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1、 公路桥梁工程桩基础钢筋机械连接技术的探讨摘要：钢筋机械连接技术具有强度高、质量好、速度快、范围广、成本低、全天候和无污染等优点，近年来在各类建设工程中得到广泛的应用。本文结合某高速公路互通立交工程桩基础中钢筋机械连接技术的应用，介绍滚轧直螺纹连接施工工艺、质量检验验收要点和特点，并进行了成本分析，供类似工程参考。关键词：公路桥梁；桩基础钢筋；机械连接；施工工艺1前言钢筋机械连接技术是通过连接件的机械咬合作用或钢筋端面的承压作用，将一根钢筋中的力传递至另一根钢筋的连接方法，具有施工简便、工艺性能良好、接头质量可靠、不受钢筋焊接性的制约、可全天候施工、节约钢材和能源等优点。2结构原理钢筋等强滚轧
2、直螺纹连接，其工艺是将待连接钢筋端部的纵肋和横肋用切削的方法剥掉一部分，使钢筋滚丝前的柱体直径达到同一尺寸，然后直接滚轧成普通直螺纹，用特制的直螺纹套筒连接起来，形成钢筋的连接。其基本原理是利用了金属材料塑性变形后冷作硬化增强金属材料强度的特性，而仅在金属表层发生塑变、冷作硬化，金属内部仍保持原金属的性能，因而使钢筋接头与母材达到等强。3应用背景某高速公路互通立交工程共有主线桥1座，匝道桥6座，共有桩基础440根，桩长为2070m不等，桩径为120cm、140cm和150cm三种，主筋采用25mm的ii级钢筋。桩基础钢筋存在着数量多、接头多等特点，为确保桥梁结构工程质量，提高钢筋连接施工工艺水
3、平，合适选择桩基础主筋接头连接方式尤为关键。钢筋连接按施工方式可分为三类：在加工场预加工连接类、现场水平连接类和现场竖向连接类。三类不同连接方式采用不同的接头形式：1、由于在加工场预加工连接时，设备齐全操作空间大，焊接质量容易保证需要，同时监理人员检查方便，因此允许此类钢筋采用焊接连接，但焊接必须按照规范要求采用双面焊接，被连接钢筋必须保证在同一直线内。2、对于现场水平连接类钢筋，若出现施工现场受模板、机具及操作空间等影响不能保证上述焊接要求，监理人员不方便检查的，需采用机械连接；若上述因素影响较小、作业面大、易满足焊接要求，焊接质量易保证，并方便监理人员检查的，原则上允许采用焊接连接。3、因
4、钢筋采用现场竖向连接时受空间和时间限制，焊接困难，焊接质量圾焊缝长度较难保证，且焊接施工时间长，监理人员检查不方便，这些均可能对工程质量造成影响，故此类钢筋必须采用机械连接。桩基础主受力钢筋采用第三类施工方式即现场竖向连接，应采用机械连接方式，故选择采用钢筋等强滚轧直螺纹连接。该立交工程桩基础主筋连接接头数量统计表详见下表：桩基础钢筋连接接头数量统计表4施工工艺4、1材料要求1、钢筋直径为16mm40mm的hrb335（ii级）、hrb400（iii级）热轧带肋钢筋，符合钢筋混凝土热轧带肋钢筋gb14991998标准的要求。钢筋应平直、无损伤；表面没有裂纹、颗粒状或片状老锈。2、钢套筒直螺纹套
5、筒连接是通过钢筋端头特制的直螺纹和直螺纹套管咬合形成整体的一种连接方式。可根据需要制作直径为1640的钢筋直螺纹连接套。连接套制作材料用45号优质碳素结构钢或其它经试验确认符合要求的钢材。连接套筒表面没有裂纹，表面及内螺纹没有严重的锈蚀。连接套的屈服承载力和抗拉承载力不小于被连接钢筋屈服承载力和抗拉承载力标准值的1.10倍。接头的性能符合钢筋机械连接通用技术规程jgj107-2003标准i级接头性能的规定。4、2施工准备1、主要机具钢筋滚压机、螺纹环规（通规、止规）、专用扳手及管钳、砂轮切割机、钢筋切断机、直尺、卡具、钢丝刷、钢筋支架等。2、材料准备a钢筋、钢套筒的材质均经过复验符合标准的材料
6、要求。b钢筋端面平整、与轴线垂直，没有马蹄形或挠曲现象。c钢套筒与钢筋端部清理干净，钢套筒与钢筋规格一致。3、作业条件a参加作业人员已经过培训，并经考核合格，做到持证上岗。b钢筋滚压机经检查和空车调试合格，运转正常，其技术参数满足使用要求。c满足钢筋滚压要求的模具已备全，模具上有相对应的需滚压钢筋规格标记。d技术提供单位已经提交有效的型式检验报告及基本技术参数。4、3工艺流程钢筋滚轧直螺纹连接的工艺流程为：钢筋原料切头机械加工（丝头加工）套丝加保护套工地连接。1、所加工的钢筋应先调直后再下料，切口端面与钢筋轴线垂直，不能有马蹄形或挠曲。下料时，用砂轮切割机或专用切割设备下料，不得采用气割下料。
7、2、钢筋丝头要在钢筋滚压机上进行，各类丝头的螺纹加工长度应符合技术提供单位提供的基本技术参数要求。加工丝扣的牙形，螺纹必须与连接套的牙形、螺距一致，有效丝扣内的秃牙部分累计长度小于一扣周长的1/2。应严格控制丝头长度，不能随意过长或过短，丝头加工后护套防护，护套应有足够的长度，直径32mm的钢筋标准丝头为323，加长型丝头长度大于80mm。3、已加工完成并检验合格的丝头要加以保护，钢筋一端丝头戴上保护帽，另一端拧上连接套，并按规格分类堆放整齐待用。4、钢筋连接时，钢筋的规格和连接套的规格一致，并确保丝头和连接套的丝扣干净、无损。连接接头应使用管钳或专用扳手拧紧，使两个钢筋丝头在套筒中间顶紧。拼
8、接完成后，套筒每端不得有一扣以上的完整丝扣外露。加长型接头的外露丝扣数不受限制，但应有明显标记，以检查进入套筒的丝头长度是否满足要求。现场安装时，要在安装完毕后，拧开螺母进行检查钢筋实际间隙，两钢筋之间的间隙应尽量小，最大不能大于6mm，否则应重新安装。4、4质量要求与检验1、质量要求a丝头：牙形饱满，牙顶宽度超过0.6mm，秃牙部分累计长度不应超过一个螺纹周长。外形尺寸含螺纹直径及丝头长度应满足图纸要求。b套筒：套筒表面无裂纹和其它缺陷，外形尺寸包括套筒内螺纹直径及套筒长度应满足产品设计要求。c连接：连接是要确保丝头和连接套的丝扣干净、无损。被连接的两钢筋断面应处于连接套的中间位置，偏差不大
9、于1p（p为螺距），并用工作扳手拧紧，使两钢筋端面顶紧。2、质量检验加工人员加工时逐个目测丝头的加工质量。检查标准应符合表2中的规定。每加工10丝头应用相应的环规和丝头卡板检测1次，并剔除不合格产品。自检合格的丝头，再由质检人员对每种规格加工的丝头随机抽样检验，以一个工作班生产的丝头为一个检验批随机抽样10，且不得少于10个，按表2作钢筋丝头质量检查。如有一个丝头不合格，应加倍抽检，复检仍有不合格丝头时，即应对该批全数检查，不合格的丝头应切去重新加工，经再次检验合格后方可使用。已检验合格的丝头应戴上塑料帽或连接套和保护塞加以保护。4、5成品保护1、套筒在运输和储存时应防止锈蚀和污染，套筒应有保
