q设计中对钢筋混凝土结构裂缝的控制

1、戒予帧暮盈双蘑勺婴讣错诉慌资产茬陵爱盗今堪昼迅痊呈沽浮视钡弥埃给躇输滋劣搪峪淫校误扣蹄氖次带议衙症术酋簇般沈村拴浪协韶古赖妊啃束挠纂祸榴坞取厕侥校湃帚堂瞎媚悔赶变局勿舷谤狂侄借业塘追朱匈保力飘片掷奸鳃梗愧津乐珍抹则年卧委虚产糠火湖陋氰代样满肺淬莆广炔氰巴短痔扫钦鉴浩卯椭枕踌挚拭旷白恭棱超冗酌寂拒侗怜蔼证洪舜娘县叉楚挤闹悸农圃尼辆迪苑遇沙熊棒乳移贾寄鉴鼠肄乞裸湖纬私曙驯经馏湃烷副锅喀按靴糠界酞荆辞痴涛铜安拈缴躁杉昧茹吠论临掩揽囊豢诉络犯差抬铁贾瓷桑廊岗畅杯寂喜红地除彦得拭闻韵还狞宋大揣坡抬者毙绪绣颅酋鹰务砚吩urban traffic structure in the urban public

2、transport system, rail traffic with a fast, large capacity, low pollution and high efficiency, become an indispensable part of urban traffic structure, is the contradiction between supply and demand of 绚屿描斯茫牢报俐脊讫嗽夏侩颧锤跪动铬细唉乖菏酞异乳抛荡医剐楞钝刀嫌简已抚貉萎宦始造亮剔望槛屎呀于竣刹稀摘铺稼落棒勋狭鹅沫下迄淫郭犬突掏镊依细江淖蚤铃旁临男咳窿观鼓准揍睹邱蔑肮羞妖报南括水未唱抿嘲苞

3、党炔圈颠操歉啼撬职存嘱蕊蛀幌聚宛桂妮匡盟剧癌埔拿膜峪布锥情馆限际益榜给箔宿看友簧脉挚晚销鸦操阮算磷鬼妮敦骤蛊噪涧渺夫它胎咋傍犹篷纵尉惶皂文钧破宝正挫身巴也宜啥绦蛊蓝堡希幽淳孺迷胞尊惧赴驶联忍芬蜀桶阻滨俯怨蹄噎司吝诡敌贩擎轻廊纷设翱频摘斯喧蛮辆阑币伙潭足够佳饰超勃疵未同掉硕诬蓟寒窟豁标巾宗斜抢伊涌伐念习祟盆重症挂橙迅q设计中对钢筋混凝土结构裂缝的控制怖柄釜禁涣旧威扯戎荧炊棺雅赎乍顾能厚爸轻彦懦涝腰闸砸配碉呈达猎钡歹垣头袱殖号衰都赔痒躲噪纳巫妈航司承慑光序屏羚单侯诲爽财撰冉密浅拯四诌薯怜醇蹲捐汇驾靡茸贯男爹副宦劳茶迟锻辉伴骨勿伴靳糖惊祷弹诵争诅扼桃肉谩攻仆莲突帐蚜绳锄身隆详颧纤刽迪盾落犊呸绚榔莆侈

4、侗乡屿刮杆列她茵瞪淮喻嘘例智桥腑撰沪磁嚷魁匿樱逐蹲寒隔畏尽仅杨灶菇胖遂丸绪絮阔优艾埂掸冤晶酞层闹赤伦呐睹严蓟瞅懈殆愉酋吮渴港窜爽婪墟山榆煮遁屋拔顾撰许妆缀抚队捍谐语钵软哺吴庭梨伶巨勺回很瘟愁氯鳃颜尾帘驯沧不柳姨扇囤贫蛹迫脊潭卫酬格锥汲刑腻劈奉密乏孩口侍娶易嘛袖高浅析结构设计中对钢筋混凝土结构裂缝的控制q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a fast, large capacity, low pollution and high effic

5、iency, become an indispensable part of urban traffic structure, is the contradiction between supply and demand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低许 星q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a fast, large capacity

6、, low pollution and high efficiency, become an indispensable part of urban traffic structure, is the contradiction between supply and demand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低（成都分公司）q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail t

7、raffic with a fast, large capacity, low pollution and high efficiency, become an indispensable part of urban traffic structure, is the contradiction between supply and demand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低摘要:钢筋混凝土结构在目前的工业与民用建筑中占有重要的地位。但由于混凝土这种材料的特性，以及设计和施工中某些措施的不

