ISSN 2658–5782
DOI 10.21662
DOI 10.21662
Electronic Scientific Journal
In this work, the propagation of blast waves in a rock mass caused by a short-term load is considered. Such loads
are typical in the construction of tunnels and other excavations using blasting. For modeling by the finite element
method, the cross-platform software COMSOL Multiphysics 5.4 was used. The explosion is reproduced in a steel tank
whose steel grade is EN 1.7220 4CrMo4. The medium in the tank has the properties of granite rock (Young’s modulus
explosion,
destruction
Before the advent of tunnel drilling machines, blasting was the only economical way to build long tunnels through hard rock where digging is not possible. Even today, this method is still used in the construction of tunnels, for example, in the construction of the Lötschberg tunnel in Switzerland.
The decision to build a tunnel using a drilling machine or blasting method involves a number of factors. Tunnel length is a key issue that needs to be addressed because large mining tunnel drilling machines have high capital costs. This means that shorter tunnels are generally less economical to build with these machines and, therefore, are usually built using blasting.
Therefore, the question remains the amount of explosives needed for safe operation.
Purpose of study: the study the propagation of waves in a rock mass caused by a short-term load.
Research methods: The explosion process is simulated by the finite element method in the cross-platform software COMSOL Multiphysics® 5.4. The Body Load tool with the Force per unit volume parameter is used to simulate the total volume loads.
The force per unit volume in COMSOL Multiphysics® 5.4 is calculated according to the equation of motion (density * acceleration = gradient of the 1st Piola-Kirchhoff stress tensor + force per unit volume). The Piola-Kirchhoff stress tensor connects forces acting in spatial directions with regions in the initial undeformed configuration. Thus, its components are defined by indices related to various configurations.
The following tasks have been completed:
As a result of the calculation, the following data were obtained:
Conclusion: The result of this work was the simulation of an explosion in a solid medium (granite) in a steel barrel. The barrel pressure and displacement field were calculated.
Also, the fracture pressure was calculated, above which the barrel will be destroyed and the simulation will stop.
This basic model of the explosion will further allow for a broader study by increasing the number of simulation parameters, for example, temperature.
