基于荷载试验的三跨简支斜桥承载能力研究.docx

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基于荷载试验的三跨简支斜桥承载能力研究

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贾毅++廖平++王永宝++赵人达

摘要：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30km·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10km·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。

关键词：荷载试验；简支斜桥；效率系数；自振特性；校验系数；承载能力

：TU312文献标志码：A

ResearchonBearingCapacityofThreespanSimplySupported

SkewBridgeBasedonLoadTestJIAYi，LIAOPing，WANGYongbao，ZHAORenda

（SchoolofCivilEngineering，SouthwestJiaotongUniversity，Chengdu610031，Sichuan，China）Abstract：Inordertounderstandthesecurityundernormaloperationstateandthecarryingcapacityunderadverseconditionsofathreespansimplysupportedskewbridgewithlargewidthspanratio，thestressanddeformationofthemainbeamundertheconditionofunbalanceloadandmediumloadwerestudiedbasedonthetestmethod.Thenaturalvibrationfrequency，deformationresponseunderdifferentdivingspeedsandtheimpactactionofbridgeundervehiclejumptestwerestudiedthroughpulsetest，barrierfreedrivingtestandobstacledrivingtest，andthetestresultswerecomparedwiththefiniteelementresults.Theresultsshowthatthemidspansectionundermediumloadisthemostunfavorableloadcondition.Themeasuredvaluesofstrainanddeflectionarelessthanthecalculatedvaluesundertheunfavorableloadconditions，andthedeformationofthemainbeamandthestressofconcretebothmeettherequirementsofthespecification.Whenthespeediswithin30km·h-1inbarrierfreedrivingtest，theimpactcoefficientsofeachspanare1.094to1.192.Whenthespeedis10km·h-1inobstacledrivingtest，theimpactcoefficientsofeachspanare1.147to1.195.Thestructuralstrengthandstiffnessofthebridgearerich，whichcanmeettheactualoperatingconditionswell.

Keywords：loadtest；simplysupportedskewbr