桥梁施工中混凝土的养护

随着桥梁科学的不断发展,桥梁施工中混凝土养护越来越重要,已成为桥梁工程施工中非常关键的一道工序。混凝土养护的好坏将直接关系到混凝土的质量,若养护工作不到位,桥梁工程混凝土将会出现裂缝、强度不达标等质量缺陷,从而严重影响桥梁结构的承载力及结构的安全性。文章就混凝土养护的重要性及桥梁混凝土养护的方法进行了探讨,以供广大桥梁施工人员参考。     

桥梁伸缩缝的装置技术

根据笔者的工程实践,对桥梁伸缩缝装置的应用现状做出了分析,重点对桥梁伸缩缝的安装技术进行了详细的阐述。     

从备苗、施工及养护谈园林绿化的异地施工

近几年 ,随着城市园林绿化建设的广泛展开 ,国内外本行业的展览交流活动及市场开放相应活跃起来 ,因此 ,园林绿化的异地施工也越来越受到重视。除了宣传交流的意义外 ,优势互补成为异地施工的重要动力。园林绿化的异地施工是指某工程项目由数百公里以外的施工队伍负责 ,其采用的施工技术及关键材料与本地施工队有较明显的区别 ,或能显示不同风格。异地施工的成功与否 ,直接影响项目的时效性和投资的经济效益。我公司作为’99昆明世博会“粤晖园”绿化工程施工单位 ,以及 2 0 0 0年上海园林花博会“我的家园”承办和绿化施工单位 ,曾为广东省…     

市政桥梁施工基本要求及施工方法

在进行市政桥梁施工的时候,需要严格按照工程基本要求展开施工,以提高施工的质量水平。文章在了解市政桥梁施工基本要求的基础上,根据施工的实际要求,对其施工方法展开深入的阐述。     

浅析园林绿化施工及养护技术

随着科学技术的不断进步,园林绿化施工及养护技术也得到了极大的提升。为确保园林绿化工程的质量,必须提高园林绿化施工及养护的技术水平。主要对园林绿化工程的特点及园林绿化施工、养护技术进行了分析与探究。     

园林工程施工及植物养护技术分析

指出了在当今的高科技发展时代,城市污染问题层出不穷,而园林绿化工程可以有效保护环境,减少目前的空气污染问题,减轻城市的大气污染压力,降低人们的工作压力,为人们提供一个更舒适、更优美的工作环境与生活环境。当前,园林的建设离不开工程的施工与植物的养护,从园林工程施工与植物养护之间的关系、园林工程施工的管理以及植物养护管理3个方面进行了分析探讨。     

关于大树移植施工技术及养护措施的探讨

随着城市建设水平的不断提高以及人们对美化生活环境的追求,如今,大树越来越广泛地运用于城市园林绿化之中。尤其是在公园、宾馆、住宅区和别墅区等公共场所及住宅,无不考虑采用移栽大树的方法,以达到在较短的时间内体现出绿化美好效果。本文结合本人多年来移植大树的方法,并结合已有的经验,提出园林大树移植的技术,为园林企业在绿化施工中提供指导。     

TD—40型抖动式林木采种装置

TD-40型抖动式林木采种装置系我所设计的球果采集器具。由于其携带方便,操作容易,作业安全,对于立地条件复杂、机械化采种困难,以手工采种为主的天然针叶母树林及采种条件恶劣的种子园,具有一定的推广应用价值。     

浅谈呼盟和大兴安岭林区桥梁建设存在的问题

文章结合工程实际 ,从设计、施工、养护方面对本地区桥梁建设存在的问题进行了分析 ,提出了解决存在问题的办法。     

关于桥梁伸缩缝的研究

本文通过对几种桥梁伸缩缝的测试,并分析了测试的数据,认为最新生产的江苏毛勒伸缩缝既可满足桥梁梁端变形需要,又可起到防水作用,同时还具有良好的舒适性和耐用性。     

关于桥面板式橡胶伸缩装置耐久性的研究

本文通过大量调查对板式橡胶伸缩装置进行了深入研究。找出其亏损的主要原因,并从设计、材料和施工工艺入手。切实解决板式橡胶伸缩装置的耐久性的问题。     

Biomass functions and expansion factors in young Norway spruce (Picea abies [L.] Karst) trees

