Numerical simulation of grooving method for floor heave control in soft rock roadway

Grooving method can restrain the deformation and destruction of surrounding rock by transferring the maximum stress to deep rock, bringing about the effective control for floor heave in soft rock roadway. Based on this important effect, and to discuss the relationship between cutting parameters and pressure-relief effect, this paper carried out a numerical simulation of grooving along bottom slab and two sides of gateway with finite difference software FLAC2D. The results show that the control effect on floor heave in soft rock tunnel can be improved by selecting appropriate cutting parameters. Appropriately increasing the crevice depth in the middle of the floor can improve the stress state of bottom slab by stress transfer. So the floor heave can be more effectively controlled. To lengthen the crevice in the corners of roadway can simultaneously transfer the maximum stresses of bottom slab and two sides to deep rock, and promote the pressure-relief effect. Extending the crevice length and crevice width on both sides within a certain range can decrease the stress concentration in the corners of roadway, and reduce the deformation of two sides. The cutting position beneficial to restrain the floor heave is close to the bottom slab.