In order to simplify the work of pre-process in finite element analysis of large scale bolted rock discontinuities,a combined element model of bolted rock discontinuities is presented based on the displacement interpolation function of discontinuity element and the stiffness matrix of bolt element.

Since pre-stressed concrete box girders usually have a large number of curve pre-stressed tendons,a type of combined element is presented to simulate the prestressed tendons of box girders,and then the number of elements can be significantly reduced.