The authors established a mathematical model between threshod wind erosion velocity and vegetation coverage based on research achievement of the resistance decomposition rule of the rough boundary layer.

Numerical simulation and analysis of smoke characteristics and critical velocity in underground railway tunnel while fire;

Furthermore, a critical velocity of air flow expression for transition from upward smoldering to flaming combustion is constructed.

The model for calculating the critical velocity in a tunnel cross-passage is established on the basis of the critical Froude theory.

Based on vibration theory,this paper presents concise methods for critical wind speed,Vcr,at which tube members start the aeolian vibration,and resonance force calculations,and analyzes the influences of resonant bending and fatigue stress on safety of web and auxiliary members that are subject to the aeolian vibration.

The three-series solution is taken up to the nonlinear differential equation of the galloping movement caused by the cross wind force acting on a high-rise structure, thus giving a reduced 3D expression in terms of steady-state response and critical wind speed.

At the same time,it analysis relative factors of smoke control in the tunnal, and gives the critical wind speed of smoke control in the typical tunnel.

Natural characteristics of long span cable stayed bridges and calculation of its critical wind velocity of flutter;

In order to determine critical wind velocity of mem- brane at first order instability, further vortex sheet on membrane is use.

The determination of the critical wind velocity is one of the main targets.