珊瑚礁灰岩可搅拌性PFC3D数值模拟研究

利用珊瑚礁灰岩地区某工程的三轴搅拌桩施工现场数据,采用PFC~(3D)离散元软件分别对不同珊瑚礁灰岩强度、厚度,以及上覆土层厚度进行数值模拟分析。模拟结果显示,当珊瑚礁灰岩强度超过4 MPa,厚度超过3 m后,三轴搅拌机竖向抗力及抵抗弯矩达到其自身性能的极限,出现卡钻、抱钻情况,从而造成三轴搅拌桩止水帷幕无法施工,而上覆土层厚度的变化则对施工几乎没有影响。用离散元模拟结果与现场实际施工情况进行比较发现:数值模拟结果与现场实际施工情况较为吻合,对现场施工有一定的指导作用。

Study on PFC 3D Numerical Simulation of Agitatability of Coral Reef Limestone

Based on the construction site data of triaxial mixing pile in a coral reef limestone area, the strengths and thicknesses of the different coral reef limestone, and the thickness of overlying soil are numerically simulated and analyzed by using PFC3D discrete element software. The simulation results show that when the strength of coral reef limestone exceeds 4 MPa and its thickness exceeds 3m, the vertical resistance and bending moment of triaxial mixer reach the limit of its own performance, then the drill pipe is stuck and held in place. As a result, the waterproof curtain of triaxial mixing pile cannot be constructed. But the change of the thickness of overlying soil has little impact on the construction. By comparing the results of discrete element simulation with the actual construction situation, it is found that the numerical simulation results are more consistent with the actual construction situation, which has a certain guiding role for the site construction.