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预应力混凝土工程施工安全技术交底内容应知应会清单
1.先张法施工的安全要求
(1)张拉时,张拉工具与预应力筋应在一条直线上;顶紧锚塞时,用力不要过猛,以防钢丝折断;拧紧螺母时,应注意压力表读数,一定要保持所需的张拉力。
(2)预应力筋放张的顺序应按下列要求进行:
1)轴心受预压的构件(如拉杆、桩等),所有预应力筋应同时放张。
2)偏心受预压的构件(如梁等),应先同时放张预压力较小区域的预应力筋,然后放张预压力较大区域的预应力筋。
(3)切断钢丝时应严格测定钢丝向混凝土内的回缩情况,且应先从靠近生产线中间处切断,然后再按剩下段的中点处逐次切断。
(4)台座两端应设有防护设施,并在张拉预应力筋时,沿台座长度方向每隔4~5m设置一个防护架,两端严禁站人,更不准进入台座。
(5)预应力筋放松时,混凝土强度必须符合设计要求,如无设计规定时,则不得低于强度等级的70%。
(6)预应力筋放张时,应分阶段、对称、交错地进行;对配筋多的钢筋混凝土构件,所有的钢丝应同时放松,严禁采用逐根放松的方法。
(7)放张时,应拆除侧模,保证放松时构件能自由伸缩。
(8)预应力筋的放张工作,应缓慢进行,防止冲击。若用乙炔或电弧切割时,应采取隔热措施,严防烧伤构件端部混凝土。
(9)电弧切割时的地线应搭在切割点附近,严禁搭在另一头,以防过电后使预应力筋伸张造成应力损失。
(10)钢丝的回缩值,冷拔低碳钢丝不应大于0.6mm,碳素钢丝不应大于1.2mm,测试数据不得超过上列数值规定的20%。
2.后张法(无粘结预应力)施工的安全要求
(1)孔道直径:
1)粗钢筋,其孔道直径应比预应力筋直径、钢筋对焊接头处外径、需穿过孔道的锚具或连接器外径大10~15mm,见下表。
冷拉Ⅱ一Ⅳ钢筋孔道直径
style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan" style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"冷拉Ⅱ~Ⅲ钢筋 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"冷拉Ⅳ钢筋 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"锚具型号 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"孔道直径(mm) style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"LMl2~16 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"40 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"LMl8~22 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"45 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"LM25~32 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"50 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"JM2—3~4 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"50 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"JM2—5~6 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"60
2) 钢丝或钢绞线:其孔道应比预应力束外径大5—10mm,其孔道面积应大于预应筋面积的两倍,见下表。
φ<sups</sup碳素钢丝束孔道直径 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"钢丝束根数 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"12 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"14 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"16 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"18 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"20 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"24 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"28 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"钢质锥形锚具 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"GZ12 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan" style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan" style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"GZ18 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan" style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"GZ24 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan" style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"孔道直径(mm) style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"40 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan" style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan" style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"45 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan" style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"53 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan" style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"镦头锚具型号 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"DM5-12~14 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"DM5—16~18 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"DM5—20~24 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"DM5—28 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"中间孔道直径(mm) style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"40 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"45 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"50 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"55 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"端部扩孔直径(mm) style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"60 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"68 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"76 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"83 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"锥形螺杆锚具 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan" style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"LZ5—14 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"LZ5—16 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan" style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"LZ5—20 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"LZ5—24 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"LZ5—28 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"中间孔道直径(mm) style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan" style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"50 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"53 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan" style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"56 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"63 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"70 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"端部扩孔直径(mm) style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan" style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"65 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"70 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan" style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"75 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"83 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"89φ<supj</sup钢绞线束孔道直径表 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"钢绞线束根数 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"4 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"5 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"6 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"7 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"8 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"9 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"12 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"JM型锚具型号 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"孔道直径(mm) style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"XM型锚具型号 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"中间孔道直径(mm) style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"端部扩孔直径(mm) style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"端部扩孔长度(mm) style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"JMl5—4 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"50 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"XMl5—4 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"50 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"75 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"240 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan" style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan" style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"XMl5—5 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"55 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"85 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"320 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"JM15—6 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"65 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"XMl5—6 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"65 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"95 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"340 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan" style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan" style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"XMl5—7 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"65 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"95 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"340 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan" style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan" style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"XMl5—8 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"70 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"110 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"390 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan" style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan" style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"XMl5—9 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"75 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"120 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"500 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan" style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan" style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"XMl5—12 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"85 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"135 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"5003) 预应力筋孔道之间的净距不应小于25mm;孔道至构件边缘的净距不应小于25mm,且不应小于孔道直径的一半;凡需起拱的构件,预留孔道宜随构件同时起拱。
(2) 在构件两端及跨中应设置灌浆孔,其孔距不应大于12m。
(3) 采用分批张拉时,先批张拉的预应力筋,其张拉应力σcon应增加αβσhp(αβ—预应力筋和混凝土的弹性模量比值。σhp—张拉后批预应力筋时,在其重心处预应力对混凝土所产生的法向应力)。或者每批采用同一张拉值,然后逐根复拉补足。
(4) 曲线预应力筋和长度大于24m的直线预应力筋,应在两端张拉,长度等于或小于24m的直线预应力筋,可在一端张拉,但张拉端宜分别设置在构件的两端。
(5) 平卧重叠构件的张拉,应根据不同预应力筋与不同隔离剂的平卧重叠构件逐层增加其张拉力的百分率,见下表。对于大型或重要工程应在正式张拉前至少必须实测二堆屋架的各层压缩值,然后计算出各层应增加的张拉力百分率。
平卧叠层浇筑构件逐层增加的张拉力百分率 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"应力筋类别 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"隔离剂类别 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"逐层增加的张拉力(%) style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"顶层 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"第二层 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"第三层 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"底层 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"高强钢丝束 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"Ⅰ style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"Ⅱ style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"Ⅲ style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"0 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"0 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"0 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"1.0 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"1.5 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"2.0 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"2.0 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"3.0 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"3.5 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"3.0 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"4.0 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"5.0 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"Ⅱ级冷拉钢筋 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"Ⅰ style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"Ⅱ style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"Ⅲ style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"0 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"1.0 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"2.0 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"2.0 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination: widow-orphan"3.0 style="margin: 0cm 0cm 0pt; text-align: center; mso-pagination:
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