The paper discusses a blasting funnel experiment on blasting holes with a diameter of 40 mm,and a theoretical analysis on the experiment data with a conclusion of critical burying depth,optimal burying depth,stain coefficient and so on.

Through the experiment, parameters of blasting runnels for explosive package in the model coal medium and critical burying depth of loose blasing are obtained.

Limit analysis of the critical depth of circular step-sloped foundation pits;

Numerical analysis about the critical depth of two-layer foundation;

Study on the critical depth and minimal thickness of static piling;

Calculation on uniform flow depth and critical depth of open channel with iterative method;

The direct solution on critical depth of horseshoe section tunnel;

Approximate solution for the critical depth of a arched turnel;

Approximate formula for calculating the critical water depth at circular cross section;

The new algorithm of nonlinear constrained optimization calculation of critical water depth problem s new algorithm;

Calculating critical water depth of trapezoids open channel by real coding based on Accelerating Genetic Algorithm;

The analysis shows that the amplitude-frequency response changed from soft to hard spring type at a critical depth which depends on the position of the liquid fuel and the ratio of the sum of the mom.