PHC管桩技术交底.doc

Pushing ahead, East, North, West development, facilitating shanty, complete xincheng West Road, stability and reconstruction of the street, Star Ding garden built century Garden District, subject public housing construction, heating the gas expansion accelerated implementation, Jing Rui River and bridge style line solid shaft, further expanded the town development. Beautiful country adhere to the advance and typical for a group to lead. According to ecological lay based, and industry increased income, and live upgrade civilization, and culture rich connotation of thought, caught built beautiful village, and whole village advance, and easily relocation, and five modified three built, project near 30 a; depth into ecological, and industry, and culture, and tourism, elements, high standards caught party original city Liu, and jade are Xia AO, model village, in province City set has benchmark. Four is equal benefits to promote sharing, coordinated development of various social undertakings. In the case of rigid spending slowing revenue growth, increase, financial 75% to the peoples livelihood, the masses have more access in the sharing. Cuoban something good and benefit. Adhere to the affordable, best, carefully cuoban village oil, water and heat, cultural, city and County columns practical, developments benefit families, bring more welfare to the masses. Development of social convenience. Acceptance of balanced development of compulsory education through the national assessment, the County vocational education center was named top School of vocational education in China, the third batch of national reform and development model through provincial . Five is to deepen reform and innovation to break bottlenecks and endogenous development of effective fire. As an engine of dynamism, adding reform key to adopting reform measures stress energy and break bottlenecks and promoting development. Pay close attention to the key areas of reform. Conscientiously implement the provincial deployment and cancel, adjustment, to undertake the administrative approval items according to Regulation 347 to further improve administrative efficiency continuing deepening reform for poverty alleviation, speeding up rural land right registration certification pilot project, encouraging the orderly transfer of land management, utilize the land resources, in order to promote scale management laid the Foundation. Actively cultivate the market. Firmly establish a market-oriented, nurturing family farms, industrial users, professional cooperation organization new market management main body 456, effectively improve the industry, intensive and marketization of encouraging support social capital into the small micro-credit, urban development, culture and tourism, public services and other areas, easing development shortfall. To promote mass innovation. To support the rural sector to use new thinking and new ideas, creative work incentives such as actively promoting financial intermediation, bring added 159 in non public enterprises, individually-1540, created a分项工程技术交底书交底部门：* 编号： 分项工程名称PHC管桩施工施工单位*工序名称PHC管桩施工施工部位*PHC管桩施工主要工序包括：场地平整、桩材验收、测量放线（桩基定位）、吊装管桩、锤击打桩、管桩焊接。