黄河下游移动式不抢险潜坝结构设计与分析

摘要

Based on the channel characteristics and the conditions of river training works on the Lower Yellow River,the structure designed project of movable and emergency-freee submerged dam was given. In considering of the pipe piles and the interaction of soil layer and the soil erosion and the water level changes,the finite element model was established with pipe piles,soil and prestressing tendon by using numerical simulation method and the displacements and forces of the pipe piles were analyzed under 12 kinds of working conditions. In addition,the uplift construction of pipe pile in submerged dam was simulated.%根据黄河下游河道特点和河道整治工程情况，给出了移动式不抢险潜坝的结构设计方案。考虑潜坝中管桩、土层的相互作用和土层的冲刷及水位的变化，采用数值模拟方法建立了潜坝中管桩、土、预应力筋的有限元模型，分析了各种工况下管桩的桩身位移和受力，并模拟了潜坝中管桩的上拔施工。结果表明：①在最大冲深情况下，桩长20 m可以满足设计要求；②冲深为10 m、洪水位情况下的管桩为最不利受力状态；③在考虑桩、土间摩擦力并假定桩身全部被淤积的泥沙覆盖条件下，在距离桩顶1m以下位置均匀向上施力即可安全拔出桩体。综合潜坝运行期管桩受力和变形情况及管桩上拔施工期的受力特征可以看出，该设计方案是可行的。