大跨径预应力混凝土梁桥孔道摩阻试验研究

发布时间：2018-01-31 15:36

本文关键词： 预应力连续梁桥摩阻试验摩阻系数施工监控　出处：《林业工程学报》2017年01期 　论文类型：期刊论文

【摘要】：为更精确地进行施工监控,结合某三跨连续梁桥,通过现场试验得出实际孔道摩阻系数。对实测得到的短、长预应力束的摩阻系数和管道偏差系数对比分析,并根据实测数据修正有限元模型,对比分析修正后支座截面顶板的应力理论计算值与现场实测值。试验得出不同长度预应力束的摩擦系数μ分别为0.254和0.282,偏差系数k分别为0.002 0和0.001 7。结果表明,实际施工过程中的摩阻系数大于规范上限值1.6%~33.3%,不同长度的预应力束的摩阻系数存在较大离散性,随着预应力束的增长,曲线处由于法向挤压力导致的摩阻损失占整体预应力摩阻损失的比重增加,长束预应力束相比较短束μ值增加了11%,k值减小了15%。支座截面顶板应力实测值与理论计算值变化趋势一致,采用实测值修正后误差减小,两次修正误差分别减少了10%和9%。
[Abstract]:In order to carry out the construction monitoring more accurately, combined with a three-span continuous beam bridge, the friction coefficient of the actual channel is obtained by field test. The friction coefficient of the short and long prestressed tendons and the deviation coefficient of the pipeline are compared and analyzed. The finite element model is modified according to the measured data. By comparing and analyzing the calculated values of stress theory and the field measured values, the friction coefficient 渭 of prestressed beams with different lengths is 0.254 and 0.282, respectively. The deviation coefficient k is 0.0020 and 0.007, respectively. The results show that the friction coefficient in the actual construction process is greater than the upper limit value of the code by 1.6% to 33.3%. The friction coefficient of prestressed beams with different lengths is discrete. With the increase of prestressed tendons, the proportion of frictional loss caused by normal extrusion force in the curve increases. Compared with the short beam 渭 value, the long beam prestressing beam increases by 11% and the value of k decreases by 15%. The measured stress of the roof of the bearing section is consistent with the theoretical calculated value, and the error is reduced after the correction of the measured value. Two correction errors were reduced by 10% and 9 respectively.
【作者单位】：南京林业大学土木工程学院;
【基金】：国家自然科学基金项目(51208262) 江苏省自然科学基金项目(BK20151520) 江苏高校优势学科建设工程资助项目(PAPD) 住房和城乡建设部科学技术项目(2011-K2-9)
【分类号】：U446;U445.57
【正文快照】： 混凝土连续梁桥由于结构受力合理、施工工艺成熟等优点广受欢迎。混凝土连续梁桥的预应力损失计算直接关系到成桥后的线形与受力情况,对于预应力损失的错误估计将会直接导致连续梁桥应力储备不足,进而导致梁体跨中下挠、腹板开裂[1]。经国内学者整理分析,设计施工不合理是桥梁

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