深基坑桩锚支护的数值模拟

The Numerical Simulation of Piled-anchor Support in Deep Foundation Pit

对利用FLAC3D进行深基坑数值模拟时经常遇到的一个关键而又常被忽视的结构单元连接问题进行了详细探讨,阐述了结构单元的连接方法、种类与性质,利用结构单元连接理论对某一采用桩锚联合支护的深基坑开挖工程进行了模拟分析,研究了桩的最大水平位移、弯矩、内力以及锚杆轴力、附近建筑物基础底面沉降随施工过程的变化规律。指出桩的最大水平位移并不是发生在桩顶处,而是在基坑开挖到的位置附近;桩的弯矩在整个桩长范围内正负交替出现;桩的受力主要为压力,而且最大值也是出现在基坑开挖到的位置附近;锚杆轴力在端部最大,然后逐渐减小,在尾部几乎为零;附近建筑物基础在靠近基坑一端有被抬升的趋势,而另一端则有下降的趋势。

This paper makes the detailed exploration into the structure unit connection that is a crucial but ignored problem often met in the numerical simulation of the deep foundation pit, expounds the methods, kinds and properties of the structure unit, and makes the simulative analysis on the excavation work of the deep foundation pit with the piled-anchor support by using the the theory of the structure unit connection, studies on the maximum horizontal displacement, bending moment, internal force of the pile, the axial force of the bolt and the settlement of the base bottom of the building nearby along with the construction process. And points out that the largest horizontal displacement of the pile occurs not at the top of the pile, but at the place of the excavation; the pile bending moment is alternately positive and negative along the length of the pile; the stress of the pile is mainly compressive one, and its maximum occurs at the place of the excavation; the maximum axial force the bolt occurs at the top of it, and decreases along the length of the bolt, and is nearly zero at the end of it, the basement of the building nearby the foundation pit goes up, and the other end goes down.