介绍了以单根桩模拟大型桩群的模型试验方法，并用该方法对埋入紧砂中的大型桩群就不同桩距和不同埋深情况共进行了１３组模型试验试验．用读数显微镜详细观测了地基土的位移场，并测出了桩端阻力与桩端沉降的关系曲线根据这些试验成果，对地基的破坏性状和桩端阻力机理进行了分析．分析结果表明，只要桩的埋深约大于１倍桩径，则地基总是以单独刺入破坏的型式发生破坏，桩端阻力为压缩机理所控制 A model test method for simulating large-scale pile groups with a single pile is introduced. With this method, 13 groups of model tests are performed on large piles buried in tight sand for different pile lengths and depths. The displacement field of the foundation soil was observed in detail with a reading microscope, and the relationship between the resistance at the end of the pile and the settlement at the end of the pile was measured. Based on these test results, the failure behavior of the foundation and the mechanism of the end resistance of the foundation were analyzed. The analysis results show that as long as the depth of the pile is more than about 1 times the diameter of the pile, the foundation will always be damaged by a single piercing damage, and the end resistance of the pile is controlled by the compressor.