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A holistic approach for the investigation of lining response to mechanized tunneling induced construction loadings

Underground Space 2018年第1期3卷 45-60页

作者： Vojtech Ernst Gall Ahmed Marwan Mario Smarslik markus Obel peter mark Gunther Meschke Inustitute for Structural Mechanics Ruhr University BochumBochunGermany Institute of Concrete Structures Ruhr University BochumBochumGermany

Design methods for segmental tunnel linings used in mechanized tunnel constructions typically employ numerical bedded beam mod-els and/or classical analytical solutions for the determination of structural forces(*** and shear and axial forces)and simple load spreading assumptions for the design of the reinforcement in joint *** effcient such methods may be,many physical details are often overlooked and/or oversimpliﬁed in the process of reducing the actual structure to a structural beam model,***-lytically derived loadings are employed,the grouting and ground reactions are reduced to a spring bedding,and the conﬁnement due to grouting at the longitudinal joint is largely not considered in reinforcement *** a design process is not able to account for,or predict,the susceptibility of tunnel linings to often observed damages that,although they may not be structurally relevant,lead to ser-viceability or durability issues,such as crack development or chipping at the segment *** methods,such as the Finite Element Method,provide an opportunity to model the segmental tunnel lining and its response to the entire TBM construction process and to explicitly model the crack development within individual segments using modern methods to model the discontinuities in *** this contribution,a holistic modeling procedure for the representation of the tunnel lining within the tunneling process is pro-posed and compared to traditional lining models.A 3D process oriented Finite Element model is used to calculate the predicted forces on the tunnel lining and the obtained results are compared with those generated by traditional ***,the predicted defor-mations are then transferred to a detailed segment model in which the nonlinear response of the segment at the longitudinal joint is mod-eled using an interface element based approach to simulate concrete cracking.

关键词： Mechanized tunneling Segmental tunnel linings Finite element method

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Influence of Repeated Variable Load on Long-Term Behavior of Concrete Elements

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Journal of Civil Engineering and Architecture 2014年第3期8卷 302-314页

作者： Toni Arangjelovski Goranmarkovski peter mark Faculty of Civil Engineering University St. Cyril and Methodius Skopje 1000 Republic of Macedonia Institute of Concrete Structures Ruhr-University Bochum Bochum 44780 Germany

The objective of this paper is to study the influence of repeated variable action on long-term behavior of concrete structural elements using quasi-permanent combination of actions, for the assessment of long-term effects （e.g., effects due to creep and shrinkage in concrete structures）, as it is proposed in Eurocodes. Extensive experimental program and analytical research using model B3 and AAEM （age adjusted effective modulus） method was performed in order to define quasi-permanent factor ψ2, for two specific loading histories. These loading histories were consist of long-term permanent action ＂G＂ and repeated variable action ＂Q＂. The variable load was applied in cycles of loading/unloading for 24 h and 48 h in period of 400 days appropriately for one series of concrete elements. 24 reinforced concrete beams, dimensions 150 mm × 280 mm × 3,000 mm, were tested. Twelve beams were made of concrete class C30/37 and 12 of concrete class C60/75.

关键词： Repeated variable actions autogenous shrinkage creep Model B3.

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Low Friction Sliding Planes of Greased PTFE for High Contact Pressures

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Open Journal of Civil Engineering 2016年第2期6卷 105-116页

作者： Lennart Bocklenberg Karsten Winkler peter mark Stefan Rybarz Institute of Concrete Structures Ruhr-Universit?t Bochum Bochum Germany Institute for Structural Engineering Structural Testing Laboratory (KIB-KON) Ruhr-Universit?t Bochum Bochum Germany

Sliding planes of PTFE are commonly used because of their excellent tribological properties. However, especially in cases of high contact pressures, PTFE suffers from its comparatively poor mechanical properties. This paper presents a sliding construction developed within an innovative experimental test-setup to enable experimental investigation of large-scale concrete members subjected to punching shear. To fulfill the special demands of the new test-setup, greased, only 0.5 mm thin sheets of PTFE were used to minimize friction between the bearing construction and the test specimen. This highly effective sliding construction leads to a dynamic friction coefficient μd,max between 0.0065 and 0.0035 while the static friction coefficient μs remains below 0.0048. Simultaneously, compressive axial stresses of more than 60 MPa occur. The paper highlights major aspects of the sliding plane’s development and demonstrates its sliding abilities.

