非饱和边坡中锚托板锚固尺寸的新算法

A new calculation method for the size of anchor plates in unsaturated slope

锚托板支护结构因为其安全稳定、经济和安装简便等优点在填方加固边坡中得到推广应用。然而目前在锚托板支护结构设计过程中,锚托板尺寸仍没有成熟的计算方法,设计过于保守。利用对数螺旋线滑移面结合极限平衡法计算得到非饱和土的主动土压力。根据土体内部平衡求出每层锚托板所需承担的拉力,得到了锚托板尺寸的计算方法,根据滑移面的位置得到了锚托板自由段拉杆的最小设计长度。将主动土压力计算结果与现有的经典文献进行了对比分析,发现主动土压力系数变化趋势与现有结论一致。分析了降雨工况和地震工况对锚托板尺寸的影响,结果表明,在降雨强度较小时对锚托板锚固尺寸的影响可以忽略,但在同时考虑强降雨和地震时,会显著增加所需的锚托板锚固尺寸,最大增大幅度可达136.71%。分析结果可为锚托板锚固尺寸的设计提供参考。

Due to its safety,stability,low cost and easy installation,anchor plate support structure has been widely used in the slope that needs to be reinforced.However,currently in the design process of anchor plate support structure,there is no mature calculation method for the size of anchor plate,resulting in overly conservative design.To address this issue,we propose using the limit equilibrium method in combination with log-spiral slip surface to calculate the active earth pressure in unsaturated soils.Based on the internal balance of the soil,the tensile force required to bear for each layer of anchor plate is calculated,and the calculation method for the size of the anchor plate is obtained.The minimum design length of the free section of the anchor plate is obtained according to the shape of the sliding surface.The calculation results of active earth pressure are compared with the existing literature,and it is found that the change trend of active earth pressure coefficient is consistent with the existing conclusions.The impacts of rainfall and earthquake conditions on the size of anchor plate are analyzed,and the results show that low rainfall intensity has a negligible effect on the size of anchor plate.However,when considering both strong rainfall and earthquake,the required anchor plate size can be significantly increased,with a maximum of 136.71%.The analysis results can provide reference for determining the size of frame anchor plates.