预应力灌浆套管中初始应力分布理论分析

THEORETICAL APPROACH FOR INITIAL STRESSES ANALYSIS IN PRESTRESSED GROUTED TUBE-TO-SLEEVE CONNECTIONS

基于弹性力学理论,对预应力灌浆套管中由于水泥浆体膨胀引起的初始应力分布进行了推导,给出了其解析解,并通过算例分析讨论了初始应力随水泥浆体自由膨胀率、钢管尺寸、水泥浆体厚度等因素的变化规律。结果表明:内管与水泥浆体界面初始法向应力小于外管与水泥浆体界面初始法向应力,但二者均随水泥浆体自由膨胀率的增加呈线性增大;内、外钢管与水泥浆体界面初始应力随内、外钢管径厚比的减小呈非线性增大,曲线呈下凹形;内、外钢管与水泥浆体界面初始应力随水泥浆体厚度的增大呈非线性增大,曲线呈上凸形。

Distributions of initial stress caused by expansive cement grout in prestressed grouted tube-to-sleeve connections are developed based on the theory of elasticity.Analytic solutions of initial stress and displacement in tubes and grout are obtained.Numerical examples are presented to discuss the relationship of initial stresses with expansive ratio of cement grout,geometry of tubes and geometry of grout.The results indicate that the initial normal stress between sleeve and grout is lower than that between tube and grout,and both increase linearly with expansive ratio of cement grout.Initial stress between tubes and cement grout increases nonlinearly with the decrease of diameter-thickness ratio of tube or sleeve,and the concave curve is presented.Initial stress between tubes and cement grout increases nonlinearly with thickness of cement grout,and the convex curve is presented.