活断层震动断裂作用下高铁路基振动台试验研究

Study on shaking table model test of high-speed railway subgrade with active fault vibration and fracture

通过考虑活动断层引起的地震作用下断裂错动的双台联动振动模型试验,研究跨越活动断裂的高铁桩承式加筋路基结构与下部地基的加速度、孔隙水压、桩土应力、桩身应变、边坡位移和沉降等变化规律,获得高铁桩承式加筋路基在活动断裂影响下的受力变形特性与工作状态。研究结果表明:走滑运动对跨越活动断裂的高铁路基结构及下部地基的影响比逆冲运动产生的影响更加显著,且两者产生的协同作用将加剧路基的变形与受力,加剧路基的变形与受力;为应对跨越活动断裂的地基液化,路堤工程必须得到重视并采取有效的排水措施;中震量级以上的活动断裂错动作用会对桩承式全断面加筋路基的工作性能产生显著影响,路基面最大沉陷可达1.2 m。

Through double-table vibration test of high-speed railway subgrade considering the effect of fault vibration and fracture,the stress and deformation properties of high-speed railway pile-bearing reinforced subgrade crossing active fault were investigated,including acceleration response,pore-water pressure,pile-soil stress,pole strain,slope displacement,settlement,etc.,and the working state of high-speed railway subgrade through active fault was analyzed.The results show that strike-slip fault movement affects the high-speed subgrade and foundation more severely than thrust movement,and the combined action of both will generate coupling effect and intensify subgrade force and deformation.In order to respond foundation liquefaction,subgrade spanning active fault must be paied attention to and effective drainage measures must be taken.Fault displacement above medium earthquake magnitude will cause obvious affection on working performance of wholesection reinforced subgrade,and the maximum settlement amount of formation level can reach more than 1.2 m.