to assess landslide hazard susceptibility and zoning in Changning County. The results showed that the area under curve(AUC)value of the I-LR model was 0.801, and the AUC value of the FR-LR model was 0.793. Both models were able to predict the probability of landslide occurrence well, with the former having slightly better predictive performance. According to the landslide susceptibility evaluation results, Changning County has been categorized into five levels of susceptibility. In the evaluation results of the I-LR model, the proportion of areas classified as highly susceptible and extremely susceptible accounted for 18.2% and 9.9% of the total area of the study area, respectively. In the evaluation results of the FR-LR model, the areas identified with highly susceptible and extremely susceptible amounted to 21.4% and 11.9%, respectively. It is mainly distributed around villages and towns and in steep slope areas.

多尺度分割方法划分斜坡单元,存在分割尺度选择主观性强、试验耗时以及划分结果适宜评价指标单一等问题。以福建武平十方镇为研究区,固定分割尺度,试验确定出多尺度分割方法中最佳同质性参数的组合,利用同质性局部方差变化率曲线厘定可能的分割尺度,不同尺度结合同质性参数组合进行斜坡单元划分。从斜坡单元与历史滑坡几何联系、斜坡单元划分原理、斜坡单元现实应用三个方面,初步建立了评价斜坡单元划分结果是否适宜的3项指标:形状指数、坡向全局莫兰指数和地形起伏度。研究结果表明,对多尺度分割优化方法的优化降低了分割尺度选择的主观性并显著减少了处理时间,适宜单元评价指标确定出的斜坡单元更加切合实际地形地貌。

The application of multi-scale segmentation method to divide slope units is confronted with issues such as subjective selection of segmentation scales, time-consuming experiments and limited suitability evaluation indicators for the results. This paper focuses on Shifang Town, Wuping County, Fujian Province as the study area, fixes the segmentation scale, and determines the optimal combination of homogeneity parameters through experimental methods in the multi-scale segmentation approach. By utilizing the homogeneity local variance change rate curve, potential segmentation scales are determined, and slope units are delineated by combining different scales with homogeneity parameter combinations. Initially, three indicators are established for evaluating the suitability of slope unit delineation results from three perspectives: geometric relationship between slope units and historical landslides, principles of slope unit delineation, and practical applications of slope units. These indicators include shape index, global Moran's I for aspect, and relief degree of landform. Case studies demonstrate that the optimization of the multi-scale segmentation method reduces the subjectivity in selecting segmentation scales and significantly decreases processing time. Additionally, the slope units determined by the suitable unit evaluation indicators are more aligned with the actual landforms and terrain features.

台风导致的输电杆塔倒塌会影响电网供电,进而造成严重的社会经济损失。因此,有必要在台风过程中对输电系统,特别是对输电杆塔进行风险预判,从而便于电力部门有效部署预防和减损措施。输电塔风致破坏易损性模型是风险评估的实用工具。结合数值气象预报风场,易损性模型能够有效支持台风实时行进过程中输电杆塔的风险预测。本研究通过考虑输电杆塔风致倒塌的物理机制和预报风速的时变特征,建立了基于精细化塔线体系有限元模型的易损性分析,并同时纳入脉动风时程不确定性的台风过程输电杆塔时变风险预判方法。以1909号超强台风利奇马行进过程中的我国东南沿海浙江省典型输电杆塔的风险预测为例,说明了所建立的易损性模型能够非常高效便捷地用于输电杆塔台风风险预报,呈现了输电杆塔实时风险预判模型的应用价值。

Abstract:The collapse of transmission towers caused by typhoons will affect the power supply of the power grid and cause both serious social and economic losses. Therefore, it is necessary to predict the risks of the transmission system, especially the transmission towers, during the typhoon process, so as to facilitate the power sector to effectively deploy prevention and loss reduction measures. The fragility model of wind-induced damage to transmission towers is a practical tool for risk assessment. Combined with the wind fields of numerical weather prediction(NWP), the fragility model can effectively support the risk prediction of transmission towers during the real-time typhoon process. This study established a fragility analysis based on a refined tower-line system finite element model by considering the physical mechanism of wind-induced collapse of transmission towers and the time-varying characteristics of the forecasted wind speed, and at the same time incorporated the time-varying risk prediction method of transmission towers during the typhoon process with the uncertainty of the fluctuating wind time series. Taking the risk prediction of a typical transmission tower in Zhejiang Province on the southeast coast of China during the process of the super typhoon Lekima(ID:1909)as an example, it is shown that the established fragility model can be employed very efficiently and conveniently for typhoon risk prediction of transmission towers, demonstrating its application value of the real-time risk prediction model of transmission towers.

