फरक पाना| Zircon Creations

Overbreak in tunneling refers to the phenomenon where rock excavation goes beyond the calculated profile, resulting in additional damage to the surrounding rock mass and increased costs to the construction project. There are several factors that can contribute to overbreak, including poor excavation sequences, unprofessional blasting procedures, and insufficient primary support. One major factor that can cause overbreak is the presence of unfavorable joints in the rock, which can lead to fractures intersecting the jointing planes and causing large pieces of material to fall out of the face during excavation. This can be mitigated using controlled blasting techniques, such as pre-splitting, trim blasting, and line drilling, which are particularly effective in large rock formations. However, these techniques may not be effective when the rock has multiple joints between blast holes, and those joints intersect the face at less than a 15-degree angle. Another factor that can cause overbrea...

Advantages of geophysical investigation methods include their ability to map subsurface variations in a non-destructive manner, and their ability to image deep and shallow subsurface structures. Limitations include their sensitivity to surface topography and the need for a clear path for wave propagation. The specific advantages and limitations of each method, such as ERT, SRT, MASW, MAM, and HVSR, can vary depending on the technique and the subsurface structure being studied. Electrical resistivity tomography (ERT) is a geophysical method that uses electrical currents to map subsurface resistivity variations. Advantages of ERT include its ability to map subsurface resistivity variations in a non-destructive manner, and its ability to image deep subsurface structures. Limitations include its sensitivity to surface topography and the need for a clear path for electrical current injection and measurement. Seismic refraction tomography (SRT) is a geophysical method that uses the travel ti...