非均匀水平应力场中井壁结构的优化设计研究

Study on Structure Optimizing Design of Mine Shaft Liner under Uneven Side Pressure

为了寻求非均匀水平应力场中井壁的合理结构,克服传统等厚井壁在非均匀水平应力场中因应力分布不均而造成井筒结构局部挤压过度而发生破坏,本文用内壁为圆、外壁为椭圆的井壁结构代替原来的等厚井壁,利用有限元数值计算软件,对井壁结构的受力和变形进行数值模拟分析,运用有限元软件的优化设计模块,对特定条件下非均匀水平应力场中井壁的断面形状进行了优化设计研究.研究结果表明:非均匀水平应力场中,等厚度的圆形井筒内壁应力分布并非均匀,不利于井筒稳定性的保持;采用外壁为椭圆形,内壁为圆形的井壁结构,可实现井壁中应力分布状态基本均匀的效果;在外壁从圆形向椭圆形过渡中存在一个最优点,偏离最优点两端越远应力分布越不均匀,这个最优点就是井壁应力分布状态最均匀的状态点,此时井壁的变形、应力分布比较合理,对井筒的稳定性非常有利.

In order to seek the mine shaft＇s reasonable structure under uneven horizontal stress field,to prevent the uniform thickness mine shaft liner to be destroyed due to partial extrusion transition by caused uneven stress distribution of the mine shaft liner in uneven horizontal stress field,in this paper,the original uniform thickness mine shaft liner is replaced by the shaft liner of the inside is the circle and the outside is the ellipse,on the base finite element numerical simulation software is applied to simulate the stress and the deformation of the mine shaft under uneven horizontal stress field,and optimization design module of finite element method is applied to optimize the shape of mine shaft＇s section in uneven horizontal stress field.Studies show that： the stress of uniform thickness mine shaft liner under uneven horizontal stress field is very irregular,this is worse to the stability of the mine shaft;That the original uniform thickness mine shaft liner is replaced by the shaft liner that the inside is the circle and the outside is the ellipse is reasonable,it is to the benefit of the stability of the mine shaft and can make the stress distribution of the mine shaft liner become more uneven,the effect that makes is dvantage;there is a best point when the outside of shaft liner is from circle to ellipse,if to be farther from this point the stress of the mine shaft is further irregular,the stress of the mine shaft in this most reasonable point is most homogeneous distribution of the stress in mine shaft,in such a case the stress distribution of the mine shaft is reasonable and is to the benefit of the stability of the mine shaft.