深层搅拌桩复合地基的优化设计

在满足承载力控制和沉降量控制要求的基础上，采用数值模拟的方法分析最优桩长和桩间距，完成了深层搅拌桩复合地基的优化设计，以达到满足建设需求的同时最大限度地节省建设费用的目的。根据深层搅拌桩复合地基的特点，讨论了复合地基承载力特征值的计算方法，分析了沉降量的构成，对沉降计算方法进行了探讨，并选用单位元法和分层总和法来评价复合地基加固区和下卧层的压缩性。结合深层搅拌桩复合地基的设计要素、承载力、荷载压力、沉降量等指标和具体数值参数，通过设置最优桩长和桩间距来求取满足承载力要求的最小总桩长，并通过编程实现了优化过程。通过程序计算，得到了一组满足地基承载力要求的桩长、基础底面积、置换率的最优数据组合，实现了对深层搅拌桩复合地基的优化设计。

Optimal design of deep-mixing pile composite foundation

On the base of meeting bearing capacity control and the requirement of settlement control, we complete the optimization design of the deep-mixing pile composite foundation by using numerical stimulation to analyse the optimal pile length and pile spacing, in order to satisfy the construction demand and meanwhile to save the construction expenditure as much as possible. According to the characteristics of the deep-mixing pile composite foundation, we have analyzed the settlement composition, discussed in depth the computational method of both the settlement and the characteristic value of composite subgrade bearing capacity; in addition we have evaluated compressibility of the reinforced area and the subjacent bed through the unit cell method and the layer-wise summation method. Concerning the index and numerical parameter of the bearing capacity, the load pressure ,also the design considerations of the deep-mixing pile composite foundation, we get the minimum pile length which satisfies the bearing capacity by setting optimal pile length and pile space. Through the calculation of computer programs, we get the optimal data combination of the basal area, the rate of displacement and the pile length which coincide the requirement of the bearing capacity; the optimization design of the deep-mixing pile composite foundation has been realized.