论文部分内容阅读
西德在冻结井筒施工中,为保证安全通常用复合井壁支护。井壁分内外两部分,外井壁为混凝土预制块,内井壁为双层钢板夹混凝土层,内外层之间为沥青层。内层井壁支护时,通常是将钢板逐块吊入井内并在井下焊接。由于钢板很厚(达71毫米),焊接工作量甚大,这在经济上,时间上和劳动组织上都是不利的,因此近年来西德在这方面做了一些改进。
West Germany in the construction of frozen boreholes, in order to ensure the safety of composite shaft lining. Shaft wall inside and outside the two parts, the outer wall of the precast concrete block, the inner wall of the double-layer steel folder concrete layer, between the outer layer of asphalt. When lining the inner lining, it is common to hang the steel plate into the well block and weld it downhole. Due to the thickness of the steel plate (up to 71 mm) and the large amount of welding work, which is unfavorable economically, time-intensive and labor-intensive, West Germany has made some improvements in this area in recent years.