CAJ | 학술논문

在大型多跨连续梁施工中,预应力施工是最为重要的分项工程,对工程质量的影响最大。某大跨度连续梁工程预应力筋张拉时实际伸长值与理论伸长值偏差较大,超出规范设定的±6%的允许范围要求。分析查找原因,进行了现场孔道摩阻试验,发现锚具锚圈口和锚下垫板口预应力损失大,且变化范围也很大,张拉力损失率平均约为10%。经过分析及认真的核算,为了保证连续梁的工程质量,确定对已经张拉的钢绞线采取补拉的措施,并启用备用束张拉。可为类似工程提供借鉴。
재대형다과련속량시공중,예응력시공시최위중요적분항공정,대공정질량적영향최대。모대과도련속량공정예응력근장랍시실제신장치여이론신장치편차교대,초출규범설정적±6%적윤허범위요구。분석사조원인,진행료현장공도마조시험,발현묘구묘권구화묘하점판구예응력손실대,차변화범위야흔대,장랍력손실솔평균약위10%。경과분석급인진적핵산,위료보증련속량적공정질량,학정대이경장랍적강교선채취보랍적조시,병계용비용속장랍。가위유사공정제공차감。
In the construction of large, multi-span continuous beams of many projects,the pre-stressing construction is the most important itemized project because it has the greatest effect on the quality of the whole project. Owing to the fact that the value of the real lengthening length of the reinforcement of a certain large-spanned continuous beam project is found to be much dif- ferent from that of the theoretical lengthening length and surpass the allowable value of ±6 % designated in the norm, the pos- sible causes are analyzed in the paper. Through the channel friction tests at the site,it is found that the loss of the pre-stressing stress at both the opening of the anchoring ring of the anchoring tools and the opening of the cushion plates under the anchoring tools is great and the variable range is very large, with the average loss rate of the pre-stressing force being about 10 %. Through analyses and serious check-calculations,it is decided that the make-up stressing be applied to the pre-stressed steel strands and the reserved steel strands be tensioned as well to ensure the engineering quality of the project. The project may serve as a useful reference for other projects of similar types.