为分析竖向附加力和季节性温度应力对井壁应变和应力发展规律的影响,并对井壁结构进行相应的优化,利用有限元软件ABAQUS建立了某双层立井井壁在自重、水平地压、竖向附加力和季节性温度应力共同作用下空间受力模型.通过相似理论分析可确定在既定井壁温度场条件下,井筒内、外壁受力状态主要受3个可变因素(外壁与内壁的厚度比Do和Di弹模比Eo/Et以及内、外壁之间摩擦系数u)的影响.通过L9(3 4)正交数值试验,获得了以上3个因素对井筒内、外壁受力大小的影响程度.根据正交试验结果可知,选择合适的内、外壁摩擦系数并提高外壁与内壁厚度比可改善双层井壁的整体受力状态.
A space axial-symmetrical FEM numerical model of a double-layer shaft lining bearing 4 kinds of external forces (its self-weight, horizontal ground pressure, vertical additional force and seasonal thermal stress) was built with the software ABAQUS. The numerical result and monitored data show an encouraged agreement. Both monitored and simulated axial strain wave is just like the atmospheric temperature changing law, and the value is accumulating with time. As is known from the similarity theory analysis result, the stress states of inside and outside lining with the calculated thermal field are mainly affected by 3 factors, i.e. ratio of thickness between outside lining and inside lining (Do/Di), ratio of elastic modulus between outside lining and inside lining (Eo/Ei), the friction coefficient of outside lining and inside lining (u). In order to optimize the structure of double-layer shaft lining, 9 numerical orthogonal tests arranged by L 9 (3 4 ) were carried out. Based on the influence degree of these 3 factors affecting on the shaft lining stress states which obtained from the L9 (3 4) orthogonal tests, a property friction coefficient and ratio of thickness between outside lining and inside lining may be chosen to improve the stress state of both inside and outside lining.