Narrow Results

Drill and blast method has been widely used as an effective excavation method for underground rock caverns or tunnels. To achieve a good blast design, an understanding on the rock dynamic response and rock fragmentation process is important. In this paper, numerical simulations are performed on a typical parallel hole cut blasting based on the discontinuous deformation analysis (DDA). The blast loading is obtained from the explicit FEM code LS-DYNA and the dynamic response of the rock mass is modeled by the DDA. Different influence factors on rock fragmentation under the blast loading are investigated, including the different delay time and various rock mass properties. Such a study will have potential applications for better drill and blast designs.

The use of blasting operations in constructions nowadays is not rare anymore. The presence of hard materials during excavation works can disrupt the progress of the project since it cannot be excavated using the conventional excavators. Indirect excavation assessment is the best way to assess the best excavation method prior to the actual excavation works. Past experiences have shown that rippers are up to the mark for soft-rocks. Nevertheless, sometimes rippers fail to reach the desired productivity and will increase the cost and time of the project. As a solution, blasting operation is normally employed in most cases. The blasting operation must be monitored and controlled especially if it is carried out at sensitive area to avoid damage to property, buildings and injuries to people. , This study looks at 2 actual case studies of controlled blast at Seri Alam and Gelang Patah, Johor, Malaysia which have different geological material. Seri Alam is a granitic area and has a lot of boulders to be blasted while Gelang Patah site comprises of old alluvium. The results showed there are differences in the blast design especially on the spacing and burden at these sites in order to achieve the desired fragmentation and to control flyrock.