火电厂RC框排架结构主厂房震害分析与设计建议

RC(钢筋混凝土)框排架结构是火电厂主厂房一种常用的结构型式,因承载的设备种类繁多,运行参数复杂,使其整体布置不规则,空间性能差,质量、刚度分布不均匀,导致结构体系的抗震性能较差.通过分析大震中RC框排架结构主厂房震害特征的共性,提出加强主厂房抗震设计的建议.     

寒冷地区机场道面混凝土破坏机理研究

寒冷地区机场混凝土道面常常发生非荷载引起的破坏-耐久性破坏，严重影响飞机的安全起降。必须尽快予以解决，解决混凝土耐久性破坏问题必须首先弄清楚破坏原因，为此，以北方寒冷地区某国际机场为研究对象，从不同角度分析混凝土的破坏机理，排除了碱骨料反应破坏的可能，在宏观性能研究和显微结构分析的基础上，提出寒区机场道面混凝土耐久性破坏的根本原因是混凝土抗渗性差，水分及腐蚀性介质渗入混凝土内部孔隙中，导致混凝土抗冻融性及耐腐蚀性劣化。     

Damage self-diagnoses feasibility of fiber-reinforced concrete structure

The seepage theory was used to explain the variation between the specific resistance of the carbon fiber reinforced cement concrete and the carbon fiber volume ratio. The electro-dynamic seepage was observed in the cement. The longer the carbon fiber is, the smaller the critical volume to produce the electro-dynamic seepage phenomenon will be. However, the forming and stirring process is harder. In general, the average length of carbon fiber is 5 mm. Under the condition of three-point bending load, the specific resistance changes with the loading process, and a good correlation could be obtained according to the load-deflection relationship. The experimental results reveal that the carbon fiber reinforced cement based composites can be used as sensors to self-diagnoses of the damage.     

煤质劣化对锅炉热量分配影响的机理分析

受能源供应紧张影响电厂经常燃用劣质煤,其主要特点是灰分、水分大而发热量低,以此特征为基础建立一种煤质劣化模型。利用炉内传热相似理论求解方法,以一300 MW燃煤机组炉膛结构设计为例分析了不同劣化程度的煤质对锅炉主要设计参数造成的影响。计算结果表明:随煤中水分和灰分增加单位辐射热量降低,并且水分的影响大于灰分;随煤灰分增加单位辐射热量与单位对流热量之比升高,但随水分增加而降低。高负荷时,随煤中水分和灰分增加炉膛出口烟温略微降低;低负荷时,随煤中灰分增加炉膛出口烟温略微降低,而随煤中水分增加略微升高。     

冻融循环作用下煤矸石混凝土的损伤特性及本构关系

考虑煤矸石粗骨料取代率(0、20％、40％、60％)的影响,开展冻融循环试验、单轴受压本构试验及声发射检测试验,研究煤矸石混凝土的损伤本构模型.结果表明:不同取代率煤矸石混凝土的相对峰值应变与冻融损伤值具有较高的相关性,所得冻融损伤值与相对峰值应变的方程可为本构模型的建立提供有效参数.煤矸石混凝土声发射特性与其荷载损伤...     

Influence of subsequent curing on water sorptivity and pore structure of steam-cured concrete

Steam-cured condition is found to cause larger porosity and worse properties of concrete compared with normal curing condition. For the sake of seeking effective measurements to eliminate this bad effect of steam-cured condition on concrete, the water sorptivity and pore structure of steam-cured concretes exposed to different subsequent curing conditions were investigated after steam-curing treatment. The capillary absorption coefficient and porosity of the corresponding concretes were analyzed, and their mechanisms were also discussed. The results indicate that water sorptivity and pore structure of steam-cured concrete are greatly influenced by the curing condition used in subsequent ages. Exposure steam-cured concrete to air condition has an obviously bad effect on its properties and microstructures. Adopting subsequent curing of immersing steam-cured concrete into about 20 °C water after steam curing period can significantly decrease its capillary absorption coefficient and porosity. Steam-cured concrete with 7 d water curing has minimum capillary absorption coefficient and total porosity. Its water sorptivity is decreased by 23% compared with standard curing concrete and the porosity is 9.6% lower. Moreover, the corresponding gradient of water sorptivity and porosity of steam-cured concrete both decrease, thus microstructure of concrete becomes more homogeneous.     

