Study on Spraying Construction Method of a Non-Water Reacting Polymer Layer in the Tunnel

Abstract

Non-water reacting double-component foamed polyurethane has been increasingly used in the field of transportation. Particularly, it is recognized that a polymer damping layer between tunnel linings and surrounding rocks can improve the seismic performance of tunnels. To facilitate the application of this polymer in tunnels, a spraying construction method of polymer damping layers was proposed. The polymer damping layer was prepared with hydraulic spraying equipment, and the construction process included the pre-treatment of the tunnel base surface, the pressure control of the spraying equipment, the adjustment of the spray gun working parameters and spraying quality control. In this paper, the effects of material ratio, material temperature, environmental factors (i.e., temperature, humidity and wind speed), spraying pressure and spray gun parameters (i.e., speed, distance from the sprayed surface and spray angle) on the layer formation were investigated. Thus, spraying parameters for better spraying performance were recommended. This study will provide technical support for polymer damping layer construction in the seismic design of tunnels.

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.…”