To study the influence of weak layer on the slip failure of surrounding rocks of coal mine roadway, numerical models of coal mine roadway with weak layer are created by using the numerical simulation software UDEC. The influencing laws on slip failure of roadway surrounding rocks under the weak layer and the lateral pressure coefficient are studied. The results show that the existence of weak layer changes the stress transmission path in the surrounding rocks and reduces the stress transmission from the deep part of surrounding rock to the coal wall and promotes the stress transmission from coal seam roof to the coal wall. The weak layer aggravates the shear failure and horizontal slip of surrounding rocks. With the increase of the thickness of the weak layer, the critical failure depth of surrounding rock increases, the shear failure of coal becomes more obvious, and the plastic zone depth and horizontal slip value of surrounding rock also further expand. The lateral pressure coefficient has an important influence on the stability of the surrounding rocks of roadway with weak layer. When the lateral pressure coefficient is 1.0, the surrounding rock of roadway is in the most stable state. When the lateral pressure coefficient is between 1.0 and 2.0, the plastic zone depth of surrounding rock will increase further with the increase of lateral pressure coefficient, and the slip value of surrounding rock will increase non-linearly.
