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为了研究斜井冻结法凿井过程中井壁结构的安全性,对哈密大南湖十号煤矿主斜井进行了现场实测,获得了主斜井冻结段井壁混凝土应变和钢筋应力的变化规律。结合混凝土极限拉压应变,分析了井壁结构的安全性,并对斜井冻结施工提出优化建议。研究表明:井壁浇筑后,混凝土应变变化可分为4个阶段,即紊乱期、应变加速增长期、应变缓慢增长期及应变稳定期,井壁真实应变应从紊乱期后开始计算;斜井井壁设计主要受拉应变控制;在大南湖十号煤矿主斜井施工中,井壁底板环向拉应变最大达1 280με,远大于混凝土设计极限拉应变,井壁圆弧段局部位置环向拉应变超过200με,井壁处于破裂危险状态。
In order to study the safety of the shaft wall structure during the shaft freezing shaft drilling, the main shaft of Da Nan Nanhu No.10 coal mine was measured on site, and the variation law of concrete strain and steel bar stress in the shaft section of the main inclined shaft was obtained. Combined with the ultimate tensile and compressive strain of concrete, the safety of wellbore structure is analyzed, and the optimization suggestion of freezing construction of inclined shaft is proposed. The research shows that the concrete strain changes can be divided into four stages after the shaft wall is poured, namely, the dislocation period, the period of accelerated strain growth, the slow strain growth period and the strain stability period. The true wall strain should be calculated after the disturbance period. Wall design is mainly controlled by tensile strain. In the construction of main inclined shaft at No.10 Mine of Dainan Lake, the circumferential tensile strain in the bottom wall of the wellbore reaches a maximum of 1,280με, which is much larger than the ultimate tensile strain of concrete design and circumferential hoop Strain exceeds 200με, borehole wall is in rupture dangerous state.