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1、大桥旋转法钻孔灌注桩基础施工摘 要:钻孔灌注桩基础在公路桥梁工程中应用比较广泛，它的施工工艺及TRANBBS技术发展也比较成熟。其优点：承载力大、稳定性好、沉降量小、冲刷的河床和不稳定的河道对它的影响小、受施工水位或地下水位高低的影响较小。关键词: 灌注桩 施工、概述海南东线高速公路（扩建）工程陵水至三亚段281954处藤桥东河大桥，长247m、宽8.5m，基础为钻孔灌注桩，其中墩桩径1.5m，桩长35.74m，桩基所处位置的地质情况如图所示。旋转法钻孔灌注桩基础的施工程序如下 ：测量放线桩位埋设护筒钻机准确就位钻孔第一次清孔质量检查吊放钢筋笼吊放导管第二次清孔灌注水下砼、施工前准备工作. 测
2、量放线开工前,我们首先对大桥的中线、水准点进行检查复核和补充，并按照满足精度要求放出7# 墩的四处位置，围堰筑岛高出正常水位0.6 m，(因施工日期为4月份，而海南6-10月份为台风降水集中期，故不予考虑)再定出桩位，距有桩2.0m范围内均需满填以满足有足够宽度的填土保护护筒不受水的浸渗。. 埋设护筒桩位测量放样后，进行护筒的埋设。以桩心为中心挖土，埋设直径为1.8m、高为2.5m钢护筒，钢护筒中心要与桩中心在同一垂线上，就位、整平。护筒四周用粘土回填，夯实，以防翻砂和漏浆，排浆洞口对准泥浆沉泥池方向。. 安装钻架和钻机用枕木设置工作平台，保证其足够的稳定性和平整度，使操作时不发生位移和摇晃。
3、检测其纵、横向误差在5cm以内，钻杆垂直度偏差为0.02，满足规范要求。. 造泥浆泥浆的作用主要是护壁和浮渣。泥浆比重小，易出现塌孔，护壁效果差；泥浆比重大，影响进尺和漏浆再利用速度。本工程 墩桩基地质是圆砾粗砂、中砂、砾砂，强风化花岗岩和闪长岩，在砂层钻孔所采用泥浆比重为1.22，强风化岩石层更换金刚石钻头，泥浆比重为1.35，为防止因泥浆比重大而“糊钻”，掺外加剂（分散剂）0.1，改善泥浆性能，增加钻进速度。、钻孔钻孔时主要应控制好二个基本参数：钻压和转速. 钻压钻头是在钻压和回转扭矩作用下切削和破碎岩土而获得进尺。为此钻进时需有一定的钻压，钻压太小，钻进速度慢；钻压太大，钻具磨耗严重。因
4、此应根据桩位地质情况，钻杆直径、桩径、钻头形式、钻头刀具数目、钻具强度等因素综合考虑，合理确定钻压。. 转速钻杆转速要考虑满足碎岩土的扭矩需要，又要考虑钻具的磨耗及孔壁稳定等情况。钻具强度一定时，钻头直径越大，转速应越慢。开钻时，先使钻头降至距孔口5cm左右启动泥浆泵，待泥浆循环几分钟后，再启动钻机慢度回转，同时慢慢降下钻头，孔口位置先慢转，孔口稳定后逐渐增加转速正常钻进。钻后，转速的控制对成孔及后期水下砼浇筑有其重要的影响，进尺速度过快，孔壁难以形成一定厚度的泥浆护壁层，易形成塌孔等事故的发生；进尺速度过慢，可能形成扩孔，影响整个分项工程施工速度，亦不可取。因而在墩桩基钻孔中，针对地质具体情
5、况，钻孔时，细砂层、粗砂层、砾砂层、岩石层进尺速度递减，以确保桩成孔质量，为工程后期顺利施工提供条件。成孔长度以钻杆总长度为准(钻头部分除外)，勿以软绳测之。钻至TRANBBS设计标高后，便开始清孔，此时将钻头提离孔底30cm左右空转，然后根据泥浆比重情况，泵入相对密度和含砂率较小的泥浆或清水，直到孔内的泥浆比重达到1.051.2之间，含砂率小于。3、钢筋笼制作及吊装我们根据吊装设备能力分节制作钢筋笼。分节制作时，钢筋接头应错开布置。钢筋笼骨架上端应设置四根吊环上穿钢管，定位于钻机平台上，以保证有足够长度的钢筋嵌入系梁中，满足设计要求。钢筋笼骨架侧边设置“筋”控制保护层厚度的部件。4、灌注水下
6、砼目前我们基本上是采用直升导管法灌注水下砼，即将导管居中插入到离孔底0.30.4m。导管上口接漏斗，在接口设隔水栓，隔绝砼与导管内水的接触，在漏斗中存备足够数量的砼后，放开隔水栓，存备的砼连同隔水栓向孔底落，将导管内的水全部压出，并使管下口埋在孔内砼中不小于1m，为了检验此数，我们根据现场进行漏斗的体积验证试验。漏斗体积图如下： 1.31.31.52.54m h6（4） 0.6 6（1.950.0940.80.9）0.5 m漏斗体积 ： 3.04 m规范中要求 ：4h141.51.440.2536.641.1/2.43.30 m 3因：，故需加体积大于0.4m的储料斗，而爬梯运料斗可容纳盘料（
7、250L）。体积大于0.4m，这样首批砼的数量可以保证，海南气温较高，浇筑此桩大概需要3.54.5h，掺入适量的缓凝剂，保持砼的和易性及浇筑的连续性。随着砼不断通过漏斗、导管灌入钻孔，孔内初期灌注的砼及其上面的泥浆水被顶托上升，相应地不断提升导管，直至孔顶灌注完毕。水下混凝土浇筑过程中，要定时检查导管的埋置深度，浇筑时砼面的理论升高值与实际上升值进行对比，严防因”护孔”而形成导管拨出砼面至桩身砼出现”断桩”或”夹渣”事故的发生，并将测量结果进行详细记录，以便为动测桩基量对其砼质量判断提供必要的依据。水下砼浇筑必须连续进行，砼要有较好的性能，施工过程中要掌握每次向导管投料后都应“翻浆”，否则，应
8、及时上下活动导管(50cm内)，防止堵塞，同时检查砼的各项性能指标，调整砼的技术参数，改善砼的和易性，顺利浇筑到桩顶灌注桩质量控制，主要于水下砼灌注的质量的好坏，砼除了具有一定的强度外，还要有较好的和易性、流动性和保水性，同时需有较长的初凝时间。由于砼是在水下灌注，影响砼质量的因素很多，主要是受水和泥沙的影响，再有施工中不允许振捣，砼的密实度和均匀性都比较差，强度远远低于陆地上浇筑的砼。为了保证其质量，首先应设计出性能优良的砼配合比,我们选用砼的水灰比为0.55，砂率48%，坍落度在18-20 cm之间。其次施工时要经常取样检查砼的性能，及时调整配合比，并加强施工管理，保证施工顺利。、注意事项
9、和事故处理.钻孔前（）、注意测量的准确性，保证护筒埋置位置准确。（）、护筒埋置时，其土质应密实不漏水和不漏浆。（）、钻具安装时应检查其垂直度和稳定性，施工过程中也应经常检查。.钻孔时（）、经常检查保证护筒内的水头高度和泥浆稠度。钻进过程中，应随时检查和记录土质情况，与设计土质对照，及时控制和调整钻进速度和泥浆稠度。（）、钻孔要连续作业，中途不能停钻。相邻桩开钻需等邻孔砼达到一定强度后才开始。终孔后要对成孔进行全面检查。（）、出现坍孔，应仔细分析查明原因和坍孔位置，然后采用小砾石夹粘土回填至坍孔位置，待回填土稳定后，采取加强泥浆稠度、加高水头和深埋护筒等措施，重新钻进。（）、钻孔偏斜、弯曲，应吊
10、住钻锥在偏斜、弯曲处，反复扫孔，或回填至偏斜、弯曲处，重新钻进。（）、钻孔漏浆，此时可适当减小水头高度，加稠泥浆，慢速转进，用冲周法钻孔时，可加入碎卵石进行冲周，加密孔壁。.成孔后成孔后，应抓紧进行清孔，吊装钢筋笼和安放导管，快速灌注水下砼。比时应注意如下几点：（）、吊装钢筋笼时，应避免冲撞孔壁，影响孔壁稳定。（）、钢筋笼吊装后，要再次检测孔内的泥浆比重、含沙率和孔底沉淀层厚度是否符合要求，否则应再次清孔。（）、导管吊装前，管内壁应擦润滑油，管接口密实不漏水。漏口的容积应满足首次埋深。（）砼拌和物，应按照设计配合比，砼的和易性、坍落度应符合要求。（）、灌注砼时，应随时测量灌注标高和导管埋深，埋
11、深不得小于1.5米。太深应及时拆管，否则导管很难拨出，就会造成断桩。灌注时，应经常提升、插进导管，防止砼塞管。（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 disciplin
12、e to manage the party, 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, discipl
13、inary ruler requirements, 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 a
14、nd the revision process; 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 th