Roots, stems, branches and needles of 160 Norway spruce trees younger than 10 years were sampled in seven forest stands in central Slovakia in order to establish their biomass functions (BFs) and biomass expansion factors (BEFs). We tested three models for each biomass pool based on the stem base diameter, tree height and the two parameters combined. BEF values decreased for all spruce components with increasing height and diameter, which was most evident in very young trees under 1 m in height. In older trees, the values of BEFs did tend to stabilise at the height of 3–4 m. We subsequently used the BEFs to calculate dry biomass of the stands based on average stem base diameter and tree height. Total stand biomass grew with increasing age of the stands from about 1.0 Mg ha⁻¹ at 1.5 years to 44.3 Mg ha⁻¹ at 9.5 years. The proportion of stem and branch biomass was found to increase with age, while that of needles was fairly constant and the proportion of root biomass did decrease as the stands grew older.     

潭邵高速公路k9+517、k10+527跨线桥上部构造施工与质量控制

本文主要介绍湘潭至邵阳高速公路k9 517,k10 527跨线桥上部构造的施工工艺，着重叙述了支架设计，模板与钢筋安装，混凝土浇注，混凝土养生和质量控制。保证了工程质量及施工安全。     

Effect of mat structure on modulus of elasticity of oriented strandboard

A model to predict bending stiffness of oriented strandboard (OSB) was tested with pilot plant experimental data. The experimental procedure developed in this study is unique in that it allows the model to be tested for extensive vertical configurations of strand angle distribution. After validation, the model was used to simulate a typical three-layer cross-oriented OSB panel with a vertical density profile and strand angle distribution measured on industrial panels. Analysis of the simulated vertical distribution of modulus of elasticity (MOE) indicated that the layers near the panel surfaces contributed much more to the effective parallel panel MOE than those close to the panel thickness center, with 80% of parallel MOE coming from the top 41% of weight and 32% of thickness. The effectiveness of methods to increase parallel bending stiffness through improving mat structure was evaluated. Increasing face/core weight ratio from 54/46 to 66/34 resulted in a 3.7% increase in simulated parallel MOE. Alignment of strands in face layers was identified having a greater potential to increase parallel MOE. Simulations with three improved strand angle distributions showed gains of 5.7, 12.0 and 19.8% in parallel MOE compared with a typical strand angle distribution of industrial OSB panels.     

沈阳地区白三叶草坪的建植与养护技术

通过对沈阳地区白三叶草坪的建植及养护管理实践,认为白三叶作为观花草坪品种,具有抗干旱、耐贫瘠、耐修剪、再生能力强、花期长等优点,在园林绿化中发挥着越来越重要的作用,取得了较好的社会效益和生态效益。文章对白三叶草坪的生物学特性、建坪技术、养护管理等分别进行了详细的介绍。     

混凝土斜拉桥整体结构在荷载组合效应作用下的有限元分析

本以吉林市临江门斜拉桥为例，应用固体力学的有限元理论，考虑荷载组合效应的影响。采用国内比较先进的Ｓａｐ９３程序进行整体结构分析。得出主梁，缆索，塔架以及其它承载结构的最大内力和最大位移。为斜拉桥的养护和维修提供必要的参数依据。     

寒冷地区窗在维护结构中的节能研究

从建筑节能的角度,分析寒冷地区窗在维护结构中的能耗问题,阐述其节能途径和技术措施。     

Genetic Variation and Phenotypic Plasticity of Quercus robur Populations and Open-pollinated Families in Lithuania

The purpose of the study was to estimate among- and within-population variation for juvenile growth and for growth rhythm traits, bud flushing and leaf colouring, in open-pollinated families of Quercus robur L. from six Lithuanian populations under different environmental conditions. Assessments were done in the nursery up to 4 yrs, and after replanting in three field trials at the age of 6 yrs. A highly significant population effect was found for bud flushing. Large family variance components were estimated for bud flushing and height. The family×site interaction was significant and more pronounced for growth cessation and height than for bud flushing. Depending on the trait, from 13 to 33% of families contributed significantly to the family×site interaction. Strongly significant site×population interaction was estimated only for bud flushing. Families with early bud flushing were taller, although the correlation was weak. Correlations between family means in bud flushing and bud flushing of parent trees varied from 0.53 to 0.60. Large CV_A estimates for the adaptive traits suggest that species have a potential to adapt to environmental changes that may occur from global warming and indicate good perspectives for gene conservation and tree breeding when using Multiple Population Breeding System.     

无粘结预应力混凝土结构施工质量控制

本文从施工角度阐述了无粘结预应力砼结构的施工质量控制及施工工艺。