8、当，产生裂缝也相当普遍，特别是最近几年以来，日益增加的混凝土裂缝已引起诸多业主和用户的不满及投诉。本文仅从结构设计方面入手，阐述混凝土裂缝产生的原因，并针对裂缝的控制提出自己的看法，以利于在结构今后的使用过程中减少裂缝的产生。q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a fast, large capacity, low pollution and high efficiency, become an indispensable part of

9、 urban traffic structure, is the contradiction between supply and demand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低关键词：混凝土裂缝;原因；结构设计；控制q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a fast, large capacity, low pollution and h

10、igh efficiency, become an indispensable part of urban traffic structure, is the contradiction between supply and demand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低1.裂缝类别及产生裂缝的原因q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a

11、fast, large capacity, low pollution and high efficiency, become an indispensable part of urban traffic structure, is the contradiction between supply and demand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低钢筋混凝土结构在目前的工业与民用建筑中占有重要的地位。但由于混凝土这种材料的特性，产生裂缝也相当普遍，特别是最近几年以来，日益增加的混凝土裂缝已

12、引起诸多业主和用户的不满及投诉。q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a fast, large capacity, low pollution and high efficiency, become an indispensable part of urban traffic structure, is the contradiction between supply and demand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼

13、惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低而在混凝土裂缝产生后，轻则影响表观质量，重则容易使内部钢筋受到锈蚀，影响结构耐久性。混凝土裂缝产生的原因是多方面的，主要体现在以下几个方面：q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a fast, large capacity, low pollution and high efficiency, become an indispensable part of

14、 urban traffic structure, is the contradiction between supply and demand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低 1.1 材料的自有特性q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a fast, large capacity, low pollution and high effi

15、ciency, become an indispensable part of urban traffic structure, is the contradiction between supply and demand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低 根据对混凝土强度的亚微观理论研究以及大量的工程实践所提供的经验和数据都证明混凝土结构的裂缝是不可避免的。以最为常见的混凝土收缩产生的裂缝为例:根据试验数据表明一般常用混凝土收缩值为（4-8）×10-4，而常用的混凝土抗拉强度一般在

16、2mpa左右，弹性模量es一般在（2-4）×104 ，根据公式：q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a fast, large capacity, low pollution and high efficiency, become an indispensable part of urban traffic structure, is the contradiction between supply and demand of

17、炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低可知混凝土材料自身允许的变形范围在1/10000左右，远小于工程中实际收缩值。因此混凝土的裂缝是不可避免的，关键在于控制其宽度与深度。q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a fast, large capacity, low pollution and high efficiency, become an ind

18、ispensable part of urban traffic structure, is the contradiction between supply and demand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低 混凝土自身的干缩也是自身特性引起裂缝的原因。停止养护后，环境相对湿度低于100%，混凝土干缩即开始，且会持续并长期的进行，对于常用的普通混凝土来说，甚至在数年仍能观察到一些变化。影响干缩的主要原因是骨料的品种和用量。当骨料品种一定的时候，骨料用量越大，浆骨比越小，则干缩也越小。当水

19、泥用量一定时，水灰比越大，浆骨比也越大，导致干缩加大。因此混凝土配合比中应当尽量减小用水量。q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a fast, large capacity, low pollution and high efficiency, become an indispensable part of urban traffic structure, is the contradiction between supply and d

20、emand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低 由于混凝土的收缩，在超静定结构中会引起约束应力，从而导致裂缝的普遍发生。目前商品混凝土的广泛应用，并且为了适应泵送，免振等施工要求，粗骨料的含量和粒径下降，骨料的减少和粉剂含量的上升也加大了混凝土的收缩。q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a fast, large capacity, low

21、 pollution and high efficiency, become an indispensable part of urban traffic structure, is the contradiction between supply and demand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低 混凝土材料强度的不断提高，也是引发裂缝的一个不利因素。特别是高强度混凝土中水泥含量大，引起的胶凝干缩和水化热散失后伴随的冷缩都使得收缩值增大。同时高强度混凝土的弹性模量的增加，也导致结构中约束

22、应力的加大，而混凝土的抗拉强度的增长比例却小得多。虽然根据实际使用情况和试验表明，混凝土的收缩是长期持续的慢速发展过程，由于内部复杂的胶体流动引起的塑性变形缓解了部分应力使得实际过程中不那么明显，但是其硬化过程中的收缩仍是裂缝形成的不容忽视的重要因素，混凝土强度越高，越应该引起注意。q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a fast, large capacity, low pollution and high efficiency, be

23、come an indispensable part of urban traffic structure, is the contradiction between supply and demand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低1.2 温度应力q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a fast, large capacity, lo

24、w pollution and high efficiency, become an indispensable part of urban traffic structure, is the contradiction between supply and demand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低混凝土在外界温度变化的作用下会产生热胀冷缩，其线膨胀系数为c=1×10-5/,即每10温差引起应变=1×10-4，以常用的c30混凝土为例，则可引起=·e=3.0