15、e implementation of the 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 fo
16、cus. Two party regulations 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
17、, adhere to the partys 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
18、Secretary Xi Jinping 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
19、cadres play an important 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
20、concisely positive advocated 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 them
21、e is not prominent, not 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
22、the situation, which 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 pr
23、ominent, not specific, 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 a
24、nd the two is likely 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 reg
25、ulations revision process 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 regulation
26、s made clear instructions. 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
27、held a special meeting 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 t
28、he central ministries 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
29、 of the Central Committee 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
30、Party of two regulations 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 th
31、e Central Committee After 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
32、basic principles of two 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 characte
33、ristics, serious discipline, 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 specifi
34、c, awaken the party constitution 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 ei
35、ghth session of the Central 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
36、established for the purpose 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 r
37、equirements. 4 second 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 in
38、itiative, for all members, 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 ver
39、tical gauge. Is this 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, in
40、sist on to. In view of 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, or
41、ganization and discipline 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 change
42、s, major changes in the 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-d
43、iscipline, put forward 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
44、 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 object from the leadership of the party members and cadres to expand to all Party me
45、mbers, fully embodies the comprehensive strictly required. The fourth is prominent key minority, seize the leadership of the party members and cadres is the key, and put forward higher requirements than the ordinary Party members. Five is to simplify, and strive to achieve concise, easy to understan
46、d, easy to remember. The revised is the ruling Party since the first insists on a positive advocate forAll Party members and the self-discipline norms, moral declaration issued to all members of the party and the National Peoples solemn commitment. criterion of a clean and honest administration consists of 4 parts, 18, more than 3600 words. After the revision of the , a total of eight, 281 words, including lead, specification and Party member cadre clean fingered self-discipline norms, etc. Part 3 members low-cost clean and self-discipline, the main contents can be summarized as fo