某钢砼结构的受损探查及加固方法

通过某框架结构工业房屋的钢筋砼梁，柱损伤的检测和分析，以及构件的受力状态的计算分析，揭示了钢砼构件产生损伤的原因，探讨了有效的加固方法，加固后鉴定表明加固结构能达到原设计要求。     

试论损伤力学在混凝土中的应用

本文在阐述损伤力学基本原理的基础上,分析了混凝土受力变形特点和损伤力学条件的关系,讨论了损伤力学在混凝土中的应用.     

Control mechanism and technique of floor heave with reinforcing solid coal side and floor corner in gob-side coal entry retaining

Floor heave is the most common convergence in gob-side entry retaining. The paper analyzes the form, process and characteristics of gob-side entry retaining with the comprehensive methods of theoretical analysis, numerical simulation and the field trial. Research results present that bending and folding floor heave is the main factor in the stage of the first panel mining; squeezing and fluidity floor heave plays a great role in the stable stage of gob-side entry retaining; the combination of the former two factors affects mainly the stage of the second mining ahead; abutment pressure is a fundamental contribution to the serious floor heave of gob-side entry retaining, and sides corners of solid coal body are key part in the case of floor heave controlling of gob-side entry retaining. Floor heave of gob-side entry retaining can be significantly controlled by reinforcing sides and corners of solid coal body, and influence rules on the floor heave of gob side entry retaining of sides supporting strength and the bottom bolt orientation in solid coal side are obtained. Research results have been successfully applied in gob-side entry retaining of G20-F23070 face haulage roadway in #2 coal mine of Pingmei Group, and the field observation shows that the proposed technique is an effective way in controlling the floor heave of gob-side entry retaining.     

火力发电厂主厂房三维结构布置设计探讨

三维设计在电力、石油、石化系统中已经得到广泛应用并取得了显著成绩,但土建结构三维设计的严重滞后已经愈发明显的限制了工艺专业三维设计的应用,成为三维设计的瓶颈.目前土建结构三维设计能否取得突破,成为信息化建设的阶段性关键工作.对于土建结构三维设计的流程、设计工作方式、多专业协同设计等方面的研究,是解决土建结构三维设计应用的核心步骤.本文针对这些焦点问题,提出了一些建议.     

主厂房采用混凝土单跨框-排架结构的抗震设计措施

讨论了火电厂主厂房框-排架结构采用钢结构还是钢筋混凝土结构体系的条件;分析了主厂房钢筋混凝土框架结构抗震性能的薄弱环节.按照现行国家标准合理判断钢筋混凝土单跨框架条款的有关规定,提出了钢筋混凝土单跨框-排架结构体系在火电厂主厂房能不能采用,如何控制结构的安全度,在工程审查和设计中如何理解和执行上述规定的意见.在总结过去工程设计经验的基础上,提出了提高钢筋混凝土单跨框架结构安全度的可靠措施.     

Hydration evolution of pre-cast concrete with steam and water curing

The hydration characteristics of pre-cast concrete considering the effects of effective initial steam-curing and water-curing duration were measured and analyzed with XRD, TG, X-ray CT, SEM-BSE and MIP techniques. The results show that the effective initial steam-curing duration for pre-cast concrete with lower water-binder ratio was 10 14 h at 50 °C and the initial water-curing duration was 7 14 d. And the hydration evolution of cement, fly ash and slag in pre-cast concrete was obtained respectively by combining the hydrochlorides and EDTA selecting dissolution methods, based on which the contents of hydrated and anhydrate in concrete were calculated and the corresponding dynamic capillary porosity was also determined. Moreover, the comparison between calculated results and experimental ones indicates that the proposed evolution models of microscopic characteristics corresponding to hydration kinetics of cemented materials could be adopted to predict the developing trend of capillary porosity and hydration-products content in pre-cast concrete with fly ash and slag under certain curing conditions.     

