深部厚粘土层内井壁工程地质特征分析

对黄淮地区厚覆盖层内百余个竖井井壁工程的调查，发现：深部厚粘土层是冻结法建井施工期断冻结管和外层井壁易破损的部位；成井后，却是两类特凿井壁强度增强的部位，也是固结沉降时形成井壁侧摩阻力的主要部位。综合大量事实，本文指出表土深部的厚粘土层存在着地压高、不冻结、塑性变形显著、摩擦阻力大等工程特性。

Engineering geological properties of deep- thick bedded clay around the shaft wall

Based on the investigation for more than one hundred shaft walls built in the thick overburden layer in Huanghuai region, the following conclusions have been obtained. Deep-thick bedded clay is the position that frozen-tube and sidewall outside the shaft is easy to fracture during the construction of the frozen shaft wall. However, after the wall has been built, the thick-bedded clay results in enhancement of the strength of shaft wall, and the development of the lateral friction resistance during consolidation of the clay layer too. A great deal of evidence has indicated that deep-thick bedded clay has engineering properties which are high earth pressure, non-frozen, distinct plastic deformation, great lateral resistance.