深基坑开挖对邻近地铁车站基坑影响的计算分析

采用有限元软件模拟分析了地铁车站基坑在施工期间邻近基坑开挖对既有车站基坑的影响,土体本构模型采用剑桥模型,分析结果表明邻近基坑的开挖会加大既有地铁车站基坑远端支护结构的水平位移和地表沉降,而近端的支护结构发生的部分回弹减少了水平位移,相应的地表沉降也减小了.所以在类似的基坑开挖过程中要对远端的支护结构和地表沉降进行重点关注.     

用FLAC3D分析地铁车站基坑开挖与支护

运用三维有限差分软件FLAC3D对深圳市地铁9号线某车站工程进行了基坑开挖与支护模拟.土体采用摩尔-库伦模型进行计算,得到了基坑开挖过程中各工况的竖直位移和水平位移.计算结果显示位移较小,基坑支护结构的设计安全可靠.基坑端部墙体在18 m范围内对基底隆起的影响较为明显,其范围相当于开挖深度.基坑端部墙体在20 m范围内对基坑侧移的影响较为明显,其范围相当于基坑宽度.地表沉降最大值点和水平位移最大值点都出现在距离基坑边缘15 m~25 m的区域内,大致相当于开挖深度.模拟结果可以作为今后设计施工的参考.     

深基坑围护结构侧向位移变化规律分析研究

根据南京市地铁四号线中保站的监测数据,分析地下连续墙的变形特征,发现基坑开挖过程中围护结构变形具有明显时空效应规律;发现随着开挖深度增加,地连墙侧移量在基底附近达到最大值;发现地连墙的变化呈现类似抛物线,地连墙侧向位移随着自身刚度增加而减小。结合平面有限元计算分析软件plaxis,利用HS本构模型对地连墙变形影响因素进行分析研究,结果建议南京地区的开挖深度为H时,其地连墙的厚度取(2.5%~3.5%)H。     

考虑渗流影响的深基坑开挖三维弹塑性数值模拟

为了分析在降水影响下地铁车站基坑的稳定性和现场实测的精确性,以沈阳某地铁车站深基坑为研究对象,根据工程地质条件及围护结构的深度和基坑开挖深度,运用ABAQUS对基坑进行了地下水渗流与开挖的三维数值模拟分析,利用试验推理法来模拟渗流问题.对基坑降水条件下开挖和支护体系的变形情况进行了验证,并将模拟结果与实测值进行了对比.结果表明,理论分析和实际监测结果较吻合,该方法对ABAQUS在基坑渗流数值模拟方面具有良好的借鉴性.     

某停车场深基坑支护方式的FLAC3D模拟分析

目的为解决某停车场基坑不同支护方式的选择问题,对该基坑开挖状态的稳定性进行研究,为基坑工程设计与计算提供参考依据.方法运用岩土工程软件FLAC3D模拟某基坑在桩锚支护下以及疏排桩锚-土钉墙联合支护下的开挖状态,分析数值模拟所得的应力与位移等值线图.结果在桩锚支护下基坑土体最大水平位移约为15.5 mm,而在桩锚-土钉墙联合支护下,其最大水平位移增大到约21.4 mm.基坑的位移引起周围土体不同程度的沉降.结论该基坑土体位移的最大值出现在基坑边坡顶缘.桩锚支护与桩锚-土钉墙联合支护都能够有效地抵抗基坑土体位移,但桩锚支护的效果更好.     

西安地铁运动公园站深基坑变形规律现场监测研究

以降低城市地铁车站深基坑开挖对周围环境影响,保障地铁工程施工安全为目的,该研究依托西安市地铁二号线运动公园车站深基坑施工,对施工过程中钢支撑轴力、桩身水平位移、基坑周围地表沉降进行了现场监测,分析了工程开挖前后一段时期内基坑变形规律.研究结果表明:围护桩变形的最大部位在距桩顶2/3的基坑开挖深度处;距基坑长边10m左右地表变形随着基坑开挖深度增加,基坑开挖初期变形速率较大,随着开挖深度的增加,速率逐渐减小;钢支撑能够有效地限制围护桩的水平位移,随着基坑开挖深度和钢支撑的增加,钢支撑的轴力随之增大,最后随时间内力趋于稳定.     

