基于Ansys的带侧向支撑桩的稳定性

为分析既有建筑物增设地下空间托换桩的稳定性,利用Ansys建立增设侧向支撑的钢筋混凝土桩的三维有限元模型,通过改变桩周土水平抗力系数的比例系数、桩周土开挖深度、桩身截面边长、桩身配筋率和载荷偏心距等参数,分析桩的受压极限承载力和相应支撑轴力的变化规律.结果 表明:桩受压极限承载力和相应支撑轴力随载荷偏心距和桩周土开挖深度的增大而减小,随着桩周土水平抗力系数的比例系数、桩身配筋率和桩身截面边长的增大而增大.根据虚拟嵌固点法提出带侧向支撑钢筋混凝土桩承载力和侧向支撑轴力的计算公式,并将公式计算值与数值模拟结果进行对比,两者吻合较好,验证计算公式的可靠性.

Stability analysis of pile with lateral support based on Ansys

To analyze the stability of underpinning piles for adding underground space in existing buildings, the three dimensional finite element model of reinforced concrete pile with lateral support is established by Ansys. By changing the proportion coefficient of the horizontal resistance coefficient of the soil around pile, the excavation depth of the soil around pile, the side length of the pile section, the reinforcement ratio of the pile and the load eccentricity, the variation law of the compressive ultimate bearing capacity and the corresponding supporting axial force of the pile is analyzed. The results show that the ultimate compressive bearing capacity and corresponding supporting axial force of the pile decrease with the increase of load eccentricity and excavation depth of soil around pile, and it increases with the increase of the proportion coefficient of the horizontal resistance coefficient of the soil around pile, the reinforcement ratio of the pile and the side length of the pile section. Based on the virtual embedded point method, the calculation formulas of bearing capacity and axial force of the reinforced concrete pile with lateral support are proposed. The calculation values of the formula are compared with the numerical simulation results, and they are in good agreement, which verifies the reliability of the calculation formula.