CAJ | 학술논문

以城鸡线2K+614 m桥5号桥墩为研究对象,通过挖开桥墩基础周围覆盖层土体的不同厚度模拟基础受冲刷程度,运用冲击振动试验法进行桥墩自振特性测试,分析桥梁基础受冲刷对桥墩自振特性的影响.结果表明:桥墩基础周围覆盖土层厚度的减少会降低桥墩的自振频率,并使桥墩的刚体摆动趋势增强;减少的土体越靠近地面对桥墩自振频率的影响越大.采用弹性系数模拟桥墩基础周围土体对桥墩的约束,建立有限元模型,并通过改变弹性系数值模拟覆盖土层厚度变化对基础的约束影响,分析基础在不同冲刷程度下桥墩自振特性的变化规律.用有限元法、能量法和同归法分析覆盖土层厚度变化对桥墩自振特性影响的结果与实测结果的比较表明:有限元法比能量法和回归法能更好地预测基础受冲刷对桥墩自振特性的影响.
이성계선2K+614 m교5호교돈위연구대상,통과알개교돈기출주위복개층토체적불동후도모의기출수충쇄정도,운용충격진동시험법진행교돈자진특성측시,분석교량기출수충쇄대교돈자진특성적영향.결과표명:교돈기출주위복개토층후도적감소회강저교돈적자진빈솔,병사교돈적강체파동추세증강;감소적토체월고근지면대교돈자진빈솔적영향월대.채용탄성계수모의교돈기출주위토체대교돈적약속,건립유한원모형,병통과개변탄성계수치모의복개토층후도변화대기출적약속영향,분석기출재불동충쇄정도하교돈자진특성적변화규률.용유한원법、능량법화동귀법분석복개토층후도변화대교돈자진특성영향적결과여실측결과적비교표명:유한원법비능량법화회귀법능경호지예측기출수충쇄대교돈자진특성적영향.
In order to analyze the natural vibration characteristics change of the pier when the bridge foun-dation was scoured, the 5th pier of the 2K+614 m bridge on the Xiachengzi-Jixi Railway was tested by the impact vibration test method (IVTM), and the scouring effects on the pier were simulated by excavating different depths of the covering subsoil around the pier. Test analysis shows that the natural vibration fre-quency of the pier decreases and the rigid body swing characteristics of the pier strengthen with the de-crease of the covering subsoil depth around the pier, and the decrease of the soil body near land surface is more effective to the natural vibration frequency of the pier. The finite element model is presented by sim-ulating the constraints of the subsoil around the pier with elastic coefficients. The effect of the covering subsoil depths on the constraints of the subsoil around the pier can be described by adjusting the elastic co-efficients. The results can be obtained from the finite element model, energy method, and regression method by comparing with the measured results. It shows that the finite element model can better forecast the effect on the natural vibration characteristics under the pier scouring than the other two methods.