采用振动方式回收PC(pipe-combination)工法桩，拔桩过程中带土量大小、拔桩带土对周边敏感环境的影响是岩土界关注的焦点。该文提出振动拔桩过程四阶段简化模型，依据振动极限状态下“桩+土+锤”的动力平衡公式，基于软土静侧摩阻力、总振动体加速度与重力加速度之比和钢管桩参数，推导出软土场地PC工法桩拔桩时钢管桩内外壁带土量的理论计算公式。根据软土地层项目的拔桩测试和数值模拟结果，理论计算、现场实测、数值模拟结果总体吻合较好。其中，现场实测误差为5%～18%,数值模拟与理论计算结果误差小于10%,验证了简化模型和计算公式的合理性。PC工法桩中钢管桩带土量的理论计算公式有助于把PC工法桩的经济性转化成适用性，并在拔桩前有针对性地提出保护周边敏感环境的措施。

The amount of attached soil and the impact on the surrounding environment during pile extraction are focused by the geotechnical engineering range when pipe-combination(PC) pile is extracted through vibration. A simplified four-stage model of the vibration pile extraction are proposed in this paper. Based on the dynamic equilibrium equation of “pile + soil + hammer” under the vibration limit condition, the theoretical calculation formula for the soil attached amount on the internal and external walls of steel pipe piles during the vibration pile extraction is established in light of static lateral friction resistance of soft soil, the ratio of total vibration acceleration to gravitational acceleration and parameters of steel pipe pile. According to the pile extraction tests and numerical simulation results of the project in soft soil area, the theoretical calculation, field measurement and numerical simulation results show a general agreement. The on-site measurement error ranges from 5% to 18%, and the error between numerical simulation and theoretical calculation is less than 10%, verifying the rationality of the simplified model and the formula. The theoretical calculation formula of attached soil amount of PC pile is helpful in transforming the economic efficiency of PC pile into applicability, and proposing measures to protect the surrounding sensitive environment before extracting PC pile.