电大《水工钢筋混凝土结构》试题5681A小抄

1、密封线内不要答题试卷号：5681 座位号: 贵州广播电视大学2011-2012学年度第二学期期末考试（开放本科）水工钢筋混凝土结构试题2012年7月题 号一二三四五总 分分 数得分 评卷人一、单项选择题（每空2分，共10分）1.我国生产的建筑用钢筋，按照外形分为（ ）。(a）光面钢筋和等高肋钢筋 (b）光面钢筋和带肋钢筋 （c）光面钢筋和非等高肋钢筋2.以下使结构进入承载能力极限状态的是（ ）（a）结构的一部分出现倾覆 （b）梁出现过大的挠度 （c）梁出现裂缝3.剪力和扭矩共同作用下的构件承载力计算，规范在处理剪、扭相关作用时（ ）。（a）不考虑二者之间的相关性 （b）混凝土和钢筋的承载力都考

2、虑剪扭相关作用 （c）混凝土的承载力考虑剪扭相关作用，而钢筋的承载力不考虑剪扭相关性4.均布荷载作用下的弯、剪、扭复合受力构件，当满足（ ）时，可忽略扭矩的影响。（a）dt0.175ftwt （b）dt0.35ftwt （c）dv0.035fcbh0 5.所谓一般要求不出现裂缝的预应力混凝土轴心受拉和受弯构件，在荷载作用下（ ）。 （a）允许存在拉应力 。（b） 不允许存在拉应力 。（c） 拉应力为零得 分评 卷 人二、填空题（每空2分，共20分）1、混凝土是由水泥、_、_ 和水按一定配合比组成的人造石材。2、混凝土的变形有两类：一类是由_而产生的受力变形；一类是由_引起的体积变形。3、在钢筋

3、混凝土结构构件中，_受力后会沿_和_接触面上产生剪应力，通常把这种剪应力称为粘接应力。由于钢筋和混凝土两者之间存在着足够的_，钢筋能很好地_在混凝土中不至产生滑移现象，从而保证二种材料一起_。得 分评 卷 人三、判断题（每小题2分，共10分。正确的给t，错误的给f）1. 对不同等级的混凝土和钢筋，要保证最小搭接长度和锚固长度。（ ）2. 建筑物的重要性不同，其结构构件的安全级别就不同，要求目标可靠指标也不同。（ ）3. 受弯构件如果钢筋配置不当，斜裂缝出现后，还可能导致斜截面受弯破坏。（ ）4. 受压构件中若轴向力的偏心距很大，则构件一定发生大偏心受压破坏。（ ）5. 混凝土强度等级对受压构件

4、的承受力影响较大。（ ）得 分评 卷 人四、简答题（每小题10分，共50分）1、如何确定混凝土的立方体抗压强度标准值？它与试块尺寸的关系如何？.2、什么是钢筋的冷拉硬化？3、什么是结构的可靠性?它包含哪些要求？4、什么叫剪跨比？以及对无腹筋梁的斜截面承载力与斜截面破坏形态有何影响？5、普通预应力混凝土构件的基本工作原理是什么？ 得 分评 卷 人五、计算题（本题10分）某柱截面尺寸bh=400500mm(级安全级别、一类环境条件），承受轴向压力设计值n=460kn，e0=520mm，计算长度l0=6.5m，采用c20混凝土，级钢筋，mm，采用对称配筋，试进行配筋计算。（fc=10 n/mm2，f

5、y=310 n/mm2，min=0.2%，b=0.544，） 试卷号：5681贵州广播电视大学2011-2012学年度第二学期期末补考水工钢筋混凝土结构试题答案（供参考）2012年7月一、 选择题1、b. 2、a 3、c 4、a 5、a二、填空题1.砂，石子。2.外负荷作用；温度和干湿3.钢筋混凝土、钢筋、混凝土、粘接力、锚固、共同工作。三、判断题1. 2. 3. 4. 5. 四、简答题1. 如何确定混凝土的立方体抗压强度标准值？它与试块尺寸的关系如何？答：我国国家标准规定以边长为150的立方体为标准试件，标准立方体试件在（203）的温度和相对湿度90%以上的潮湿空气中养护28d，按照标准试验

