摘要
为更好地指导高速铁路桥预应力混凝土梁预应力孔道摩阻损失系数的测试,在对比分析应变分布法和拉力比法这2种测试方法的预应力孔道摩阻损失系数计算公式的基础上,分别推导这2种方法的预应力孔道摩阻损失测试误差敏感系数计算公式,研究钢束参数对测试误差敏感系数的影响规律,并通过大量实测数据的统计结果验证理论分析结论。研究表明:拉力比法相对简便,适合在工程中推广运用,但其计算精度对测试误差的敏感性较高,并且在钢束角度差和钢绞线长度相同的条件下,孔道偏差系数的计算精度对测试误差的敏感性高于孔道摩擦系数的计算精度对测试误差的敏感性,且钢束角度差越小,钢绞线越短,测试误差的敏感性越大,而钢绞线的长度差对测试误差敏感性的影响不具规律性。为提高用拉力比法测试预应力孔道摩阻损失系数的精度,建议测试过程中钢束的角度差不宜小于3°,钢绞线的长度不宜小于15m。
In order to better guide the prestressed duct friction loss coefficient test of the prestressed con- crete beam of high speed railway bridge, based on the comparison and analysis of two calculation formulas for friction loss coefficient test methods, namely, the strain distribution method and tension ratio method, the calculation formulas for the test error sensitivity of the two test methods were derived respectively. The influence law of steel strand parameters on test error sensitivity coefficient was studied and theoretical analysis conclusion was validated by the statistical results of a large number of measured data. Research shows that tension ratio method is relatively simple and convenient, and suitable for application and popu- larization in engineering. But its calculation accuracy is more sensitive to test error. Besides, under the condition that the angle difference between test steel strands is the same and the length of steel strands is the same too, the sensitivity of calculation accuracy to the test error of duct deviation coefficient is more sensitive than that of duct friction coefficient. The study also shows that the test error sensitivity becomes greater with smaller differences of steel strand bending angles and shorter steel strands. The length differ- ence between steel strands has influence on test error sensitivity, but does not have regularity. To improve the test precision of the friction loss coefficient of prestressed duct by tension ratio method, it is suggested that the difference of steel strand angles should be no less than 3° and the steel strand length should be no less than 15 m in test process.s：
出处
《中国铁道科学》
EI
CAS
CSCD
北大核心
2015年第6期31-36,共6页
China Railway Science
基金
国家自然科学基金资助项目(51248009/E080502)
关键词
后张预应力混凝土梁
预应力
孔道摩阻损失
拉力比
测试误差
敏感性
Post-tensioned prestressed concrete beam
Prestress
Duct friction loss
Tension ratio
Test error
Sensitivity