钢管塔力学性能卓越,应用广泛,但其钢管杆件长细比较大,水平放置易在低风速下发生涡激共振现象。钢管构件长期振动易使钢结构疲劳损伤甚至破坏,严重影响输电塔结构正常服役安全。针对钢管塔构件涡激振动现象开展试验研究,并提出有效的阻尼控制方法。首先,开展了原尺输电塔钢管杆件气动效应研究。对槽型插板节点钢管弱轴向涡激振动响应及尾流展向特性进行分析。其次,引入尾流振子模型,探究了增加阻尼比对钢管杆涡振响应的理论抑制效果的提升。最后,根据理论计算结果开展调谐质量阻尼器(tuned mass damper, TMD)控制试验,通过加装TMD对钢管振动响应进行了控制,振幅最多可以下降95.8%,表明TMD可有效提高钢管塔在复杂风环境下的结构稳定性,保证钢管服役期间的安全。

Steel tube towers have excellent mechanical properties and are widely used. However, the slenderness ratio of their steel tube members is relatively large, and when placed horizontally, vortex-induced resonance is prone to occur at low wind speeds. Long-term vibration of steel tube members can easily cause fatigue damage or even destruction of the steel structure, seriously affecting the normal service safety of the transmission tower structure. This paper conducts experimental research on the vortex-induced vibration phenomenon of steel tube tower components and proposes effective damping control methods. Firstly, the aerodynamic effect research of the original-scale transmission tower steel tube members was carried out. The vortex-induced vibration response in the weak axial direction of the steel tube at the slot-shaped gusset plate joint and the characteristics of the wake in the spanwise direction were analyzed. Secondly, the wake oscillator model was introduced to explore the enhancement effect of increasing the damping ratio on the theoretical suppression effect of the vortex vibration response of the steel tube. Finally, the tuned mass damper(TMD)control test was carried out based on the theoretical calculation results. The vibration response of the steel tube was controlled by installing TMD, and the amplitude can be reduced by up to 95.8%, indicating that TMD can effectively improve the structural stability of the steel tube tower in a complex wind environment and ensure the safety during the service period of the steel tube.

为保证我国电力能源输送通道安全,减小舞动给电力系统带来的危害,引入轴向时滞速度反馈控制策略对输电线舞动进行控制。利用Hamilton原理建立了带时滞特征的覆冰输电线非线性舞动方程。经归一化和Galerkin离散后,得到输电线舞动常微分方程。利用多尺度法分别推导了主共振幅频响应方程和一阶稳态近似解,及谐波共振幅频响应方程,分析了不同参数对输电线振动的影响。研究结果表明:主共振响应下输电线舞动幅值随时滞值变化呈现出周期性,随控制系数增加而减小,随外部激励增加而增加; 不同谐波共振类型表现出不同特性。采取轴向时滞速度反馈控制策略抑制输电线舞动时,需要综合考虑不同参数对输电线振动的影响,通过调整时滞参数来调整共振区范围和幅值来达到最佳效果。

To ensure the safety of power energy transmission channel and mitigate the hazards posed by line galloping, an axial time-delay velocity feedback control has been implemented. Utilizing Hamilton's principle, a nonlinear galloping equation characterized by time-delay features for iced transmission lines was established. Following normalization and Galerkin discretization, the ordinary differential equation for galloping was derived. The multi-scale method facilitated the derivation of the main resonance amplitude-frequency response equation and the first-order steady-state approximation, as well as the harmonic resonance amplitude-frequency response equations. The influence of various parameters on the amplitude of iced transmission lines vibrations was analyzed. The conductor amplitude of the primary resonance exhibits periodicity as time-delay values vary. The amplitude diminishes with increased control coefficients and increases with external excitation. Different characteristics are displayed among various harmonic resonance types. When implementing an axial time-delay velocity feedback control strategy to suppress galloping, it is essential to comprehensively assess the impact of various parameters on the vibrations of iced transmission lines. By adjusting the time-delay parameters, the range and amplitude of the resonance zone can be modified to achieve optimal results.

