基于增量法的框架预应力锚杆永久性边坡支护结构的位移计算

Calculation of displacement of permanent slope supporting structure with frame prestressed anchor by means of increment method

在框架预应力锚杆边坡支护工程中,由于锚杆和预应力的存在,使得边坡受力复杂.考虑到边坡土体和预应力锚杆的协同工作关系,利用杨光华在基坑支护中的增量法理论,仅考虑锚杆自由段的弹性变形和锚杆预应力,推导出锚杆水平位移的计算公式;结合有限元分析软件FLAC3D,通过对工程实例的数值模拟来验证推导公式的合理性,得到较为理想的结果.公式计算结果和数值模拟反映出变形趋势基本一致.为框架预应力锚杆支护的永久性边坡位移控制提供一种相对量化且简单的计算方法.

Because of the existence of the anchor bars and prestress in the slope supporting structure with frame prestressed anchor,the force within the slope is made very complicated.Considering the cooperative work of slope soil and prestressed anchor and using the increment method theory of Yang Guanghua for foundation pit supporting,the formula of anchor horizontal displacement was derived,where both the elastic deformation of free part of the anchor and its prestress only were taken into consideration.Applying finite element analysis software FLAC3D to an engineering case,the rationality of the formula was verified by the numerical simulation,and a comparatively ideal result obtained.The results from both the formula and numerical simulation were basically the same.Therefore,the formula presented here would provide a quantitative and simple calculation method for displacement control of permanent slope supporting structure with frame prestressed anchor bars.