【摘要】 新响琴峡大桥是新建株六铁路复线上一座大跨度预应力混凝土桥。在交付运营约2年后,该桥出现了混凝土裂缝和表面剥落等病害。为了查明病害产生的原因,运用有限元软件ANSYS建立有限元仿真模型,对该桥的温度分布和温度应力进行分析。分析结果表明:最大横向日照温度梯度出现在冬天,沿腹板板厚的最大温差为17.5℃,此时箱梁内侧的最大横向温度拉应力为2.34 MPa。可见,由日照引起的横向温度应力是该桥出现病害的主要因素之一。因此,在道砟桥面混凝土铁路桥梁设计中,应对日照引起的横向温度梯度和温度应力予以重视。更多还原

【Abstract】 New Xiangqin Gorge Bridge is a long-span PC bridge on the newly-built Zhuzhou-Liupanshui double-track railway.Deteriorations of concrete crack and surface spalling were detected in the bridge after 2 years of service.An FEM simulation model using the ANSYS is developed to analyze the temperature distributions and thermal stresses in the bridge in order to identify the causes of the deteriorations.The analysis results indicate that the maximum temperature gradient of solar radiation occurs in winter.The maximum temperature differential through the thickness of the web plate is 17.5 ℃,and consequently the maximum transversal tensile thermal stress inside the box girder is 2.34 MPa.It is evident that the transversal thermal stress induced by solar radiation is one of the main factors causing the deteriorations in the bridge.Therefore,due attention shall be paid to the transversal temperature gradients and the thermal stresses induced by solar radiation in designing ballast-covered concrete railway bridges.更多还原