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1、浅谈空心板梁先张法预制施工技术李莉莉（河南万里路桥有限公司 河南郑州 450000）摘要：结合工程特点，争创优质工程，笔者优化了施工工艺提高工程质量，对空心板梁先张法预制施工技术进行了详细的阐述，以供读者参考。关键词：空心板梁；先张法；预制；施工技术某工程空心板：板高95cm，中板底宽124cm，中板顶宽104cm，边板底宽Bcm，边板顶宽B-10cm。空心板预应力钢绞线采用符合标准预应力混凝土用钢绞线(GB/T52242003)的低松弛钢铰线，其标准抗拉强度fpk=1860Mpa，直径s15.2mm，公称面积140mm2，弹性模量Ey=1.95105Mpa。配备OVM15、BM15型锚具。一
2、、张拉台座建造张拉台座由承力支架、台面、横梁和定位板组成。1、根据钢绞线的全部张拉力，将承力支架设计成传力梁式用钢筋混凝土浇筑，长为4.5m(传力梁全长为110.5m，中间为素混凝土结构)，宽为50cm，高为50cm，端部预埋钢板用于焊接固定钢横梁。2、台面是制作空心板的底模，必须平整光滑，建造平台时将基础夯实整平，浇筑15cm厚混凝土基础，并在基础上浇筑5cm厚水磨石作为底模，钢板与两侧的5号槽钢和中间4cm4cm横向角铁焊接，为确保底模的平整度和顺直度，施工过程中，水准仪和经纬仪跟踪测量。3、横梁是将预应力钢绞线的张拉力传给承力支架的构件，用20mm厚钢板焊接成长260cm，宽50cm，高
3、40cm的箱体，里面每隔10cm高横焊一块20mm厚钢板，以保证其刚度和稳定性，避免受力后产生变形和翘曲。4、定位板是固定预应力钢筋位置的，用厚度为20mm的钢板制作，宽为20cm，根据钢绞线的排布位置在定位板上开孔，孔直径30mm左右，以利于25mm精扎螺纹钢筋穿过。二、先张法施工程序1、施工前的准备工作 钢绞线下料时应考虑10cm丝杆伸进底模长度，一般约为110m左右，将钢绞线按照图纸设计逐根穿入预应力失效硬塑料管。 检查张拉机具及其他相关机具，使之处于完好状态。 原材料试验及底模检查，报监理验收。 检查施工现场电力及水源的供应情况是否能保证施工。2、梁体放样在台面刷隔离剂之前，将每条张拉
4、线上的每片空心板梁按梁端距离1.0m准确放样到台面上。3、将活动横梁施放到位，并将千斤顶和油泵施放到位。4、穿10cm丝杆连接钢绞线 沿台面在梁体端部放置一根方木，防止脱模剂污染钢绞线。 在固定钢横梁的定位板内按照图纸要求相应穿入10cm丝杆，并装配线杆连接器，连接钢绞线。 钢绞线全部连接完后，在10cm丝杆的另一端穿入高强螺母，连接深入活动横梁的10cm丝杆，并在其一端穿入高强螺母，在两个钢横梁之间对称放入两个千斤顶，以此作为张拉钢绞线初应力的支撑点。5、钢绞线张拉 钢绞线的张拉采用张拉力和伸长值双控制的方法，张拉控制应力采用K0.72R by=1339Mpa,跨径13米预制板每根钢绞线张拉
5、力为132.17KN；跨径20米预制板每根钢绞线张力为187.46KN。 钢绞线的理论伸长值L（mm）按下式计算： L=（PPL）/（APEP）式中：PP钢绞线的平均张拉力（N） L钢绞线的下料长度（mm） AP钢绞线的截面积（mm2） EP钢绞线的弹性模量（N/mm2）13、20米空心板梁的理论伸长值计算见下表：跨径(M)AP(mm2）EP(MPPa)L(mm)PP(N)L(mm)1398.7195.01031100075520140199.810311000187460737初应力以下的推算伸长值L2采用应力张拉到20与40的伸长量的差值（用小顶对称张拉时量测） 初应力以下的推算伸长值当小
6、顶张拉到20con时油表读数：跨径(M)F=f=20%con小顶读数（(MPPa)回归方程式f=a+bf=0.5+0.2243F11326.446.43 2037.5（边）8.912037.5（中）8.91 量测出此时小千斤顶油表读数时对应的伸长值（L1）40con张拉控制应力由大千斤顶完成 跨径(M)F=f=40%con8267（1）f=a+bf=0.4571+0.0232F18259（2）f=a+bf=0.4929+0.02333F113370.16（边）9.04（边）9.13（边）343.72（中）8.43（中）8.51（中）20562.5（边）13.51（边）13.62（边）525（中
7、）12.64（中）12.74（中） 量测出此时对应油表读数的伸长值L2，L2=L2-L1作为初应力以下的推算伸长值从初应力至最大张拉应力之间的实测伸长值L1对应的油表读数计算。跨径(M)f=ncon/2(KN)82671#f=a+bf=0.4571+0.0232F182592f=a+bf=0.4929+0.02333F113925.4（边）21.93（边）22.08（边）859.3（中）20.39（中）20.54（中）201406.3（边）33.08（边）33.3（边）1312.5（中）30.91（中）31.11（中）L/=L1+L2的长度即为预应力钢绞线的实际张拉伸长值。将理论伸长值与实际伸
8、长值进行校核，实际伸长值与理论伸长伸的差值控制在6以内，否则暂停张拉，待查明原因并采取措施予以调整后，方可继续张拉。张拉过程中尽量避免出现滑丝断丝，同一构件内断丝数不得超过该断面钢丝总数的1，若超过需及时更换。当张拉到计算伸长值对应的油表读数与计算的油表读数一致，且实际伸长值与计算所得的伸长值一致应力达到1.05con，停止张拉持荷2min后，整体张拉放张油表回零，进行二次张拉达到设计应力实测伸长值与理论伸长值控制在6以内。进行锚固，锚固方式是旋转丝杆上的螺母紧压固定横梁上锚垫板，固定在横梁上，丝杆端与钢绞线采用连接器连接。所用螺母、丝杆采用开封中原预应力公司产品。6、绑扎钢筋钢筋绑扎工作应在
