框架预应力锚杆边坡支护结构抗震简化设计方法

Simplified Seismic Design Method of Frame Supporting Structure with Prestressed Anchors for Slope Stability

为了能够准确地进行框架预应力锚杆边坡支护结构动力分析及抗震设计,通过对该类结构进行震害分析,推导出地震作用下动土压力计算公式,建立了框架预应力锚杆支护结构的动力计算模型,并采用力法进行了求解。基于建立的动力分析模型和震害模式,给出了其抗震设计方法。考虑了地震响应沿坡高放大效应,根据极限平衡理论和破坏模式建立了框架预应力锚杆边坡支护结构的动力稳定性验算模型。将提出的方法应用于工程实例,并用有限元法进行了对比分析。结果表明:提出的分析模型具有较高的精度,是一种简单、实用的分析与设计方法;地震作用下最危险截面发生在边坡中偏上部位;梁柱截面尺寸是延性设计和发生斜压破坏的主要控制因素。

To be able to accurately carry out dynamic analysis and seismic design of the frame supporting structure with prestressed anchors, seismic damage modes of frame supporting structure with prestressed anchors were analyzed. The calculation formula of anchoring slope dynamic earth pressure was deduced under earthquake. Dynamic calculation model of frame supporting structure with prestressed anchors was established and the solutions were derived by force method. Seismic design methods were established based on proposed calculation model. Considering the amplification effect of seismic response along the slope depth on the stability of slope, a calculation method for dynamic stability of slope frame supporting structure with prestressed anchors was set up according to the damage modes and the limit equilibrium theory. Finally the proposed method was applied in an actual engineering project. The finite element software was used to analyze the seismic performance of this case in order to verify the proposed method. The results indicate that the proposed method has higher accuracy, and is simple and practical. Under earthquake the most dangerous section occurs at the upper part of slopes, and the section size of the beam and the column is the main control factor of ductility design and baroclinic destruction.