京客隆中庭大跨度井字梁施工总结.doc

京客隆酒仙桥商场“一优两示范”工程验收资料京客隆中庭大跨度井字梁楼盖施工总结一、概况：京客隆酒仙桥商场位于朝阳区酒仙桥路与酒仙桥南路的交叉口，是一座集超市、商场、停车场、人防、办公多功能为一体的大型公共建筑。建筑面积75090 m2，檐高28.2m，局部34m。地下一层，地上5层，局部七层。中庭位于建筑物中间部位G-J6-14轴之间，建筑面积1028m2，空间位置从首层至三层,其层间高度达18m，采用井字梁施工，梁截面高度为1500mm、1600mm，主筋25、32，箍筋12；顶板配筋12200双层双向。主梁跨度19.50m，最大梁跨度达50.4m。混凝土强度等级框架柱C50，梁C45，顶板C30。顶板厚度120mm。 中庭梁位置图因此中庭顶板梁的施工为本工程施工难点之一，下面是该部位的施工总结：二、工程施工难点：1、跨度相对较大。主梁跨度最大达到50.4米，且该部位为井字梁楼盖，主次梁相对较密，因此施工中控制梁的起拱高度相对也比较困难。2、对支撑模板的脚手架的要求高。支撑模板体系采用满堂红脚手架，最大立杆高度将近16.5米，因此脚手架的稳定性要求也高。3、梁侧模支设难度高。中庭井字梁高度为1500mm、1600mm，模板支设也是难点之一。4、梁柱接头钢筋非常密，增加施工难度。三、施工技术质量保证措施：1、技术方案的选择：工程施工，技术先行，考虑到中庭位置是工程的一个难点也是重点，项目技术部成立方案编制小组，负责方案的编制工作。通过现场考察，并查找相关技术规范规程，对脚手架单杆承载力和整体稳定性进行了验算。梁板模板及龙骨的强度稳定性也进行了精细的验算，最终确定的方案如下：脚手架方案钢管选用48mm，壁厚3.5mm，扣件应采用可锻铸铁制作的扣件；梁下立杆间距600900mm，横杆步距1200mm；板下立杆间距12001200mm，横杆步距1200mm；梁板脚手架体系之间通过横杆相连，形成一整体，见下图示意。本工程脚手架下部支设于地下室上，因此可以不考虑基础沉降问题，但是必须考虑对地下室顶板梁进行支撑，以减少中庭部位施工对地下室顶板梁造成的影响。支撑形式为在地下一层中庭范围内搭设脚手架12001200mm，步距1200mm，对地下室顶板梁进行支撑，将中庭施工荷载部分传递到地下室底板。梁模板方案及支撑体系底模、侧模采用15mm厚多层板。次龙骨为50100mm木方横放，间距200mm。排木选用100100mm木方，沿梁长方向通长设置间距300mm。主龙骨100100mm木方，梁下通长设置三道，间距600mm。侧模支设方式：模板选15mm厚多层板，次龙骨50100mm木方立放，间距250mm；沿梁高方向设置16对拉螺栓2-3道。立柱483.5mm钢管，横向水平杆483.5mm，梁下立杆间距600900mm，横杆步距1200mm布置，四周布置剪刀撑，并与柱形成抱柱附着连接，中间沿东西向每道梁下设一道剪刀撑。具体见下图所示： 顶板模板材料的选用及支撑体系顶板模板为12mm厚竹胶板；次龙骨50100mm木方，东西向布置，间距300mm立放；主龙骨100100mm木方，南北向布置，间距1200mm；立柱、横向水平杆483.5mm钢管，沿立柱间距1200mm布置。具体根据现场实际情况选定钢管间距。 梁柱节点设计 在工程结构施工中，框架结构梁柱接头如果处理不好，容易产生混凝土外观的蜂窝麻面以及梁柱的不规则形状。为了避免以上情况发生，对梁柱接头模板采取如下措施： 梁柱接头模板由专人进行制作，利用计算机进行放样，以保证梁柱接头模板的尺寸准确性。梁柱接头模板与梁模板一次支设，以确保梁柱接头的方正。布料杆安放位置及加固措施中庭部位为长度51.5米，宽度21.5米，布料杆为半径10米，因此在此范围内设置两处布料杆安放位置即可。考虑到布料杆的配重及浇灌混凝凝土产生的动荷载，应将该位置支撑体系进行加固。加固措施为在该跨顶板下将立柱加密，横杆加密处理。布料杆位置的移动必须采用塔吊运输，严禁使用人为挪动。详见下图：2、脚手架搭设及拆除模板支撑系统对于高支模大跨度的非预应力混凝土结构施工来说，支撑是一关键。该工程使用钢管排架作为大跨结构的施工支撑，合理的脚手架支撑体系是保证顶板施工顺利进行最为关键的环节。搭设脚手架搭设必须配合施工进度搭设，一次搭设高度不应超过相邻连墙件以上两步。每搭设完一步脚手架后，应按规定校正步距、纵距、横距及立杆的垂直度。垫板应按定位线放置，垫板采用不小于50mm厚的木垫板。立杆搭设：开始搭设立杆时，应每隔6跨设置一根抛撑，待连墙件安装稳定后，方可拆除抛撑。当搭至有连墙件的构造点时，在搭设完该处的立杆、纵向水平杆、横向水平杆后，应立即设置连墙件。纵、横向水平杆的搭设：纵向水平杆在同一步中应四周交圈，用直角扣件与内外角部立杆固定。剪刀撑、横向斜撑的搭设应随立杆、纵向和横向水平杆等同步搭设。所有立杆与横杆相交处节点，必须在纵横方向均加设水平杆。所有梁底两侧立杆均必须加设剪刀撑。梁底模板支撑架最上面一个节点处必须加设双扣件。检查与验收构配件检查与验收检查钢管、扣件产品质量合格证，检查进场抽样检测报告等。模板支架在搭设过程中应对杆件的设置、连接件、构造措施跟踪检查。架体搭设完毕在支设模板前，对架体进行验收，必须满足施工方案的设计、构造及规范要求。在浇筑混凝土前，对模板系统、模板支架系统进行验收；在浇筑过程中，检查是否超载，观察模板及支架变形情况。脚手架拆除措施准备工作：应全面检查脚手架的扣件连接、连墙件、支撑体系等是否符合构造要求；应根据检查结果补充完善施工组织设计及施工方案中的拆除顺序和措施，经主管部门批准后方可实施。进行脚手架拆除安全技术交底；将脚手架上杂物及地面障碍物清除干净。拆除脚手架：拆除作业必须由上而下逐层进行，严禁上下同时作业；连墙件必须随脚手架逐层拆除，严禁先将连墙件整层或数层拆除后再拆除脚手架；分段拆除高差不应大于两步，如高差大于两步，应增设连墙件加固。3、顶板梁模板支设模板支设工艺流程支模板竖向支撑加竖向支撑的水平拉杆安装梁模板的龙骨支梁底模校正标高 绑梁钢筋支梁侧模安装板底模铺模板及补边角模板复查校正板模板标高 绑板筋预检验收。模板的起拱起拱是减小挠度最行之有效的方法，它不但能抵消梁的下挠产生的视觉效果影响，而且它使作用在梁上的一部分竖向荷载转化为水平力传给支座，在梁的横截面间形成轴向压力，从一定程度上防止了梁的裂缝的产生。本工程对中庭部位井字梁按主梁、一级次梁、二级次梁进行划分，并分别起拱。南北向轴线位置为主梁，东西向梁为一级次梁，其余为二级次梁，见下图示意： 主梁起拱高度按0.3，h195000.358.5mm，因此主梁起拱高度取60mm。一级次梁起拱由于地面装饰的要求，一级次梁起拱高度为20mm。二级次梁起拱由于二级次梁跨度较小，梁支模高度已随一级次梁进行了调整，所以二级次梁不起拱。模板安装 梁支柱采用483.5钢管,每排支柱设水平拉杆,沿梁的轴线方向设置。底楞上沿梁轴线方向铺梁底模木楞。侧模与底模固定方法为侧模夹底模。侧模木楞沿梁轴线方向设置。钢管、侧楞、斜撑、底楞相互之间用于扣件固定牢靠。顶板模板与梁侧模接缝,梁侧模与梁底模之间接缝，设单面粘胶海绵条防止漏浆。面板安装时，所有的锯缝都应用刨子刮平，以达到硬拼严丝合缝。