吉林九站松花江特大桥模型与实桥车辆振动试验分析

介绍了吉林九站松花江特大桥的模型和实桥车辆振动试验情况。数据表明 ,该桥在正常使用荷载的作用下 ,箱梁处在正常的弹性范围内工作 ,安全储备较大 ,安全可靠。     

EXPERT SYSTEM FOR COMPREHENSIVE ASSESSMENT TOBRIDGE SERVICE PROPERTY USING FUZZY THEORY

PREFACE'Amonghighwaybridgesthercstandcon-siderableunfitbridges.Therefore,itismoreimPortanthowtoevaluatethebearingcapacityandtheseheceproPertyofthebridgesproPerly.Inordertoknowwhetherthebridgesneedrepairingornot,itisurgenttosetupacertainstandardfortheoldbridges.ltiswellknownthatbeemethodsareaPpliedintheassessmentofthebridget(l)evaluahngthebridgebyvisualinsPeCtion,(2)evaluatingthebridgebythetheoreticalanaly-sis,(3)evaluatingthebridgebyloadtesting.Althoughthefirstmethodiseasytodo,thcconclusi…     

Encounters with Pinyon-Juniper Influence Riskier Movements in Greater Sage-Grouse Across the Great Basin

Fine-scale spatiotemporal studies can better identify relationships between individual survival and habitat fragmentation so that mechanistic interpretations can be made at the population level. Recent advances in Global Positioning System (GPS) technology and statistical models capable of deconstructing high-frequency location data have facilitated interpretation of animal movement within a behaviorally mechanistic framework. Habitat fragmentation due to singleleaf pinyon (Pinus monophylla; hereafter pinyon) and Utah juniper (Juniperus osteosperma; hereafter juniper) encroachment into sagebrush (Artemisia spp.) communities is a commonly implicated perturbation that can adversely influence greater sage-grouse (Centrocercus urophasianus; hereafter sage-grouse) demographic rates. Using an extensive GPS data set (233 birds and 282,954 locations) across 12 study sites within the Great Basin, we conducted a behavioral change point analysis and constructed Brownian bridge movement models from each behaviorally homogenous section. We found the probability of encountering pinyon-juniper among adults was two and three times greater than that of yearlings and juveniles, respectively. However, the movement rate in response to the probability of encountering pinyon-juniper trees was 1.5 times greater for juveniles. Parameter estimates indicated a 6.1% increase in the probability of encountering pinyon-juniper coupled with a 6.2 km/hour increase in movement speed resulted in a 56%, 42% and 16% increase in risk of daily mortality, for juveniles, yearlings, and adults, respectively. The effect of pinyon-juniper encounters on survival was dependent on movement rate and differed among age class. Under fast speed movements (i.e., flight), mortality risk increased as encountering pinyon-juniper increased across all age classes. In contrast, slower speeds (i.e., average) yielded similar adverse effects for juveniles and yearlings but not for adults. This analytical framework supports a behavioral mechanism that explains reduced survival related to pinyon-juniper within sagebrush environments, whereby encountering pinyon-juniper stimulates riskier movements that likely increase vulnerability to visually acute predators.     

荆州长江公路大桥桩基施工与质量检测

介绍了荆州市长江公路大桥钻孔灌注桩基础的施工方案、施工工艺及质量检测,为同类桥梁施工提供可借鉴之经验。     

基于模拟器的通航风险评价及其应用

为了从通航安全角度对桥梁设计方案的优劣进行比选,应用大型船舶操纵模拟器结合层次分析法,建立了基于模拟器的通航风险评价模型．利用该模型对厦门高集海堤开口桥的两种设计方案的通航风险进行了评价．试验表明：该模型的研究与应用可为评价通航水域桥梁设计方案的优劣提供一种新途径．     

铜陵路桥静载试验

详细介绍铜陵路桥静载试验,试验内容包括试验方法、试验加载车辆确定及控制断面、应变片布设和测试内容等。通过对桥梁结构物直接加载后进行有关测试,记录和分析工作,以达到了解桥梁结构在试验荷载作用下的实际工作状态。在本桥静载试验过程中完全按照既定的试验方案进行,效果良好。     

桥山林区油松采种基地结实原因及调查分析

近年来,山西、陕西等省份油松种子产量较正常年份减少幅度较大,有些地方甚至绝收,已严重地阻碍了林业生态工程建设步伐。本文就桥山林区油松采种基地结实原因进行分析调查。     

九站松花江特大桥风致响应分析

运用桥梁振动理论,对九站松花江特大桥进行了风致响应分析,着重分析阵风引起的抖振内力,计算结果表明,该桥无需做风洞实验,能够满足抗风设计要求。     

春、秋季东海大桥海上风电场水域大型底栖动物群落结构及其与环境因子的关系

为探明工程建设后东海大桥风电场水域大型底栖动物群落结构特征,利用底层拖网资料和环境调查数据,采用相对重要性指数、等级聚类、多元统计等方法对该水域大型底栖动物群落结构及其与环境因子的关系进行分析。春、秋季共发现17种大型底栖动物种类,隶属5目10科14属,十足目占绝对优势,其比率为76.5%,其中以长臂虾科和梭子蟹科占优,比率分别为29.4%和17.6%。春季优势种为葛氏长臂虾(Palaemon gravieri)、三疣梭子蟹(Portunus trituberculatus)和安氏白虾(Exopalaemon annandalei),秋季优势种为安氏白虾和葛氏长臂虾,春、秋季对底栖动物资源量贡献最大的种类不同。春、秋季底栖动物Margalef丰富度指数(D)、Pielou均匀度指数(J')和Shannon多样性指数(H')平均值分别为1.05、0.47和0.83,多样性指数季节间变异不显著。等级聚类(CLUSTER)和非度量多维标序排序(NMDS)表明,东海大桥风电场水域大型底栖动物群落可分为春季和秋季2个组群,单因子相似性分析(ANOSIM)表明2个组群差异极显著(R=0.954,P0.01)。冗余分析(RDA)表明,温度和盐度是影响东海大桥风电场水域大型底栖动物群落结构变异的最主要环境因子,其季节变异主要体现在繁殖群体的季节演替上。东海大桥风电场水域是安氏白虾、葛氏长臂虾和三疣梭子蟹等重要渔业资源的栖息地和繁殖场所,群落结构的变异与底栖动物的繁殖生态习性密切相关,具有典型的季节特征。     

大运河景观价值感知对游客遗产保护意愿的影响研究——以无锡清名桥历史文化街区为例

大运河景观价值感知与地方认同的强化对培育游客遗产保护意愿具有重要意义.以大运河世界文化遗产典型旅游目的 地——无锡清名桥历史文化街区为案例,基于游客问卷的数据分析,构建了大运河景观价值感知、地方认同与游客遗产保护意愿的结构方程模型,探讨了三者之间的相关性和结构性关系.结果 表明:大运河景观价值感知与游客遗产保护意愿存在...