Strain-based design for buried pipelines subjected to landslides

Landslides are one of the key problems for stability analysis of pipelines in the western region of China where the geological conditions are extremely complicated. In order to offer a theoretical basis for the pipe-soil interaction, the general finite element program ABAQUS is used to analyze the distribution of pipe strain caused by landslide through which the pipeline passes. In this paper the Ramberg-Osgood constitutive equation is used to study the strain-based mechanical characteristics of pipelines. Different calculation schemas are designed by considering the change of spatial relationship between pipeline and landslide, and the change of D/t, diameter-thickness ratio of pipeline. The results indicate that the pipeline is primarily subjected to tension stress when the landslide crosses the pipeline perpendicularly, the pipe strain is a maximum along the central axis of the landslide, and reverse bending occurs on pipeline at both edges of the landslide. The pipeline is primarily subjected to friction force caused by the downward movement of the landslide, and the friction force is relatively small when the landslide is parallel to the pipeline. The pipe strain is in proportional to D/t, and this means decreasing D/t can help to improve security of pipelines subjected to the landslide.

Applying an Ordinal Priority Approach Based Neutrosophic Fuzzy Axiomatic Design Approach to Develop Sustainable Geothermal Energy Source

Geothermal energy is considered a renewable,environmentally friendly,especially carbon-free,sustainable energy source that can solve the problem of climate change.In general,countries with geothermal energy resources are the ones going through the ring of fire.Therefore,not every country is lucky enough to own this resource.As a country with 117 active volcanoes and within the world’s ring of fire,it is a country whose geothermal resources are estimated to be about 40%of the world’s geothermal energy potential.However,the percentage used compared to the geothermal potential is too small.Therefore,this is the main energy source that Indonesia is aiming to exploit and use.However,the deployment and development of this energy source are still facing many obstacles due to many aspects from budget sources due to high capital costs,factory construction location,quality of resources,and conflicts of the local community.In this context,determining the optimal locations for geothermal energy sites(GES)is one of the most important and necessary issues.To strengthen the selection methods,this study applies a two-layer fuzzy multi-criteria decision-making method.Through the layers,the Ordinal Priority Approach(OPA)is proposed to weight the sub-criteria,the main criterion,and the sustainability factors.In layer 2,the Neutrosophic Fuzzy Axiomatic Design(NFAD)is applied to rank and evaluate potential locations for geothermal plant construction.Choosing the right geothermal energy site can bring low-cost efficiency,no greenhouse gas emissions,and quickly become the main energy source providing electricity for Indonesia.The final ranking shows Papua,Kawah Cibuni,and Moluccas as the three most suitable cities to build geothermal energy systems.Kawah Cibuni was identified as the most potential GES in Indonesia,with a score of 0.46.Papua is the second most promising GES with a score of 0.45.Next is the Moluccas,with a score of 0.39.However,the three least potential sites among the 15 studied sites are Lumut Balai,Moluccas and Patuha,with scores of 0.08,0.11 and 0.17,respectively.The conclusion of this study also classifies positions into groups to aid in decision-making.

Study on the Design Criteria for Prestressed Concrete Pavements

With a concrete pavement slab prestressed, its load carrying capacity can be significantly increased; thus a thinner slab may be used for the same loading. Prestressing modify the structural behavior of the pavement slab and there is a greater resistance to impact, vibration and overloading. This paper discusses the major design considerations necessary in the successful construction of prestressed concrete pavements and presents a design procedure developed to predict the compressive stress due to prestressing in the pavements at early stage, during service and after cracking. Variation in the approach for repetitive and nonrepetitive loads is clearly distinguished. Check on the recovery after cracking for overloading in prestressed pavements is also needed. Finally, a design example is illustrated the application of the approach developed.

Disaster prevention design criteria for the estuarine cities:New Orleans and Shanghai The lesson from Hurricane Katrina

The accurate prediction of the typhoon （hurricane） induced extreme sea environments is very important for the coastal structure design in areas influenced by typhoon （hurricane）. In 2005 Hurricane Katrina brought a severe catastrophe in New Orleans by combined effects of hurricane induced extreme sea environments and upper flood of the Mississippi River. Like the New Orleans City, Shanghai is located at the estuarine area of the Changjiang River and the combined effect of typhoon induced extreme sea en- vironments, flood peak runoff from the Changjiang River coupled with the spring tide is the dominate factor for disaster prevention design criteria. The Poisson-nested logistic trivariate compound extreme value distribution （PNLTCEYD） is a new type of joint probability model which is proposed by compounding a discrete distribution （typhoon occurring frequency） into a continuous multivariate joint distribution （ typhoon induced extreme events）. The new model gives more reasonable predicted results for New Orleans and Shanghai disaster prevention design criteria.