地铁车站深基坑动态施工过程变形规律与数值仿真分析

以南京地铁虹桥站深基坑工程为依托,结合土体开挖过程中基坑各项监控量测数据,利用FLAC 3D软件建立车站深基坑的三维数值仿真模型,对基坑的开挖和支护动态施工过程进行模拟,对比研究数值仿真的变形计算结果与监控量测数据,研究结果表明:(1)地连墙水平位移在墙身范围内,大致呈"弓"形,随着基坑的开挖而呈非线性增加,位移峰值出现在基坑开挖工作面附近。(2)地表土体受基坑开挖的影响范围主要在基坑边1H(H为基坑深度)范围内,不同工况下沉降曲线大致呈抛物线形,且沉降峰值呈线性增加,峰值沉降发生在0. 5H附近;在同一工况条件下,随着时间的推移,不同距离位置处的土体位移呈现不断重分布的过程,但整体曲线仍呈"凹"形。(3)基坑隆起量也与基坑开挖过程有关,土体的最大隆起量发生在基坑中轴线附近,随着开挖深度的增加隆起量呈非线性增加。(4)支撑的架设对围护结构的变形和土体的沉降控制能起到良好的正面作用,延迟支撑架设对变形的发展极为不利。     

既有暗挖车站上盖增层基坑施工力学响应

在既有地铁车站结构上方进行上盖增层拓建项目时,基坑的部分围护桩处于车站的顶拱位置,或近邻车站侧壁位置,基坑开挖后围护桩的稳定性会降低。研究基坑的施工力学响应,可以为地下空间的拓建提供参考依据。文章采用现场监测与三维有限元数值分析相结合的方法,研究了基坑施工过程中桩体位移形状、位移大小和受力的变化规律。结果表明:增层基坑围护桩的最大水平位移量仅为基坑开挖深度的0.037%,其控制变形效果显著;支护体系的空间效应显著,内支撑对桩体受力模式有较大影响;桩后注浆加固与桩底和既有结构固结改善了桩体位移曲线;第3道支撑拆除后位移和内力均达到最大,此时施工风险较高。     

黄土深基坑桩锚联合支护结构变形与稳定性分析

为保证某临近地铁车站深基坑在施工过程中安全,采用数值模拟的方法分析了该基坑临近地铁车站一侧桩锚联合支护结构在施工过程中的变形情况,并对其进行稳定性分析.分析表明:临近地铁车站一侧基坑支护结构最大侧移发生在离坑顶约7 m处,最大侧移为13.4 mm;最大地表沉降出现在距离基坑边约4m处,最大沉降量为8.81 mm;桩锚联合支护结构具有较好的稳定性,能够有效控制基坑在开挖过程中变形,工程深基坑的开挖没有影响到地铁车站安全.     

某黄土深基坑复合土钉墙变形监测分析

依托某高速铁路明挖隧道黄土深基坑工程土钉墙支护结构，对深基坑施工过程中周边地表竖向位移、基坑侧壁深层水平位移、基坑坑底隆起进行监测，根据变形监测结果分析了基坑随施工进行和时间变化产生的变形情况，总结了深基坑的变形规律。结果表明：基坑周围地面沉降随基坑开挖深度增加而增加，现场监测基坑周围地表沉降最大值为7.43 mm;随着基坑开挖施工进行，土钉墙支护对基坑整体变形约束较小，呈现整体向基坑内部的倾斜变形，最大水平位移出现在基坑顶部附近深度约0.5 m处，变形值为10.84 mm;基坑整体变形较小，安全储备大，但考虑到湿陷性黄土遇水强度会显著降低的特性，为了保证基坑安全，选取的基坑设计参数是合理的；施工中须做好坑外防渗、排水。研究结果可为同类条件的基坑设计和施工提供借鉴。     

基于生态适宜性评价的皖北县域生态功能区划研究――以颍上县为例

以皖北颍上县县域为研究范围,基于研究区域现状发展情况选取评价因子,构建生态适宜性评价指标体系,运用层次分析法量化各评价因子权重,构建评价模型;利用地理信息系统空间分析技术,对各个因子进行空间分析后叠加处理,得出颍上县县域生态适宜性分区;进而从统筹城乡建设与生态环境的角度,划定县域生态功能分区,为研究区域生态控制线划定提供了技术支撑,为其他类似地区生态控制线划定提供参考。     

