桩基础施工技术交底.doc

桩基础施工技术交底
一、材料
1、水泥标号32.5；
2、碎石：花岗岩最大粒径30mm ，级配合理，针片状颗粒含量≤25%，含泥量≤2%，强度达到要求；
3、可采用中粗河砂，含泥量≤5%；
4、水用自来水；
5、钢筋：纵筋Ⅱ级钢，横向加劲筋及螺旋筋Ⅰ级钢。
以上材料必须有合格证，并按规定抽检，经监理认可。
二、桩基施工工艺
（一）围堰筑岛：围堰采用编织袋装砂，围堰尺寸按图施工，内填砂筑岛。
（二）钢护筒采用夺取10mm的A3钢板卷制。在焊接接头焊缝处加厚10mm宽20cm的钢带，护筒底脚处加厚10mm宽30cm的钢带作为刀脚。双用双面焊，不得漏水。用桩锤自重下沉。
（三）泥浆采用优质膨润土制备，在岸上设泥浆池。要检测其粘度（进出）和相对密度（进出）。
（四）成孔工艺：钻进前将泥浆加入孔内，用泥浆泵进行循环供浆。钻进过程中，掌握好浓度，使泥浆既起护壁及悬浮钻渣作用，又不致于因太浓影响钻进速度。钻机准确就位，先快速钻进。专业人员作好记录。泥浆比重控制在1.2~1.35，粘度控制在18~22S。待钻进至微风化基岩达到设计标高或入微化深度为桩的直径时，通知书监理工程师验孔，合格证后终孔清碴。
（五）钢筋笼制安：分节制作按长安放。钢筋笼采用加劲筋（间距2m ）成型法，布好螺旋筋，笼内每隔2m设置△内撑，沿圆周方向在主筋上分段焊接4个保护耳环，主筋焊接在同一搭接区断面内接头率不大于50%。安放采用函节安放，两节接头互相焊接，主筋同一搭接断面接头率不大于50%。钢筋定位后，将主筋或其延长筋焊接在护筒上。声测管同时固定在钢筋笼上放下，其上下两端要用铜板封牢，以免漏进泥浆。安放完毕后，立即放下导管进行二次清孔。
（六）灌注水下砼：
1、桩基础砼标为C25，按实验室提供的配合比施工。坍落
Pile Foundation Construction Technology Details
One, materials
1, cement grade 32.5;
2, Stone: Granite maximum size 30mm, level with the management, F & E particles content ≤ 25%, mud content ≤ 2%, strength to meet the requirement;
3, can be used in coarse river sand, mud content ≤ 5%;
4, water with tap water;
5, bar: Ⅱ grade steel longitudinal reinforcement, transverse reinforcement bars and spiral steel bar grade Ⅰ.
These materials must be qualified certificate, as required sampling, approved by the Commissioner.
2, Pile Foundation Construction Technology
(A) of the cofferdam construction Islands: cofferdam installed using sand bags, cofferdam size according to the drawings, which fill sand island built.
(B) the casing is to win the A3 steel 10mm roll. Welds in the welded joints of steel 20cm wide and 10mm thick, thick casing the foot end of the strip as a 10mm wide-30cm knife foot. Dual-use double-sided welding, not leaking. Sink with a pile hammer weight.
(C) use of high-quality bentonite mud, mud pools located in the shore. To test its viscosity (and out) and relative density (and out).
(D) hole technology: drilling mud before adding the hole with mud pump for slurry loop. Drilling process, the master concentration, so that both mud residue from the Wall and the role of floating drilling, drilling yet should not affect the speed because of too strong. Drill accurately in place, the first fast drilling. Professional make records. Mud GDP 1.2 to 1.35, viscosity control in the 18 ~ 22S. When the breeze of rock drilling to reach the design elevation, or about nature of the depth of pile diameter, the notice of inspection hole supervising engineer, the certificate after the final hole clean ballast.
(E) reinforcement cage system security: the section produced by Changan release. Reinforced with steel cage reinforcement (spacing 2m) molding method, a good spiral reinforcement fabric, a cage within the support intervals of 2m △ set, along the circumferential direction on the section in the longitudinal bars welded four protection rings, welded longitudinal bars within the same overlapping area section joint rate is not greater than 50%. Section by letter placed placed, two each welded joint, joint reinforcement, the same lap section rate is not greater than 50%. Bar positioning, will extend the reinforcement longitudinal bars or welded on the casing. Acoustic tube fixed to the steel cage at the same time lay down, use their upper and lower ends of copper seal firmly to avoid leakage into the mud. Placed immediately after the second drop tube for clean hole.
(F) pouring underwater concrete:
1, concrete piles labeled C25, provided by laboratories with more than construction. Collapse in