Application of consequence-based design criteria in regions of moderate seismicity

Current design criteria and prineiples of earthquake engineering design are reviewed,including safety factors, probabilistic approach,and two-level and muhi-level functional design ideas.The modern multi-functional idea is discussed in greater details.When designing a structure,its resistance to and the intensity of the earthquake action are considered. The consequence of failure of the structure is considered only through a rough and empirical factor of importance,ranging usually from 1.0 to 1.5.This paper suggests a method of'consequence-based design,'which considers the consequences of malfunctioning instead of simply an importance factor.The main argument for this method is that damage to a structure located in different types of societies may have very different consequences,which are depeudant on its value and usefulness to the society and the seismicity in the region.

基于可靠性的液化气体运输船新颖C型货物围护系统设计衡准

从结构可靠性分析方法入手,分析液化气体运输船新颖C型货物围护系统的载荷、抗力和模型的随机性。建立新颖C型货物围护系统的极限状态方程,参照国际船级社协会新编的《C型独立液货舱的屈服、屈曲和疲劳评估的有限元分析流程建议》(Recommendation No.174)的相关要求开展新颖构造货物围护系统有限元计算和可靠度分析方法研究,对新颖C型货物围护系统(双体罐和三体罐)进行应力分析和可靠性计算。采用可靠性的第一水准法构建新颖C型货物围护系统的设计衡准,并确定各分项系数,研究结果为制定符合可靠性标准的新颖C型货物围护系统规范和基于可靠性方法的结构强度准则提供参考。

内层钢板外层高强度混凝土复合井壁受力特性与支护结构参数优化分析

针对内层钢板外层高强度混凝土复合井壁的厚度设计,以受均匀围压的内层钢板外层高强度混凝土复合井壁得出的弹性解析解为基础,对内层钢板采用Mises屈服准则,外层高强度混凝土采用统一强度理论,研究复合井壁的初始屈服临界状态.以内层钢板和外层高强度混凝土均未屈服为条件,提出复合井壁的设计流程.结果表明,当内半径、围压以及材料给定时,存在外半径和分层半径的最佳取值范围,在此范围内选择外半径和对应的分层半径,内层钢板和外层高强度混凝土均不会达到屈服.与模型试验进行对比,发现试验中内半径、外半径、分层半径和材料给定的复合井壁,当围压等于设计围压时,外半径和分层半径处于最佳取值范围;当围压继续增大时,外层高强度混凝土先于内层钢板屈服.弹性解与屈服准则相结合,得到复合井壁设计流程为:通过规范及工程地质条件确定井壁内半径和围压值,选定复合井壁的材料,采用屈服准则求得外半径和分层半径的最佳取值范围.

欧洲标准体系下的城市轨道交通桥梁结构设计分析——在埃及斋月十日城铁路项目中的应用研究

埃及斋月十日城铁路项目作为埃及“首条欧美体系下27.5 kV电气化铁路项目”,是近年来中资企业按照欧美标准及欧美管理体系执行的重点海外轨道交通项目之一,其执行标准、设计流程及技术方案有别于国内一般城市轨道交通项目。本文以桥梁结构设计为背景,首先分析欧洲标准体系下桥梁设计阶段划分、设计的重难点以及相应解决措施,其次梳理桥梁各结构采用的规范和设计原则,最后详细分析本项目桥梁结构的设计内容,包括梁型的确定、简支梁结构体系、预应力箱梁、桥面系、结构计算软件及桥梁美观等,旨在为今后采用欧标的海外桥梁设计提供一定的借鉴及参考。

激光清洗效果评价体系及系统研究

为判断激光清洗效果,优化激光清洗工艺参数,对激光清洗效果进行评价就显出重要性。利用1000 W级激光清洗机进行激光清洗实验,结合实验数据,运用机器视觉技术及表面性能测试技术从宏观和微观两个方面对激光清洗后的效果进行评价,提出清洁度、粗糙度、清洗效率3种评价指标;根据评价指标制定激光清洗效果等级评价体系“Lcq”,基于此体系开发激光清洗效果智能评估系统。测试结果表明:该激光清洗效果等级评价体系客观准确,系统运行稳定,可指导激光清洗设备现场作业,从而更快地调整激光清洗机参数,提高清洗效果。

