基于荷载试验的三跨简支斜桥承载能力研究

为了解某宽跨比较大的三跨简支斜桥在正常运营状态下的安全性和不利状态下的承载力，基于试验方法研究了在偏载和中载等不利荷载工况下的主梁应力和变形。通过脉动试验、无障碍行车试验、有障碍行车试验研究了该桥的自振频率、不同行车速度下的变形响应及跳车试验下的冲击作用，将测试结果与有限元结果进行了对比。结果表明:跨中截面中载为最不利荷载工况，在不利荷载工况下，实测应变和挠度均小于计算值，主梁变形和混凝土应力均满足规范要求；当行车速度在30 km·h^-1以内跑车试验时，各跨冲击系数为1.094~1.192；当行车速度为10 km·h-¹跳车试验时，各跨冲击系数为1.147~1.195；该桥的结构强度和刚度具有一定的富裕度，能较好地满足实际运营状况。

Research on Bearing Capacity of Three-span Simply Supported Skew Bridge Based on Load Test

In order to understand the security under normal operation state and the carrying capacity under adverse conditions of a three span simply supported skew bridge with large width span ratio, the stress and deformation of the main beam under the condition of unbalance load and medium load were studied based on the test method. The natural vibration frequency, deformation response under different diving speeds and the impact action of bridge under vehicle jump test were studied through pulse test, barrier free driving test and obstacle driving test, and the test results were compared with the finite element results. The results show that the mid span section under medium load is the most unfavorable load condition. The measured values of strain and deflection are less than the calculated values under the unfavorable load conditions, and the deformation of the main beam and the stress of concrete both meet the requirements of the specification. When the speed is within 30 km·h^-1?in barrier free driving test, the impact coefficients of each span are 1.094 to 1.192. When the speed is 10 km·h^-1?in obstacle driving test, the impact coefficients of each span are 1.147 to 1.195. The structural strength and stiffness of the bridge are rich, which can meet the actual operating conditions well.