在方钢管型钢再生混凝土组合柱低周反复荷载试验研究的基础上,通过ABAQUS有限元软件建立了该组合柱的数值计算模型,分析了组合柱的应力云图及变形特征,研究了组合柱的滞回曲线和骨架曲线,通过与试验的对比验证了模型的合理性。结果表明,反复水平荷载作用下柱脚方钢管屈曲鼓起,内部型钢达到屈服且再生混凝土被压碎,组合柱呈压弯塑性铰破坏模式。在分析参数的范围内,方钢管强度可以大幅度提升组合柱承载力,但却在一定程度上减小了组合柱的延性。提高方钢管的壁厚,组合柱的承载力大幅度提升。合理设计组合柱的剪跨比对其抗震性能的发挥十分重要,故在实际工程中应避免短柱脆断和长柱失稳; 此外,随着再生骨料取代率的增加,组合柱的承载力提升较小,其延性随取代率的增加略有降低。

Based on the low cycle repeated load tests on the steel-reinforced recycled concrete filled square steel tube composite columns, the numerical calculation model of composite columns was established by ABAQUS finite element software in this paper. The stress nephogram and deformation characteristics of composite columns were analyzed, and the hysteresis curves and skeleton curves of composite columns were also studied. In addition, the reasonableness of numerical model was also verified by comparing with the test results. The results show that square steel tube column base buckled and bulged under repeated horizontal loads, the internal profile steel of composite column reaches yield and the recycled concrete is crushed, and the composite column exhibits a compression bending plastic hinge failure mode. Within the range of the analyzed parameters, the strength of square steel tube can substantially increase the bearing capacity of columns, but it reduces the ductility of columns to a certain extent. By increasing the wall thickness of square steel tube, the bearing capacity of columns is substantially increased. Reasonable design of the shear span ratio of composite columns is crucial for their seismic performance, so in practical engineering, the brittle fracture of short columns and instability of long columns should be avoided. Furthermore, as the replacement rate of recycled aggregate increases, the load carrying capacity of the combined column improves less, and their ductility decreases slightly with the increase of substitution rate.

为适应装配式建筑的发展需求并实现钢-混组合梁的快速装配化,提出了一种基于高强螺栓连接的装配式组合梁。为研究该新型装配式组合梁的纵向受弯性能及连接件的可靠性,对该组合梁进行了正位两点加载受弯试验,得到了组合梁的破坏模式、荷载-挠度曲线、跨中截面应变分布曲线、荷载-滑移曲线等特征曲线; 并基于受弯试验建立了三维实体有限元模型,分析了预制混凝土板强度、水泥基灌浆料(cement-based grouting material, CGM)强度、高强螺栓预紧力以及抗剪连接程度对该装配式组合梁抗弯性能的影响规律。试验和有限元分析结果表明:组合梁的破坏模式为混凝土板压碎的弯曲破坏,在高强螺栓连接下组合梁表现出较好的组合作用; 预制混凝土板强度的增加对组合梁的极限承载力有所提高,但整体增幅并不是很明显; CGM强度和高强螺栓预紧力对组合梁极限承载力影响不大,但螺栓预紧力的增加能提高组合梁在弹性阶段的整体刚度; 当抗剪连接程度超过0.7后,提高连接程度对组合梁的受弯性能影响不明显。所得结论为该新型装配式组合梁的应用提供了参考。

