利用极限分析上限解理论分析了泥浆护壁作用下阳角处槽壁的稳定性，建立了失稳面为对数螺旋锥面的三维失稳模型，得到内耗散功率、重力功率、泥浆压力功率的表达式，通过求解能量平衡方程得到了槽壁安全系数的上限解，并研究了在不同参数（泥浆容重、泥浆液面深度和内摩擦角等）下槽壁安全系数的变化规律．结果表明，随着泥浆容重、黏聚力、内摩擦角的增加，槽壁安全系数增大；随着泥浆液面深度、开挖深度、开挖步长的增加，槽壁安全系数减小．

Three-dimensional limit analysis was utilized to determine the stability of the convex corner in a slurry-supported trench. Analytical solutions were derived for the safety factor of the convex corner stability in a slurry-supported trench. The failure surface has the shape of logarithm helicoids, with outline profile defined by a log-spiral curve. Power expressions were obtained for dissipation rate, gravity and slurry pressure. By solving the energy balance equation, the equation of safety factor for convex corner stability was obtained. The slurry weight ratio, the slurry surface depth, the angle of internal friction and other parameters were discussed. The result indicates that the stability factor increases with increasing slurry and soil bulk density ratio, cohesion, friction angle, but it decreases with decreasing slurry level depth and trench depth ratio, trench width and depth ratio.