Research on stress distribution and deformation law of surrounding rock of deep and large mining height gob-side entry retaining

Abstract

To study the mechanical properties of high water filling materials, achieving the purpose of filling the side of the roadway, through uniaxial compression tests on high water materials with different water-cement ratios, we analyze the relationship of uniaxial stress-strain and the relationship of strength and maintenance at different stages. Taking Xishan Coal and Electricity Tunlan Mine as the engineering background, the deformation characteristics of the surrounding and the stress evolution law were investigated by numerical analysis. The results show that with the increase of water-cement ratio, the strength of high-water filling material decreases obviously, the uniaxial compressive strength of the material is 6.62 MPa when the water-cement ratio is 1.5∶1, 4.08 MPa when the water-cement ratio is 2∶1, and 2.85 MPa when the water-cement ratio is 2.5∶1, which are reduced by 38% and 60%, respectively; in the tunneling stage, the maximum roof and floor movement is 45.6 mm, and the maximum roof and floor movement is 203.0 mm during mining. During the period of roadway retention, the roadway is greatly affected by mining within 30 m of the advance working face, and the roof obviously sinks.

Keywords

• gob-side entry retaining
• large mining height
• high water filling
• numerical simulation
• stress evolution
• law of deformation