ABSTRACT
Filed measurements, model tests and numerical analyses are underway to establish a standard to evaluate soundness of deformed tunnel lining. The present paper reports on the results of (1) case studies of tunnels deformed by squeezing earth pressure; (2) 1/30 scale model lining tests; (3) crack propagation analysis, and (4) development of design method for countermeasures against deformed tunnels. Notably it refers to the effects of countermeasures against earth pressure. To sum up the contents; 1) Back-fill grouting can vastly improve the strength of defective tunnel lining with opening behind lining; 2) rock-bolting or inner reinforcement exhibit an ample effect of reinforcement, provided it is preliminarily treated with back-fill grouting; and 3) invert concrete excels in the effect of displacement suppression, but for the purpose of enhancing the structural strength, combination with other lining countermeasure is advocated.
