Study on surrounding rock pressure of deep jointed rock tunnel based on pressure arch theory

To study the calculation method of rock pressure in jointed rock tunnels, based on the theory of tunnel pressure arch, the influence of rock hardness, integrity, and shear strength of structural planes on tunnel pressure arch was analyzed through discrete element numerical simulation. Multiple linear regression was applied to fit the multi factor rock pressure formula, and the applicability of the fitting formula was analyzed in combination with engineering support. The results indicate that the range of pressure arch in jointed rock tunnels is the deflection point from the arch crown to the direction of maximum principal stress; The height of tunnel pressure arch decreases with the increase of joint spacing and shear strength of structural planes, and the influence of rock mechanics parameters on the height of pressure arch is relatively small; Compared with the measured rock pressure on site, the calculation error is within 15%. The proposed formula for surrounding rock pressure has good applicability and provides a new approach for calculating the surrounding rock pressure of jointed rock.