教学课程资源库 更多>>

关键词： 核电厂   地震交互作用   管道物项   模拟仿真   冲击能量  

摘要： 为评估地震灾害中核电厂非安全级管道物项跌落对安全级管道物项的交互作用影响,采用模拟仿真分析与试验验证相结合的方法对管道物项间的冲击过程进行研究。本文建立了管道冲击有限元仿真模型,采用ABAQUS有限元分析软件对核电厂常用安全级管道进行冲击仿真,将管道内截面通流面积减小至50%~55%作为损伤极限,得到不同高度下的冲击极限质量,并采用冲击试验对模拟仿真结果进行验证。研究结果表明,当管道型号规格一定时,其损伤极限主要取决于下落物体的能量,受到高度的影响较小;进行核电厂安全级管道设计布局时,应保证挂在上方的非安全级管道冲击能量小于其能够承受的极限能量。

关键词： 一流课程   教学内容   教学方法   实践教学   师资力量   课程评价  

摘要： 本文深入探讨了《混凝土结构基本原理》一流课程的构建。通过分析课程的教学现状与教学难点,从教学内容、教学方法、实践转化、师资力量加强以及课程评价体系完善等多个方面开展一流课程的构建。研究旨在提高《混凝土结构基本原理》课程的教学质量,有效培养学生解决实际工程问题的能力和创新思维,培养专业基础扎实和实践创新能力的土木工程人才。

关键词： 显微摄像技术   碳酸钙   沉淀溶解平衡   同离子效应  

摘要： “沉淀溶解平衡”具有微观和抽象的特点,导致学生在理解沉淀溶解平衡影响因素时存在困难。利用显微摄像技术探究同离子效应对CaCO3沉淀溶解平衡的影响,可直观地观察到肉眼无法观察到的沉淀形态和沉淀数量的变化及过程。实践证明,将这些信息以图片或视频的形式呈现给学生,可在一定程度上帮助学生理解和记忆这部分知识。

关键词： 高速铁路   地震预警   神经网络   震级   峰值地震加速度  

摘要： 破坏性地震对高速铁路安全会造成严重的影响。为使高速铁路地震预警系统快速获得可靠的Ⅰ级地震警报,基于日本K-NET台网记录的强震动数据,提出一种基于震级阈值(M=5.5)和峰值地震加速度阈值(PGA=40 cm/s^(2))的深度学习高速铁路现地阈值地震预警方法。设计一种结合卷积神经网络、循环神经网络和注意力机制的混合神经网络架构,并在该网络架构的基础上,训练两个独立的模型,分别用于预测震级和峰值地震加速度是否超过阈值。同时,根据震级阈值和峰值地震加速度阈值设置4个警报预测级别。基于混合神经网络模型对震级和峰值地震加速度的预测,每个台站将发布相应的警报预测级别。警报预测级别4表示台站附近有高震级事件且存在潜在破坏。在P波到达后3 s,对于相同的测试数据集,和基线模型相比,混合神经网络模型对于震级预测和峰值地震加速度预测有更好的性能,且震级预测的准确率达到97.26%,PGA预测的准确率达到98.89%,警报预测级别的准确率到达96.31%。将该方法应用于2021年2月13日发生于日本福岛的7.3级地震,结果表明,在P波到达后10 s内,警报预测级别的准确率达到90%,平均预警时间超过19 s。

关键词： 地震作用   桥梁结构   能量耗散   抗震性能优化  

摘要： 本文深入探讨了地震作用下桥梁结构的能量耗散机制以及抗震性能优化方法。首先阐述了地震能量输入的特点和对桥梁结构产生的影响,接着详细分析了桥梁结构中不同构件和装置的能量耗散原理。通过理论研究、数值模拟与实际案例相结合的方式,讨论了当前提高桥梁抗震性能的多种优化策略,包括结构体系优化、耗能装置应用等方面。旨在为今后桥梁结构在地震频发地区的设计、建造与维护提供科学依据,以提升桥梁在地震灾害中的安全性和可靠性。

关键词： 震源机制   中国地震台网中心   目录产出   复核  

摘要： 震源机制解是描述震源特性的重要参数,对了解地震断层的运动方式和动力学机制等具有重要作用。目前中国地震台网中心具备自主产出全球M≥6.0和中国台站密集地区M≥4.0地震震源机制解的能力,其通过全球GSN共享台和中国区域测震台采用多种反演方法产出,根据不同需求分别产出自动结果和人工复核结果,产出时效性强,目录完整性高。本文介绍了震源机制产出系统主要流程,展示了2022年1月—2023年12月自动产出结果527个和人工复核结果261个,并将产出结果进行可靠性分析和评价,表明了中国地震台网中心震源机制结果目录的稳定性和准确性。本文还对比了自动产出结果与人工复核结果,验证了自动产出结果具有较高的可靠性。自动产出结果对震后快速响应、震源破裂过程产出、应急会商等具有重要意义,人工复核结果可为孕震机理研究、区域应力场研究等提供帮助。