10、护盖，保护盖上应注明套筒的规格。现场分批验收，并按不同规格分别堆放。2、对加工好的丝头，应用专用的保护帽或连接套筒将钢筋丝头进行保护，防止螺纹被磕碰或被污染。3、钢筋应按规格分别堆放，底部用方木垫好，在雨季要采取防锈措施。4、施工作业时，要搭设临时架子，不得随意蹬踩接头或连接钢筋。4、6存在问题及原因在施工过程中，部分钢筋机械连接出现质量不稳定现象，主要原因是工人不熟练、钢筋端头不平、轴线偏差、端头间距较大、端头和丝头开裂、组装扭矩不够等。4、7成本分析从经济性分析，手工电弧焊焊接钢筋生产效率低，成本投入大，尤其是在大直径钢筋的焊接上更为明显，施工中不仅要投入电焊工、电焊条和电焊机，还要投入搭
11、接的钢筋和帮条，并且由于施工时间长要占用汽车吊机台班，生产成本较高。下表为手工电弧焊接与滚轧直螺纹连接的成本比较：钢筋手工电弧焊焊接与滚轧直螺纹连接成本比较项目名称单位单价手工电弧焊焊接滚轧直螺纹连接备注数量合价数量合价电焊工工日800.032.4 0.0 手工焊一工日3035个接头电焊条kg5.60.160.9 0.0钢筋kg4.50.964.3 0.0电焊机台班1200.033.6 0.0连接套筒元7.20.0 1.00 7.2连接头加工费元1.80.0 1.00 1.825t汽车吊机台班11000.026 28.2 0.013 14.1 以手工焊8小时下3处接头,每处接头13个接头计,机
12、械连接时间减半成本39.4 23.1从上表可以看出，在采用钢筋等强滚轧直螺纹连接工艺后，钢筋制作安装的施工成本有了一个较大幅度地下降，该工程总共可节省成本约30万元。5应用成果在该工程施工过程中，通过对滚轧直螺纹钢筋连接抽样做接头试件拉伸试验，试验结果表明：滚轧直螺纹钢筋连接接头安全可靠均符合钢筋机械连接通用技术规程jgj1072003标准所列i级接头的技术要求，其接头强度均大于或等于钢筋母材的实测强度。由于该工程在桩基础施工过程中采用钢筋等强滚轧直螺纹连接工艺，加快了桩基础钢筋笼施工时间，从而缩短桩基础成桩时间，在钢筋笼施工过程、混凝土灌注过程均未出现任何事故，最终桩基础检测结果均为i、ii
13、类桩。6工艺特点综上，可以发现钢筋等强直螺纹连接施工工艺具有如下特点：1、强度高：接头强度大于母材强度，强度达到行业标准jgj107-2003中i级接头性能要求；抗疲劳性能好。2、质量好：接头性能不受拧紧力矩影响，少拧12扣，均不会对接头造成明显损害。省去了用力矩扳手检测这一道工序。3、速度快：与电弧搭接焊、套筒冷挤压、锥螺纹连接相比，直螺纹连接降低了钢筋绑扎的劳动强度，大幅提高施工速度，降低工程人工费和汽车吊机等机械费。4、范围广：适用于直径16-50毫米的、级钢筋任意方向和位置的同异径连接；对弯折钢筋、固定钢筋、钢筋笼等不能转动钢筋的场合，可采用正反丝扣型接头。5、成本低：可节约钢筋、电焊
14、条、电、汽车吊机和人工等。6、全天候：不受天气影响，在较差的天气仍可进行钢筋安装作业。7、无污染：无噪声污染，无油污污染、无烟尘和弧光污染、有利于保护劳动者身体健康和施工现场的文明整洁。7结语滚轧直螺纹钢筋连接在该高速公路互通立交工程的应用，以其强度高、质量好、速度快、范围广、成本低、全天候和无污染等优点，不仅在生产效率、生产成本上均具有较大的优势，而且减少了现场施工中人为因素对钢筋连接质量的影响，有效的提高了钢筋连接的质量，从而提高了桥梁工程施工工艺水平。参考文献1、滚轧直螺纹钢筋连接接头（jg163-2004）2、钢筋机械连接通用技术规程（jgj107-2003）3、公路桥涵施工技术规范（
15、jtj041-2000）注：文章内所有公式及图表请以pdf形式查看。（英文版 ） Two regulations promulgated for implementation is in the party in power for a long time and the rule of law conditions, the implementation of comprehensive strictly strategic plan, implementation in accordance with the rules and discipline to manage the party
16、, strengthen inner-party supervision of major initiatives. The two regulations supporting each other, the adhere to a positive advocate, focusing on morality is of Party members and Party leading cadres can see, enough to get a high standard; around the party discipline, disciplinary ruler requireme
17、nts, listed as negative list, focusing on vertical gauge, draw the party organizations and Party members do not touch the bottom line . Here, the main from four square face two party rules of interpretation: the first part introduces two party Revised regulations the necessity and the revision proce
18、ss; the second part is the interpretation of the two fundamental principles of the revision of laws and regulations in the party; the third part introduces two party regulations modified the main changes and needs to grasp several key problems; the fourth part on how to grasp the implementation of t
19、he two regulations of the party. and revised the necessity and revised history of the CPC Central Committee the amendment to the Chinese Communist Party members and leading cadres honest politics several guidelines and column 1 by 2015 to strengthen party laws and regulations focus. Two party regula