出版业上市公司治理结构与经营业绩关联性研究

选取国内12家出版业上市公司为对象,运用多元线性回归方法构建公司治理结构评价模型,基于2011-2014年的横截面和时间序列数据实证研究了公司治理结构对经营业绩的影响。结果发现,我国出版业上市公司治理结构不完善,治理水平较低,未能完全建立现代企业治理体制,整体绩效表现不理想,财务杠杆过低,可持续增长能力缺乏。在深入剖析出版业上市公司治理中存在的问题和薄弱环节的基础上,从规范公司制度、构建职业经理人市场、优化股权结构、构建科学的股权激励机制、提升财务杠杆作用和产业升级等方面提出了促进出版业上市公司发展的政策建议。     

预应力钢桁架在高温(火灾)下的力学特性分析

高温(火灾)环境会改变预应力钢桁架力学特性,影响其安全性能。采用结构力学与火灾科学理论,对拉索式预应力钢桁架进行研究,探讨了高温(火灾)环境下不同拉索布置方式和拉索数目及杆件长度变化对预应力钢桁架力学特性的影响。研究表明:温度变化、拉索布置方式和拉索数目对预应力钢桁架力学特性产生较大影响,但杆件长度变化几乎不影响其拉索应力。研究成果对改善高温(火灾)下预应力钢桁架受力特性及对预应力钢桁架预应力体系布置等具有一定的参考价值。     

PID auf Aneuploidie des Embryos?

Definition of problem

At least in some cases, testing for aneuploidy as part of preimplantation genetic diagnosis (PGD) can be medically useful for pregnancy care. The current legal situation in Germany seems to not generally exclude PGD to detect a maldistribution of chromosomes in an embryo, but testing would require approval by a PGD ethics committee on a case-by-case basis and a well-reasoned application by the concerned woman. This article examines ethically and legally whether fundamental reasons prevent PGD commissions from admitting requests to perform aneuploidy tests as part of PGD.

Arguments

Three constellations – each with differing ethical implications – can be distinguished in which testing for aneuploidy could be considered or could occur: Testing for aneuploidy can (i) be the main reason for in vitro fertilization (IVF), which in itself is not medically indicated; (ii) IVF is done as infertility treatment in which case PGD and aneuploidy testing could be done additionally; or (iii) PGD with IVF is indicated in order to prevent a congenital disease or chromosomal aberration leading to a diagnosis of aneuploidy as an incidental or additional finding. Ethical arguments which could lead to a general rejection of aneuploidy testing are the prevention of discrimination against people with aneuploidy, as well as the protection of embryos. These concerns oppose constellation (i), but do not apply to (ii) and (iii). Yet there are at least three ethical arguments in favour of an admissibility of a request for aneuploidy testing: the “good practice” of IVF, the duty to the emerging child and the parent’s right to have a voice in the discussion.

Conclusion

Aneuploidy testing as part of PGD is not ruled out by legal or ethical reasons and should be openly discussed by the relevant German ethics commissions.

     

地铁控制中心“优秀调度员”胜任力特征模型构建

地铁行车调度指挥是地铁运输生产的组织指挥中枢,调度员担负着组织指挥列车安全、正点、高效运行的重要任务,其胜任能力决定了地铁的运营安全和运输效率。依据胜任力理论,采用BEI关键行为事件访谈法,借助Spencer字典编制出优秀调度员初始胜任力特征群,使用SPSS工具对再次访谈结果进行统计分析,并运用Amos软件对探索性因子进行验证,进而构建出核心能力、综合能力与专业能三个维度16项特征的二阶胜任力模型,此模型能有效的鉴别优秀调度员和普通调度员的胜任特征,今后对"优秀调度员"的选拔与培养具有一定理论和现实意义。     

皖西地区民居改造中的表皮更新研究 ——以金寨县小南京村为例

近年来,由于新材料、新技术以及旧材料的新属性不断地被挖掘,建筑的外表皮开始具有空间上的连续性继而成为独立的部分而成为设计的重点。皖西地区由于独特的地理条件,其民居表皮在建造及更新时,更具有"因地、因材、因时制宜"等特点。本文以皖西地区金寨县小南京村民居为例,探讨该地区民居外表皮的材质、色彩以及做法等,为类似丘陵地区民居外表皮更新保护提供可行性建议。     

