Tunnel Squeezing Deformation Control and the Use of Yielding Elements in Shotcrete Linings: A Review

Abstract

Shotcrete lining shows high resistance but extremely low deformability. The utilization of yielding elements in shotcrete lining, which leads to the so-called ductile lining, provides a good solution to cope with tunnel squeezing deformations. Although ductile lining exhibits great advantages regarding tunnel squeezing deformation control, little information has been comprehensively and systematically available for its mechanism and design. This is a review paper for the purpose of summarizing the development history and discussing the state of the art of ductile lining. It begins by providing a brief introduction of ductile lining and an explanation of the importance of studying this issue. A following summary of supporting mechanism and benefits of ductile lining used in tunnels excavated in squeezing ground conditions is provided. Then, it summarizes the four main types of yielding elements applied in shotcrete lining and introduces their basic structures and mechanical performances. The influences of parameters of yielding elements on the supporting effect are discussed and the design methods for ductile lining are reviewed as well. Furthermore, recommendations for further research in ductile lining are proposed. Finally, a brief summary is presented.

A Study on the Results of Risk Analyses Applying the Concept of Rock Mass Stand-Up Time for Underground Mining Sites

“…Selected results of the vertical time-dependent displacement of the tunnel wall over different periods at 40, 50, and 60 GSI levels are shown in Figure 9. Analyses of the modelling results revealed that tunnel wall vertical displacement obtained using the FEM approach gave close values to those calculated using Formula (27). The comparative results are in good agreement with those obtained by [1,3,5,6].…”

“…In underground tunnels, creep processes are generally observed together with the contraction of the tunnel section diameter with time [15,26]. This behaviour can be considered a compression and swelling phenomenon of weak and soft rocks [27,28]. Swelling is defined as the volume change of rocks containing clay particles, such as montmorillonite and other components, with high swelling capacity [29].…”

An Experimental Study of the Mechanical Properties of Partially Rehabilitated Cable Tunnels

“…From the aspect of tunnel lining and reinforcement, Nie [ 18 ] analyzed the piezo resistivity for an inner-adhesive-type carbon fiber reinforced plastic tunnel reinforcement; Zhou [ 19 ] studied the dynamic response of the lining structure in a long tunnel subjected to a non-uniform seismic load; Sun [ 20 ] studied the spraying construction method of a non-water reacting polymer layer in the tunnel; Zheng [ 21 ] discussed the use of yielding elements in shotcrete linings in tunnel squeezing deformation control; Wang [ 22 ] studied the response characteristics of cross tunnel lining under a dynamic train load; and Zhang [ 23 ] studied the sustainability performance of reinforced concrete structures in tunnel lining induced by a long-term coastal environment.…”

“…As for polymer materials, most research has focused on the polymer materials modified with fibers and inorganic materials: Li [14] studied the anisotropic mechanical response and strain localization of a metallic glassy-fiber-reinforced polyethylene terephthalate fabric; Lionetto [15] studied carbon fiber reinforced polymers; Park [16] studied a microwave composite forming process based on a sic mold for manufacturing fiber metal laminate; and Lou [17] investigated the fatigue performance of an asphalt mixture reinforced by basalt fiber. From the aspect of tunnel lining and reinforcement, Nie [18] analyzed the piezo resistivity for an inner-adhesive-type carbon fiber reinforced plastic tunnel reinforcement; Zhou [19] studied the dynamic response of the lining structure in a long tunnel subjected to a non-uniform seismic load; Sun [20] studied the spraying construction method of a non-water reacting polymer layer in the tunnel; Zheng [21] discussed the use of yielding elements in shotcrete linings in tunnel squeezing deformation control; Wang [22] studied the response characteristics of cross tunnel lining under a dynamic train load; and Zhang [23] studied the sustainability performance of reinforced concrete structures in tunnel lining induced by a long-term coastal environment.…”