基于数值分析结果的双曲拱桥静载试验

Static Load Test of Double Curved Arch Bridge Based on Numerical Analysis Results

双曲拱桥由于自身结构设计缺陷导致整体性及耐久性较差,为保证现存双曲拱桥使用过程中的安全,多采用加固改造的方式对桥梁结构强度进行补充,为探究老旧双曲拱桥控制截面位置及对应应变和挠度,特以midas Civil数值分析结果为试验依据,开展双曲拱桥的静载试验研究,数值模拟结果显示,双曲拱桥负弯矩最大值出现在拱脚位置,轴力最大值出现在拱顶位置,分别选取桥梁第8、9跨拱脚、拱顶和L/4处为静载试验测试截面,在各内力最不利处布载,试验结果显示:第9跨测试截面应变实测值略小于计算值,第8跨拱顶截面处应变存在横向波动,中梁应变最小为13,边梁处应变最大值为26,各截面应变平均校验系数最大值为0.91,结构实测参数能够反映实际结构的受力特征,主梁受力性能符合设计要求,各工况下主拱肋最大挠度发生在工况4作用下的第8跨拱顶截面,截面最大挠度为2.49 mm;各工况下挠度实测值均小于理论计算值,最大校验系数小于0.99,表明主拱肋在弹性工作范围内,但桥梁整体刚度偏小。

Due to its structural design defects,the integrity and durability of double curved arch bridges are poor.In order to ensure the safety of existing double curved arch bridges in the process of use,reinforcement and transformation are often adopted to supplement the structural strength of bridges.In order to explore the position of the control section and the corresponding strain and deflection of the old double curved arch bridge,the static load test of the double curved arch bridge is carried out based on the results of midas Civil numerical analysis.The results show that the maximum negative bending moment of the double curved arch bridge occurs at the arch foot position and the maximum axial force at the arch top position.The 8th and 9th span arch foot,arch top and L/4 of the bridge were selected as the static load test section,and the load was distributed at the most unfavorable internal forces.The test results showed that:The measured strain value of the 9th cross section is slightly less than the calculated value.The strain at the 8th cross section of the arch arch has transverse fluctuations.The minimum strain of the middle beam is 13,the maximum strain value of the side beam is 26,and the maximum average strain check coefficient of each section is 0.91.Under each working condition,the maximum deflection of the main arch rib occurs in the section of the 8th span arch under the action of working condition 4,and the maximum deflection of the section is 2.49 mm.The measured value of deflection under each working condition is smaller than the theoretical calculation value,and the maximum calibration coefficient is less than 0.99,which indicates that the main arch rib is within the elastic working range,but the overall stiffness of the bridge is small.