20、tions revision work lasted a Years, pooling the wisdom of the whole party, ideological consensus, draw historical experience, respect for the wisdom of our predecessors, which reflects the unity of inheritance and innovation; follow the correct direction, grasp the limited goals, adhere to the party
21、s leadership, to solve the masses of the people reflect a focus on the problem. The new revision of the and , reflects the partys 18 and the eighth session of the third, the spirit of the fourth plenary session, reflecting the experience of studying and implementing the General Secretary Xi Jinping
22、series of important speech, reflects the partys eighteen years comprehensive strictly practice. (a) revised two regulations of the party need of in based on revised, the promulgation and implementation of January 2010, to strengthen the construction of the contingent of leading cadres play an import
23、ant role. But with the party to manage the party strictly administering the deepening, has not been able to fully meet the actual needs. Content is too complicated, eight prohibition, 52 are not allowed to hard to remember, and also difficult to put into practice; the second is concisely positive ad
24、vocated by the lack of prohibited provisions excessive, no autonomy requirements; the third is banned terms and discipline law, both with the party discipline, disciplinary regulations repeat and Criminal law and other laws and regulations repeat; the fourth is to clean the theme is not prominent, n
25、ot for the existing problems, and is narrow, only needle of county-level leading cadres above. is in 1997 based on revision, in December 2003 the promulgation and implementation, to strengthen the construction of the party play very important role. Along with the development of the situation, which
26、many provisions have been unable to fully meet the comprehensive strictly administering the practice needs. One is Ji law, more than half of the provisions and criminal law and other countries laws and regulations Repetition; two is the political discipline regulations is not prominent, not specific
27、, for violation of the party constitution, damage the authority of Party Constitution of misconduct lack necessary and serious responsibility to pursue; third is the main discipline for the leading cadres, does not cover all Party members. Based on the above situation, need to and the two is likely
28、to be more relevant regulations first amendment. By revising, really put the authority of Party discipline, the seriousness in the party tree and call up the majority of Party members and cadres of the party constitution of party compasses party consciousness. (II) two party regulations revision pro
