Without efficient solution to the existing social problem, disastrous consequences, such as economic collapse, social unrest, and even military conflicts, will be brought to our society.

Then using the approximate solution as initial value of iteration, the nonlinear equations for the closest point of collapse are solved directly by Newton-Raphson method.

In the drilling process, should be kept clean hole soil, encountered hole collapse, shrinkage and other abnormal situations, timely solution.