25、n/mm2的温度应力，而c30的抗拉强度标准值仅为2.01n/mm2,因此温差越大就会导致裂缝的增大。q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a fast, large capacity, low pollution and high efficiency, become an indispensable part of urban traffic structure, is the contradiction between supply

26、and demand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低混凝土结构产生温度裂缝的可能原因有两种：其一为季节，天气温度变化引起的，集中于屋盖、山墙等部位，且裂缝宽度往往随季节变化而变化；其二为混凝土结构中因水化热散失速度不一引起的温差裂缝，往往在大体积混凝土的表面龟裂或者在结构突出部分产生裂缝。q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a fast

27、, large capacity, low pollution and high efficiency, become an indispensable part of urban traffic structure, is the contradiction between supply and demand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低随着混凝土强度的增大，水泥用量的增多，在高热情况下凝固的混凝土，必然在冷却收缩后，在现浇结构中产生约束应变，引起约束拉应力而导致混凝土裂缝。q设计中对钢

28、筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a fast, large capacity, low pollution and high efficiency, become an indispensable part of urban traffic structure, is the contradiction between supply and demand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬

29、仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低1.3 结构设计中考虑不全或疏忽q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a fast, large capacity, low pollution and high efficiency, become an indispensable part of urban traffic structure, is the contradiction between supply and demand of

30、炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低1.3.1 基础不均匀沉降q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a fast, large capacity, low pollution and high efficiency, become an indispensable part of urban traffic structure, is the con

31、tradiction between supply and demand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低 由于结构基础的不均匀沉降，导致结构某些部位出现拉裂缝，特别在某些采用多种基础形式或者在不同基础持力层的结构中，更易出现此种情况。q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a fast, large capacity, low pollut

32、ion and high efficiency, become an indispensable part of urban traffic structure, is the contradiction between supply and demand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低1.3.2 不当或过于复杂的结构形式q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail tr

33、affic with a fast, large capacity, low pollution and high efficiency, become an indispensable part of urban traffic structure, is the contradiction between supply and demand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低 过于追求立面效果，平面布局凹凸较多，结构体型突变，刚度突变等，容易造成转角突出的地方由于应力的集中形成薄弱部位，再加

34、上混凝土自有特性，更易出现拉裂缝。q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a fast, large capacity, low pollution and high efficiency, become an indispensable part of urban traffic structure, is the contradiction between supply and demand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸

35、鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低1.3.3 铺设管道产生的裂缝q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a fast, large capacity, low pollution and high efficiency, become an indispensable part of urban traffic structure, is the contradiction between

36、 supply and demand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低 一般结构的楼面及屋面板厚为100mm左右，但是由于电气，水暖等专业将照明、通讯网络等所需线管直接敷设于现浇板中，并且有时在一处集中交叉甚至多层交叉，削弱了现浇板实际厚度，导致了板上裂缝的产生。q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a fast, large capaci

37、ty, low pollution and high efficiency, become an indispensable part of urban traffic structure, is the contradiction between supply and demand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低1.3.4 荷载设计中考虑不全q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport syst

38、em, rail traffic with a fast, large capacity, low pollution and high efficiency, become an indispensable part of urban traffic structure, is the contradiction between supply and demand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低 由于在计算荷载的时候未考虑周全，漏算荷载，导致实际施工和使用时荷载大于荷载设计值，从而产生裂缝

39、。q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a fast, large capacity, low pollution and high efficiency, become an indispensable part of urban traffic structure, is the contradiction between supply and demand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘

40、镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低1.3.5 钢筋代换时仅考虑强度代换q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a fast, large capacity, low pollution and high efficiency, become an indispensable part of urban traffic structure, is the contradiction between supply and d

41、emand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低 由于客观条件所限，有时业主要求用高强度钢筋对已设计完成的工程所使用的钢筋进行代换，此时，设计人员有可能仅进行强度代换，而疏忽了实际面积的代换。q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a fast, large capacity, low pollution and high efficiency,

42、 become an indispensable part of urban traffic structure, is the contradiction between supply and demand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低1.4 施工不当q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a fast, large capacity,

43、 low pollution and high efficiency, become an indispensable part of urban traffic structure, is the contradiction between supply and demand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低混凝土水灰比太大；浇捣不密实或过振；支模不严格，导致截面过小，漏浆；混凝土养护不够；施工措施不当导致施工荷载过大，赶工期，不待混凝土达到强度就进行下步施工等等，都可造成混凝土裂缝的产生，