关键词： Sliding Plane PTFE Innovative Test-Setup Experiments

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Human blastomere rotation in early cleavage embryos is not associated with reduced implantation: Evidence from time-lapse videography

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Asian pacific Journal of Reproduction 2019年第6期8卷 297-298页

作者： Emma P Langdon Yan-he Liu Phillip L Matson peter J mark School of Human Sciences the University of Western AustraliaCrawleyWestern Australia 6009Australia School of Medical and Health Science Edith Cowan UniversityJoondalupWestern Australia 6027Australia Reproductive Medicine Center Tianjin United Family HospitalTianjinChina Fertility North Joondalup Private HospitalJoondalupWestern Australia 6027Australia

Dear Editor,Time-lapse videography of human embryos allows for the easy visualization of the embryos without removing them from the protective environment of the incubator[1],the measurement of various morphokinetic(quantitative)parameters[2],and the identification of abnormalities of growth(qualitative parameters)such as direct cleavage[3],reverse cleavage[4]and intercellular contact of blastomeres[5].

关键词： Human embryos Blastomere rotation Time-lapse videography

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哥伦比亚河上过桥难

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商业周刊（中文版） 2015年第3期 31-32页

作者： peter Robison mark Niquette 谭天

从俄勒冈州波特兰到华盛顿州温哥华、跨越哥伦比亚河的那座老朽的大桥．并没有真正的名字。西海岸最繁忙的卡车动脉5号州际公路途经的这座大桥，人称州际大桥，已有98年历史，是美国境内最危险的一座桥梁。

关键词：哥伦比亚华盛顿州俄勒冈州温哥华波特兰大桥西海岸境内

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资秩学院单元8 1999-2000年膨胀泡沫稳定器

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世界建筑导报 2004年第Z1期 116-121页

作者： Takuya Onishi ,peter Thomas,mark Prizeman 指导教师指导教师

我们的短期城市研究由于以下资料和条件的限制而是被迫的: ●专利权:一种19世纪的发明物,通过它国家、公司或个人可以在一个特定的时期内对一个构思设立所有权。 ●灾难:一种对正常生活不可预见的阻断,需要采取特殊的补救措施。在这种... 详细信息

我们的短期城市研究由于以下资料和条件的限制而是被迫的: ●专利权:一种19世纪的发明物,通过它国家、公司或个人可以在一个特定的时期内对一个构思设立所有权。 ●灾难:一种对正常生活不可预见的阻断,需要采取特殊的补救措施。在这种情况下该项目的背景是城市被地震所摧毁。 ●土尔其:一个被北安那托利亚不恰当的边界线一分为二的国家,在此研究期间遭受了两次大地震的袭击。 ●快速发展区:对迅速扩展的特殊地区,对一种灾难给出建筑学上的建议。

关键词：稳定器轻微损伤建筑类型充气结构薄膜结构气袋地震

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ABB公司的创新型模块化感应牵引电动机适应性达到了新的高度

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电气牵引 2012年第2期 35-37,66页

作者： peter J Isberg mark Curtis

列车通常是适应不同的铁路运输提供商的各自技术规格而定制的。每一个新的设计需要另外的独立原始设备制造商（OEM）提供各种独特的列车专用部件。传统上，牵引电动机是车辆制造商所需的众多定制部件之一。这些电动机需要精心设计，以... 详细信息

列车通常是适应不同的铁路运输提供商的各自技术规格而定制的。每一个新的设计需要另外的独立原始设备制造商（OEM）提供各种独特的列车专用部件。传统上，牵引电动机是车辆制造商所需的众多定制部件之一。这些电动机需要精心设计，以确保其功能和品质，从而导致增加了整个价值链中的复杂性，对制造所需的时间造成了负面影响。为了克服这些问题，ABB公司研发了新系列的内置灵活的感应牵引电动机，以便采用单个模块设计来满足特定客户的需求。

关键词：牵引电动机 ABB公司感应原始设备制造商适应性模块化创新型模块设计

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采用激光技术加工异型孔

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现代制造 2012年第10期 48-50页

作者： peter Thompson． mark Barry

当今涡轮发动机部件异型孔的激光加工成为了最热门的主题，无论航空发动机还是陆基涡轮机制造企业及其供应商都对此领域表现出了极大兴趣，他们往往提出异型孔的形状，但受制于技术、经验或是工业设备水平的限制，要想得到理想形状的孔... 详细信息

