(整理)从根本上减少断桩基础补强处理

1、从根本上减少断桩根底补强处理1钻孔桩断桩的原因分析1 analysis of the causes of drilling pile broken pile1.1 钻孔桩成孔质量问题造成的断桩原因分析1.2 drilling pile hole quality problem caused by the fault reason analysis由于泥浆护壁差、孔内水头压力不够等原因,在清 孔后灌注混凝土过程中由现孔壁坍塌,造成断桩.由于 清孔过程中未对孔内泥浆含砂率进行严格限制,造成在 灌注混凝土过程中混凝土上沉渣过厚,导管内混凝土压 力缺乏以推动该部份沉渣,致使混凝土浇注中断.局部 在河床

2、上通过筑岛法施工的钻孔桩根底,由于河床外表 有一层流塑性淤泥层,在混凝土浇筑过程中河床淤泥层 顺孔壁流进钻孔内,致使混凝土浇注中断.Due to poor slurry-supported, hole head pressure is not enough, the hole cleaning after the collapse of hole wall, appeared in the process of pouring concrete pile breaking. Due to the black hole to hole the mud in the process of sand

3、 ratio to carry on the strict control, cause in the process of pouring concrete on concrete to the too thickness of sediment, intraductal concrete pressure is not enough to push the ministry of sediment, the concrete pouring. Part on the river built by island construction method of bored pile founda

4、tion, because the surface of the river a laminar flow plasticity silt layer, river bed silt layer in the process of concrete pouring flow in the wall of hole in drilling, the concrete pouring.1.3 钢筋笼及浇筑混凝土用导管的问题造成断桩的原因分析1.2 reinforcing cage and concrete analysis of the cause of broken pile with cath

5、eter questions导管接头严重漏水,造成导管外泥浆及水进入导 管,使导管内混凝土离析,导管堵塞,混凝土浇筑中断,造成断桩.Outside the pipe joint serious leaks, causing catheter mud and water into the pipe, the pipe inside the concrete segregation, catheter blockage, concrete pouring, caused the broken pile.由于钢筋笼主筋焊接及箍筋绑扎存在问题,在混凝 土浇筑过程中,钢筋笼卡住导管,致使导管难以提起,

6、混凝土浇筑中断,形成断桩.Because of reinforcing cage of main reinforcement welding and stirrup binding problem exists, in the process of concrete pouring, steel reinforcement cage stuck pipe, causing them to mention, concrete pouring, form the broken pile.1.3 浇筑用混凝土的问题造成断桩的原因分析1.3 casting with concrete problems

7、 analysis of the cause of broken pile混凝土塌落度过小,或和易性较差,造成导管堵塞, 混凝土浇筑中断,造成断桩.由于混凝土供给问题,造 成浇筑时间过长,浇注混凝土时首盘混凝土已经凝固, 混凝土浇筑难以继续,造成断桩.由于混凝土中由现凝 结的水泥块或石头等大块杂物,造成导管堵塞,混凝土 浇筑难以继续,造成断桩.Fall through small concrete, or poor workability, causing catheter blockage, concrete pouring, caused the broken pile. Caused b

8、y supply problems of concrete, pouring time is too long, when pouring concrete before concrete has solidified, concrete pouring is difficult to continue, caused the broken pile.Due to condensation of concrete of concrete blocks or stones, etc. Large pieces of debris, causing catheter blockage, concr

9、ete pouring is difficult to continue, caused the broken pile.2钻孔桩断桩的预防举措2 drilled pile pile breaking prevention measures2.1 增强成孔质量限制2.1 to strengthen quality control into a hole护筒采用钢板制作,采用人工开挖埋设,护筒底部与土层相接处用粘土夯实,护筒外面与原土之间用粘土 填满、夯实,土工布严防地表水从该处渗入.为保证护 筒内外水头的压力差护筒内水位应高由护筒外水位1.5m,护筒埋设深度3m以上,同时,如果在成孔范围内有流

10、塑性淤泥等软弱夹层,应将护筒埋设穿越该软弱 层.Buried liners made of steel plate by artificial excavation, protection and soil layer at the bottom of the barrel as clay compaction, liners between with the original soil outside the clay fill and compaction, fight infiltration of surface water from there. In order to ensure

11、 the protection of cylinder head of pressure difference inside and outside cylinder liners outside water level of 1.5 m, the water level should be higher than steel liners buried depth of more than 3 m, at the same time, if the hole radius flow plasticity silt soft interlayer, protecting tube should

12、 be embedding through the weak layer.使用泥浆护壁,泥浆质量符合标准要求.对于地质 条件差的钻孔,使用优质泥浆.成孔后进行清孔,清孔 后泥浆比重、胶体率、含砂率、沉渣厚度等符合标准要 求.Use the slurry-supported, mud quality conform to the requirements of the specification. For drilling with poor geological conditions, the use of high quality mud. Into a black hole after h

