Experimental and numerical investigation on rock breaking of conical pick assisted by abrasive water jet gridding pre-cutting method

In the excavation of rock tunnels, conical picks face lots of problems, such as insufficient rock breaking capacity, low rock breaking efficiency and high wear rate. In order to solve these problems, a new rock breaking method is put forward to combine conical pick with abrasive water jet gridding kerfs (AWJGK). The effects of kerf depth cut by abrasive water jet (AWJ), grid geometry size and pick arrangement on rock breaking performance are studied by orthogonal experiment. Meanwhile, numerical simulations based on finite element method (FEM) model are carried out to study the performance of conical pick and obtain the optimum operating parameters The results show that the average rock breaking volume increases by 322.81%, the average pick equivalent stress decreases by 19.83%, and the maximum pick equivalent stress decreases by 31.65% on average. Moreover, optimal parameters are obtained under certain conditions that can provide a reference for practical application.