【摘要】 设计并完成2个比尺1∶8的边坡大型振动台模型试验,通过水平向(X向)、竖直向(Z向)和水平竖直双向(XZ双向)3种激振方式,研究汶川波地震作用下重力式挡墙、桩板式挡墙、锚杆格构式框架和预应力锚索格构式框架护坡位移模式及变化特性,并且分析各支挡结构的抗震性能。研究表明:(1)X向或XZ双向激振下,重力式挡墙和桩板式挡墙在激振加速度峰值AXmax≤0.4 g时的永久位移,以及Z向激振下桩板式挡墙和预应力锚索框架护坡的永久位移可忽略不计;(2)X向激振下,当激振加速度峰值AXmax>0.4 g时,重力式挡墙位移模式为向土体方向滑动和绕墙踵向土体方向转动的耦合,且以滑动为主,而桩板式挡墙位移模式为向土体方向滑动。Z向激振下,当激振加速度峰值AZmax>0.267 g时,重力式挡墙位移模式为向土体方向滑动和绕墙踵向土体方向转动的耦合。XZ双向激振下,AXmax>0.4 g和AZmax>0.267 g时,重力式挡墙位移模式为向土体方向滑动与绕墙趾向土体外侧转动的耦合,且以转动为主,而桩板式挡墙位移模式则为离开土体向外侧滑动与绕基础向土体外侧转动的耦合,且以滑动为主;(3)X向和XZ双向激振下,预应力锚索框架和锚杆框架的位移模式相同,都是沿坡体向土体外侧及边坡下端移动。Z向激振下,当激振加速度峰值AZmax>0.267 g时,锚杆格构式框架护坡位移模式为向土体外侧和边坡上端移动逐渐转变为向土体方向和边坡上端移动;(4)X向或Z向激振下,桩板式挡墙抗震性能优于重力式挡墙,而XZ双向激振下,重力式挡墙抗震性能优于桩板式挡墙。无论哪种激振方式,预应力锚索格构式框架护坡抗震性能优于锚杆格构式框架护坡。更多还原

【Abstract】 Two slope models with the geometric scale of 1∶8 were designed and two large-scale shaking table model tests were performed to study the seismic displacement modes,its characteristics and aseismic behavior of four retaining structures including gravity retaining wall,sheet-pile retaing wall,anchor lattice frame structure and prestressing anchor lattice frame under seismic loading and in three excitation directions including X-,Z-,and XZ-direction respectively.The results show that:(1) In X direction or XZ-direction excitation,the seismic permanent displacements of gravity retaining wall and sheet-pile retaining wall are negligible at the peak excitaion acceleration AXmax≤0.4 g.In Z-direction excitation,the seismic permanent displacements of sheet-pile retaining wall and prestressing anchor lattice frame are also negligible.(2) In X-direction excitation and at AXmax>0.4 g,the seismic displacement mode of gravity retaining wall is the slide-based coupling of the sliding to filling soil mass and the rotating inward about base,and the seismic displacement mode of sheet-pile retaining wall is the sliding to filling soil mass.In Z-direction excitation and at the peak excitation acceleration AZmax>0.267 g,the seismic displacement mode of gravity retaining wall is the coupling of the sliding to filling soil mass and the rotating inward about base.In XZ-direction excitation and at AXmax>0.4 g,and AZmax>0.267 g,the seismic displacement mode of gravity retaining wall is the rotation-based coupling of the sliding to filling soil mass and the rotating outward about base,and the seismic displacement mode of sheet-pile retaining wall is the slide-based coupling of the sliding from filling soil mass and the rotating outward about base.(3) In X-or XZ-direction excitation,the seismic displacement mode of prestressing anchor lattice frame is the translation of outward and lower of the slope and same as that of anchor lattice frame structure.In Z-direction excitation and at AZmax>0.267 g,the seismic displacement mode of the translation of outward and upper of the slope of anchor lattice frame structure is gradually transformed into the translation of inward and upper of the slope.(4) The aseismic performance of sheet-pile retaining wall is better than that of gravity retaining wall at X-or Z-direction excitation,but poor than that of gravity retaining wall in XZ-direction excitation.The aseismic performance of prestressing anchor lattice frame is better than that of anchor lattice frame structure at X-,Z-,and XZ-directions excitation.更多还原