Q-system Rock Mass Classification Calculator

A free, simple Q-system rock mass classification calculator. Q-value gives a description of the rock mass stability of an underground opening in jointed rock masses. High Q-values indicates good stability and low values means poor stability.

What is the Q-system?

The Q-system is a widely recognised method for classifying the stability of underground excavations in jointed rock masses. It distils a handful of geotechnical parameters—such as joint set count, roughness, and water inflow—into a single Q-value that captures the overall quality of the rock mass. A higher Q-value points to more stable rock conditions, while a lower Q-value flags areas that might need extra support or design adjustments.

Why and When to Use the Q-system

The Q-system suits everything from tunnelling to building caverns, helping you quickly get a grip on rock quality and make decisions on support. Whether you're designing a new excavation or keeping tabs on changing ground conditions in an active project, the Q-system streamlines a lot of technical data into one straightforward metric. This lets engineers, geologists, and planners compare sites, monitor developments over time, and stay one step ahead of any stability issues.

Our free Q-system calculator brings all this to your screen with just a few clicks. Input some basic rock mass details—like joint spacing and groundwater conditions—and the tool does the maths. You'll get a clear Q-value that reflects how strong or weak the rock mass might be, along with insights on what that means for reinforcement or excavation design. It's an ideal tool if you want practical, no-fuss evaluations without burying yourself in complex software or manual calculations.

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