钢绞线张拉过程中伸长值超差原因分析

针对Φ15.24 mm 1 860 MPa钢绞线张拉过程中实际伸长值与设计伸长值偏差超过±6%,钢绞线的性能不能满足要求的问题,对该段钢绞线进行取样检验,并重新计算理论伸长值。结果显示,将钢绞线的横截面积由原来的公称面积140 mm2改为实际面积141 mm2,弹性模量由2.01×105MPa改为产品质保书上的检验数据1.96×105MPa,钢绞线与孔道的摩擦因数取0.17,孔道每米局部偏差对摩擦的影响因数取0.002,张拉端至计算截面曲线孔道部分切线的夹角之和取0.087 7 rad后,重新计算的理论伸长值与实际伸长值偏差在±3.5%以内。

Elongation oversize cause analysis during tension of steel strand

The steel strand was sample selected and tested, the theoretic elongation was calculated again according to the problem that the deviation is over ± 6% of actual elongation and designing elongation in diameter 15.24 mm 1 860 MPa steel strand tension process, properties of steel strand can＇t reach requirements. Results show： the deviation of calculating theoretic elongation and actual elongation is within ± 3.5% after the cross-sectional area of steel strand is changed from former nominal area 140 mm2 to actual area 141 mm2 , elastic modulus is changed from 2.01× 10^5 MPa to test datum 1.96 × 10^5 MPa of product inspection certificate, the friction factor of steel strand and pore canal is 0.17, the influence of pore ca- nal partial deviation each meter on friction is 0. 002, the included angle summation of tension end and calculating section curve pore canal tangent is 0. 087 7 rad.