方桩基础施工技术总结.doc

【精品文档】如有侵权，请联系网站删除，仅供学习与交流方桩基础施工技术总结.精品文档.方桩基础施工技术总结一、工程概况京承高速公路（高丽营沙峪沟段）工程第18合同段潮白河大桥主桥，基础采用方桩基础，桩基截面尺寸为2.5m×1.0m。 其中9#轴9-1桩，设计桩长26m，导墙顶标高30.924m，设计桩底标高-0.415m，设计桩顶标高25.585m。二、施工准备1、机械设备桩基施工配设：液压抓斗一台、吊车二台、导管2套。钢筋加工机具：电焊机4台、切筋机、对焊机、弯曲机各一台。搅浆设备：搅浆机一台。开挖和清理泥土：挖掘机、装载机各一台。2、人员组织机构情况：3、材料供应：桩基砼全部采用商品砼，钢筋采用三级钢筋，生产厂家经监理工程师审批后方可使用。本桥桩基所需C30砼共计3060m3钢筋全部为三级钢筋 12：120075kg22：98928kg32：66264kg所有材料均需经试验合格，并经监理工程师批准后方可进场，进场时间按照进度计划的要求分批组织进场。施工人员组成表序号岗位人数备注1管理人员122工班长33液压抓斗64钢筋制安205砼浇注86泥浆配置47后勤辅助5合 计58主要施工机械设备表序号项 目类 型单 位数量备 注1液压抓斗BH-12台1成孔2吊车50、16T台各1吊装钢筋笼、浇砼3电焊机315KW台4钢筋笼制作4切断机台1钢筋笼制作5对焊机100KW台1钢筋笼制作6弯曲机台1钢筋笼制作7搅浆机BZ10台1拌制泥浆8挖掘机220台1开挖导墙9装载机40台2清理泥土10导 管 26套1灌注水下砼三、施工方案（一）测量放样1、场地平整后，用经过标定的全站仪测设出桩位中心及轴线，报请监理工程师复测合格后，放出导墙开挖边线。2、导墙开挖后，再精确测设出导墙内边线。3、导墙施工完毕后，在顶板上测设出桩位控制点及高程控制点，并以此控制桩基施工。（二）导墙施工导墙采用砖混结构，底板及顶板采用20cm厚C20钢筋砼，中间砌筑37cm砖墙，导墙内侧间距为265cm×105cm，导墙深3m。导墙沟槽开挖后，重新精确测设出导墙边线，然后浇筑底板砼，待底板砼具有一定强度后，砌筑导墙竖墙，然后将导墙后用土分层夯填至原地面高度，支模，浇筑顶板砼。50cm 104106cm 50cm（三）调制护壁泥浆本桩使用的泥浆采用膨润土泥浆。泥浆在泥浆池内配制，泥浆池设在9#墩上游桥梁红线以外，容积120m3，底部及四周铺设塑料薄膜，防止泥浆渗漏。膨润土泥浆的主要成分为：膨润土粉、水。1、泥浆配比泥浆生产及使用是按照：拌和生产静置水化使用回收处理再使用废弃的顺序进行。泥 浆 配 合 比材料名称单 位数 量水Kg/m3970膨润土（内含纯碱5 Kg/m3）Kg/m3752、泥浆生产泥浆生产采用自制泥浆搅拌机，平均生产效率为10m3/h，生产时按水土。所生产的泥浆应达到以下标准：标 称数 值比重1.04粘度24Pa.s含砂量03、泥浆使用在成孔过程中，泥浆用泵送注入孔内,维持孔稳定,悬浮钻屑。在浇注混凝土的同时用泥浆泵将泥浆回收，底层与淤积物接触并受混凝土污染的泥浆则废弃。（四）成孔1、成孔方式采用意大利BH12液压抓斗为施工机械，并根据方桩的厚度，选配100厘米厚的斗体成槽。液压抓斗成孔是靠斗体重量和液压闭斗，抓取土体提出地面而成孔，随着土体的抓进，槽孔内补入泥浆保证孔内稳定，在钻进过程中要保证浆面高度，防止槽孔坍塌并随时检查孔的垂直度。为保证垂直度，施工时随抓随测，并每抓23抓将斗体旋转180度。2、成孔时间及深度2004年6月23日上午10时开始抓孔，2004年6月23日上午10时至24日23时结束，累计抓孔时间37小时，累计进尺31.4m，其中：进尺0m至22m段，累计进尺22m，共用时14小时，平均每小时进尺1.57m进尺22m至31.4m段，累计进尺9.4m，共用时23小时，平均每小时进尺0.4m。3、地质情况在钻进过程中及时对地层变化情况进行记录，并取具有代表性的土样按顺序放至取样盒内，标明每段样品所代表地层的起始、终止标高和最大粒径。成孔后绘制实际地质柱状图，并与设计地质柱状图进行比较，确认地层变化情况，并报请设计代表及监理确认桩基承载力是否满足设计要求。地质情况如下：标高31.61628.424m，亚粘土；标高28.42423.224m，卵石，最大粒径40cm；标高23.22420.924m，亚粘土；标高20.92419.324m，卵石，最大粒径20cm；标高19.32418.424m，亚粘土；标高18.4248.924m，卵石，最大粒径20cm；标高8.924-0.476m，卵石，板结，最大粒径20cm；（五）验孔孔深采用皮尺下端系垂球测量；孔径、中心位置及倾斜度采用孔规检测，孔规尺寸为2.5m×99.5m，长7m。成孔质量标准项 目实测偏差孔的中心位置（mm）50孔径（mm）2500×1000倾斜度0.5孔深31.4m（六）清孔槽孔抓到设计孔深后，停滞1小时，待泥浆中的悬浮物沉入到孔底后，用抓斗把孔内淤积清出，达到规范要求。砼浇筑之前，泥浆的主要性能指标参数符合要求，孔底淤积物厚度应小于设计要求（20cm）。