Chapter 11
Monitoring during construction S. Miliziano Sapienza University of Rome
G. Russo University of Naples Federico II
A. de Lillis Sapienza University of Rome
D. Sebastiani Geotechnical and Environmental Engineering Group
CONTENTS 11.1 Introduction......................................................................................................317 11.2 Relevant physical quantities and measurement techniques ..............................319 11.2.1 Tunnel monitoring .................................................................................319 11.2.1.1 Conventional tunnelling ......................................................... 320 11.2.1.2 Mechanized tunnelling ........................................................... 322 11.2.2 Surface monitoring ............................................................................... 325 11.3 Calculations for monitoring purposes – warning thresholds .......................... 329 11.4 Concluding remarks .........................................................................................331 Authorship contribution statement ............................................................................331 References ................................................................................................................. 332 11.1
INTRODUCTION
During tunnel construction, as for many other civil engineering works, data are collected, processed and interpreted with the aim of observing the performance of the system under construction. The whole of all these activities is named monitoring, and it is commonly included in a risk control and management strategy. Monitoring should ensure the timely detection of any warning signs of instability in the response. Monitoring should also allow the optimization of the design during construction and the assessment of the technical-economic efficiency of the employed excavation procedures in terms of production parameters (e.g. advancement speed, power consumption and tool wear). Furthermore, monitoring data constitute a useful documentation for the resolution of any legal dispute between the parties (contracting entity, contractor and third parties). Another crucial goal of monitoring plans should be the real-time assessment of the environmental impact of tunnel excavation. Three main types of monitoring can be identified: for geotechnical and structural purposes, for the workers’ health and safety and for avoiding machines damages. A common factor for all of them is the minimization of the typical risks of underground
DOI: 10.1201/9781003256175-11
