2.The Distinct Element Method(DEM)is a discontinuum-based numerical method especially applicable to solve the discontinuity problems in jointed rock mass.
3.This paper presents an efficient method of modelling jointed rock by using the boundary ele-ment method via the concept of multiregion and non-linear model of joint and fault.
4.Mechanical strength of pipe coating and its thickness of standard paintcoat must be ensured in the pipe coating production lines,two pipes in the course of coating must be flexibly jointed.