井壁竖直附加力变化规律模拟试验研究

Study on variation of vertical additional force on shaft lining by simulation tests

利用大型竖井模拟试验台,对冲积层疏排水过程中立井井壁受到的竖直附加力的变化规律开展了模拟试验研究。试验结果表明:竖直附加力随含水层降压量的增大而线性增加,随深度增大而增大,随土层中粗颗粒含量增多而增大。分析计算表明:应采用竖向可缩新型井壁结构防止井壁因冲积层疏排水而破坏。

The simulation tests were carried out to study the variation of the vertical additional force acted on shaft lining by surrounding soils during dewatering of alluvium by means of multi-function rig in vertical shaft. On the basis of the analysis of the test data, the additional force linearly increased with variation of water pressure in the aquifer, and increased with the increase of the depth and with the content of coarse soil particle in the overburden layer. According to calculations, it was necessary to adopt a new type of structure of the shaft lining with vertically yieldable segments for reason of safety.