关键词： 海上地震采集   宽频采集   宽方位采集   高密度采集  

摘要： 近些年我国海上油气勘探精度不断提高,传统拖缆采集、海底电缆采集等海上地震数据采集方式难以满足岩性圈闭勘探精度要求。以“两宽一高”为代表的高精度海上地震采集技术逐渐成为我国海上地震采集发展趋势。重点对宽频地震采集技术、宽方位地震采集技术、高密度地震采集技术原理、优势及应用现状进行了探讨。

关键词： 多动力因素   耦合作用   结构破坏  

摘要： 针对近海和河口地区的水利工程与海洋工程中的混凝土结构工程经受风、浪、流等多种复杂动力因素的影响作用状况,提出风浪流耦合作用下混凝土构件破坏问题研究,文中详细分析了国内外相关研究现状和发展态势,剖析了相关研究不足与缺陷及空白处,从中梳理出需要研究的目标,详细阐述了研究思路和研究方法及研究内容,指出了本问题的研究意义与价值及创新点,为本问题的研究指明了方向和道路,及为后续研究打下一定的基础和提供了相关条件。In view of the concrete structure engineering in offshore and estuarine areas under the influence of wind, wave, current and other complex dynamic factors, a study on the failure of concrete components under the coupled action of wind, wave and current is proposed. The present situation and development trend of relevant research at home and abroad are analyzed in detail, and the deficiencies, defects and gaps of relevant research are analyzed. The research goal is sorted out, the research ideas, research methods and research content are elaborated, and the research significance, value and innovation of this problem are pointed out, which points out the direction and road for the research of this problem, and lays a certain foundation and provides relevant conditions for the follow-up research.

关键词： Seismic response  

摘要： During the large-scale development of deep coalbed methane in the Daji block on the eastern edge of Ordos Basin, using horizontal wells combined with large-scale volume fracturing, some wells experienced fracturing interference under similar fracturing techniques and technical parameters, significantly affecting the fracturing transformation and gas production outcomes. Through precise 3D seismic interpretation in the early stage, it was found that faults were not developed in the block, suggesting that the development of local micro-scale fractures might be a significant factor causing fracturing interference in horizontal wells. Focusing on the deep No. 8 coal seam in the study area, we rely on high-quality 3D seismic data characterized by "two wide and one high" features. Through OVT (Offset Vector Tile)domain processing, we obtained five-dimensional seismic data encompassing time, space (3D coordinates), offset (or source-receiver distance), and azimuth. For the first time, we employed azimuthal statistics to investigate the development degree, orientation, and developmental stages of micro-scale fractures. The research findings indicate that micro-scale fractures are generally well-developed in the study area, with five major fracture zones observed, and the degree of micro-scale fracture development is higher in the southern part compared to the northern part. The development of fractures is controlled by two phases of regional tectonic activity, exhibiting two distinct planar distribution directions. Specifically, fractures oriented in the near EW and NW directions were formed during the Yanshanian tectonic activity, while fractures oriented in the near SN and NE directions were formed during the Himalayan tectonic activity. By integrating regional tectonic stress fields from different periods, field outcrops, imaging logging, and array sonic logging data, we verified the reliability of our research findings on the degree and direction of fracture development

关键词： Karst spring   Hydrogeology   Hydrochemistry   Environmental isotopes   Iran  

摘要： Understanding the hydrogeology of karst aquifers is essential for developing a comprehensive drinking-water safety plan for the Hashtgerd Basin in north Iran. This study investigates the development and dynamics of karst aquifers and their interaction with alluvial aquifers in the region, which is crucial for ensuring sustainable water resources. Approximately 15% of the basin is covered by karst rocks, supplying 30% of the area's drinking water. The hydrodynamical, hydrochemical, and isotopic properties of water from six springs, four Qanats, and four alluvial wells during wet and dry seasons are analyzed. Findings indicate that the predominant water types in all samples are calcium and magnesium-bicarbonate, resulting from the dissolution of calcite and dolomite. A linear relationship (close to the local meteoric water line) was found between delta O-18 and delta H-2 contents of precipitation, surface water, karst water, and alluvial water, with ranges from -10 to +2 parts per thousand and from -70 to +7 parts per thousand, respectively (vs Vienna Standard Mean Ocean Water). No clear effect of evaporation processes on water isotopic content was detected. Hydrograph analysis suggests short water residence times (a few months) in the karst aquifers. The study concludes that pumping from new wells in the downstream alluvial aquifer could damage karst springs, as some of the karst water discharges into the alluvium. These findings provide critical insights for the sustainable management of the region's water resources.