模板拆除现场模板拆除实行申请拆模制度，梁板浇筑10天以后，压同条件混凝土试块，如果能够满足要求，工长提交拆模申请，经现场技术负责人签字认可后，工长方可组织木工进行模板拆除作业，并向监理报告。拆除时，先要在支撑体系的上层铺设一层木跳板，人站在上部的木跳板上拆模。拆除时先降低U托，拆除支撑的钢梁和木方，然后拆除第一块模板，接着逐块拆除。拆除上层的模板用人工往下倒运，不得直接往地上扔。待顶板模板拆完后，再拆除支撑排架。 4、钢筋绑扎钢筋工程材料钢筋作为大跨度屋面梁这一重要结构中的精骨，选材需确保品质稳定过硬，优先选用国内大厂生产的钢材，需无锈蚀、无污染，并按规定检验合格。钢筋接头控制与施工 对于大跨度钢筋混凝土结构来说，钢筋接头在所难免，关键在于其位置与接头质量的控制。该工程大梁主筋接头采用冷挤压套筒连接，选择此种接头的原因是质量保证且施工方便，但其缺点是使梁局部主筋间、排距变小，给混凝土浇筑造成一定困难，所以主筋接头应尽量少设。本工程中保证底筋跨中6m范围内无接头，其它位置任意40d范围内接头数不超过主筋总数的1/3，施工中严格控制每一个接头的连接质量，按规范要求逐一检查。另外，由于梁的箍筋箍口因主筋较密无法按规范弯成135，则采用封闭焊接，以确保梁的抗剪承载力和刚度。 钢筋制作安装 大梁钢筋制作中，尺寸精确是关键，否则将影响钢筋连接和安装的质量及梁截面的大小，甚至出现质量事故。该大跨梁钢筋绑扎安装时，先在已支好的梁底模上弹好梁宽的控制线，而后由下而上一排排安放主筋，挤压连接，并用钢管搭设支架辅助施工。大梁底筋较密，则在每排钢筋间设置垫铁，保证排距，操作中保证上下排钢筋对齐，以保证浇筑时混凝土流入畅通和振捣棒得以插入。另外，由于大梁的钢筋较多，自重较大，梁底保护层垫块则采用与梁混凝土同级别的去石混凝土特别制作。 5、混凝土浇筑混凝土材料要求该工程采用的商品混凝土，碎石选用13cm粒径，坍落度严格控制在180200mm，要求具有良好的和易性，以确保能够通过大梁密集的钢筋，流淌充实大梁的任一部位，且不发生离析现象，其初凝时间控制在7小时左右。 混凝土浇筑施工 施工用两个布料杆置于预先设置的位置，塔吊协助浇筑。先梁后板，梁施工到板底。梁先施工下部400-500高砼，必须将石子振人钢筋内部，梁下部防止出现浆料分离，砼班长要对振捣人员现场交底。梁上部1000高采用一个坡度，分层浇筑，分层厚度500左右。梁砼浇筑后要进行不少于三遍的找平，抹压，并对表面裂缝进行后期处理（在初凝前）。对砼塌落度要求现场为200mm左右，出站控制在240mm。砼可泵送时间3.5小时。和易性要好，砼缓凝时间在6-8小时。搅拌站现场设调度、质检配合工程部控制浇筑强度协调。现场要设专人检测砼和易性，发现石子与浆分离的、和易性差的砼，及时通知搅拌站质检员处理。为防止大石子混入砼内，砼泵上设钢筋箅子，孔径35mm。混凝土养护 大梁顶面及屋面板采用麻袋覆盖并浇水养护；大梁侧面及底面采用延迟拆模的方法，因为所有大梁模板均采用进口黑漆大板制作，接头处用胶带贴严，密封性能较好，这样既能防止混凝土内的自由水份蒸发，又起到一定的保温效果，防止大梁因温度收缩而产生的裂缝，梁侧模拆除时间需达28天，这样梁混凝土已达设计强度，质量已能保证。结束语：对于钢筋混凝土结构的施工，在保证工程质量的同时还应时刻警惕安全事故的发生，尤其是大跨度、高空间混凝土构件的施工。本工程中，通过选择合理的模板支撑体系，在控制钢筋保护层及混凝土的施工质量的问题，采取了有效的措施，从而在防止了大梁混凝土收缩裂缝及温度裂缝的产生取得了良好的效果。附：施工效果图拆除模板后效果图井字梁钢筋绑扎效果图English is the most widely spoken language in the history of our planet, used in some way by at least one out of every seven human beings around the globe. Half of the worlds books are written in English, and the majority of international telephone calls are made in English. English is the language of over sixty percent of the worlds radio programs. More than seventy percent of international mail is written and addressed in English, and eighty percent of all computer text is stored in English. English has acquired the largest vocabulary of all the worlds languages, perhaps as many as two million words, and has generated one of the noblest bodies of literature in the annals of the human it is now time to face the fact that English is a crazy language - the most lunatic and loopy and of all languages. In the crazy English language, the blackbird hen is brown, blackboards can be green or blue, and blackberries are green and then red before they are ripe. Even if blackberries were really black and blueberries really blue, what are strawberries, cranberries, huckleberries, raspberries, and gooseberries supposed to look add to this insanity there is no butter in buttermilk, no egg in eggplant, no grape in grapefruit, no bread in shortbread, neither worms nor wood in wormwood, neither mush nor room in mushroom, neither pine nor apple in pineapple, neither peas nor nuts in peanuts, and no ham in a hamburger. (In fact, if somebody invented a sandwich consisting of a ham patty in a bun, we would have a hard time finding a name