粗砂层上扩底墩竖向承载性状的数值模拟

为了分析粗砂层上埋深14.5 m扩底墩的竖向承载性状,建立了三维有限元非线性数值模型.可以发现计算与实测的Q-s曲线非常接近;墩底端阻力的发挥严重滞后于墩侧摩阻力,墩顶荷载主要由端阻力承担,属摩擦端承型;扩大头侧面与土体接触处产生裂缝,裂缝首先在侧面下部产生,随荷载增加逐渐向上发展直至贯通,最大裂缝宽度达4.6 mm;墩底压缩区主要集中在距墩底1.6倍墩底直径范围内.

Numerical Simulation of Vertical Bearing Behavior of Belled Pier Ended on the Coarse Sand

In order to analyze the vertical bearing behavior of belled pier embedded in coarse sand at the depth of 14.5m,a three-dimensional non-linear finite-element numeric model is established.The results show that Q-s curves calculated and measured are close to each other.The end bearing of pier has a delayed action compared with that of side-friction,the loads on the top of pier are mainly borne by end bearing,so the pier belongs to friction and end-bearing model.It is known that the crack initiates between the side face of enlarged end and the soil.The crack appears firstly on the bottom of the side face,and with the increase of the loads it develops upwards gradually till going through,the maximal width of crack achieves 4.6mm.The compression zone of pier is in range from the bottom of the pier to the depth of 1.6 times diameter of the bottom of the pier.