长距离泵送混凝土砌碹支护研究

Study of Arching Support by Long Distance Concrete Pumping

某矿-400 m水平水仓位于地质构造复杂区域内且底板极具亲水膨胀性,在高构造应力、高地应力以及高膨胀应力的作用下,原有普通锚网索喷支护方案无法维持水仓围岩的基本稳定;根据现场地质条件及围岩破坏原因剖析,结合原支护方案的不足,决定对水仓围岩采用全断面钢筋混凝土砌碹支护方案。首次将长距离泵送混凝土技术引进到矿山砌碹支护中,弥补了普通人工砌碹的不足,取得了良好的技术效果与经济效益。研究结果表明:处于软弱膨胀岩层中的水仓,仅通过锚网索喷很难维持巷道的基本稳定;对松动围岩二次注浆加固后,可有效提高围岩的自身承载能力和支护结构的整体性;全断面钢筋混凝土砌碹支护结构,可有效控制巷道的严重底鼓变形。

The water sump of a certain coal mine at -400 m level is located in a complicated geological structure zone with an extremely water-swellable floor. Under the functions of high tectonic stress, in-situ stress and expansion stress, the previous common support by bolt, mesh, shotcrete and cable can no longer keep the essential stability of wall rock of the sump. Based on the analysis of in-situ geological conditions and wall rock failure reasons, and in view of the deficiencies of the original support design, a full-face reinforced concrete arching method was adopted for the support of the sump＇s wall rock. The long distance concrete pumping technology was introduced for the first time in mine arching support, which covered the shortage of common manual arching and obtained good technical effects and economic benefits. The research results show that it is very hard to keep the stability of sump in a soft rock stratum with great expansivity only by the support with bolt, mesh, shotcrete and cable. A secondary grouting can effectively improve the wall roek＇s carrying capacity and the integrity of support structure while a full-face reinforced concrete arching can control the serious floor heave of roadway.