for it.)To make matters worse, English muffins werent invented in England, fries in France, or Danish pastries in Denmark. And we discover even more culinary madness in the that sweetmeat is made from fruit, while sweetbread, which isnt sweet, is made from this unreliable English tongue, greyhounds arent always grey (or gray); panda bears and koala bears arent bears (theyre marsupials); a woodchuck is a groundhog, which is not a hog; a horned toad is a lizard; glowworms are fireflies, but fireflies are not flies (theyre beetles); ladybugs and lightning bugs are also beetles (and to, a significant proportion of ladybugs must be male); a guinea pig is neither a pig nor from Guinea (its a South American rodent); and a titmouse is neither is like the air we breathe. Its invisible, inescapable, indispensable, and we take it for granted. But, when we take the time to step back and listen to the sounds that escape from the holes in peoples faces and to ex- the paradoxes and vagaries of English, we find that hot dogs can be cold, darkrooms can be lit, homework can be done in school, nightmares can take place in broad daylight while morning sickness and daydreaming can take place at night, tomboys are girls and midwives can be men, hours - especially happy hours and rush hours - often last longer than sixty minutes, quick- sand works very slowly, boxing rings are square, silverware and glasses can be made of plastic and tablecloths of paper, most are dialed by being punched (or pushed?), and most bathrooms dont have any baths in them. In fact, a dog can go to the bathroom under a tree - no bath, no room; its still going to the bathroom. And doesnt it seem a little bizarre that we go to the bathroom in order to go to the is it that a woman can man a station but as man cant woman one, that a man can father a movement but a woman cant mother one, and that a king rules a kingdom but a queen doesnt rule a? How did all those Renaissance men reproduce when there dont seem to have been any Renaissance writer is someone who writes, and a stinger is something that stings. But fingers dont grocers dont, haberdashers dont, hammers dont ham, and humdingers dont the plural of tooth is teeth , shouldnt the plural of booth be ? One goose, two geese - so one moose, two One index, two indices - one Kleenex, two If people ring a bell today and rang a bell yesterday, why dont we say that they a ball? If they wrote a letter, perhaps they also their tongue. If the teacher taught, why isnt it also true that the preacher? Why is it that the sun shone yesterday while I shined my shoes, that I treaded water and then trod on the beach, and that I flew out to see a World Series game in which my favorite player flied we conceive a conception and receive at a reception, why dont we grieve a and believe a? If a horsehair mat is made from the hair of horses and a camels hair brush from the hair of camels, from what is a mohair coat made? If adults commit adultery, do infants commit infantry? If olive oil is made from olives, what do they