注浆微型钢管桩抗弯性能研究

Research on flexural performance of grouting micro-steel pile

为探讨注浆微型钢管桩的抗弯性能,对不同钢管管径、壁厚以及砂浆强度的12根试件,采用正交试验方案进行纯弯曲试验,基于试验结果提出极限抗弯承载力表达式,并采用有限元软件ANSYS建立模型进行验证。结果表明:注浆微型钢管桩的弯曲全过程可分为3个阶段,即,弹性阶段、弹塑性阶段和强化阶段;对注浆微型钢管极限荷载敏感性大小为,钢管管径>钢管壁厚>砂浆强度等级;不同规程计算的极限抗弯承载力与试验差异较大,本研究所提出的注浆微型钢管桩极限抗弯承载力表达式与试验结果吻合较好,钢管的抗弯承载力约占注浆微型钢管桩总抗弯承载力的78%,管内砂浆约占22%;有限元模拟结果显示,管内砂浆对微型钢管桩的抗弯性能有较大的提升,验证了所提出的注浆微型钢管桩抗弯承载力表达式的正确性。

In order to explore the flexural performance of grouted micro steel pipe piles,12 specimens with different steel pipe diameters,wall thicknesses and mortar strengths were subjected to pure bending tests using orthogonal test schemes,and the ultimate flexural bearing capacity expression was proposed based on the test results.Formula,and use the finite element software ANSYS to establish a model for verification.The results show that the whole bending process of grouting micro steel pipe pile can be divided into three stages,namely:elastic stage,elastoplastic stage and strengthening stage;the sensitivity to the ultimate load of grouting micro steel pipe is steel pipe diameter>steel pipe wall thickness>mortar strength grade;the ultimate flexural bearing capacity calculated by different regulations is quite different from the test.The expression of the ultimate flexural bearing capacity of the grouted micro steel pipe pile proposed in this paper is in good agreement with the test results.The flexural bearing capacity of the steel pipe It accounts for about 78%of the total flexural bearing capacity of the grouted micro steel pipe piles,and the mortar in the pipe accounts for about 22%.The finite element simulation results show that the mortar in the pipe greatly improves the flexural performance of the micro steel pipe piles.The correctness of the expression of the flexural bearing capacity of the grouted micro-steel piles proposed is recommended to be promoted.