摘要
为了进一步认识深厚表土中斜井冻结井壁的受力特征,建立了地层冻结—井筒掘砌—冻结壁解冻全过程模拟的平面有限元模型,通过温度场与应力场的顺序耦合,得到了解冻过程中井壁的受力规律。结果表明:解冻前、后井壁的受力模式不变,一般情况下,井壁仰拱内缘中心为受拉控制点,内缘边墙与仰拱交点为受压控制点;解冻过程中,控制点应力逐渐增大,完全解冻后井壁受力最为不利,可按此时的受力状态进行斜井井壁的初步设计;通过调整井壁厚度与仰拱半径可有效改善井壁的受力情况;在永久使用阶段,井壁的受力模式及控制点位置不会随埋深增加而变化,而水平侧压力系数λ对二者均可做出改变;此外,井壁各点应力与埋深、λ均呈线性关系。
In order to further understand the mechanical characteristics of freezing inclined shaft lining in the thick topsoil,a plane finite element model of the ground freezing-inclined shaft excavation and lining-frozen wall thawing process was established. With the sequential coupling of the temperature field and stress field,the mechanical law of shaft lining was obtained. The results showed that before and after the thawing,the mechanical mode of shaft lining was same. Generally,the inner edge center of inverted arch was the tensile control point and the intersection point of inner straight wall and inverted arch was the compressive control point. During the thawing process,the stress of the control points would steadily increase. After fully thawing,the stress of shaft lining would be most unfavorable and the preliminary design of the shaft lining could be conducted on this stress status. With the adjustment of the shaft lining thickness and inverted arch radius,the stress condition of shaft lining could be efficiently improved. In the permanent service stage,the mechanical mode and the control point locations would not be changed with the depth increased while the lateral pressure coefficient λ could change both them. In addition,the stress of shaft lining would have a linear relationship with depth and λ.
出处
《煤炭科学技术》
CAS
北大核心
2016年第5期133-139,共7页
Coal Science and Technology
基金
国家高技术研究发展计划(863计划)资助项目(2012AA06A401)
关键词
斜井
冻结井壁
表土
受力规律
冻结壁解冻
mine inclined shaft
freezing shaft lining
topsoil
mechanical law
frozen wall thawing