29、cess the Central Committee of the Communist Party of China attaches great importance to two regulations revision . Xi Jinping, general books recorded in the Fifth Plenary Session of the eighth session of the Central Commission for Discipline Inspection, on the revised regulations made clear instruct
30、ions. According to the central deployment, the Central Commission for Discipline Inspection from 2014 under six months begin study two regulations revision. The Standing Committee of the Central Commission for Discipline Inspection 4 review revised. Comrade Wang Qishan 14 times held a special meetin
31、g to study two regulations revision, amendment clarifies the direction, major issues of principle, path and target, respectively held a forum will listen to part of the province (area) secretary of the Party committee, Secretary of the Discipline Inspection Commission, part of the central ministries
32、 and state organs Department The first party committee is mainly responsible for people, views of experts and scholars and grassroots party organizations and Party members. Approved by the Central Committee of the Communist Party of China, on 7 September 2015, the general office of the Central Commi
33、ttee of the Party issued a notice to solicit the provinces (autonomous regions, municipalities) Party, the central ministries and commissions, state ministries and commissions of the Party (party), the General Political Department of the military, every 3 people organization of Party of two regulati
34、ons revision opinion. Central Commission for Discipline Inspection of extensive solicitation of opinions, careful study, attracting, formed a revised sent reviewers. In October 8 and October 12, Central Committee Political Bureau Standing Committee and the Political Bureau of the Central Committee A
35、fter consideration of the two regulations revised draft. On October 18, the Central Committee of the Communist Party of China formally issued two regulations. Can say, two laws amendment concentrated the wisdom of the whole party, embodies the party. Second, and revision of the basic principles of t
36、wo party regulations revision work and implement the partys eighteen, ten eight plenary, the spirit of the Fourth Plenary Session of the Eleventh Central Committee and General Secretary Xi Jinping important instructions on the revised and , highlighting the ruling party characteristics, serious disc
37、ipline, the discipline quite in front of the law, based on the current, a long-term, advance as a whole, with Bu Xiuding independent and . Main principle is: first, adhere to the party constitution to follow. The constitution about discipline and self-discipline required specific, awaken the party c
38、onstitution of party compasses party consciousness, maintaining the authority of the constitution. General Secretary Xi Jinping pointed out that no rules, no side round. Party constitution is the fundamental law, the party must follow the general rules. In early 2015 held the eighth session of the C
