基于地震作用的预应力锚索抗滑桩边坡加固应用优化研究

为研究地震作用下预应力锚索抗滑桩边坡防护的滑坡推力计算方法,通过找出作用在潜在滑坡面抗滑桩结构上的受力荷载,测算出作用于锚索抗滑桩上的滑坡推力,提出以锚索抗滑桩正负弯矩相等的控制方法和K法来设计预应力锚索抗滑桩边坡防护结构。通过对比不同方法说明所提出的预应力锚索抗滑桩边坡加固的设计方法符合工程实际。以汶川地震中某滑坡工程为对象,研究其稳定性问题。结果表明,采用桩身相等的正负弯矩控制法时,锚索抗滑桩的受力更合理,桩顶位移变化量最小,其抗震加固能力最好,在具体工程中,更有利于锚索抗滑桩桩身配筋设置。实践证明,利用预应力锚索结构原理进行边坡抗滑桩设计,可以保证设计的预应力锚索抗滑桩结构的安全经济性。

Seismic action-based study on optimization of application of anti-slide pile with pre-stressed anchor cable to slope reinforcement

In order to study the method of calculating landslide thrust for the slope protected by anti-slide pile with anchor cable under seismic action，the landslide thrust acting on the anti-slide pile with anchor cable is calculated through finding out the stress and load acting on the structure of anti-slide pile for the potential slipping plane，and then a slope protection structure reinforced by the anti-slide pile with anchor cable designed by means of the control method of equalizing positive and negative bending moments and K-method is proposed herein． Through comparing the results from different methods，it is explained that the design method for the slope reinforcement made by anti-slide pile with anchor cable is consistent with the engineering practice concerned． By taking the reinforcement project for a landslide occurred in Wenchuan Earthquake as the study case，its stability is studied． The result shows that when the control method of equalizing positive and negative bending moments is adopted，the stress of the anti-slide pile with anchor cable is more reasonable with the minimum change of the displacement of the pile top，thus the seismic reinforcement capacity is the best，which is more favorable to the reinforcement arrangement of the body of the anti-slide pile with anchor cable． The practice demonstrates that if the anti-slide pile for slope is designed by the structural principle of pre-stressed anchor cable，the safety and economy of the designed structure of the anti-slide pile with pre-stressed anchor cable can be ensured．