6、方法测得的抗压强度作为混凝土的立方体抗压强度。试块尺寸越小，抗压强度值越高。2.什么是钢筋的冷拉硬化？答：冷拉是将钢筋拉伸超过屈服强度并达到强化阶段中的某一应力值，然后放松。若立即重新加荷，此时屈服点将提高。表明钢筋经冷拉后，屈服强度提高，但伸长率减小，塑性性能降低，也就是钢材性质变硬变脆了。此称冷拉硬化。3.什么是结构的可靠性?它包含哪些要求?答：结构的可靠性是指结构在规定的时间（设计基准期）内，在规定的条件下，完成预定功能的能力。结构的可靠性要求包括以下三个方面：安全性、适用性和耐久性。4.什么叫剪跨比？以及对无腹筋梁的斜截面承载力与斜截面破坏形态有何影响？答：剪跨比是剪跨a和截面有效高度

7、ho的比值，其中a为集中荷载作用点到支座截面或节点边缘的距离。对梁顶直接施加集中荷载的无腹筋梁，剪跨比是影响受剪承载力的主要因素。试验表明，随着剪跨比的减少，斜截面受剪承载力有增高的趋势。一般来说，3 时常为斜拉破坏。当1 时可能发生斜压破坏。13时，一般是剪压破坏。5.普通预应力混凝土构件的基本工作原理是什么？答：所谓预应力混凝土结构，就是在外荷载作用之前，先对混凝土预加压力，造成人为应力状态。它所产生的预压应力能抵消外荷载所引起的部分或全部拉应力。这样，在外荷载作用下，裂缝就能延缓或不致发生，即使发生了，裂缝宽度也不会开展过宽。五、计算题 解：n/mm2，mm，h0=ha=50040=46

8、0mm8，应考虑纵向弯曲的影响，mmmm，应按实际偏心距mm计算。 先假定为大偏心受压，可得：故构件为大偏心受压。mmmm mm=1663mm2mm2winger tuivasa-sheck, who scored two tries in the kiwis 20-18 semi-final win over england, has been passed fit after a lower-leg injury, while slater has been named at full-back but is still recovering from a knee injury aggr

9、avated against usa.both sides boast 100% records heading into the encounter but australia have not conceded a try since josh charnleys effort in their first pool match against england on the opening day.aussie winger jarryd hayne is the competitions top try scorer with nine, closely followed by tuiv

10、asa-sheck with eight.but it is recently named rugby league international federation player of the year sonny bill williams who has attracted the most interest in the tournament so far.the kiwi - with a tournament high 17 offloads - has the chance of becoming the first player to win the world cup in

11、both rugby league and rugby union after triumphing with the all blacks in 2011.id give every award back in a heartbeat just to get across the line this weekend, said williams.the (lack of) air up there watch mcayman islands-based webb, the head of fifas anti-racism taskforce, is in london for the fo

12、otball associations 150th anniversary celebrations and will attend citys premier league match at chelsea on sunday.i am going to be at the match tomorrow and i have asked to meet yaya toure, he told bbc sport.for me its about how he felt and i would like to speak to him first to find out what his ex

13、perience was.uefa hasopened disciplinary proceedings against cskafor the racist behaviour of their fans duringcitys 2-1 win.michel platini, president of european footballs governing body, has also ordered an immediate investigation into the referees actions.cska said they were surprised and disappoi

14、nted by toures complaint. in a statement the russian side added: we found no racist insults from fans of cska. baumgartner the disappointing news: mission aborted.the supersonic descent could happen as early as sunda.the weather plays an important role in this mission. starting at the ground, condit

15、ions have to be very calm - winds less than 2 mph, with no precipitation or humidity and limited cloud cover. the balloon, with capsule attached, will move through the lower level of the atmosphere (the troposphere) where our day-to-day weather lives. it will climb higher than the tip of mount evere

16、st (5.5 miles/8.85 kilometers), drifting even higher than the cruising altitude of commercial airliners (5.6 miles/9.17 kilometers) and into the stratosphere. as he crosses the boundary layer (called the tropopause),e can expect a lot of turbulence.the balloon will slowly drift to the edge of space

17、at 120,000 feet ( then, i would assume, he will slowly step out onto something resembling an olympic diving platform.they blew it in 2008 when they got caught cold in the final and they will not make the same mistake against the kiwis in manchester.five years ago they cruised through to the final an

18、d so far history has repeated itself here - the last try they conceded was scored by englands josh charnley in the opening game of the tournament.that could be classed as a weakness, a team under-cooked - but i have been impressed by the kangaroos focus in their games since then.they have been concentrating on the sort of stuff that wins you tough, even contests - strong defence, especially on their own goal-line, completing sets and a good kick-chase. theyve been great at all the unglamorous stuff that often goes unnoticed in the stands but not by your team-mate