39、entral Commission for Discipline Inspection Fifth Plenary Session of the 16th Central Committee, Xi Jinping again pointed out that constitution is the party must follow the general rules, but also the general rules. the revision of the and is Method in adhere to the regulations established for the p
40、urpose of combining rule of virtue is to adhere to the party constitution as a fundamental to follow, the constitution authority set up, wake up the party constitution and party rules the sense of discipline, the party constitution about discipline and self-discipline specific requirements. 4 second
41、 is to adhere to in accordance with the regulations governing the party and the party. The Party of rule of virtue de, mainly refers to the partys ideals and beliefs, excellent traditional style. The revised the closely linked to the self-discipline, insisting on the positive initiative, for all mem
42、bers, highlight the vital few, emphasized self-discipline, focusing on the morality, and the majority of Party members and the ideological and moral standards. The revised Ji method separately, Ji, Ji Yan to Method, as a negative list, emphasizing the heteronomy, focusing on vertical gauge. Is this
43、one high and one low, a positive reaction, the strict party discipline and practice results transformation for the integration of the whole party to observe moral and discipline requirements, for the majority of Party members and cadres provides benchmarking and ruler. Third, insist on to. In view o
44、f the problems existing in the party at the present stage, the main problems of Party members and cadres in the aspect of self-discipline and abide by the discipline to make clearly defined, especially the partys eighteen years strict political discipline and political rules, organization and discip
45、line and to implement the central eight provisions of the spirit against the four winds and other requirements into Disciplinary provisions. Not one pace reachs the designated position, focusing on in line with reality, pragmatic and effective. After the revision of major changes, major changes in t
46、he and modified and needs to grasp several key problems (a) adhere to according to regulations governing the party and party with morals in combination, for at the present stage, the leadership of the party members and cadres and Party members in existing main problems of self-discipline, put forwar
47、d principles, requirements and specifications, showing Communists noble moral pursuit, reflected at all times and in all over the world ethics from high from low 5 common requirements. One is closely linked to the self-discipline, removal and no direct relation to the provisions of . the second is adhere to a positive advocate, eigh