Diagnostics of Conditions of Ice Walls, Jet-Grouting Fences and Concrete Slurry Walls After Accidents in Underground Construction of St. Petersburg by Crosshole Sounding Method

The paper presents the methodology and examples of diagnosing the condition of emergency man-made underground fences in St. Petersburg (Russia). Diagnostic methods are crosshole acoustic and ultrasonic sounding from holes or embedded tubes. The investigation uses crosshole sounding apparatus APZ-1 developed by LLC “Geodiagnostika.” The results of determining the condition of the ice wall of the escalator tunnel of the Zvenigorodskaya metro station, the soil–cement fence of the sewer shaft and the concrete slurry walls of the road half-tunnel in Western High-Speed Diameter are considered.