摘要
对冻结管受力的理论分析和模拟试验研究表明，在安装阶段，冻结管的应力很小，可略去不计；在积极冻结阶段，受管材冷缩、冻土冷缩和冻土冻胀的作用，冻结管轴向受拉（压）并向井外弯曲在该阶段后期，纯拉（压）应力σ１由正最大值向负值转变，且数值变小；而纯弯曲应力σｗ则趋于稳定，其值虽较大但对后期冻结管的安全无害．在掘砌施工阶段，冻管的受力大小决定于冻结壁的变形，σ１和σｗ随时间的变化规律与冻结壁的蠕变规律相似，σｗ与冻结壁的位移成正比．因此，减小冻结壁变形是防止冻结管断裂的最主要措施．
Theoretical analyses and simulatingtests on stresses in freezing pipes were carried out, andthe following results were obtained. Stresses in freezing pipes are very small during the installation of freezing pipes, so that they can be neglected. In active freezing phase, owing to thermal contraction of freezingpipes and frozen soils, and owing to frost heave of soilbody, freezing pipes are axially stretched (or compressed) and are bent towards the outside of frozensoil wall. In the last part of the active freezing phase,axial tensile stressσ1 in freezing pipes changes frompositive maximum to negative value, and the absolutevalue of σl is small; bending stress σw in freezingpipes tends to be stable, although the value of σw isnot small, but it is not harmful to the freezing pipes inexcavating--lining phase. Stresses in freezing pipes depend on the displacement of frozen soil wall duringthe excavating--lining phase. The dependence ofσl and σw on time is similar to the creep law of frozensoil wall. σw is direct proportional to the displacement of frozen soil wall. Therefore, reducing the displacement of frozen soil wall is main measure to betaken to prevent freezing pipes from fracture.
出处
《冰川冻土》
CSCD
北大核心
1999年第1期33-38,共6页
Journal of Glaciology and Geocryology
关键词
冻结管
冻结壁
模拟试验
受力分析
矿井
freezing pipes, frozen soil wall, modelling test, stress analysis