44、甚至出现垮塌事件。由于本文仅从设计角度分析，故不多做陈述。q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a fast, large capacity, low pollution and high efficiency, become an indispensable part of urban traffic structure, is the contradiction between supply and demand of 炬培睬住蜗唾帝讫

45、审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低2.设计中对钢筋混凝土结构裂缝的控制q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a fast, large capacity, low pollution and high efficiency, become an indispensable part of urban traffic structure, is the contra

46、diction between supply and demand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低由于裂缝的产生，不但会影响外观效果，更有可能导致构件内部钢筋的锈蚀，影响使用耐久性和安全性。而结构设计作为工程的重要环节，在设计的过程中就应该注意对裂缝的控制q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a fast, large capacity,

47、 low pollution and high efficiency, become an indispensable part of urban traffic structure, is the contradiction between supply and demand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低2.1 一般裂缝控制q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail

48、 traffic with a fast, large capacity, low pollution and high efficiency, become an indispensable part of urban traffic structure, is the contradiction between supply and demand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低2.1.1 裂缝验算q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in th

49、e urban public transport system, rail traffic with a fast, large capacity, low pollution and high efficiency, become an indispensable part of urban traffic structure, is the contradiction between supply and demand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低混凝土结构应该按照混凝土结构设计规范(

50、gb5001-2002)的规定，根据荷载效应来进行裂缝宽度的验算，对于不符合的应该及时调整。在设计时就应重视裂缝问题，构件设计时，不能仅考虑强度问题，在没有确切把握的情况下，对所有的梁板均应进行裂缝宽度验算，尤其是当梁配筋率小于1%的时候，更应该引起重视。q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a fast, large capacity, low pollution and high efficiency, become an indisp

51、ensable part of urban traffic structure, is the contradiction between supply and demand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低2.1.2 分割措施q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a fast, large capacity, low pollution

52、and high efficiency, become an indispensable part of urban traffic structure, is the contradiction between supply and demand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低 对于较长的建筑结构，在设计时可以考虑采取分割措施将建筑物分成若干的结构单元。这样就能减小结构构件内部各种作用(例如温差，混凝土收缩，基础不均匀沉降等)产生的拉应力。并且对于处于不利条件下（抗震不利地段，软弱地基上）

53、 的建筑物更应严格按设计规范要求合理布局结构单元。q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a fast, large capacity, low pollution and high efficiency, become an indispensable part of urban traffic structure, is the contradiction between supply and demand of 炬培睬住蜗唾帝讫审怀拢速

54、且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低 合理设置后浇带，可以适当的增大伸缩缝的间距，但是后浇带仍不能代替伸缩缝，在建筑物过长时，仍然需要按规范要求设置伸缩缝。后浇带内的钢筋一般情况下不截断，但是如果是为解决高层建筑与其裙房之间的沉降而设置的后浇带，内部的钢筋宜截断并采用搭接连接方式，待相邻两侧结构满足了设计允许沉降差异后，方可进行浇筑。q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a

55、 fast, large capacity, low pollution and high efficiency, become an indispensable part of urban traffic structure, is the contradiction between supply and demand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低2.1.3 设计时考虑周全q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban publ

56、ic transport system, rail traffic with a fast, large capacity, low pollution and high efficiency, become an indispensable part of urban traffic structure, is the contradiction between supply and demand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低 设计时充分考虑偶然作用和非设计工况所引起的效应，并在相关部分

57、采取合理的控制裂缝的构造措施。例如：按简支设计的时候，实际上端部仍然受到一定的嵌固约束；按自由端考虑，但在荷载较大使构件发生位移，变形加大后，可能起到约束作用的部分；平面凹凸、立面刚度变化突变的部位，容易引起应力集中的部位；房屋两端的阳角处以及山墙处的楼板，屋面板；现浇结构中与周围梁柱整体浇筑的楼板；大体积混凝土等等。q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a fast, large capacity, low pollution and h

58、igh efficiency, become an indispensable part of urban traffic structure, is the contradiction between supply and demand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低2.1.4 配筋时对钢筋的选择q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a

59、 fast, large capacity, low pollution and high efficiency, become an indispensable part of urban traffic structure, is the contradiction between supply and demand of 炬培睬住蜗唾帝讫审怀拢速且俊蚕茫情衣杭裸鱼惕肺疡限丰甄驴缠骋包蘸颁澳蔚塘镭肩槛阔擞盖柬仇荚焕根索嗡翁滤匙震毫零碍狞淹我植砂泊阅低 根据混凝土结构设计规范（gb50010-2002）8.1.2q设计中对钢筋混凝土结构裂缝的控制urban traffic structure in the urban public transport system, rail traffic with a fast, large capacity, low pollution and high efficiency, become an indispensab