高速公路中央分隔带护栏立柱稳定性分析及加固方案研究

Stability and Reinforcement of Guardrail Posts in Central Separate Belt of Expressways

现行中国高速公路安全规范对护栏立柱地基土的压实度没有给出明确的规定,致使中央分隔带内护栏立柱的承载力因为种植土和回填土的存在得不到充分地发挥。为此,对护栏立柱进行了一系列准静态横向加载试验,发现表征立柱横向承载力的临界载荷与表征地基土强度的静力触探锥尖极限阻力之间有近似的线性关系。并基于这一关系,提出了一种对应临界载荷的简化土反力分布模型。最后根据该模型及现场立柱的埋置状况,提出了一种用钢板加固护栏立柱的有效方法。

There are no clear prescriptions to the compaction degree of foundation soil in the current highway safety specification in China.So the bearing capacity of guardrail posts decreases because of plant soil and backfill in the central separate belt.A series of lateral quasi-static loading tests were carried out.The approximate linear relation was found between the critical load representing lateral bearing capacity of posts and the ultimate cone tip penetration resistance of CPT representing soil strength.Based on the relation,a reduced distribution model of soil reaction on posts was put forward corresponding to the critical load.Finally,according to the model and the embedding conditions of posts in situ,an effective method of using one steel plate to reinforce one post was presented.