电大《水工钢筋混凝土结构》试题5681B小抄.doc

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9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、配有螺旋钢筋的混凝土圆柱体试件的抗压强度高于轴心抗压强度的原因是螺旋钢筋（ ）。（A）参与了混凝土的受压工作 （B）约束了混凝土的横向变形 （C）使混凝土不出现细微裂缝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）钢筋生锈3、材料图也叫正截面受弯承载力图，其形状（ ）。（A）与梁上的弯矩包络图相同 （B）与梁内的纵筋布置情况有关 （C）与梁内的箍筋和弯起筋用量有关4、大偏心受拉构件设计时，若已知A's，计算出b，则表明（ ）（A）A's过多 （B）A's过少 （C）As过少 5、在下列减小受弯构件挠度的措施中错误的是（ ） （A） 提高混凝土强度 （B）增大截面高度 （C）增大构件跨度得 分评 卷 人二、填空题（每空2分，共20分）1、T截面连续梁在负弯矩段，由于翼缘处在受拉区，应按_截面计算；在正弯矩段，按_截面计算。2、抗剪钢筋也称作腹筋，腹筋的形式可以采用_和_。3、预应力和非预应力混凝土轴心受拉构件,在裂缝即将出现时，它们的相同之处是混凝土的应力达到_，不同处是预应力构件混凝土的应力经历了从受_到受_的变化过程，而非预应力构件混凝土的应力是从_变化到_。可见二者的抗裂能力是_构件的大。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. 适筋梁弯曲将要破坏时，受压边缘混凝土应力最大。 （ ）2. 轴向压力对构件斜截面受剪承载力总是有利的。 （ ）3. 在适筋范围内的钢筋混凝土受弯构件中，提高混凝土强度等级对于提高正截面抗弯承载力的作用是不很明显的。（ ）4. 混凝土受压破坏也是由于内部微裂缝扩展的结果。（ ）5. 先张法轴拉构件完成全部预应力损失后，预应力筋的总预拉力NpII=50kN，若加载至混凝土应力为零，外载N0>50kN。（ ）得 分评 卷 人四、简答题（每小题10分，共50分）1、什么是伸长率？.2、水工钢筋混凝土结构中，引起裂缝的非荷载因素主要有哪些？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）一矩形截面简支梁(级安全级别、一类环境条件），截面尺寸为b×h=200×500mm而不能改变。混凝土强度等级为C25，钢筋为级。持久设计状况下，承受弯矩设计值M210kN·m。试进行截面钢筋计算。（fc=12.5N/mm2，fy=310 N/mm2，a=60 mm ，a'=35mm, min=0.15%，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考试水工钢筋混凝土结构试题答案（供参考）2012年9月一、 选择题1、B. 2、A 3、B 4、B 5、C二、填空题1.矩形，T形。2.弯起钢筋；箍筋3.ft、压、拉、0、ft、预应力。三、判断题1 × 2. × 3. 4. 5. ×四、简答题1. 什么是伸长率？答:钢筋试件拉断后的伸长值与原长的比率。2.水工钢筋混凝土结构中，引起裂缝的非荷载因素主要有哪些？答：主要有温度变化，混凝土收缩，基础不均匀沉降，塑性坍塌，钢筋锈蚀，碱骨料化学反应等。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。1<<3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(按双排截面配筋, a=60，h0=h-a=500-60=440mm （，）可采用双筋截面，考虑受压钢筋为单排， 取a'=35mm >minbh0=132mm2Winger 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 aggravated against USA.Both sides boast 100% records heading into the encounter but Australia have not conceded a try since Josh Charnley's effort in their first pool match against England on the opening day.Aussie winger Jarryd Hayne is the competition's top try scorer with nine, closely followed by Tuivasa-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 both rugby league and rugby union after triumphing with the All Blacks in 2011."I'd 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 Fifa's anti-racism taskforce, is in London for the Football Association's 150th anniversary celebrations and will attend City's 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 it's about how he felt and I would like to speak to him first to find out what his experience was."Uefa has opened disciplinary proceedings against CSKA for the "racist behaviour of their fans" during City's 2-1 win.Michel Platini, president of European football's governing body, has also ordered an immediate investigation into the referee's actions.CSKA said they were "surprised and disappointed" by Toure's 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, conditions 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 Everest (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 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 and so far history has repeated itself here - the last try they conceded was scored by England's 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. They've been great at all the unglamorous stuff that often goes unnoticed in the stands but not by your team-mates.It is as though their entire tournament has been preparation for the final.In Johnathan Thurston, Cooper Cronk, Cameron Smith and either Billy Slater or Greg Inglis at full-back they have a spine that is unmatched in rugby league. They have played in so many high-pressure games - a priceless asset going into Saturday.The Kiwis are a lot less experienced but winning a dramatic match like their semi-final against England will do wonders for their confidence.They defeated Australia in the Four Nations final in 2010 and the last World Cup, and know they can rise to the big occasion.水工钢筋混凝土结构试题 第9页（共6页） 水工钢筋混凝土结构试题 第10页（共6页）