<Emphasis Type="Italic">Moral Enhancement</Emphasis> durch Neurochirurgie? Machbarkeit und ethische Vertretbarkeit

Problem

Several influential bioethicists propagate “moral enhancement”. Some argue that this is the only way to save humanity from its own demise. Since the suitability of medical moral enhancement has been challenged with empirical arguments, some bioethicists put the idea forward to use neurosurgery, particularly deep brain stimulation. The paper investigates two questions: (1) Is moral enhancement through neurosurgery feasible, and if yes, to what extent? (2) Is moral enhancement ethically justifiable, insofar it is possible?

Arguments

These ad hoc propositions refer to a handful of experimental brain surgeries in severely mentally disabled persons and to historical psychosurgery. The present proposals for neurosurgical moral enhancement might be appropriate for reducing aggressiveness or sexual drive, so that less self-control would be required for morally adequate behavior. Theoretically, it can be imagined that neurosurgical interventions could increase self-control; however, no evidence exists for this idea so far. According to Tanner and Christen’s model of moral intelligence, all interventions proposed could manipulate at the utmost one of five components of the moral intelligence, namely the moral resoluteness. None of the proposed interventions aims at the improvement of the other four components, namely the moral compass, the moral sensibility, the moral problem solving or the moral commitment.

Conclusion

Comprehensive moral enhancement cannot be effectuated by neurosurgery, neither by recent nor by proposed neurosurgical methods. At most, future closed-loop systems that automatically deregulate certain impulses might produce a moral-conform behavior. However, such a technically controlled moral-conform behavior could be acknowledged as moral behavior only within a utilitarian ethics.

     

Breite Einwilligung (<Emphasis Type="Italic">broad consent</Emphasis>) zur Biobank-Forschung – die ethische Debatte

Definition of the problem

Ethical aspects of biobanking research are receiving increasing attention in the literature. It is particularly controversial which model of consent should be implemented in research biobanks.

Arguments

This paper outlines the ethical controversy surrounding various models of consent into biobank-based research. Following a brief introduction of established consent models, it delineates the development of alternative approaches and discusses the ethical and regulatory challenges associated with these. Relevant ethical principles are highlighted.

Conclusion

The article concludes that there are good reasons to trial a combination of initial broad consent with consent to governance for future biobanking research in Germany.

     

Ethisches Handeln in der Berufspraxis: Das Triadengespräch als Methode des Lernens aus Misserfolgen

Definition of the problem

The starting point of this paper is the question of how the four ethical principles of professional work – respect for autonomy, care for beneficence, nonmaleficence, and justice – can be realized in professional practice. Along the physician-patient relationship the ethical foundation of any medical action is explained. An important part of this is learning from dissatisfying treatments. Therefore, the distinction between error and failure is explained.

Arguments

As an actionable approach for processing dental failures, the methodology of the triad conversation is presented in an empirical study. For this purpose, 21 failures were reconstructed in interviews with dentists. It will be shown whether and how a modified understanding of the dental failure was made possible by the triad conversation. The method is evaluated from the perspective of all involved dentists.

Conclusion

The results of the study show that the triad conversation, as a way of expansive learning, can obtain a prominent position for incorporating the experience of dental practitioners into professional knowledge, while at the same time creating an open culture for learning from failures. Finally, ethical implications dealing with failure in contrast to dealing with errors are discussed.

     

基于模糊综合评价方法的高铁噪声影响评估

我国高速铁路建设发展迅速的同时也加剧了高铁噪声对沿线居民的生活影响,现有的普通铁路噪声相关分析评价方法不能很好地适用于高铁噪声评估研究。本文选取京沪高铁安徽段为研究对象,采用模糊综合评判方法来评估高铁噪声对居民的影响,考察了受影响人群的心理干扰和生理干扰程度,以及高铁噪声暴露实测值等影响因素,经过全面的阐述剖析与具体的量化数值计算,得出了在京沪高铁安徽段的居民受噪声影响为轻度的结论。很大程度上这也为高铁噪声评估方法提供了新的参考依据。