Stability Evaluation of Inclined Elliptical Cavities Under Subgrade Loads and Factor Impact Analysis
To prevent road disasters caused by secondary activation of goafs seriously threatening highway safety,stress superposition method was used to superpose additional stress fields under subgrade loads calculated on the basis of Boussinesq equation with initial stress fields to obtain stress state at any point around the cavity.Elliptical cavity stability was assessed by using Mohr-Coulomb strength criterion,and reliability of stability evaluation was verified by comparing with previous research results.The maximum subgrade load that the elliptical cavities could remain stable was calculated by using dichotomy method,and influences of subgrade load width ratio,subgrade load eccentricity ratio,major-minor axis ratio of elliptical cavity,and elliptical inclination angle on elliptical cavity stability were discussed.The results show that when the major axis of elliptical cavity is along horizontal direction,the stress concentration effect of elliptical cavities caused by increases of major-minor axis ratio of elliptical inclination and subgrade loads is super-imposed,resulting in the maxi-mum subgrade load decreases with the increase of major-minor axis ratio.When the major axis of elliptical cavity is along vertical direction,horizontal stress concentration effects caused by the initial stress field and the additional stress field weaken each other,and the foundation with elliptical cavities can withstand greater subgrade loads.
万方数据
维普
