上软下硬地层中大直径竖井机械化施工方法

Mechanized Construction Method of Large-Diameter Vertical Shafts in Upper-Soft and Lower-Hard Strata

针对上软下硬地层中大直径竖井机械化建造困难的问题,以深圳大坪区间2标段2#工作井为背景,提出一种适用于上软下硬地层的大直径竖井机械化施工方法。该方法在软岩段采用CJM沉井掘进机进行施工,在软硬交界段进行工法转换,在硬岩段采用机械破岩方式施工。本文对前述大直径竖井机械化施工方法的施工流程、关键施工技术进行详细研究,并对其预制拼装竖井结构设计理论进行研究,提出一种大直径竖井装配式井筒结构设计方案,最后对大直径竖井机械化施工过程中井筒结构内力和周围地层影响进行研究,结果表明该方法对竖井周围地层影响较小,井筒结构受力最不利位置位于土岩交界面以上附近位置。

Aiming at the difficulty of mechanized construction of large-diameter shafts in the upper soft and lower hard strata,a mechanized construction method for large-diameter shafts in the upper soft and lower hard strata is proposed with the background of the 2#working well in section 2 of Shenzhen Daping Interval.This method adopts a CJM sinkhole boring machine for construction in the soft rock section,converts the working method in the soft and hard junction section,and adopts a mechanical rock-breaking method for construction in the hard rock section.In this paper,the construction process and key construction technology of the aforementioned mechanized construction method of the large-diameter shaft are studied in detail,and the prefabricated assembled shaft structure design theory is studied,and a large-diameter shaft assembled shaft structure design scheme is proposed,and finally,the internal force of the shaft structure and the influence of the surrounding strata in the process of mechanized construction of the large-diameter shaft are studied,and the results show that this method has a small influence on the surrounding strata of the shaft,and the most unfavorable location of the shaft structure force is one of the most unfavorable locations of the shaft structure.The most unfavorable position of the shaft structure force is located near the position above the soil-rock interface.