深厚冲积层井筒修复内层钢板高强钢纤维混凝土复合井壁研究及应用

针对板集煤矿副井井筒修复的复杂工程条件,提出采用内套内层钢板高强钢纤维混凝土复合井壁结构。首先,对该种新型井壁结构力学特性进行了模型试验研究,结果表明:在井壁结构中高强钢纤维混凝土的极限压应变可达(-3 710~-3 750)με,显著提高了井壁结构的延性特征;由于内层钢板的约束作用,井壁内缘钢纤维混凝土也处于三向受压状态,钢纤维混凝土抗压强度提高了1.822~1.974倍,从而显著提高了该种复合井壁的承载能力;在板集煤矿副井井筒修复工程中首次应用了内层钢板高强钢纤维混凝土复合井壁,并通过现场实测结果表明,2个监测水平钢纤维混凝土应变分别为-290με和-359με,远小于试验实测的极限压应变值,说明目前该种新型井壁结构混凝土变形小,井壁结构安全可靠。

Research and application of high strength steel fiber concrete compound shaft lining with inner steel plate in deep alluvium shaft repair

Aiming at the complicated engineering conditions of auxiliary shaft repair in Banji Coal Mine,the inner sleeve of composite shaft lining structure of high strength steel fiber concrete with inner steel plate is proposed.Firstly,the mechanical properties of new type of shaft lining are studied by model test,the results show that the ultimate strain of high strength steel fiber concrete in shaft lining structure can reach -3 710με to -3 750με,and the ductility of shaft lining structure is obviously improved.Due to the role of inner plate restraint,the steel fiber concrete at the inner edge of shaft is compressed in three directions,and the steel fiber concrete compressive strength increased 1.822 to 1.974 times,which significantly improved the bearing capacity of composite shaft lining.Then,the first application of inner steel plate of steel fiber high strength concrete composite shaft lining in Banji Coal Mine auxiliary shaft repairmen,and the site measurement results show that the two monitoring level of strain in steel fiber concrete is respectively -290με and -359με,which is far less than the ultimate compressive strain.It shows that deformation of new type of shaft lining concrete is small,and the structure of shaft lining is safe and reliable.