Analytical Solutions of Hydraulic Tunnel With a Consideration of Variation of Principal Stresses Orders and Different Elastic Moduli in Tension and Compression

Abstract:

Based on the unified strength theory and elasticbrittleplastic model,analytical solutions of elasticplastic for circular hydraulic tunnel are introduced considering the principal stresses orders under different engineering conditions,different elastic moduli in tension and compression,the intermediate principal stress and softening.The influences of different tension and compression modulus ratios and the intermediate principal stresses on the critical pressure and ultimate pressure for hydraulic tunnels are discussed.The example analysis results show that the first principal stress should be reasonably considered,if different elastic moduli in tension and compression are neglected,large errors may be resulted in.Traditional elasticplastic solutions of hydraulic tunnel based on an assumption that the geotechnical materials have the same elastic moduli in tension and compression may bring out a more conservative engineering design.A consideration of different elastic moduli in tension and compression reflect the true mechanical property of geotechnical materials,therefore,an economic and safety design is obtained.This result provides some reference value for engineering design and a theory basis for the elastoplastic analysis circular hydraulic tunnels.

Key words:elastic moduli in tension and compression; principal stresses orders; hydraulic tunnel; analytical solution