摘要
为探明某公路深挖边坡进行锚杆支护的时效,采用公路路基设计规范方法确定支护方案,并对规范方法所作“每根锚杆承担相同下滑力”的简化和假定下的锚杆支护方案采用FLAC^3D进行计算。通过对边坡与锚杆的应力状态和分布形式进行分析得出,在分级锚固支护下的边坡位移分布规律、各层锚杆轴力分布规律与所处层位的关系、潜在滑动面分布规律,并基于此分析了支护方案的安全性与合理性;通过对计算结果进行分析得出,采用规范方法的锚杆支护方案各层锚杆抗拉发挥程度不一致,所得稳定系数达不到规范要求的安全系数,方案偏于不安全;基于对现有方案的分析,采用FLAC^3D在总锚杆长度不变的基础上对方案进行优化,通过分析计算,优化后的方案稳定系数满足设计要求;最后,针对深挖边坡锚杆锚固工程的设计和施工,提出相关建议。
In order to find out the effectiveness of anchor support for deep excavation of a highway,the highway roadbed design method is used to determine the support scheme.The support scheme simplified and in assumption of"the same sliding force for each anchor to bear"according to the standard method is calculated by FLAC^3D.By analyzing the stress state and distribution form of the slope and the anchor,the distribution law of the slope displacement under the hierarchical anchoring support,the relationship between the axial force distribution of each layer anchor and the position of the layer,and the distribution law of the potential sliding surface are obtained.Based on this,safety and rationality of the support program is analyzed.Through analysis and comparison,it is concluded that the tensile stress of the anchorage of different layers of the bolt support scheme through the standard method is inconsistent,and the obtained stability coefficient does not meet the safety factor required by the specification.The scheme is unsafe.Based on the analysis of the existing scheme,FLAC^3D is used to optimize the scheme based on the constant length of the total bolt.Through analysis and calculation,the optimized stability factor of the scheme meets the design requirements.Finally,relevant suggestions are put forward for the design and construction of deep excavation anchor bolting engineering.
作者
马小斐
李海平
徐建强
MA Xiaofei;LI Haiping;XU Jianqiang(China Merchants Chongqing Communications Technology Research & Desigh Institute Co.,Ltd.,Chongqing 400067,China;National Local Joint Engineering Laboratory for Road Engineering and Disaster Prevention and Reduction Technology in Mountainous Areas,Chongqing 400067)
出处
《公路交通技术》
2019年第4期14-20,27,共8页
Technology of Highway and Transport