清孔后实测指标项目实测值沉淀层厚度（mm）60清孔后泥浆指标相当密度1.05粘度19Pa.s；含砂率1；（六）钢筋笼制作1、加工场地钢筋笼加工在桩位附近就近加工，场地平整碾压后，铺设一层卵石，用方木搭设加工平台，平台经调平后方可使用，钢筋下料及焊接均在平台上进行。2、加工方法钢筋笼采用整体加工，整体下笼。主筋采用闪光对焊，箍筋采用电弧焊及绑扎。3、技术要求（1）钢筋焊接前，根据施工条件进行试焊，合格后方可正式施焊。（2）焊工持证上岗。（3）凡施焊的各种钢筋均有材质证明书或实验报告单。焊条、焊剂有合格证，各种焊接材料的性能符合现行钢筋焊接及验收规程（JGJ18）的规定。各种焊接材料分类存放并妥善管理，并采取防止腐蚀、受潮变质的措施。（4）焊条采用506焊条，焊条烘干后使用。（5）接头采用搭接焊时，两钢筋搭接端部应预先折向一侧，使两接合钢筋轴线一致，接头双面焊缝的长度不应小于5d,单面焊缝的长度不应小于10d（d为钢筋直径）保证有效的焊缝长度。焊接过程中不可焊伤主筋。（6）施工现场采取挂牌标识，标牌内容应明确焊接时的搭接方式，焊接长度，焊条型号，电焊机电流量，焊工姓名及上岗证号。（7）由于方桩基础钢筋笼N4筋间距仅为30cm左右，无法采用导管法灌注水下砼，经项目公司技术部、设计代表、总监办、驻地办、施工单位现场协商，钢筋笼中间N4筋间距调整为82cm，将N4筋位置做相应调整，根数不变，层于层之间交替布置。其钢筋布置详见下图。（8）由于设计给出的箍筋及加强筋直径仅为12cm，满足不了吊装要求，因此我单位增设了两组直径为22cm的纵向桁架及加强箍筋，间距2m，以保证钢筋笼不变形。 4、质量评定钢筋位置允许偏差检 查 项 目允许偏差（mm）实测偏差（mm）受力钢筋间距±20±10箍筋、横向水平钢筋、螺旋筋间距0，-20-10钢筋骨架尺寸长±10±9宽、高±5±4保护层厚度±10±10（七）钢筋笼下设1、起吊本工程中方桩钢筋笼重8.4吨，长22.1米。施工中采用两台汽车吊起吊，50t吊车吊起前端，4点起吊，16t吊车吊起后端，两点起吊，当钢筋笼被两台吊车抬起后3m高后，50t吊车吊钩升高，16t吊车吊钩高度不变，将钢筋笼在空中直立，重量全部由50t吊车承担，摘掉16t吊车吊钩，由50t吊车将钢筋笼吊入槽孔就位。在吊放过程中平稳起降，避免变形，确保顺利入槽。2、定位下钢筋笼过程中，通过导墙上的控制点严格控制钢筋笼位置，确保中心位置及保护层符合设计及规范要求，钢筋笼标高通过吊筋长度控制。3、安设吊筋将提前计算好长度的吊筋焊在钢筋笼上，焊接长度要满足规范要求，然后用方钢穿入吊环内，将钢筋笼悬挂在导墙上，保证钢筋笼顶面标高符合要求。 （八）浇注水下砼水下砼采用导管法灌注，砼采用商品砼，搅拌运输车入斗，吊车提斗，浇注工作必须连续进行。砼浇筑程序为：1、配制导管（1）导管长度计算导管长度=31.40.400.5=31.5m（2）导管排序根据导管长度配置导管根数，底节长度为3m，中间配9节3m导管，顶节配1节1.5m导管。按拼装顺序编号记录，以便计算拆管长度时使用。（3）导管连接导管采用内直径30cm的钢管，用丝扣连接，连接处加密封胶垫，导管连接要顺直、严密，接口无磨损。导管使用前按规范要求做闭水试验。（4）闭水试验在浇注砼之前导管要做闭水试验，试验合格后方可使用。试验压力确定根据公路桥涵施工技术规范规定，水密试验的水压不应小于导管壁可能承受灌注砼时最大内压力P的1.3倍。本桥8#墩导墙至桩底最深，导管的内压力也最大，因此取8#墩的导管内压力P作为代表值。P按下式计算：PchcwHw式中：P导管可能受到的最大内压力（kPa）； c砼拌和物的重量（取24kN/m3）hc导管内砼柱最大高度（m）以预计最大高度计，为15m；w井孔内泥浆的重量（取1.05kN/m3）；Hw -井孔内泥浆的深度（m），为30.4m。则：P=24×10-1.05×30.4=208.08 kPa 试验压力1.3×P=1.3×208.08=270.50kPa取试验压力P0.4Mpa试验方法邀请监理一同进行导管闭水试验。将导管拼装，两端封闭，注满水，用手压泵进行加压，当压力表读数达到试验压力时，持压10分钟，然后撤压，在按试验压力加压、持压、撤压，反复加压3次，如导管接头无漏水，则证明此导管合格，经监理工程师批准后，可以用于灌注水下砼。 2、导管安设导管拼装完毕后，经监理检查合格后，用吊车将导管下入孔中，导管底口距孔底40CM，导管支撑在导管架上，导管架用槽钢制成，导管架支撑在导墙上。3、浇筑水下砼（1）计算首批砼用量灌注前首先计算首批砼用量，确保封底成功。首批灌注混凝土得数量应满足导管首次埋置深度（1.0m）和填充导管底部的需要，本工程中8#墩首批砼用量最大，故按8#墩首批砼用量来控制。首批所需混凝土数量可按下面公式计算： VA×B（H1H2）d2h1÷4V-灌注首批混凝土所需数量（m3）；A-桩截面长度（m），为2.5m；B-桩截面宽度（m），为1.0m；H1 -桩孔底至导管底间距（m），取0.40m；H2-导管初次埋置深度（m），取2m；d-导管直径（m），为0.26m；h1-桩孔内混凝土达到埋置深度H2时，导管内混凝土柱平衡导管外泥浆压力所需的高度（m）。 