格构式框架护坡地震动位移模式的振动台试验研究

 通过1个比尺1∶8的边坡大型振动台模型试验，研究锚杆格构式框架护坡在地震作用下的位移模式及其变化特性。模型试验以汶川波作为设计输入地震波，采用水平(X)向、竖直(Z)向和水平竖直(XZ)双向等3种激振方式。研究结果表明：(1)  X向单向激振时，支挡结构的动位移模式为：当激振加速度峰值AXmax≤0.4 g时，离开土体向外侧平移；当AXmax = 0.6 g时，绕支挡结构的下端向土体方向或边坡下方转动；当AXmax≥0.8 g时，挤向边坡土体方向移动，同时向边坡下方移动与绕支挡结构下端向土体方向转动的耦合。(2)  Z向单向激振时，支挡结构的动位移模式为：当AZmax≤0.267 g时，离开土体向外侧移动，同时发生向边坡下方移动与绕结构下端向土体方向转动的耦合；当AZmax≥0.400 g时，挤向边坡土体方向平移与绕结构下端向土体方向转动的耦合。(3) XZ双向激振时，支挡结构的动位移模式为：离开土体向外侧平移，与绕结构下端向土体方向或边坡下方转动的耦合。

SHAKING TABLE MODEL TEST STUDY OF SEISMIC DISPLACEMENT MODE OF SLOPE WITH ANCHOR LATTICE FRAME STRUCTURE

A slope model with the geometric scale of 1∶8 was designed and a large-scale shaking table model test was performed to study the seismic displacement mode of anchor lattice frame structure and its characteristics under Wenchuan earthquake loading with three excitation directions including X，Z，and XZ direction respectively. The results show that：(1) Under X direction excitation，the seismic displacement mode of the proposed retaining structure is the translation from filling soil mass at the peak exciting acceleration AXmax≤0.4 g，the rotation inward or lower slope about the lower of retaining structure at AXmax = 0.6 g，and the coupling of the translation to filling soil mass and the rotation inward about the lower of retaining structure at AXmax≥0.8 g. (2) Under Z direction excitation，the seismic displacement mode of the proposed retaining structure is the coupling of the translation from filling soil mass and the rotation inward about the lower of retaining structure at AZmax≤0.267 g，the coupling of the translation to filling soil mass and the rotation inward about the lower of retaining structure at AZmax≥0.400 g. (3) Under XZ direction excitation，the seismic displacement mode of the proposed retaining structure is the coupling of the translation from filling soil mass and the rotation inward about the lower of retaining structure.