13、ole, hole cleaning after the mud weight, colloid ratio, sand ratio, sediment thickness conform to the requirements of the specification.2.2限制浇筑混凝土用导管质量2.2 control of pouring concrete tube quality为预防导管接头与导管漏水,施工中我们通过严格 的事前、事中、事后限制,保证导管制作并具备以下条 件：To prevent pipe joint and the pipe is leaking, we throu

14、gh strict during construction in advance, matter and afterwards control, guarantee the catheter produced and satisfy the following conditions:足够的抗拉强度,能承受其自重和盛满混凝土的重MoSufficient tensile strength, able to bear its weight and the weight of the filled concrete.各节的安装接头所用的胶垫及法兰的对接位置,预 先试拼并作好标记,按插导管时须按试拼时的

15、状态对号 拦装,所有的法兰盘接头均须垫入5-7mm厚的橡胶垫圈,安放时须对正放平,拧紧螺栓,严防漏水.Each section of the installation of rubber mat used inthe connector and flange of the docking position, try to spell and tag them in advance in accordance with the inserted catheters should be according to the state reserved block, when try to spell

16、 all flange joints shall be mat in 5-7 mm thick rubber gasket, when put on is flat, tighten the bolt, protected from leaking.尽可能使用内径30cm以上的导管,并且内径应一 致,其误差应小于± 2mm,内壁须光滑无阻,组拼后须 用球塞、检查锤作通过试验.As far as possible use of more than 30 cm inner diameter tube, and the inner diameter should be consistent

17、, the error should be less than + /- 2 mm,inner surface should be smooth and shine, spellers ball plug, check after the hammer made by experiment.最下端一节导管长度要长一些,一般为 4米,其底 端不得带法兰盘,以便在羟丙基甲基纤维素混凝土内更 容易拔起.每节导管的长度要整洁统一,便于丈量长度,并作由标记和记录.The bottom section duct length is longer, generally for 4 meters, the b

18、ottom of the flange, so that in the concrete internal pull up more easily. Each section of the tube length to tidy uniform, is advantageous for the measurement of length, and make a marked and recorded.导管使用前做好水密性试验.导管要布置在钢筋笼 中央.Tube well water tightness test before use. Tube is arranged in the cente

19、r of the steel reinforcement cage.3.3限制钢筋笼加工质量3.3 control of reinforcing cage and processing quality钢筋笼主筋焊接一般应采用对焊,以保证焊口平 顺,当采用搭接焊时,要保证搭接局部不在钢筋笼内形 成错台.钢筋骨架应有强劲的内撑架,保证在运输及吊 装过程中不变形.Reinforcing cage main reinforcement welding butt welding should be used commonly, to ensure that the joint smooth, when

20、lap welding is used, to ensure the lap part is not formed in the steel reinforcement cage fault. Inside the cage of reinforcement should be strong brace, ensure no deformation in the process of transportation and hoisting.3.4 增强混凝土生产运输过程限制3.4 to strengthen the concrete production and transportation

21、process control混凝土拌合运输水平均应能够满足灌注混凝土的 要求,保证在灌注过程中能够满足现场需要.Concrete mixing transport capacity should be able to meet the requirements of pouring concrete, guarantee in the filling process can meet the needs of the scene.混凝土配合比应满足灌注水下混凝土要求,即和易 性、流动性都比拟好,粗骨料粒径小于导管内径的1/8 cOf concrete should meet the requ

22、irements of pouring underwater concrete, namely the workability and fluidity is good, the aggregate particle size less than 1/8 of the tube inner diameter.3.5 灌注混凝土过程中的限制3.5 the control in the process of pouring concrete灌注首盘混凝土时,限制导管底部有2540cm的空间,保证首盘混凝土能顺利地灌注.同时,首盘混凝 土的灌注量应至少保证灌注后将导管口埋入1m以上.在灌注混凝土过程

23、中,应随时对导管埋入深度进行测 量,导管埋入深度遵循埋 6拔4的原那么,即导管埋入 6 米后,拔起并撤除4米,土工膜保证导管埋置深度在 2 6米之间.在施工过程中,中途中断浇注时间不宜走过 30分钟,整个桩的浇注霎时间不宜过长,尽量在8小时内完毕.混凝土施工中间每间断30分钟后,要上下串一上导管,预防混凝土失去流动性,提升导管困难,增 加发生事故的可能性.Perfusion first set concrete, the control at the bottomof the tube is 25 40 cm space, can guarantee the first concrete perfusion smoothly. At the same time, the