电厂主厂房隔声吸声墙体建筑构造探讨

对电厂主厂房的建筑隔声吸声墙体构造进行了探讨,结合工程实际情况提出了具体的构造要求和实验数据,可供有关设计人员参考.     

水工建筑物混凝土损坏及防治

文章介绍导致混凝土碳化、冻融损坏的原因,并提出了防治措施。     

Damage statistical mechanics model of top coal in steep top caving coal

Damage statistical mechanics model of horizontal section height in the top caving was constructed in the paper. The influence factors including supporting pressure, dip angle and characteristic of coal on horizontal section height were analyzed as well. By terms of the practice project analysis, the horizontal section height increases with the increase of dip angle β and thickness of coal seam M. Dip angle of coal seam β has tremendous impact on horizontal section height, while thickness of coal seam M has slight impact. When thickness of coal seam is below 10m, horizontal section height increases sharply. While thickness exceeds 15m, it is not major factor influencing on horizontal section height any long.     

矿井复杂地质构造综合探测技术应用研究

针对矿井复杂地质构造,利用瞬变电磁和反射地震方法相结合,对相应的探测技术方法进行综合研究。通过对淮南某矿F108-3断层带综合探查,结果表明,综合物探技术对矿井复杂地质构造体分辨能力较强,对构造体的空间特征及其含水状况判断准确,可以为矿井安全生产提供技术依据。     

Damage model of fresh concrete in sulphate environment

A model of damage to fresh concrete in a corrosive sulphate environment was formulated to investigate how and why the strength of corroded concrete changes over time. First, a corroded concrete block was divided into three regions: an expanded and dense region; a crack-development region; and a noncorroded region. Second, based on the thickness of the surface corrosion layer and the rate of loss of compressive strength of the corroding region, a computational model of the concrete blocks’ corrosion-resistance coefficient of compressive strength in a sulphate environment was generated. Third, experimental tests of the corrosion of concrete were conducted by immersing specimens in a corrosive medium for 270 d. A comparison of the experimental results with the computational formulae shows that the calculation results and test results are in good agreement. A parameter analysis reveals that the corrosion reaction plays a major role in the corrosion of fresh concrete containing ordinary Portland cement,but the diffusion of the corrosion medium plays a major role in the corrosion of concrete mixtures containing fly ash and sulphate-resistant cement. Fresh concrete with a high water-to-cement ratio shows high performance during the whole experiment process whereas fresh concrete with a low water-to-cement ratio shows poor performance during the late experiment period.     

湿热养护条件下混凝土材料的弹性及非弹性特征

开发了一套新的测试系统能动态检测湿热养护条件下混凝土材料的弹性及非弹性特征,通过计算机综合分析评价.迅速绘出任一时刻的检测波形,计算出动弹性模量和该时刻的衰减率.根据测试结果分析评价了湿热养护条件下混凝土材料的弹性及非弹性特征.     

中国煤炭资源洁净潜势评价指标探讨

进行煤炭资源洁净潜势的评价研究,是从源头上控制煤源污染、从而达到合理开采和洁净利用煤炭资源目标的重要工作和必由途径。煤中有害物质种类、有害物质毒性、有害物质迁移能力以及我国现行的环境保护标准等指标,是建立我国煤炭资源洁净潜势评价体系时应当考虑的主要内容。     

由碳纤维加固技术看混凝土结构综合加固技术

以碳纤维加固技术为例,分析得出混凝土加固方法各有优劣,这就为综合加固技术的采用提供了必要性,通过介绍某10层新建综合楼的加固方法,证明采用综合加固技术是可行的,最后,论述了综合加固技术设计的方法．