多维度评价及优化黄芪瞬时高温灭菌工艺

为优化黄芪瞬时高温灭菌(high temperature short time,HTST)工艺参数并多维度考察其对黄芪质量的影响,基于指标相关性的权重系数(criteria importance though intercrieria correlation,CRITIC)法采用正交设计优化黄芪灭菌工艺参数,以灭菌温度、灭菌时间、药材粉碎粒度为考察因素,以灭菌率、5种化合物含量及1,1-二苯基-2-苦基肼自由基(1,1-diphenyl-2-picrylhydrazyl,DPPH·)清除率为考察指标,通过直观及方差分析评价灭菌对3个考察指标的影响;并运用液质联用技术(liquid chromatography-mass spectrometry,LC-MS)确认指纹图谱共有峰的结构,以偏最小二乘回归分析法分析共有峰与抗氧化活性的谱效关系。结果显示,灭菌温度是具有显著影响的因素(P<0.05),最佳灭菌工艺参数为灭菌温度(170±2)℃,灭菌时间5 s,粉碎粒度50目;按优化工艺灭菌后的3批样品微生物水平均符合药典规定,5种化合物含量及DPPH·清除率与灭菌前比较无明显变化;灭菌前后指纹图谱相似度均大于0.900;谱效学分析相关性结果与化合物单体抗氧化的试验结果及其结构特点基本一致。综上所述,瞬时高温灭菌对黄芪中微生物具有明显杀灭作用且对其质量无明显影响,表明该方法适用于黄芪药材灭菌。

层次分析-基于指标相关性的权重确定法结合正交设计优化党参、黄芪、茯苓复合饮料提取工艺

目的应用正交实验设计,结合层次分析法(analytic hierarchy process,AHP)和基于指标相关性的权重确定法(criteria importance through intercriteria correlation,CRITIC)优化党参、黄芪、茯苓复合饮料的提取工艺。方法以总皂苷、总黄酮、总多糖和出膏率作为考察指标,通过AHP、CRITIC、AHP-CRITIC对各指标进行权重系数赋值,应用正交实验综合评分法对正交实验结果进行分析,优选党参、黄芪、茯苓复合饮料的提取工艺参数。结果AHP-CRITIC确定权重系数结果科学合理,根据权重系数结合正交实验综合评分法所得综合评分结果优选出最佳提取工艺为:药材加18倍量水提取2次,每次60 min,在最佳提取工艺条件下,该复合饮料的总皂苷含量为32.21 mg/100 g,总黄酮含量为41.48 mg/100 g,总多糖含量为6.245 mg/100 g,出膏率为16.34%。结论优选的提取工艺操作简便、稳定,提取率高,可用于党参、黄芪、茯苓复合饮料的制备。

语言测试混合方法研究的设计类型与质量标准

混合方法研究是教育研究领域的“第三种研究范式”,它能整合质性和量化研究方法,更有效地解决复杂的研究问题,因而逐渐应用在语言测试研究领域。考察混合方法研究设计类型后发现,语言测试混合方法研究可分为“无名有实”“半名半实”“名实兼备”三种类型,且当前语言测试混合方法研究仍有潜力需要挖掘。探究混合方法研究质量的评价标准、模型与指标,有助于找寻当前语言测试混合方法研究存在问题的根源,提升语言测试混合方法研究的质量。混合方法研究的应用可以推动语言测试学科的发展,也将助益我国全面建设外语能力测评体系。

Optimal Design Criteria of Tandem Configuration for High-Load Compressor Cascades

Axial overlap(AO)and percent pitch(PP)are considered as key position configuration parameters that affect the tandem cascade performance.The objective of the current study is to investigate the optimal design criteria for these two parameters in tandem cascades of subsonic highly-loaded two-dimensional compressors.Before that,the influence mechanisms of AO and PP are explored separately.Research results show that higher PP is beneficial for decreasing rear blade(RB)load,but an invalidity of gap flow occurs when it approaches 1.The change in AO has an influence on the adverse pressure gradient of the front blade(FB),and it also affects the gap flow strength and FB wake development.Then,the optimal design criteria for AO and PP are obtained in a large design space,which clarifies the matching relationship of the two parameters at different operating conditions.The best global range of AO is about-0.05 to 0.05 while PP is between 0.85 to 0.92,and PP should be smaller to avoid performance degradation as AO increases.According to the fault tolerance in practical applications,PP should be closer to the lower bound to ensure that the deterioration boundary is wide enough.

洱源县土官村水库黏土心墙坝的反滤设计及复核

设计合理的反滤层是防止黏土心墙坝防渗体渗透破坏非常有效的措施,滤土排水是反滤层设计的根本要求,但当前的反滤设计中,仅通过保护料和被保护料级配曲线的特征粒径来确定相关反滤准则,忽略了密实度等因素对渗透性的影响,因此,根据排水准则确定了反滤料的级配后,仍需根据实际的碾压标准开展土体渗透特性试验,以验证在坝体实际填筑的条件下,反滤料和防渗土料是否满足层间排水关系;通过对有无保护情况下防渗土料抗渗透破坏能力的对比,且对于试验过程中反滤料是否发生淤塞失效的观察,可以判断反滤料是否能够对防渗土料起到一定的反滤保护作用,然而除了特征粒径,当前对于反滤层滤土能力仍缺乏最直接的判断依据,相关判别标准仍需进一步研究。

