Measurement and analysis of the internal displacement and spatial effect due to tunnel excavation in hard rock

•Pre-embedding intelligent multi-point extensometers before excavation.•Estimating loss displacement with 3 LDP curve equations, Hoek equation is optimal.•Internal displacement passes through initial growth, rapid growth, stable convergence.•Temporal curve is similar to a creep test curve for rock subjected to graded loading.•Measuring points farther from the side wall are less affected by the spatial effect.