当今涡轮发动机部件异型孔的激光加工成为了最热门的主题，无论航空发动机还是陆基涡轮机制造企业及其供应商都对此领域表现出了极大兴趣，他们往往提出异型孔的形状，但受制于技术、经验或是工业设备水平的限制，要想得到理想形状的孔非常困难。

关键词：激光技术激光加工异型孔理想形状发动机部件航空发动机制造企业工业设备

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The current perspective of the PA 1957 gas well pillar study and its implications for longwall gas well pillars

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International Journal of Mining Science and Technology 2021年第1期31卷 117-126页

作者： peter Zhang Daniel Su Chris mark CDC NIOSH Pittsburgh Mining Research DivisionPittsburghPA 15236USA Mine Safety and Health Administration PittsburghPA 15217USA

Many states rely upon the Pennsylvania 1957 Gas Well Pillar Study to evaluate the coal barrier surrounding gas *** study included 77 gas well failure cases that occurred in the Pittsburgh and Freeport coal seams over a 25-year *** the time,coal was mined using the room-and-pillar mining method with full or partial pillar recovery,and square or rectangle pillars surrounding the gas wells were left to protect the *** study provided guidelines for pillar sizes under different overburden depths up to 213 m(700 ft).The 1957 study has also been used to determine gas well pillar sizes in longwall mines since longwall mining began in the 1970 *** original study was developed for room-and-pillar mining and could be applied to gas wells in longwall chain pillars under shallow ***,under deep cover,severe deformations in gas wells have occurred in longwall chain ***,with a better understanding of coal pillar mechanics,new insight into subsidence movements induced by retreat mining,and advances in numerical modeling,it has become both critically important and feasible to evaluate the adequacy of the 1957 study for longwall gas well *** this paper,the data from the 1957 study is analyzed from a new perspective by considering various factors,including overburden depth,failure location,failure time,pillar safety factor(SF),and floor *** pillar SF and floor pressure are calculated by considering abutment pressure induced by full pillar recovery.A statistical analysis is performed to find correlations between various factors and helps identify the most significant factors for the stability of gas wells influenced by retreat *** analyzing the data from the 1957 study,the guidelines for gas well pillars in the 1957 study are evaluated for their adequacy for roomand-pillar mining and their applicability to longwall *** modeling is used to model the stability of gas wells by quantifying the mining-induced s

关键词： Gas well pillar Pennsylvania 1957 gas well pillar study Room-and-pillar mining Longwall mining

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Rapid range expansion predicted for the Common Grackle(Quiscalus quiscula)in the near future under climate change scenarios

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Avian Research 2021年第4期12卷 569-575页

作者： peter Capainolo Utku Perktaş mark DEFellowes Division of Vertebrate Zoology-Department of Ornithology American Museum of Natural HistoryCentral Park West@79th StreetNew YorkNY 10024-5192USA People and Wildlife Research Group School of Biological SciencesUniversity of ReadingWhiteknightsReading RG66ASUK Depart-ment of Biology(Zoology Section Biogeography Research Laboratory)Faculty of ScienceHacettepe UniversityBeytepe06800 AnkaraTurkey

Background:Climate change due to anthropogenic global warming is the most important factor that will affect future range distribution of species and will shape future biogeographic *** much effort has been expended in understanding how climate change will affect rare and declining species we have less of an understanding of the likely consequences for some abundant *** Common Grackle(Quiscalus quiscula;Linnaeus 1758),though declining in portions of its range,is a widespread blackbird(Icteridae)species in North America east of the Rocky *** study examined how climate change might affect the future range distribution of Common ***:We used the R package Wallace and six general climate models(ACCESS1-0,BCC-CSM1-1,CESM1-CAM5-1-FV2,CNRM-CM5,MIROC-ESM,and MPI-ESM-LR)available for the future(2070)to identify climatically suitable areas,with an ecological niche modelling approach that includes the use of environmental ***:Future projections suggested a significant expansion from the current range into northern parts of North America and Alaska,even under more optimistic climate change ***,there is evidence of possible future colonization of islands in the Caribbean as well as coastal regions in eastern Central *** most important bioclimatic variables for model predictions were Annual Mean Temperature,Temperature Seasonality,Mean Temperature of Wettest Quarter and Annual ***:The results suggest that the Common Grackle could continue to expand its range in North America over the next 50 *** research is important in helping us understand how climate change will affect future range patterns of widespread,common bird species.

关键词： Annual mean temperature Climate change Common Grackle Ecological niche modelling Range shift Seasonality

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