To meet the development needs of prefabricated buildings and facilitate the rapid assembly of steel-concrete composite beams, a prefabricated composite beam based on high-strength bolted connections is proposed. The longitudinal flexural performance and connector reliability of the assembled composite beam were investigated through orthotropic two-point loading bending tests. Damage modes, load-deflection curves, mid-span section strain distribution curves, and load-slip curves of the assembled beam were obtained. A three-dimensional solid finite element model was established based on the flexural test, and the effects of precast concrete slab strength, cement-based grouting material(CGM)grout strength, high-strength bolt preload and shear connector degree on the flexural performance of the composite beam were analyzed. Test and finite element analysis results show that the combined beams mainly exhibit bending damage of the crushed concrete slab, demonstrating better performance under high-strength bolt connections. Increased concrete slab strength improves ultimate bearing capacity, although the overall increase is not substantial. CGM grout strength and high-strength bolt preload have minimal influence on ultimate bearing capacity but improve overall stiffness in the elastic phase. Beyond a shear connection degree of 0.7, further increasing the degree has limited effect on bending performance. These findings provide valuable insights for the application of this new type of assembled composite beam.

连梁作为高层建筑结构体系中重要的耗能构件,要求其具有较强的抗震性能。双连梁通过提高跨高比,降低连梁内力,在地震作用下表现出良好的延性。为此,在采用双连梁的基础上考虑基体材料与钢板的影响,提出钢板-纤维增强混凝土组合双连梁,并使用有限元软件对试验试件进行数值模拟,对其混凝土裂缝发展、钢板和钢筋应力、钢板沿梁跨的内力分布进行探究分析。并对钢板-纤维增强混凝土组合双连梁的跨高比、含钢率、配箍率、纵筋配筋率、纤维增强混凝土强度和连梁中间开缝间距等进行参数分析。结果表明:纵筋配筋率、含钢率、纤维增强混凝土强度和跨高比对钢板-纤维增强混凝土组合双连梁的抗震性能影响相对较大; 纤维增强混凝土的使用有利于钢板性能的充分发挥; 双连梁左、右梁内的受力基本相同,双连梁可以近似按左、右梁转角刚度相同进行等效。

The coupling beam is an important energy dissipation component in the structural system of high-rise buildings, which requires great seismic resistance performance. The double coupling beam shows good ductility under earthquake action by increasing the span-to-depth ratio and reducing the internal force of the coupling beam. In this paper, considering the influence of matrix material and steel plate, the plate-fiber reinforced concrete composite double coupling beam is proposed. The finite element software is used to numerically simulate the test specimens, and the development of concrete cracks, the stress of the steel plate and steel bars, and the internal force distribution of steel plate along the coupling beam span are investigated and analyzed. The parameters of span-to-depth ratio, steel plate ratio, stirrup ratio, longitudinal reinforcement ratio, fiber reinforced concrete strength and middle joint spacing of the plate-fiber reinforced concrete composite double coupling beam are analyzed. The results show that the longitudinal reinforcement ratio, steel plate ratio, fiber reinforced concrete strength and span-to-depth ratio have a great influence on the seismic performance of the plate-fiber reinforced concrete composite double coupling beam. The utilization of fiber reinforced concrete is beneficial for the full utilization of steel plate performance. The forces in the left and right beams of the double coupling beams are essentially the same. The double coupling beam can be approximately equivalent based on the same corner stiffness of the left and right beams.

加筋土结构作为一种新型岩土工程构筑物,在公路、铁路等交通基础设施中的应用逐渐广泛。因设计、施工不当等原因,加筋土结构易产生变形,严重时甚至坍塌,因此有必要探讨结构破坏特性、分析失效原因,以供工程界参考。文中收集了146个加筋土结构破坏案例,统计分析了结构类型、面板类型、筋材类型、填料类型、结构高度、加筋级数和结构用途等结构特性。总结归纳了结构坍塌、面板变形、顶部沉降、地基承载失效和筋材断裂等常见失稳现象。剖析了设计、施工、材料、降雨、地震和使用不当等致灾原因,以期厘清加筋土结构失效的关键因素。提出了相应改善对策以提高工程质量。研究结果表明:加筋土结构的破坏为综合性破坏,面板变形、顶部沉降和地基破坏为最常见的3种原生破坏模式,原生破坏模式会逐渐转化为其它次生破坏模式; 降雨、地震和使用不当为导致结构破坏的主要外部因素,施工、设计和材料选用不当为导致结构破坏的主要内部因素。建议选用抗剪切刚度较大的面板形式以增强结构的抗变形能力; 严格遵循规范条文对结构进行分级设计和材料选取以提升结构的稳定性; 针对降雨和地震等自然灾害,应加强针对性设计,并辅以数值模拟的手段进行性能评估。