1、场地整平 桩基施工前，先进行基坑开挖，基坑开挖依据由内向外的原则进行开挖，开挖至设计标高后，对坑底碾压后进行基桩施工，采用下基坑打桩。2、桩材验收 本工程使用的PHC管桩由厂家集中制作，我公司负责质量验收，对于进场管桩首先应检验厂家出具的“产品合格证”。对运到施工现场的管桩进行检验，并做好检查记录与标识工作。3、测量放线 桩位测放及标高测量仪器采用全站仪（NTS-322）、水准仪（S3）和塔尺。对业主提供的建筑施工控制点、高程基准点等关键部位应重点保护，并列详细文字资料备案。同时对业主提供的测量标志、图纸资料进行复核和复测，结果一周内报监理工程师审核。施工控制点应采取严密的防护措施，应不定期进行复检，发现异常或偏差超出规范要求之后要立即进行纠正。轴线测放完成后和每批桩位测放完成经自检合格后，填写测量放线报验单和工程定位测量放线记录，并提交监理工程师验收。监理工程师验收合格后方可进入下道工序进行施工。不经验收的桩点严禁使用。技术人员负责将已验收的桩点向施工机台进行交接，交接后的桩点由施工机台负责保护，发现桩点被破坏时应及时上报现场技术人员处理。4、吊装管桩 施工场地承载力不够时，桩机下面可铺设厚钢板，保证桩机平稳；桩架直立垂直于地面。桩帽大小要选择合适。送桩杆要根据桩型和送桩深度，用合适材料制作。送桩杆上标有送桩标高符号并且每0.5m画一道标示线。桩位经监理工程师验收后可进行底桩就位、对中与调直。 底桩就位前在桩身上画出以米为单位的长度标记，并从下至上表明桩的长度，一边观察桩的入土深度和记录每米沉桩锤击数。 用单点吊将管桩吊直，先将管桩头部插入桩锤下面的桩帽套内，接着用人工扶住管桩下端，将管桩尖就位在白灰圈内。将打桩架导杆进行调整，保证导杆的垂直度，同时保证桩身、桩帽、桩锤中心线重合。进行管桩对位、调直。这道工序对沉桩质量起到关键作用，对中不正确，成桩后桩位偏差就会超过规范要求。调直采用两台经纬仪在离打桩架15m之外成正交方向进行观察校正，调直控制分两步，第一步先要观测桩机导杆的垂直度，直至符合要求；第二步用经纬仪观测桩的垂直度，保证垂直度在0.5%以内。桩的垂直度要进行反复多次调整，尤其是第一节桩要严格保证其垂直度，确保桩垂直导向作用，桩入土3m后严禁用桩机调整其垂直度。底桩垂直度控制在0.5%以内。桩身一经调直，在施打过程中不可轻易摆动导杆和走动打桩架，打桩机上应配备长条水准尺，以便随时量测桩身的垂直度。施工前用吊车将要施工的桩吊到桩机跟前桩机起桩安全距离范围内。每套桩配套摆放，吊车配合桩机喂桩。严禁桩机远距离强行拉桩。桩起吊时要轻吊轻放，防止碰撞，减少振动，防止桩身裂损。5、锤击沉桩 对于浅层地基土比较松软的情况，底桩沉入时不打开柴油锤油门，让锤自重把底桩压入土中。 开始沉桩时应采取低提锤、轻打下的措施，随着沉桩加深，沉桩速度减慢，起锤高度可逐渐增加。 打桩时桩帽与桩周围的间隙应控制在510mm之间，锤与桩帽、桩帽与桩之间垫弹性垫，锤击压实后的厚度不小于120mm。锤、桩帽以及桩身应在同一中心线上。 施工过程中要根据实际情况对柴油锤进行调档，由1档逐渐升至4档。 沉桩过程中要注意观测桩的垂直度，若桩身垂直度偏差超过1%，应找出原因，设法纠正。当桩尖进入较硬土层后，严禁用移动桩架等强行回扳的方法纠偏。 打桩较难下沉时，要注意检查落锤有无倾斜偏心，特别要注意检查桩垫、桩帽是否合适，不合适要及时更换。每根桩宜连续一次打完，不要中断，以免难以继续打下。 打桩要严格按有关标准做好每米锤击数、总锤击数、入土深度、最后贯入度、锤型、落距等原始记录，焊口也要作好焊接隐蔽记录。 沉桩过程中出现贯入度反常、桩身倾斜、位移、桩身或桩帽破损等异常情况时，应立即停止沉桩，待查明原因并进行处理后，方可继续施工。6、管桩焊接 当底桩桩顶露出地面0.5-1.0m时暂停锤击，进行管桩接长工序。 PHC管桩焊接采用CO2气体保护焊接。焊接前，要清除桩接头处的泥渣、除锈，表面应清洁干净，露出金属光泽；PHC管桩下节沉至离地面0.51.0m时，先在下节桩桩头上扣上一个驳桩导向箍夹具，然后吊起上节桩，放入夹具内就位。接桩时上下节桩段应保持对直，错位偏差不宜大于2mm。上下节桩对准后用经纬仪找上节桩的垂直度，符合要求以后，用钢丝刷清除桩接头处的泥土等脏物。 用电焊枪在接缝剖口四周均匀对称电焊4-6点，待上下接桩固定后拆除夹具再分层施焊，施焊应对称进行。上下节桩接头处如有间隙，采用斜铁片垫实并与桩焊接牢固。PHC管桩接头按要求进行分三层焊接，内层焊渣必须清理干净后方可施焊外一层，焊缝应连续、饱满，且根部必须焊透。焊缝焊好后，焊工应敲掉焊缝表面的焊渣进行自检，不合格的部分应及时补焊，经专检员和监理确认后才能进行施打，并且作好电焊隐蔽记录。同一结构物在同一深度内焊缝接头数量不能超过该结构物总桩数的50% 焊接接头应在自然冷却后才可继续沉桩，冷却时间不宜少于8min，严禁用水冷却或焊接后立即沉桩，并且抽取该结构物焊缝接头总数的10%进行探伤试验。 所有焊工必须持证上岗，随时接受业主和监理的监督检查。PHC管桩焊接质量标准预制混凝土管桩焊接质量要求要达到焊缝质量标准要求。其检查项目及允许偏差见下表。管桩焊接质量要求及允许偏差序号检查项目允许偏差检查方法 单位 数值1上下节端错口外径700mm卡尺量mm2焊缝咬边深度 0.5卡尺量mm3焊缝加强层高度 02 用焊缝测规检查mm4焊缝加强层宽度02用焊缝测规检查mm5 外观焊缝电焊质量 无气孔、无焊缝、无裂缝直观检查mm6电焊结束后停歇时间1.0表测定min7、送桩焊接完成后，让焊缝冷却8-10min后应立即施打，中途不得人为停锤。在送桩之前，应预先算好送桩深度，并选择合适的送桩器，在送桩器上作明显标志。送桩杆与桩身应在同一中心线上，送桩杆上的桩帽与桩周围间隙控制在510mm之间，送桩杆与桩之间垫有一定厚度的平整弹性垫。送桩时要做好锤击数、锤跳高度、贯入度等原始记录。用水准仪控制桩顶设计标高的偏差。桩位偏差、桩顶标高偏差应符合下表的要求。桩位偏差、桩顶标高允许偏差表序号检查项目允许偏差检查方法 单位 数值1 桩位偏差100+0.01H用钢尺量mm2桩数为13根桩基中的桩150+0.01H用钢尺量mm3桩数为416根桩基中的桩100用钢尺量mm4桩数大于16根1/2桩径或边长用钢尺量mm5桩顶标高1/2桩径或边长用钢尺量mm注：H为施工现场地面标高与桩顶设计标高的距离。8、停锤标准管桩停锤标准应符合以下原