局部荷载作用下立井井壁破坏形式研究

Damage form research of shaft sidewall under local load

针对立井井壁受局部荷载破坏问题,如因破壁注浆压力过大而导致的井壁破坏,采用有限元数值分析的技术手段,利用大型通用软件ANSYS建立了钢筋混凝土立井井壁的三维有限元模型,详细分析了其在局部荷载作用下应力、应变以及最终失稳形态,找出了其最先破坏位置以及破坏发展过程,指出了与均布荷载作用下破坏形式的不同,为实际工程中立井井壁加固位置的确定及破壁注浆极限压力的确定提供一定的理论依据。同时将ANSYS的屈曲分析应用到立井井壁极限承载力的分析中,避免了繁琐的理论解析过程,建立了一种能够迅速判断立井井壁在局部荷载作用下极限承载力的方法,可以为壁后注浆加固工程进行及时的指导,在现实工程中有着极为广阔的应用。

The purpose of this paper is to solve the problem of the damage of shaft sidewall under local load, such as the sidewall damage caused by the too much grouting pressure. The three-dimensional finite element model of reinforced concrete shaft sidewall is established by the software of ANSYS. The stress, strain and instability form of it under local load are analysed detailedly. The first damage site and destruction development process are pointed out, and the difference of damage form under even load and under local load is pointed out, which can provide theory support for the determination of reinforcing site of shaft sidewall and the limit grouting pressure in project. The flexion analysis of ANSYS is used to analyse limit bearing capacity of shaft sidewall, which can avoid cumbersome theoretical analysis. A method which can judge the limit bearing capacity of shaft sidewall rapidly is established. It can supply guidance for grouting reinforcing projects, and it has a very broad prospects in projects.