h1wHw/c1.03×32.063/241.38m 则：首批砼用量V2.5×1.0×（0.42.0）3.14×0.262×1.38÷4 6.07m3 各部尺寸见图1。图1（2）实际首批砼用量本工程水下砼灌注计划采用吊车提斗、砼搅拌运输车直接送砼入料斗的方法施工，首先在导管内安放球胆，然后用砼搅拌运输车加大油门连续向料斗内输送砼，直至一车砼放完，这样首批砼用量就等于砼搅拌运输车的容量，砼运输车的容量为8m3，因此实际首批砼用量为8m3，大于理论首批砼用量6.07 m3，满足封底要求。（3）灌注水下砼首批砼落下后，应连续灌注，灌注时间不得长于首批砼的初凝时间。每车砼灌注前必须检查坍落度，不合格不允许施工，砼坍落度应控制在18cm22cm。砼灌注过程中，要经常测探孔内砼面的位置，计算导管埋深，导管在砼中埋深应控制在26M。为防止钢筋笼上浮，当砼顶面距钢筋笼底面1m左右时，应降低砼灌注速度，当砼面上升至钢筋笼底面4m以上时，提升导管，使其底口高于钢筋笼底面2m以上，方可恢复灌注速度，直至砼浇筑到设计高程。考虑到上层浮浆问题，为保证桩头砼质量，一般砼要超浇50100cm，以保证混凝土强度，多余部分在承台施工前必须凿除，桩头应密实、无松散层。灌桩将近结束时，应核对混凝土的灌入数量，以确保混凝土的灌注高度是否正确。每根桩按规范规定制取三组试件，两组自检试验，一组见证试验。试件制作采用标准试件边长15cm的立方体，制作前必须润湿与砼接触的物品，振捣成型；制作整个过程不许超过初凝时间，试件制作完毕在初凝之前不许移动，并用湿麻袋覆盖，保证其养护条件：温度20±5，湿度大于50；在初凝后试件移至标准养护室内进行养生并标明试件制作时间及砼部位，其标养条件为温度20±2湿度大于95。待试件达到强度进行抗压强度试验。灌注时间：2004年6月25日5：45至8：08，共计1小时23分钟。灌注方量：理论方量65m3，实际使用方量76m3，超灌系数1.2。4、渣土及弃浆处理施工过程中所产生的渣土先集中堆放在施工场地，用装载机运至指定的弃土场地。废弃的泥浆先注入沉渣池，待沉淀固结以后用自卸卡车运至指定的弃土场地。四、商品砼质量控制措施1、进行砼施工前一天，以书面的形式将砼的用量及技术要求送往商品砼厂家，以便其配备足够的原材料及运输车辆。2、派试验室人员前往混凝土厂家，检查原材料的质量及储备数量是否满足要求，搅拌设备及运输车辆是否满足需要，合格后方可开盘。3、搅拌过程中，试验员随时检测混凝土的各项指标，并填写出厂记录单，记录每车的出厂时间、坍落度及重量，运输车辆需持试验员填写的出厂记录单，并经灌注现场技术员核对无误后，方可使用。4、在施工现场由厂家技术人员与监理工程师、现场技术员一起检测混凝土的各项指标，不合格的砼绝对不允许使用。并共同制作砼试件。5、严禁运输车辆中途随意加水。方桩施工工艺流程图平整场地导墙施工钻机成孔终孔验收清孔验收下放钢筋笼下导管浇注砼桩基检测钢筋笼验收钢筋笼制作钢筋下料搭设平台（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, strengthen inner-party supervision of major initiatives. The two regulations supporting each other, the < code > adhere to a positive advocate, focusing on morality is of Party members and Party leading cadres can see, enough to get a high standard; < rule > around the party discipline, disciplinary 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 and 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 the implementation of the two regulations of the party. < code > and < Regulations > 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 < Chinese Communist Party discipline and Punishment Regulations > column 1 by 2015 to strengthen party laws and regulations focus. 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, adhere to the party's leadership, to solve the masses of the people reflect a focus on the problem. The new revision of the < code > and < rule >, reflects the party's 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 the party's eighteen years comprehensive strictly practice. (a) revised two regulations of the party need of < the ICAC guidelines > in < in 1997 Leaders as members of the Communist Party of China clean politics certain criteria (Trial) > 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 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 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 theme is not prominent, not for the existing problems, and is narrow, only needle of county-level leading cadres above. < rule > is in 1997 < Chinese Communist Party disciplinary cases (Trial) > 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 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 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 < the criterion of a clean and honest administration > and < rule > 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 regulations 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 regulations < > 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 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 the 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 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 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 the 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, < code > and < Regulations > revision of the basic principles of two party regulations revision work and implement the party's 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 < low political criterion > and < Regulations >, highlighting the ruling party characteristics, 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 < rule > and < rule >. 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 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 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 < code > and < rule > is Method in adhere to the regulations 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 requirements. 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 party's ideals and beliefs, excellent traditional style. The revised the < code > closely linked to the "self-discipline", insisting on the positive