灌浆拉索索力的试验研究

Experimental Study on Cable Force of Grouted Prestressed Cable

为研究索长、边界条件和附加质量等对灌浆拉索索力计算的影响规律,以灌浆吊杆和体外索等为工程背景,采用?15.2高强度钢绞线模拟拉索,开展24个裸索、24个外套PVC管拉索以及24个灌浆拉索模型的索力试验,并推导带均布附加质量的拉索索力计算公式;分析边界条件、灌浆附加质量以及拉索长度等参数对索力的影响规律,比较计算公式的误差和适用性。结果表明:试验拉索索力计算中,边界条件可以假定为铰接,需要考虑外套套管和灌浆等附加质量的影响;灌浆拉索索力计算误差大都在15.0%以内且随附加质量线密度的增加而逐渐增大。研究结果可以为灌浆拉索索力计算提供依据。

The purpose of this paper is to study the influence of cable length, boundary condition and additional mass on the calculation of the grouting cable force, and provide the basis for cable force calculation. With the suspenders of arch-bridge and external prestressed cables being selected as the engineering background, 24 bare prestressed cable test models, 24 prestressed cable test models with outer PVC tube but without grouting inside as well as 24 grouting cable test models were made with ?15.2 high strength steel strands, and the cable force tests were firstly carried out. Secondly, the cable force calculation formula with uniform added mass was derived. Finally, the influence of the boundary conditions, cable length and added mass of grouting on cable force was analyzed, and the calculation error and applicability of different formulas were also analyzed and compared. The results show that the hinged boundary conditions meet the requirements of cable force calculation, and the added mass of outer tube and mortar should be taken into account. The errors of most of the calculation values of grouted cable force are smaller than 15.0% by using the derived formula, and increase with the increase of the line density of added mass. The results can provide a basis for the calculation of grouted cable force.