Abstract:

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.

Key words: deep-mixing pile, composite foundation, bearing capacity of foundation, foundation settlement