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为探讨高陡横坡段桩柱式桥梁双桩基础的破坏模式及承载机理,根据相似理论,进行了复杂荷载作用下45°,60°及75°三种边坡坡度的桥梁双桩基础室内模型试验。试验结果表明:柱顶组合荷载对坡体的影响,仅限于浅层2～4倍桩径范围内;复杂荷载作用导致的边坡整体失稳为系统主要破坏模式;高陡横坡段前后桩柱的内力分布规律与陡坡单桩及双排抗滑桩差异显著,桩、柱顶端均存在较大负弯矩,柱顶及桩顶边界条件均非完全自由;桩柱内力与位移均随柱桩高度比(h/l)呈非线性增长,且重力二阶效应(P-Δ效应)显著;柱顶负弯矩随边坡坡度增加而增大,但柱底正弯矩随之减小;桩身最大正弯矩及桩顶水平位移均随边坡坡比的增加而呈非线性增长。
In order to discuss the failure mode and bearing mechanism of double-pile foundation for high-steep cross-section piles, according to the similar theory, the double-pile foundation of the bridge with 45 °, 60 ° and 75 ° slope under complex load Model test. The experimental results show that the effect of combined load on the slope is limited to 2 ~ 4 times of shallow pile diameter, the overall failure of the slope caused by complex load is the main failure mode of the system, The internal force distribution of the column is significantly different from that of the steep single-pile and double-row anti-slide piles. There is a large negative moment at the top of pile and column, and the boundary conditions of the column top and top of the pile are not completely free. The pile height ratio (h / l) increases nonlinearly, and the second-order gravity effect (P-Δ effect) is significant. The negative column bending moment increases with the increase of slope gradient, but the positive column moment decreases The maximum positive moment of pile and horizontal displacement of pile top all increased nonlinearly with the increase of slope ratio.