海南省装配式整体卫生间方案评价标准及要点分析

该文旨在评价海南省装配式整体卫生间方案的标准及要点,以促进海南省在卫生间建设领域的发展。通过分析相关标准和要点,可以为海南省在选择和实施装配式整体卫生间方案时提供指导和参考。同时作为国家标准及地方标准的补充,拟建立一套针对海南省特殊环境要求的装配式整体卫生间的评价体系。通过三亚中央商务区企业孵化基地项目,综合考虑成本、材料、集成化程度、装配化程度等指标,结合《装配式建筑评价标准》及《绿色建筑评价标准》,提出综合性指数评分表,旨在为海南省装配式整体卫生间发展提供可行的评价标准,推动装配式整体卫生间的可持续发展。

设计叙事研究的学科背景与概念界定

目的立足于设计学科的发展特征分析设计叙事研究的学科背景,根据学科特征对设计叙事研究的相关概念加以界定,尝试建构属于设计学科的叙事评判标准。方法立足学界研究现状,系统梳理设计叙事研究的学科背景与发展趋势,用比较研究法详细论证叙述学与叙事学、叙事设计与设计叙事、叙事性设计等概念的异同,并对是否叙事的判断标准加以界定。结论从设计学科的叙事研究的深度与广度考虑,在表述整个学科时统一用叙事学、设计叙事研究称谓较为合理。在具体的研究过程中,关于叙述还是叙事的使用建议根据实际情况而定。可依据两种概念指涉的异同,参照各自表述对象及内容而定。可把“是否有人物参与”和“是否产生状态改变”作为叙事与否的最重要评判标准,充分考虑设计学科与叙事学科的特征与关系,建构开放多元的设计叙事评判标准,为后续设计叙事学的建立奠定前期基础。

中国高速铁路轨道设计标准在东南亚地区的适应性研究

东南亚国家尚未建立本地的高速铁路标准体系,印尼雅万高铁、泰国曼谷至呵叻高铁等“一带一路”合作项目所在国均以中国高铁的技术标准为基础开展建设,由于国情不同,中国高速铁路标准无法直接套用在东南亚高速铁路项目中。依托印尼雅万高铁、泰国曼谷至呵叻高铁项目具体案例,从主要设计原则、工程材料、钢轨定尺、轨道结构选型、预制轨道板、无缝线路几个方面内容进行研究,分析中国高速铁路轨道设计标准在东南亚地区的适应性。主要结论如下:(1)钢筋、混凝土可采用当地材料,需对比强度、化学元素含量等特性,合理选择;(2)东南亚国家地区的钢轨一般从中国进口,因此定尺长需考虑港口吊装基础设施、既有海运条件、境外公路和铁路运输等影响因素,建议采用50 m轨;(3)结合当地气候条件,从经济性角度考虑合理优化无砟轨道结构,可采用普通钢筋混凝土轨道板;(4)中国跨区间无缝线路技术完全能适应东南亚地区线路条件。

小型模块式轻水堆燃料组件临界热流密度研究进展

小型模块化反应堆(SMR)在“双碳”大背景下具有广阔的应用前景,对实现能源低碳化转型和能源技术变革等方面具有重要意义。它与常规轻水堆(压水堆和沸水堆)相比堆芯设计差异大,主要表现在小型堆运行功率低、压力低、流速低、堆芯高度低以及功率分布更畸形等,从而导致水冷SMR燃料组件临界热流密度(CHF)研究面临更多难点和挑战。本文综述了CHF机理模型研究、经验关系式研究、子通道分析程序开发等三个方面的发展现状,分析了小型模块式轻水堆CHF研究的特点和难点,并以清华大学研发的一体化全功率自然循环小型压水堆NHR200-Ⅱ为例,介绍了其临界热流密度分析的关键方法研究。

儿童少年卫生学课程实验技能考核指标的设计与思考

儿童少年卫生学是公共卫生与预防医学学科的重要组成部分,但对技能考核指标的设计与应用未见报道.本研究围绕儿童少年卫生学实验技能考核设计三级指标,对重要性、有效性、难度进行评价,结果表明指标体系能有效反映学生对于儿童少年卫生学实验技能的掌握程度.

神东矿区长距离定向钻探技术研究

基于神东矿区井下长距离定向钻机精准探测施工实践,充分发挥长距离定向钻机具备的探测精度高、探测距离远、可以随时灵活调整钻头方位的特点,以掘进工作面先探后掘超前探测施工、远距离疏放上覆采空区积水施工以及断层构造准确探测施工为工程实例,研究了长距离定向探测钻孔的轨迹设计方法和施工工艺,并通过对各种钻孔施工工艺及工程经验进行总结,分析研究了探测过程中相关的判定标准,得出了以钻孔孔口返水量、返水颜色、返渣沉淀物特征、孔口气体成分含量和钻进阻力为主的钻探成果判定因素指标,形成了长距离定向探测施工的科学判定依据。