Deformation of soil masses during construction of shallow utility tunnels

Abstract

IntroductionThe method outlined in [1] for analysis of ground-surface settlement demonstrates its dependence on the distance to the axis of the tunnel, D and H, characteristics of the soil (considering the stratification of the soils), and the excess-soil factor V L . Burland et al. [2] have developed a method in which a formula is given for the argument of the inflection point on the curve of the function of ground-surface settlements during the opening of a tunnel. Excavations [3], which have modified the Peck method [1], supplementing it with a moisture-content characteristic, have also come into use. Figure 1 shows a surface-settlement diagram based on the empirical methods cited with parameters entering as component parts of the formulas.Construction practice demonstrates that methods employed to calculate settlement for deep tunnels are not always applicable for shallow tunnels. In contrast to deep transportation tunnels, the diameter of utility tunnels D = 3-4 m, the depth of embedment H = 4-8 m, and the relative depth of embedment χ = H/D does not exceed 3. Method for Prediction of Surface Settlement During Opening of Shallow TunnelsTo substantiate prediction of surface deformations during the opening of shallow tunnels, a series of projects were subjected to in-situ settlement measurements, which were then compared with data acquired by empirical methods for deep tunnels (Table 1). Figure 2 shows the 4-m-diameter storm-drain collector along the Gruzinskii Street line in Moscow, which is being constructed by the shielded method by a Lovat RME 163 SE series 23300 tunneling unit with a soil surcharge. The depth of embedment was 4.0-8.0 m (the analyses were performed by the N. M. Gersevanov Scientific-Research Institute of Foundations and Underground Structures, and scientific accompaniment by the Scientific-Research Institute of Foundations and Structures and the ANO ANTTs RAASN). A characteristic feature was that the shield passed close to the surface in the fill Results are cited for theoretical and experimental investigations of the prediction of deformations of the ground surface and buildings, which develop during the opening of shallow utility tunnels constructed by the shielded method, and also measures taken to reduce the deformations that occur as a consequence of such an opening.

A Critical Review of the Sustainability of Multi-Utility Tunnels for Colocation of Subsurface Infrastructure

“…The final inclusion step was based on the analysis of the 59 articles, where sustainability claims in this analysis defined as "a concrete statement about the sustainability consequences of using MUT instead of OCE" were sought. The occurrence of this type of claim was used as the final selection criterion, which led to exclusion of articles that focused on soil conditions (Il'ichev et al, 2011), BIM technologies (Wu et al, 2018;Ge and Xu, 2019;Hu and Zhang, 2019) and seismic performance (Chen et al, 2010(Chen et al, , 2018Jiang et al, 2010; of using MUTs without discussing the implications on sustainability. After this final selection stage, 21 articles remained for further analysis.…”