基于二维离散单元法,对沉桩过程中钙质砂颗粒破碎情况进行了模拟。采用簇粒来模拟易破碎的钙质砂颗粒,并用形状与变形特性相同的聚粒单元来模拟不可破碎颗粒,对这两种单元特性进行对比,分析不同桩型的沉桩过程、桩周土体的力学响应、沉桩过程中钙质砂的颗粒破碎现象。结果表明:破碎颗粒将引起桩侧土体级配的重新调整,与桩体接触好于不可破碎土体;桩处于颗粒破碎的钙质砂中,其沉桩速度较快,对地基土扰动小于未发生颗粒破碎的情况;对于不同桩型、不同土层,桩体压入过程中,桩周土体应力场分布具有相似性;靠近桩端附近,土中水平应力和竖向应力急剧增大,形成应力核;同等条件下发生颗粒破碎的钙质砂地基土中,桩端应力峰值高于不可破碎土体。 Based on the two-dimensional discrete element method, the calcification of calcareous sand particles during pile driving was simulated. Clusters were used to simulate the fragile calcareous sand particles. The particles with the same shape and deformation characteristics were used to simulate the non-crushable particles. The characteristics of these two elements were compared and the pile-sinking process was analyzed. The mechanical response of the body, the particle crushing phenomenon of calcareous sand during pile driving. The results show that the broken particles will cause the gradation of the soil on the pile side to be readjusted and come into better contact with the pile than the unbreakable soil. The pile is located in the calcareous sand with broken grains and settles quickly, No particle breakage occurs; for different pile types, different soil layers and piles, the distribution of stress field in the soil around the pile has similarities; near the pile end, horizontal stress and vertical stress in the soil increase sharply , Forming stress nuclei; under the same conditions, the peak value of pile end stress is higher than that of unbreakable soil in calcareous sand foundation soil broken by particles.