深厚表土层冻结壁厚度计算方法研究

Research progress of the frozen wall thickness in deep alluvium

针对冻结法凿井工程面临的表土层厚度不断增加,而现有冻结壁的设计理论滞后于工程实践的问题,目前冻结壁的设计和计算多数是将冻结壁视为均质和各向同性的厚壁圆筒,基于弹性和弹塑性理论进行计算的结果已经不能适用于未来深厚表土层的冻结法凿井工程,文章综述了冻结壁厚度设计理论的研究现状和存在的问题,并提出了考虑冻结壁径向非均匀的粘弹性分层计算模型,考虑径向非均质条件,井帮的径向变形较均质冻结壁小25%～30%,可以充分发挥冻结壁的承载和变形性能,有效减小冻结壁的厚度,具有一定的的工程应用价值。

According to the problem of design theory laging behind engineering application,with the thickness increasing of deep alluvium for the freezing shaft-sinking engineering,the frozen wall is regarded as homogeneous and isotropic thick wall cylinder while designing and calculating,and the calculate results based on the elastic and elastic-plastic theory can＇t apply to the freezing shaft-sinking engineering in the future.In this paper,frozen wall thickness design theory of the present research situation and the existing problems were summarized.The radial creep displacement of heterogeneous frozen wall will reduce 25 % ~ 30 % when the homogeneous frozen wall,so the bearing capacity and deformation performance of frozen wall can befully used and the thickness of frozen wall can be reduced efficiently.