深基坑土钉支护的参数优化设计

为了降低土钉墙的工程造价并保证安全,建立了土钉墙参数优化设计模型,对土钉道数、土钉直径、土钉长度、土钉水平间距、土钉竖向间距和土钉倾角等参数进行优化设计·对于土钉墙参数这样复杂的优化设计问题,传统的方法很容易陷入局部最优解,而遗传算法(GA)是一种全局优化方法,但在迭代过程中经常出现未成熟收敛、振荡和迭代过程缓慢等缺点·为此提出进退搜索算法与遗传算法结合,并提出改进措施而构成改进混合遗传算法(IHGA)·工程实例的结果表明这种IHGA的优化设计结果不仅保证了深基坑的稳定性,而且使其工程材料成本大大降低·

Parameter Optimization of Soil-Nailed Wall of Deep Foundation Pit

To reduce the cost of soil-nailed wall of deep foundation pit and ensure its safety, a model was developed for its parameter optimization, including the number of lines of nails, their horizontal/vertical space, diameter and length. Traditional methods are apt to get locally optimization solution when used for complex optimum design problems like the parameters of soil-nailed wall. In this respect the genetic algorithm(GA)is a method available to get global optimum, but it often has such shortcomings as premature convergence and oscillation in iterative process. Therefor, a forward-and-backward searching algorithm is proposed in combination with GA and some measures for improvement, thus forming an improved hybrid genetic algorithm(IHGA) which, as proved by an engineering example, offers an optimum design that not only provides the stability for deep foundation pit but also reduces the cost of engineering materials.