9、张拉结束8小时后进行，以策安全。 准确调整箍筋和纵向钢筋位置，保证与设计要求一致，用20#22#铁丝进行绑扎。 绑扎铰缝预埋连接钢筋，焊接支座预埋钢筋，伸缩缝预埋筋，护栏预埋筋及绑扎芯模固定钢筋。7、安装侧模、端模 绑扎完成后，将脱模剂均匀的用毛刷涂到模板的面板上，侧模用龙门吊机协助起吊钢模，人工安装。模板用螺栓、螺母连接，模板接缝处垫海绵条，确保不漏浆。 侧模拼装就位后，下侧用钢管螺栓支撑牢固，上面用钢筋拉杆将两侧模板拉紧加固，保证梁板宽度。 端模板用卡口与侧模连接。8、混凝土浇筑，安装芯模 混凝土浇筑分二次进行，开始先浇筑底板，混凝土面至芯模底，振捣密实后，穿放芯模，用空压机充气至规定要求
10、，用钢筋卡环 将芯模固定在设计位置，再从一端开始第二次浇筑，浇筑到顶面振捣密实后，抹平，拉毛。 在第二次浇筑混凝土的过程中，振捣棒应从芯模两侧同时振捣，以防止充气芯模左右移动，避免振捣棒端头接触芯模，出现穿孔漏气现象，且注意不得碰撞预应力钢筋，防止预应力筋受到损坏或断裂伤人。 所用的芯模事先检查充气胶囊是否漏气，检查验收合格后才可使用。 每次浇筑混凝土都要按规定制作试件，以检验板梁强度并确定钢绞线放张时间。 每条生产线上的构件一二次连续浇筑完成。9、拆除侧模、端模和芯模 待混凝土强度达到2.0MPa时，拆除侧模、端模和芯模。 拆除侧模先将侧模底部的木支撑拆掉，然后将上端的对拉杆拆掉， 最后将每
11、块侧模间的连接螺丝拆除，人工将侧模抬到空心板梁浇筑作业区以外，及时清理模板上的残余物，以便下次安装。 侧模拆除要小心，不要碰掉预制板的边角，拆掉模板后要先凿出钢筋预埋件，动作要轻敲慢击，以减少对板梁的损伤。 侧模拆除完成后，继续覆盖养生。10、放松预应力钢绞线，切割钢绞线 将每槽梁最后制作的试件进行抗压试验，当强度达到90%以上后进行放松钢绞线。 放松钢绞线采用整体放张，具体操作步骤如下： a)放张前同时对两台顶推式千斤顶进油，千斤顶活塞的行程满足构件滑动位移长度b)安装活动横梁与固定横梁间的杆-杆连接器。并拧紧张拉活动横梁上的螺母。c)对千斤顶油缸进油（必须严格控制进油压力，取钢绞线同等张力
12、），待活动横梁受力后，拧松固定横梁上的高强螺母。d)两台千斤顶同时缓缓回油，由于钢绞线的失效长度不一，部分经失效处理的钢绞线在构件放张后仍处于张紧状态，且失效长度越大，应力越大。因此切断钢绞线时应注意避免因施加瞬间预应力较大，造成梁板骤然滑动，构件端部钢绞线外缘混凝土及构件棱角破坏严重。所以切断钢绞线时应由放张端向另一端切断且根据先失效长，后失效短，再切不失效；先外后内逐根切断钢绞线的方法进行。结束后注意测量起拱值，钢绞线张拉及放张情况必须如实填写记录资料，钢绞线端部要涂防锈漆。11、空心板梁出槽 用现场的龙门架起吊，出槽，堆放到存梁区，继续养护到28天。 堆放时支点位置要准确，避免预制板产生
13、负弯矩（最大叠放不超过三片）。 将每块预制板两端伸出的钢绞线用砂轮切割机进行割断，涂刷防锈漆，以防止钢绞线锈蚀。 空心板孔用预制好的混凝土块封死，并用砂浆抹平与空心板端头一致。三、结语综上所述，只有科学合理、精心施工、保证工期、降低成本、消灭通病，提高质量，严格按照国家优质产品质量标准控制每一道工序的施工，才能最终使成品梁片片创优。参考文献： 1王雅莉.先张法预应力空心板梁预制工艺及质量控制要点J甘肃科技, 2009,(01) 2李志劲.空心板梁预制场平面规划和模板设计J广西城镇建设, 2008,(06) 3何江.先张法预应力空心板梁放张方法的探讨J铁道标准设计, 2005,(08) 54（英
14、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, strengthen inner-party supervision
15、 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 requirements, listed as negative list, focusi
16、ng 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 process; the second part is the interpret
17、ation 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 the two regulations of the party. and
18、 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 regulations revision work lasted a Years,
19、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 partys leadership, to solve the masses of
20、 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 series of important speech, reflects
21、 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 important role. But with the party to mana
22、ge 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 advocated by the lack of prohibited pr
23、ovisions 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, not for the existing problems, and is
24、 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 many provisions have been unable to
25、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, for violation of the party constit
26、ution, 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 to be more relevant regulations firs
27、t 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 process the Central Committee of the Co
28、mmunist 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 instructions. According to the central deplo
29、yment, 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 meeting to study two regulations revision,
30、 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 and state organs Department The fir
31、st 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 Committee of the Party issued a notice to
32、 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 regulations revision opinion. Central Commis
33、sion 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 After consideration of the two regula
34、tions 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 two party regulations revision work a
35、nd 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 discipline, the discipline quite in fron
36、t 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 constitution of party compasses party
37、 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 Central Commission for Discipline Ins
38、pection 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 purpose of combining rule of virtue i
39、s 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 is to adhere to in accordance with
40、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 members, highlight the vital few, empha
41、sized 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 one high and one low, a positive rea
42、ction, 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 of the problems existing in the party
43、 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 discipline and to implement the central ei
44、ght 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 the and modified and needs to grasp s
45、everal 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 forward principles, requirements and speci
46、fications, 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, eight prohibition 52 are not allowed to about the content of the negative list moved into synchronization amendment . Three is for all the party members, will apply objec