大吨位船舶撞击作用下秀山连岛大桥塔墩基础稳定性分析

Stability Analysis of the Foundation of Main Pier of Xiushan Island Bridge under the Collision of Large Tonnage Ship

以秀山大桥秀山侧主墩为依托,采用平洞勘察、岩体力学试验、岩体质量评价等手段综合研究岩体力学参数值;构建了索塔、桩基、地基数值模型,提出利用节点等效集中荷载模拟上部结构传递到基础荷载的方法,分析了万吨级船舶撞击下桩基础截面内力、位移以及地基塑性区分布。结果表明:采用等效荷载方法模拟基础受力是可行的; 10万吨级船舶撞击作用下,桥轴线两侧变形受力不对称,船撞一侧桩基除受水平作用外,还受到拉拔作用,但仍处于受压状态;两侧基础内力均小于允许值,地基基本处于弹性状态,仅局部强风化层存在塑性区,表明基础满足防撞要求。

Indoor tests,site tests and wave velocity tests of rock masses of bridge foundation are carried out to evaluate the rock mass quality and recommended mechanical parameter values with reference to the engineering rock mass standards.A numerical model for the interaction between pile foundations and foundations was constructed.And a method for simulating the collision of 10,000-ton ships with the equivalent concentrated load of the nodes was proposed to study the internal forces of the pile foundation and the distribution of the plastic zone under the equivalent load.The results show that the method is feasible.Under the impact of a 100,000-ton ship,the deformation on both sides of the bridge axis is asymmetrical.The piles on the side where the ship hits are not only subjected to the horizontal effect,but also subjected to the drawing effect,but they are still under pressure.Both sides of the base pressure internal forces are less than the allowable value,the foundation is basically in the elastic state,only a local strong weathering layer exists plastic zone,indicating that the foundation meets the anti-collision requirements.