Variation trend analysis and Comparison of basic parameters of blasting Pattern design different methods in tunnel faces

Blasthole diameter and tunnel cross section are very important parameters in designing blasting pattern. Any change in these two parameters can have a significant impact on the economic and technical parameters of the design including specific charge and specific drilling. Several models have been proposed for the design of blasting patterns that can generally be categorized in two models: models based on parallel cuts and models based on angular cuts. Selection of one of these models or methods for initial design pattern is important. In this study، initially، a software is designed for Convenience of calculation. Effective parameters on blasting design such as rock and explosive properties are kept constant to study the effect of other basic parameters including blasthole diameter and tunnel cross section on parameters such as specific drilling and specific charge. Various models and methods have been studied in this research. The result show that the average blast holes number in angular method is more than parallel method for constant hole diameter and tunnel sectional area. Specific charge in parallel methods is often more than angular method. Also specific drilling، in some range of hole diameter and sectional area is higher for angular method and in other ranges parallel method Shows higher values but they are generally very close together.