Reinforced soil structure is gradually used in transportation infrastructure such as highways and railways as a new type of geotechnical engineering structure. Due to its structural characteristics, the reinforced soil structure is prone to deformation and even collapse in severe cases, so it is necessary to study the damage characteristics and analyze the failure reasons for the reference of the engineering community. In this paper, 146 failed reinforced soil structures were collected and statistically analyzed for structural characteristics such as structure type, panel type, reinforcement type, filler type, structure height, structure tier, and functional use. Common failure phenomena such as structure collapse, panel deformation, settlement, foundation bearing failure, and reinforcement fracture were qualitatively summarized. Causes of failure such as design, construction, materials, rainfall, earthquakes, and overload were analyzed in order to clarify the key factors for failure of reinforced soil structures. Corresponding improvement countermeasures were proposed to improve the engineering quality. Based on the research results, this paper has drawn the following main conclusions: the destruction of reinforced soil structure is comprehensive destruction, panel deformation, top settlement and foundation failure are the three most common primary failure modes, and the primary failure mode will gradually transform into other secondary failure modes. Rainfall, earthquake and improper use are the main external factors leading to structural damage, and improper construction, design and material selection are the main internal factors leading to structural damage. This paper suggests select panels with large shear stiffness to enhance the deformation resistance of the structure; strictly follow the provisions of the code to carry out graded design and material selection of the structure to improve the stability of the structure; for natural disasters such as rainfall and earthquakes, targeted design should be strengthened, and performance should be evaluated by numerical simulation.

为了给孔内深层强夯法(SDDC工法)处理Q₂湿陷性黄土地基设计方案提供优化参数,以西安灞桥某地基处理项目为背景,基于离散元数值方法和原位测试技术,研究不同黄土地层参数、不同SDDC工法设计参数对湿陷性黄土地基的挤密效果的影响,并提出优化建议,最后基于试验段实测结果进行了对比验证。研究表明,SDDC工法对细粒径、粒径比小和刚度低的地基挤密效果更显著,土体的初始孔隙率、剪切模量和泊松比变化对地基挤密效果的影响较小。适当增大夯击能和成孔直径,可有效提高地基挤密效果,橄榄型锤对地基的挤密宽度影响更显著,矩形锤对挤密影响深度更有优势。本场地建议SDDC工法的设计参数是:采取橄榄型锤施工,单次夯击能不宜低于800 kJ、成孔直径D=1.2～1.4 m; 受施工扰动影响,地表以下及桩底以上2 m范围内挤密效果较差,建议采取其他辅助压实手段消除端部效应。

In order to provide an optimal design scheme for the treatment of Q₂ collapsible loess foundation by super down-hole dynamic compaction(SDDC)method, based on a foundation treatment project in Ba Bridge, Xi'an, the compaction effect of different parameters of loess and different SDDC design parameters on collapsible loess foundation was studied using discrete element numerical method and in-situ tests, and the optimization suggestions were put forward. Finally, it is verified based on the measured results of the test section. The results show that the SDDC method is more effective for the foundation with fine particle size, and low particle size ratio and low stiffness, and the changes of initial porosity, shear modulus and Poisson's ratio of soil have little influence on the foundation compaction effect. Appropriately increasing the tamping energy and hole diameter can effectively improve the compaction effect of the foundation. The conical hammer has a more significant effect on the compaction width of the foundation, and the rectangular hammer has more advantages on the compaction depth.The design parameters of SDDC method construction, recommended for this site are: adopt conical hammer for construction, the single tamping energy should not be less than 800 kJ, and the hole diameter D=1.2～1.4 m. Due to the influence of the construction disturbance, the compaction effect is poor within the range of 2 m below the surface and above the pile bottom, and other auxiliary compaction methods are recommended to eliminate the end effect.