make baby oil from? If a vegetarian eats vegetables, what does a humanitarian eat? (And Im beginning to worry about those authoritarians.)And if pro and con are opposites, is congress the opposite of you have to believe that all English speakers should be committed to an asylum for the verbally insane. In what other language do people drive in a parkway and park in a driveway? In what other language do people recite at a play and play at a recital? In what other language do privates eat in the general mess and generals eat in the private mess? In what other language do people ship by truck and send cargo by ship? In what other language can your nose run and your feet can a slim chance and a fat chance be the same and a bad licking and a good licking be the same, while a wise man and a wise guy are opposites? How can sharp speech and blunt speech be the same and quite a lot and quite a few the same, while overlook and oversee are opposites? How can the weather be hot as hell one day and cold as hell the next? How can the expressions Whats going on? and Whats coming off? mean exactly the samton and unbutton and tie and untie are opposites, why are loosen and unloosen and ravel and unravel he same? If bad is the opposite of good, hard the opposite of soft, and up the opposite of down, why are badly and goodly, hardly and softy, and upright and downright not opposing pairs? If harmless actions are the opposite of harmful why are shameful and shameless behavior the same and pricey objects less expensive than priceless appropriate and inappropriate remarks and passable and impassable mountain trails are opposites, why are flammable and inflammable materials, heritable and inheritable property, and passive and impassive people the same and valuable objects less treasured than invaluable ones? If uplift is the same as lift up, why are upset and set up opposite in meaning? Why are pertinent and impertinent, canny and uncanny, and famous and infamous neither opposites nor the same? How can raise and raze and reckless and be opposites when each pair contains the same is it that when the sun or the moon or the stars are out, they are visible, but when the lights are out, they are invisible; that when I clip a coupon from a newspaper I separate it, but when I clip a coupon to a newspaper, I fasten it; and that when I wind up my watch, I start it, but when I wind up this essay, I shall end is a crazy can expressions like Im mad about my flat, No football coaches allowed, Ill come by in the morning and knock you up, and Keep your pecker up convey such different messages in two countries that purport to speak the same can it be easier to assent than to dissent but harder to ascend than to descend? Why it is that a man with hair on his head has more hair than a man with hairs on his head; that if you decide to be bad forever, you choose to be bad for good; and that if you choose to wear only your left shoe, then your left one is right and your right one is left? 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