Scale Model Study on Water Seepage from Cracked Lining Structure

Abstract

The calculation of water pressure behind a cracked lining structure requires determination of the crack width, amount of water seepage and the value of water pressure. Regarding the relationship among lining structure crack, water seepage and water pressure, self-made concrete splitting specimens and Chongqing University developed cavitation acoustic shock test system are used to study water seepage in the specimens. The test results show: water pressure and crack width are main factors influencing water seepage; at a given crack width, excessive water pressure imposes local load on the lining structure, aggravating its cracking; when the crack is excessively wide, water pressure changes slightly but flow rate increases considerably affecting traffic in the tunnel. Meanwhile, increased pressure from surrounding rock compresses the crack in the lining structure and reduces flow rate. The study results can provide reference to treatment of defects in tunnels at different depths in different areas.