Surface Settlement during Tunneling: Field Observation Analysis

Abstract

We address the effect of three groups of factors on supplementary ground surface displacements during tunnel construction. The first group of factors includes the engineering and geological properties of the massif in which the tunneling is conducted; the second group includes the structural features of the designed tunnels and surrounding buildings, and the third group includes the engineering parameters of the tunneling process. The research takes advantage of the geotechnical monitoring data obtained during the construction of underground facilities and the engineering parameters of shield tunneling during construction of single- and double-track Moscow underground lines by using EPB (earth pressure balance)–TBM (tunnel boring machines) in different soils. The dependence of additional displacements, occurring above the designed tunnel, on the TBM pressure, is addressed in detail. The presence of a close interdependence is evidenced by a correlation coefficient equal to 0.77. No dependence of the settlement on the diameter or depth of the designed tunnel, the distance from the tunnel axis to the monitored object, the loading that comes from a building in the affected area, or the boring rate was identified. The consideration of this parameter can be used to predict the soil displacement around the tunnel at construction facilities having similar geological profiles and boring parameters.

Keywords

• EPB–TBM
• shield tunnel
• metro
• ground surface settlement
• operating tunneling parameters
• monitoring