【摘要】 基于实际工程样机，设计1∶40缩尺的咬合桩筒型基础模型，在均质砂土中开展室内模型试验，在水平-弯矩荷载、竖向荷载下对地基承载能力和基础失稳模式进行研究，并用有限元对同尺寸缩尺模型建模分析对比，结果表明：1）在水平-弯矩荷载的作用下，咬合桩筒裙与内部土体整体性较好，基础的失稳模式主要是产生较大的刚体转动和少量的整体水平滑移；同尺寸模型试验和有限元在基础失稳时的极限承载力结果的偏差为4.9%，筒后侧壁土压力逐渐增大，筒前侧壁土压力先增大后减小，在埋深约1/3处土压力较大，说明基础发生了平动及转动。2）在竖向荷载的作用下，筒型基础筒裙与承台带动内部土体一起变形，基础主要发生整体剪切破坏，试验和有限元在基础失稳时的极限承载力结果偏差为6.05%，筒侧土压力先减小后增大。更多还原

【Abstract】 Based on an actual engineering prototype, a 1∶40 secant piled bucket foundation model was designed, and indoor model tests were conducted in homogeneous sand. The bearing capacity of the foundation and the instability mode of the foundation were studied under horizontal bending moment load and vertical load. Finite element modeling and analysis of the same size scaled model were compared. The results showed that: 1) under the action of horizontal bending moment load, the bite pile skirt has good integrity with the internal soil, and the instability mode of the foundation is mainly characterized by large rigid body rotation and a small amount of overall horizontal sliding; The deviation between the ultimate bearing capacity results of the same size model test and finite element analysis during foundation instability is 4.9%. The soil pressure on the rear wall of the cylinder gradually increases, while the soil pressure on the front wall of the cylinder first increases and then decreases. The soil pressure is relatively high at about one-third of the burial depth, indicating that the foundation has undergone translational and rotational movements. 2) Under the action of vertical load, the skirt of the cylindrical foundation and the bearing platform drive the internal soil to deform together, and the foundation mainly undergoes overall shear failure. The deviation between the ultimate bearing capacity results of the test and finite element analysis during foundation instability is 6.05%, and the soil pressure on the cylinder side first decreases and then increases.更多还原